JP7744816B2 - Ship control device, control method, and control program - Google Patents

Description

The present invention relates to a ship control device, control method, and control program.

For example, Patent Document 1 describes a technology for generating propulsive force for a ship and supplying power to onboard electrical loads. To improve fuel efficiency, the technology in Patent Document 1 controls the main engine, auxiliary engines, and shaft generator based on the current rotational speeds of the propeller and motor, thereby operating the main engine in a fuel-efficient operating state.

JP 2010-116070 A

The present invention aims to propose a technology that suppresses the deterioration of fuel efficiency of ships using a method different from that described in Patent Document 1.

In order to solve the above problem, one embodiment of the present invention provides a ship control device that includes a main engine for generating propulsive force for propelling the ship; an auxiliary engine for generating electric power to be supplied to an inboard bus; a shaft generator connected to the output shaft of the main engine and capable of selectively generating electric power to be supplied to the inboard bus by rotation of the output shaft, and generating propulsive force for propelling the ship by outputting torque using electric power supplied via the inboard bus; a rotational speed acquisition unit that acquires the current rotational speed of the main engine and a target rotational speed of the main engine; a power consumption acquisition unit that acquires the current amount of power consumed within the ship; a calculation unit that calculates, based on the current rotational speed and the target rotational speed, a required propeller torque, which is the torque required for a propeller of the ship to set the rotational speed of the main engine to the target rotational speed; and a control unit that controls the main engine, the auxiliary engine, and the shaft generator based on the current required propeller torque and the amount of power consumed.

A method for controlling a ship according to one embodiment of the present invention includes a main engine for generating propulsive force for propelling the ship, an auxiliary engine for generating electric power to be supplied to an inboard busbar, a shaft generator connected to the output shaft of the main engine and capable of selectively generating electric power to be supplied to the inboard busbar by rotation of the output shaft, and generating propulsive force for propelling the ship by outputting torque using electric power supplied via the inboard busbar, and the steps of acquiring the current rotational speed of the main engine and a target rotational speed of the main engine, acquiring the current amount of power consumed in the ship, calculating a required propeller torque, which is the torque required to set the rotational speed of the main engine to the target rotational speed, based on the current rotational speed and the target rotational speed, and controlling the main engine, the auxiliary engine, and the shaft generator based on the current required propeller torque and the amount of power consumed.

A control program for a ship according to one embodiment of the present invention is a control program for a ship equipped with a main engine for generating propulsive force for propelling the ship, an auxiliary engine for generating electric power to be supplied to an inboard busbar, and a shaft generator connected to the output shaft of the main engine and capable of selectively generating electric power to be supplied to the inboard busbar by rotation of the output shaft, or generating propulsive force for propelling the ship by outputting torque using electric power supplied via the inboard busbar. The control program for a ship causes a computer to execute the following steps: acquiring the current rotational speed of the main engine and a target rotational speed of the main engine; acquiring the current amount of power consumed in the ship; calculating a required propeller torque, which is the torque required to set the rotational speed of the main engine to the target rotational speed, based on the current rotational speed and the target rotational speed; and controlling the main engine, the auxiliary engine, and the shaft generator based on the current required propeller torque and the amount of power consumed.

In addition, any combination of the above, or mutual substitution of the components or expressions of the present invention between methods, devices, programs, temporary or non-temporary storage media on which programs are recorded, systems, etc., are also valid aspects of the present invention.

This invention makes it possible to suppress the deterioration of a ship's fuel efficiency through a new method.

1 is a block diagram schematically illustrating a marine vessel according to a first embodiment. FIG. 2 is a functional block diagram of an ECU according to the first embodiment. 4 is a flowchart illustrating processing of an ECU according to the first embodiment. 4 illustrates an example of the relationship between required propeller torque, power consumption, and operation mode in the first embodiment. 3A to 3C are diagrams illustrating the operating states of the main engine, the auxiliary engine, and the shaft generator for each operation mode of the first embodiment. 10 is a map illustrating an optimum power generation ratio between the auxiliary machinery and the shaft generator. 10 is a modified example of a map illustrating an optimum power generation ratio between the auxiliary machine and the shaft generator. FIG. 10 is a block diagram schematically illustrating a marine vessel according to a second embodiment. FIG. 10 is a functional block diagram of an ECU according to a second embodiment. 10 is a flowchart showing a process of an ECU according to a second embodiment. FIG. 10 is a diagram illustrating an example of the relationship between required propeller torque, power consumption, and operation mode in the second embodiment. 10 is a flowchart showing a specific process of step S204 in the first mode or the fourth mode in the second embodiment. FIG. 10 is a diagram for explaining a method for determining a provisional value of the charge amount of a battery. 4A and 4B are diagrams for explaining a method for determining the discharge amount of a battery and the power generation amount of an auxiliary device. 10 is a flowchart showing a specific process of step S204 in the second mode in the second embodiment. FIG. 4 is a diagram for explaining a method for determining the maximum torque of the main engine. 10A and 10B are diagrams for explaining a method for determining the discharge amount of a battery and the power generation amount of a shaft generator. 10 is a flowchart showing a specific process of step S204 in a third mode according to the second embodiment. FIG. 10 is a diagram for determining the power generation ratio of each auxiliary machine.

In the following embodiments and variants, identical or equivalent components and parts are given the same reference numerals, and redundant explanations are omitted where appropriate. Furthermore, the dimensions of the parts in each drawing are enlarged or reduced as appropriate to facilitate understanding. Furthermore, some parts that are not important for explaining the embodiments are omitted from each drawing.

1 is a block diagram that schematically illustrates a marine vessel 1 according to a first embodiment. The marine vessel 1 includes a telegraph 10, a propulsion generating unit 20, an auxiliary machine 30, an AC grid 40, and an ECU (electronic control unit) 100. The propulsion generating unit 20 includes a main engine 21, a shaft generator 22, and a propeller 23. The AC grid 40 includes an AC distribution panel 41, an inverter/converter 42, and an inverter 43. The inverter/converter 42, the auxiliary machine 30, the AC grid 40, and an onboard load 80 are connected via an onboard bus 60.

Telegraph 10 is located, for example, on the bridge and supplies propulsion force command values to ECU 100.

The main engine 21 generates thrust for propelling the vessel 1 by rotating and driving the propeller 23 via the output shaft 21a. The main engine 21 can be an internal combustion engine, such as a diesel engine. The output shaft 21a of the main engine 21 is connected to the shaft generator 22 and the propeller 23. The main engine 21 is driven at a rotational speed corresponding to a thrust command value from the telegraph 10. Note that the telegraph 10 can input commands based on the vessel's speed (surface speed or water speed), and the thrust command value may be a value indicating the rotational speed required to achieve the vessel's speed.

The shaft generator 22 is configured to selectively function as a generator that generates electricity to be supplied to the inboard bus 60 by rotating the output shaft 21a of the main engine 21, and as an electric motor that generates propulsion force for propelling the vessel 1 by outputting torque using electricity supplied via the inboard bus 60. The shaft generator 22 is disposed on the output shaft 21a of the main engine 21 between the main engine 21 and the propeller 23. The electricity generated by the shaft generator 22 is supplied to the AC grid 40 via the inverter/converter 42. The rotational driving force of the shaft generator 22 is transmitted to the propeller 23 via the output shaft 21a of the main engine 21, thereby providing propulsion force for the vessel 1.

The auxiliary equipment 30 generates electricity used within the vessel 1. The auxiliary equipment 30 includes an auxiliary engine (not shown) and an auxiliary generator (not shown) that is driven by the auxiliary engine to generate electricity to be supplied to the inboard bus 60. The auxiliary equipment 30 is, for example, a diesel generator composed of a diesel engine and an auxiliary generator. The rotational driving force generated by the diesel engine of the auxiliary equipment 30 is converted into electricity by the auxiliary generator.

The power generated by the auxiliary machinery 30 is supplied to the AC distribution panel 41 of the AC grid 40 via the onboard bus 60. Furthermore, the power generated by the shaft generator 22 is supplied to the AC distribution panel 41 via the inverter/converter 42. The AC distribution panel 41 distributes the supplied power and supplies it to the onboard loads 80 via the inverter 43. The onboard loads 80 include loads from all equipment that receives power via the onboard bus 60 and consumes it on the ship 1, such as lighting equipment, air conditioning equipment, navigation equipment, and electric pumps installed on the ship 1, as well as the main engine 21, shaft generator 22, auxiliary machinery 30, AC grid 40, and ECU 100.

The ECU 100 comprises an integrated control ECU 101, a main engine ECU 102, an auxiliary engine ECU 103, and a power control ECU 104. The main engine ECU 102 and auxiliary engine ECU 103 control the main engine 21 and auxiliary engine 30, respectively. The power control ECU 104 controls the supply and demand of electricity on board the ship by controlling the AC distribution panel 41, inverter/converter 42, and inverter 43 of the AC grid 40. The integrated control ECU 101 optimally integrates and controls the main engine ECU 102, auxiliary engine ECU 103, and power control ECU 104 at a higher level. The ECU 100 may comprise the integrated control ECU 101, main engine ECU 102, auxiliary engine ECU 103, and power control ECU 104 integrated within a single device, or these ECUs may be separately provided in separate devices. The ECU 100 of this embodiment is an example of a control device for the boat 1.

The rotational speed sensor 71A is attached to the output shaft 21a of the main engine 21 and measures the rotational speed of the main engine 21. The rotational speed sensor 71B is attached to the rotating shaft of the propeller 23 and measures the rotational speed of the propeller 23. The rotational speed signals measured by the rotational speed sensors 71A and 71B are supplied to the ECU 100. The power consumption sensor 72 is provided between the inverter 43 and the onboard loads 80 and measures the current power consumption Pd within the ship 1. The power consumption Pd here is the power consumed by the onboard loads 80, that is, the power consumed by equipment in the ship 1 that receives power via the onboard bus 60. The power consumption signal measured by the power consumption sensor 72 is supplied to the ECU 100.

Figure 2 is a functional block diagram of ECU 100. Each functional block shown in Figure 2 and other figures can be realized in hardware terms using electronic elements and mechanical parts, such as a computer CPU, and in software terms using computer programs, but here we depict functional blocks realized by the cooperation of these elements. Therefore, those skilled in the art will understand that these functional blocks can be realized in various ways using a combination of hardware and software.

The ECU 100 includes an acquisition unit 110, a calculation unit 120, an operation mode determination unit 130, a control unit 140, and a memory unit 150. The acquisition unit 110 includes a rotational speed acquisition unit 111 and a power consumption acquisition unit 112.

The rotational speed acquisition unit 111 acquires the current rotational speed Ne of the main engine 21, the current rotational speed Np of the propeller 23, and the target rotational speed of the main engine 21. The current rotational speed Ne of the main engine 21 is acquired, for example, from the measurement value of the rotational speed sensor 71A. The current rotational speed Np of the propeller 23 is acquired, for example, from the measurement value of the rotational speed sensor 71B. The target rotational speed of the main engine 21 is acquired, for example, based on the propulsion force command value input from the telegraph 10. The power consumption amount acquisition unit 112 acquires the current power consumption Pd within the vessel 1. The current power consumption Pd within the vessel 1 is acquired, for example, from the measurement value of the power consumption amount sensor 72.

The calculation unit 120 calculates the required propeller torque based on the current rotational speed Ne and the target rotational speed of the main engine 21. The required propeller torque is the torque required in the propeller to make the current rotational speed Ne of the main engine 21 equal to the target rotational speed. In this embodiment, the calculation unit 120 calculates the required propeller torque Tp using PID control based on, for example, a comparison between the current rotational speed Ne of the main engine 21 and the target rotational speed.

The operation mode determination unit 130 determines the operation mode based on the current required propeller torque Tp and the power consumption Pd. The operation mode and its determination method will be described later.

The control unit 140 controls the main engine 21, the auxiliary engine 30, and the AC grid 40. The control unit 140 also controls the shaft generator 22 through integrated control of the main engine 21, the auxiliary engine 30, and the AC grid 40. The control unit 140 controls the main engine 21, the auxiliary engine 30, and the shaft generator 22 based on the current required propeller torque Tp and the power consumption Pd.

The memory unit 150 stores various programs, reference values, thresholds, etc.

It is known that the main engine 21 has better fuel economy when operated at high loads than when operated at low loads. It is also known that generating electricity using the shaft generator 22 by supplying rotational driving force from the main engine 21 to the shaft generator 22 via the output shaft 21a, rather than using the auxiliary engine 30, results in better fuel economy because the main engine 21 can be operated at a higher load. Furthermore, the main engine 21 generally has a better optimal fuel economy than the auxiliary engine 30.

The inventors have come to recognize the following problem. Conventionally, there has been no technology for controlling the main engine 21, auxiliary engine 30, and shaft generator 22 in a way that improves fuel efficiency across the entire vessel. Below, we will explain in detail a method for solving this problem.

Figure 3 is a flowchart showing processing S100 of the ECU 100 in the first embodiment.

In step S101, the acquisition unit 110 acquires the current rotation speed Ne of the main engine 21, the current rotation speed Np of the propeller 23, the target rotation speed, and the current power consumption Pd of the vessel 1. The acquisition unit 110 supplies the acquired current rotation speed Ne and target rotation speed of the main engine 21 to the calculation unit 120, and supplies the acquired current rotation speed Ne of the main engine 21, the current rotation speed Np of the propeller 23, and the current power consumption Pd to the operation mode determination unit 130.

In step S102, the calculation unit 120 calculates the current required propeller torque Tp based on the current rotational speed Ne and the target rotational speed. The calculation unit 120 supplies the calculation result of the current required propeller torque Tp to the operation mode determination unit 130.

In step S103, the operation mode determination unit 130 determines the operation modes of the main engine 21, the auxiliary engine 30, and the shaft generator 22 based on the current rotational speed Ne, the current required propeller torque Tp, and the power consumption Pd. A specific method for determining the operation mode in the first embodiment will be described using Figure 4. Figure 4 illustrates an example of the relationship between the required propeller torque Tp, the power consumption Pd, and the operation mode in the first embodiment. This relationship between the required propeller torque Tp, the power consumption Pd, and the operation mode is determined in advance for each rotational speed Ne.

The map in Figure 4 defines a first operating region R1 in which the required propeller torque and power consumption ranges are set so that the fuel efficiency of the main engine is better than a predetermined fuel efficiency standard. A second operating region R2 is defined outside this first operating region R1. The first operating region R1 includes a low-power consumption region R1A in which the power consumption range is set below the first power consumption reference value Pr1, and a high-power consumption region R1B in which the power consumption range is set equal to or above the first power consumption reference value Pr1. The second operating region R2 includes a low-torque, low-power consumption region R2A in which the required propeller torque range is set below the first torque reference value Tr1 and the power consumption range is set below the second power consumption reference value Pr2, and a high-torque, low-power consumption region R2B in which the required propeller torque range is set above the second torque reference value Tr2 and the power consumption range is set below the third power consumption reference value Pr3.

Here, the fuel efficiency of the main engine refers to the output per unit of fuel consumption in the main engine [kWh/g]. Alternatively, the fuel efficiency of the main engine may be the fuel consumption per current unit of output in the main engine [g/kWh]. Therefore, "fuel efficiency better than a specified fuel efficiency standard" here means that the output per unit of fuel consumption in the main engine is equal to or greater than a specified output standard value, or the fuel consumption per current unit of output in the main engine is equal to or less than a specified consumption standard value.

In the example of Figure 4, the operating point D of the vessel 1, which is determined by the current required propeller torque Tp and the current power consumption Pd, is included in the second operating region R2. In the second operating region R2, the first mode is basically set as the operating mode, except in cases corresponding to the fourth and fifth modes described below (when the operating point D is included in the low-torque, low-power consumption region R2A or the high-torque, low-power consumption region R2B). The first mode is used during normal operation, and the propulsive force of the vessel 1 is generated by the torque generated by the main engine 21 without the aid of propulsive force from the shaft generator 22.

Figure 5 shows the operating states of the main engine 21, the auxiliary engine 30, and the shaft generator 22 for each operating mode. Here, the operating state of the main engine 21 includes an operating state in which the main engine 21 is operating and an idling state in which the main engine 21 is idling. The operating state of the auxiliary engine 30 includes an operating state in which the auxiliary engine 30 is operating and an stopped state in which the auxiliary engine 30 is stopped. The operating state of the shaft generator 22 includes an idling state in which the shaft generator 22 is idling, a power generation state in which the shaft generator 22 generates electricity by receiving rotational driving force from the main engine, and a torque output state in which the shaft generator 22 outputs torque by receiving power from the inboard bus 60. Note that although both the main engine 21 and the shaft generator 22 are described as "idling" here, a power connection/disconnection mechanism such as a clutch (not shown) may be provided in the power transmission system to stop the main engine 21 and the shaft generator 22 and disengage the clutch. As shown in Figure 5, when the operating mode is the first mode, the main engine 21 is in operation, the auxiliary engine 30 is in operation, and the shaft generator 22 is in an idling state.

When operating point D is within the low power consumption region R1A, the second mode is determined as the operating mode (see Figure 4). Furthermore, when operating point D is within the high power consumption region R1B, the third mode is determined as the operating mode. It is known that the main engine 21 can be operated with the best fuel economy at a load that is neither too low nor too high. The second and third modes allow the main engine 21 to operate with good fuel economy in an operating range that is neither too low nor too high. The second mode is used when the vessel 1 has sufficient power reserves to handle an increase in power consumption Pd. As shown in Figure 5, when the operating mode is the second mode, the main engine 21 is in operation, the auxiliary engine 30 is stopped, and the shaft generator 22 is in a generating state. When the operating mode is the third mode, the main engine 21 is in operation, the auxiliary engine 30 is in operation, and the shaft generator 22 is in a generating state.

When operating point D is within the low-torque, low-power consumption region R2A, the fourth mode is determined as the operating mode (see Figure 4). The fourth mode is used when propulsion control is required at extremely low loads (where operation using the main engine 21 would result in poor fuel economy). When the operating mode is the fourth mode, the main engine 21 is in an idling state, the auxiliary engine 30 is in operation, and the shaft generator 22 is in a torque output state (see Figure 5).

When operating point D is within the high-torque, low-power consumption region R2B, the fifth mode is determined as the operating mode (see Figure 4). The fifth mode is used when the vessel 1 has a power surplus, the main engine is operating near maximum load, and it is desired to further increase the propeller torque, and the shaft generator 22 supplements the propulsive force of the main engine 21. The premise for the fifth operating mode is that the main engine torque Tm is operating at or near maximum torque at the current rotational speed. When the operating mode is the fifth mode, the main engine 21 is in an operating state, the auxiliary engine 30 is in an operating state, and the shaft generator 22 is in a torque output state.

The operation mode determination unit 130 supplies the operation mode determination result to the calculation unit 120. It is preferable to set hysteresis at the boundaries of each operation mode in Figure 4 to prevent frequent switching of the operation mode. The map shown in Figure 4 may be determined appropriately in advance by conducting experiments, etc. The same applies to Figure 11, which will be described later.

In step S104, the calculation unit 120 calculates the torque and power generation amount of the main engine 21, auxiliary engine 30, and shaft generator 22 based on the result of determining the operation mode. This is explained below for each operation mode.

When the operation mode is the first mode, the torque Tm of the main engine 21 and the power generation amount Pdg of the auxiliary engine 30 are expressed by the following equations (1) and (2).
Tm=Tp Formula (1)
Pdg=Pd Formula (2)
In this way, in the first mode, the main engine 21 alone outputs torque equivalent to the required propeller torque Tp, and the power consumption amount Pd is covered by the power generation amount Pdg of the auxiliary engine 30.

When the operating mode is the second mode, the torque Tm of the main engine 21 and the power generation amount Psg of the shaft generator 22 are expressed by the following equations (3) and (4).
Tm=Tp+Pd/ηsg/Ne*C Formula (3)
Psg=Pd Formula (4)
Here, ηsg is the power generation efficiency of the shaft generator 22 and is set based on the specifications of the shaft generator 22. C is a constant for converting the rotational speed into torque. In this way, in the second mode, the main engine 21 generates torque for supplying a rotational driving force to the shaft generator 22 to generate electricity, in addition to torque corresponding to the required propeller torque Tp. The power consumption Pd is covered by the power generation amount Psg of the shaft generator 22. In this way, by covering the power consumption Pd using the shaft generator 22 when the power consumption Pd is small, fuel efficiency can be improved compared to when power is generated using the auxiliary equipment 30.

When the operating mode is the third mode, the torque Tm of the main engine 21, the power generation amount Pdg of the auxiliary engine 30, and the power generation amount Psg of the shaft generator 22 are expressed by the following equations (5) and (6).
Tm=Tp+Psg/ηsg/Ne*C Formula (5)
Pdg+Psg=Pd Formula (6)

In the third mode, the power generation ratios of Pdg and Psg relative to Pd are determined, for example, based on a map showing the optimal power generation ratios of the auxiliary machinery 30 and the shaft generator 22, as shown in FIG. 6. As shown in FIG. 6, when the power consumption Pd is relatively large, the power generation ratio is set so that the proportion of the power generated by the auxiliary machinery 30 and the shaft generator 22 in the total power generation is higher than when the power consumption Pd is relatively small. Furthermore, when the required propeller torque Tp is relatively large, the power generation ratio is set so that the proportion of the power generated by the auxiliary machinery 30 in the total power generation is higher than when the required propeller torque Tp is relatively small. For example, the power generation ratio of the auxiliary machinery 30 may be set to increase linearly or nonlinearly as the current power consumption Pd or the required propeller torque Tp increases, or the power generation ratio of the auxiliary machinery 30 may be set to increase stepwise as the current power consumption Pd or the required propeller torque Tp increases. This allows the auxiliary machinery 30 and the shaft generator 22 to operate efficiently, thereby improving fuel efficiency.

In this way, in the third mode, as in the second mode, the main engine 21 generates torque equivalent to the required propeller torque Tp, as well as torque for supplying rotational driving force to the shaft generator 22 to generate electricity. Furthermore, the power consumption Pd is covered at an optimal power generation ratio by the power generation amount Pdg of the auxiliary engine 30 and the power generation amount Psg of the shaft generator 22. When the power consumption Pd is large and the power generation amount Psg of the shaft generator 22 cannot cover all of the power consumption Pd, power can be generated using the auxiliary engine 30, thereby preventing power shortages.

When the operating mode is the fourth mode, the torque Ts of the shaft generator 22 and the power generation amount Pdg of the auxiliary machine 30 are expressed by the following equations (7) and (8).
Ts=Tp Formula (7)
Pdg=Pd+Tp/ηsg*Np/C Formula (8)
Thus, in the fourth mode, the shaft generator 22 alone outputs torque equivalent to the required propeller torque Tp, and the power generation amount Pdg of the auxiliary machine 30 provides the amount of power required to rotate and drive the shaft generator 22 in addition to the power consumption amount Pd. When the required propeller torque Tp and the power consumption amount Pd are small, the shaft generator 22 outputs torque equivalent to the required propeller torque Tp, which suppresses operation of the main machine 21 at low loads and suppresses deterioration of fuel efficiency.

When the operating mode is the fifth mode, the torque Ts of the shaft generator 22 and the power generation amount Pdg of the auxiliary machine 30 are expressed by the following equations (9) and (10).
Pdg=K1(Tp-Tm) Formula (9)
Ts=(Pdg-Pd)*ηsg/Np*C Formula (10)
Here, K1 is a coefficient for converting torque into electric energy. In the fifth mode, the power generation amount Pdg of the auxiliary machine 30 has an upper limit of Pdgmax. Pdgmax is the maximum power generation amount that can be output by the auxiliary machine 30 and is determined in advance based on the specifications of the auxiliary machine 30. In this way, when the required propeller torque Tp is large and the power consumption amount Pd is small, the torque Tm of the main machine 21 can be prevented from becoming too large by having the shaft generator 22 output torque, and therefore deterioration of fuel efficiency can be suppressed.

The calculation unit 120 supplies the calculation results of the torque and power generation amount of the main engine 21, auxiliary engine 30, and shaft generator 22 to the control unit 140.

In step S105, the control unit 140 controls the main engine 21, the auxiliary engine 30, and the shaft generator 22 based on the supplied calculation results. The control unit 140 controls the main engine 21, the auxiliary engine 30, and the shaft generator 22 so as to achieve the above-mentioned operating state, torque, and power generation amount corresponding to the determined operating mode.

After step S105, process S100 ends.

As described above, in this embodiment, the control unit 140 controls the main engine 21, the auxiliary engine 30, and the shaft generator 22 based on the current required propeller torque Tp and the current power consumption Pd. According to this configuration, by using the current required propeller torque Tp and the current power consumption Pd, the main engine 21, the auxiliary engine 30, and the shaft generator 22 can be operated with an appropriate energy output distribution while ensuring the necessary propulsion force and power supply for the vessel 1, thereby making it possible to effectively improve fuel efficiency throughout the vessel.

In this embodiment, when the vessel's operating point D is within the second operating region R2 outside the first operating region R1, the control unit 140 places the main engine 21 and auxiliary engine 30 in an operating state and the shaft generator 22 in an idling state. When the operating point D is within the low power consumption region R1A, the control unit 140 places the main engine 21 in an operating state, the auxiliary engine 30 in a stopped state, and the shaft generator 22 in a generating state. When the operating point D is within the high power consumption region R1B, the control unit 140 places the main engine 21 and auxiliary engine 30 in an operating state and the shaft generator 22 in a generating state. The required propeller torque and power consumption range in the first operating region R1 are set so that the fuel efficiency of the main engine 21 is better than a predetermined fuel efficiency standard. With this configuration, placing the shaft generator in a generating state allows the main engine 21 to operate in a more fuel-efficient operating region, thereby improving the fuel efficiency of the main engine 21. Furthermore, since the main engine 21 generates electricity, which is more fuel-efficient than the auxiliary engine 30, the amount of fuel consumed for power generation can be reduced. Furthermore, if the power generation capacity Psg of the shaft generator 22 is insufficient to match the current power consumption Pd, the auxiliary equipment 30 can be operated to supply power, thereby preventing power shortages.

In this embodiment, when operating point D is within the low-torque, low-power consumption region R2A, the control unit 140 puts the main engine 21 into an idling state, the auxiliary engine 30 into an operating state, and the shaft generator 22 into a torque output state. According to this configuration, when the required propeller torque Tp and power consumption Pd are small, torque is output by the shaft generator 22, which prevents the main engine 21 from operating at a low load, thereby preventing a deterioration in fuel efficiency.

In this embodiment, when operating point D is within the high-torque, low-power consumption region R2B, the control unit 140 places the main engine 21 and auxiliary engine 30 in an operating state and the shaft generator 22 in a torque output state. According to this configuration, when the required propeller torque Tp is large and the power consumption Pd is small, the shaft generator 22 is caused to output torque, thereby preventing the torque Tm of the main engine 21 from becoming too large, thereby preventing a deterioration in fuel efficiency of the main engine 21.

In this embodiment, when the auxiliary equipment 30 is in an operating state and the shaft generator 22 is in a generating state, if the power consumption Pd is relatively small, the control unit 140 increases the proportion of the power generation amount Psg of the shaft generator 22 in the total power generation amount (Pdg + Psg) of the auxiliary equipment 30 and the shaft generator 22 compared to when the power consumption Pd is relatively large. With this configuration, when the power consumption Pd is small, the shaft generator 22 generates power preferentially, preventing the auxiliary equipment 30 from operating in a low-load range where fuel efficiency is poor, thereby improving fuel efficiency.

Modifications to the embodiment are described below.

The above-mentioned thresholds and constants are set in advance taking into consideration the fuel efficiency, transient response, risk of misfire and knocking of the main engine 21, etc., but they may also be corrected or changed in accordance with changes in the performance of the main engine 21 due to deterioration of the main engine 21 or changes in fuel properties while monitoring the actual operating conditions of the main engine 21.

In the embodiment, an example is shown in which the power generation ratio between the shaft generator 22 and the auxiliary machine 30 is determined using the map shown in Figure 6, but this is not limited to this, and the vertical axis, horizontal axis, plotted values, etc. may be interchanged as appropriate. For example, as shown in Figure 7, a map may be used in which the vertical axis represents the power consumption amount Pd and the horizontal axis represents the required propeller torque Tp.

In the embodiment, the shaft generator 22 is controlled by executing the process shown in FIG. 3, but this is not limiting. For example, the main engine 21, the auxiliary engine 30, and the shaft generator 22 may be controlled based on output data of a computational model that includes at least the current required propeller torque and the amount of power consumed by the vessel as input data, and includes the torque Tm of the main engine 21, the power generation amount Pdg of the auxiliary engine 30, and the torque Tsg of the shaft generator 22 or the power generation amount Psg of the shaft generator 22 as output data. This computational model may be a trained model that has been trained by machine learning using a neural network, for example.

Second Embodiment A second embodiment of the present invention will now be described. In the drawings and description of the second embodiment, components and members that are the same as or equivalent to those in the first embodiment will be denoted by the same reference numerals. Explanations that overlap with the first embodiment will be omitted as appropriate, and the description will focus on the configurations that differ from the first embodiment.

Figure 8 is a block diagram schematically illustrating a marine vessel 1 according to a second embodiment. The AC grid of the marine vessel 1 according to the second embodiment further includes a battery 44 and a bidirectional inverter/converter 45. The battery 44 is a battery that can be repeatedly charged and discharged, such as a lead-acid battery, a nickel-metal hydride battery, or a lithium-ion battery. The battery 44 is connected to the AC distribution panel 41 via the bidirectional inverter/converter 45. An SOC sensor 73 is attached to the battery 44 to detect the SOC (state of charge) of the battery 44. The SOC sensor detects the SOC based on, for example, the voltage of the battery 44. The bidirectional inverter/converter 45 can selectively convert AC current from the AC distribution panel 41 to DC current and supply it to the battery 44 when charging the battery 44, and convert DC current from the battery 44 to AC current and supply it to the AC distribution panel 41 when discharging the battery 44. The bidirectional inverter/converter 45 is controlled by the power control ECU 104.

Figure 9 is a functional block diagram of the ECU 100 of the second embodiment. The acquisition unit 110 of the ECU 100 of the second embodiment further includes an SOC acquisition unit 113 that acquires the SOC of the battery 44. The SOC acquisition unit 113 acquires the SOC from, for example, the SOC sensor 73.

Figure 10 is a flowchart showing processing S200 of the ECU 100 in the second embodiment. Steps S201 to S205 in Figure 11 are essentially the same as steps S101 to S105 in Figure 3, except where otherwise noted, and therefore, explanations of overlapping content may be omitted.

In step S201, the acquisition unit 110 acquires the current rotation speed Ne of the main engine 21, the current rotation speed Np of the propeller 23, the target rotation speed, the current power consumption Pd of the ship, and the SOC. The acquisition unit 110 supplies the acquired current rotation speed Ne, target rotation speed, and SOC of the main engine 21 to the calculation unit 120, and supplies the acquired current rotation speed Ne of the main engine 21, the current rotation speed Np of the propeller 23, and the current power consumption Pd to the operation mode determination unit 130.

After that, after step S202, in step S203, the operation mode determination unit 130 determines the operation modes of the main engine 21, auxiliary engine 30, and shaft generator 22 based on the current rotation speed Ne, the current required propeller torque Tp, and the power consumption Pd.

Figure 11 illustrates the relationship between the required propeller torque Tp, power consumption Pd, and operating mode in the second embodiment. As shown in Figure 11, in the second embodiment, the second operating region includes, in addition to regions R2A and R2B, an extremely low torque, extremely low power consumption region R2C in which the required propeller torque range is set below the lower limit value TpR2 of the required propeller torque in the low torque, low power consumption region R2A and the power consumption range is set below the extremely low power consumption reference value PrVL, which is smaller than the second power consumption reference value Pr2. In the extremely low torque, extremely low power consumption region R2C, operation is performed in the sixth mode. The sixth mode is an operating mode designed for operation at low ship speeds, such as in a harbor. In the sixth mode, when the SOC of the battery 44 is greater than a threshold value, the main engine 21 is in an idling state, the auxiliary engine 30 is in a stopped state, and the shaft generator 22 is in a torque output state. In the sixth mode, the power consumption Pd (including the amount of power required to drive the shaft generator 22) is entirely supplied by the battery 44, reducing fuel consumption and improving fuel efficiency. Furthermore, the main engine 21 and auxiliary engine 30 can be stopped, allowing for extremely quiet operation.

In step S204, the calculation unit 120 calculates the torque and power generation amount of the main engine 21, the auxiliary engine 30, and the shaft generator 22, and the charge or discharge amount of the battery 44 based on the result of determining the operation mode. Here, using Figure 12, the calculation method when the operation mode in step S204 is the first mode or the fourth mode will be explained. In the first mode or the fourth mode, the battery charge amount Pc, discharge amount Pb, and power generation amount Pdg of the auxiliary engine 30 are calculated as described below using Figure 12.

In step S301, the calculation unit 120 determines whether the power consumption Pd is smaller than Pgm. In the fourth mode, the power consumption Pd includes the power required to generate torque in the shaft generator 22. Here, Pgm is the amount of power obtained by subtracting a predetermined power generation margin m from the maximum power generation capacity Pdgmax of the auxiliary machine 30, and is expressed by the following equation (11).
Pgm=Pdgmax/m Formula (11)
The power generation margin m is set in advance taking into consideration the type of ship, equipment specifications, operation mode, etc., as well as the range of sudden fluctuations in power consumption. If the power consumption amount Pd is smaller than Pgm (Y in S301), step S204 proceeds to step S302.

In step S302, calculation unit 120 determines whether or not the SOC is smaller than the low SOC reference value _EL . If the SOC is smaller than the low SOC reference value _EL (Y in S302), step S204 proceeds to step S303.

In step S303, the calculation unit 120 calculates a provisional value Pc1 of the amount of power to be charged to the battery 44 (hereinafter referred to as the "battery charge amount") according to the SOC. A method for calculating the provisional value Pc1 of the charge amount of the battery 44 will be described using FIG. 13. FIG. 13 shows a map in which the relationship between the SOC and the provisional value Pc1 is set so that the provisional value Pc1 of the charge amount of the battery 44 decreases as the SOC increases. The calculation unit 120 calculates the provisional value Pc1 of the charge amount of the battery 44 using the map of FIG. 13. Furthermore, for example, the provisional value Pc1 of the charge amount of the battery 44 may be calculated to decrease linearly or nonlinearly as the SOC increases, or the provisional value Pc1 of the charge amount of the battery 44 may be calculated to decrease stepwise as the SOC increases.

In step S304, the calculation unit 120 determines whether (Pc1 + Pd) is smaller than Pgm. If (Pc1 + Pd) is smaller than Pgm (Y in S304), step S204 proceeds to step S305.

In step S305, the calculation unit 120 calculates the charge amount Pc of the battery 44 and the power generation amount Pdg of the auxiliary machine 30 using the following equations (12) and (13).
Pc=Pc1 Formula (12)
Pdg=Pc+Pd Formula (13)

Returning to step S304, if (Pc1 + Pd) is not smaller than Pgm (N in S304), step S204 proceeds to step S306. In step S306, the calculation unit 120 calculates the charge amount Pc of the battery 44 and the power generation amount Pdg of the auxiliary machine 30 using the following equations (14) and (15).
Pc=Pgm-Pd Formula (14)
Pdg=Pgm Formula (15)

Returning to step S301 or S302, if the power consumption amount Pd is not less than Pgm (N in S301) or if the SOC is not less than the low SOC reference value _EL (N in S302), step S204 proceeds to step S307. In step S307, calculation unit 120 determines whether the SOC is less than the high SOC reference value _EH . The high SOC reference value _EH is greater than the low SOC reference value _EL . If the SOC is not less than the high SOC reference value _EH (N in S307), step S204 proceeds to step S308.

In step S308, the calculation unit 120 calculates the amount of power Pb to be discharged from the battery 44 (hereinafter referred to as the "discharge amount of the battery 44") and the power generation amount Pdg of the auxiliary machine 30 using the following equation (16).
Pd=Pb+Pdg Formula (16)
Here, the discharge amount Pb of the battery 44 and the power generation amount Pdg of the auxiliary device 30 are calculated in an allocation or ratio according to the power consumption amount Pd. For example, as shown in Fig. 14 , the discharge amount Pb of the battery 44 and the power generation amount Pdg of the auxiliary device 30 are calculated so that the sum of the discharge amount Pb of the battery 44 and the power generation amount Pdg of the auxiliary device 30 increases as the power consumption amount Pd increases.

Returning to step S307, if the SOC is smaller than the high SOC reference value _EH (Y in S307), step S204 proceeds to step S309. In step S309, the calculation unit 120 determines whether the power consumption Pd is smaller than the maximum fuel-efficient power generation amount Pdgbest of the auxiliary device 30. The best fuel-efficient power generation amount Pdgbest of the auxiliary device 30 is the power generation amount when the fuel efficiency of the auxiliary device 30 is optimal, and is determined in advance based on the specifications of the auxiliary device 30. If the power consumption Pd is smaller than the maximum fuel-efficient power generation amount Pdgbest of the auxiliary device 30 (Y in S309), step S204 proceeds to step S310.

In step S310, the calculation unit 120 calculates the charge amount Pc of the battery 44 and the power generation amount Pdg of the auxiliary machine 30 using the following equations (17) and (18).
Pc = Pdgbest - Pd Equation (17)
Pdg=Pdgbest Formula (18)

Returning to step S309, if the power consumption Pd is not smaller than the maximum fuel consumption power generation Pdgbest of the auxiliary device 30 (N in S309), step S204 proceeds to step S311. In step S311, the calculation unit 120 calculates the charge amount Pc of the battery 44 and the power generation amount Pdg of the auxiliary device 30 using the following equations (19) and (20).
Pc=0 Formula (19)
Pdg=Pd Formula (20)

After steps S305, S306, S308, S310, and S311, processing of step S204 in first mode or fourth mode ends.

Next, using Figure 15, we will explain the calculation method when the operating mode in step S204 is the second mode.

In step S401, the calculation unit 120 calculates the maximum torque Tmmax of the main engine 21 according to the current rotation speed Ne of the main engine 21. A method for calculating the maximum torque Tmmax of the main engine 21 will be explained using Figure 16. Figure 16 shows a map that sets the relationship between the rotation speed Ne and the maximum torque Tmmax. The calculation unit 120 calculates the maximum torque Tmmax of the main engine 21 using the map in Figure 16.

In step S402, the calculation unit 120 determines whether the power consumption amount Pd is smaller than Psm, where Psm is the amount of power obtained by taking into account a predetermined power generation margin m from the maximum power generation amount Psgmax of the shaft generator, and is expressed by the following equation (21).
Psm=Psgmax/m Formula (21)
The maximum power generation capacity Psgmax of the shaft generator 22 is expressed by equation (22).
Psgmax=(Tmmax-Tp)*ηsg*Ne/C Formula (22)
If the power consumption amount Pd is smaller than Psm (Y in S402), step S204 proceeds to step S403.

In step S403, calculation unit 120 determines whether or not the SOC is smaller than the low SOC reference value _EL . If the SOC is smaller than the low SOC reference value _EL (Y in S403), step S204 proceeds to step S404.

In step S404, the calculation unit 120 calculates a provisional value Pc1 of the charge amount of the battery 44 based on the SOC. Step S404 is similar to step S303 described above, and therefore its description will be omitted.

In step S405, the calculation unit 120 determines whether (Pc1 + Pd) is smaller than Psm. If (Pc1 + Pd) is smaller than Psm (Y in S405), step S204 proceeds to step S406.

In step S406, the calculation unit 120 calculates the charge amount Pc of the battery 44 and the power generation amount Psg of the shaft generator 22 using the following equations (23) and (24).
Pc=Pc1 Formula (23)
Psg=Pc+Pd Formula (24)

Returning to step S405, if (Pc1 + Pd) is not smaller than Psm (N in S405), step S204 proceeds to step S407. In step S407, the calculation unit 120 calculates the charge amount Pc of the battery 44 and the power generation amount Psg of the shaft generator 22 using the following equations (25) and (26).
Pc=Psm-Pd Formula (25)
Pdg=Psm Formula (26)

After step S406 or S407, in step S408, the calculation unit 120 calculates the torque Tm of the main engine 21 using the following equation (27).
Tm=Tp+Psg/ηsg/Ne*C Formula (27)

Returning to step S403, if the SOC is not smaller than the low SOC reference value _EL (N in S403), step S204 proceeds to step S409. In step S409, calculation unit 120 determines whether the SOC is smaller than the high SOC reference value _EH . Step S409 is the same as step S307 described above. If the SOC is not smaller than the high SOC reference value _EH (N in S409), step S204 proceeds to step S410.

In step S410, the calculation unit 120 calculates the discharge amount Pb of the battery 44 and the power generation amount Psg of the shaft generator 22 using the following equation (28).
Pd=Pb+Psg Formula (28)
Here, the discharge amount Pb of the battery 44 and the power generation amount Psg of the shaft generator 22 are calculated in an allocation or ratio according to the power consumption Pd. For example, as shown in Fig. 17 , when the power consumption Pd is equal to or less than the power consumption reference value Pdr, the power generation amount Psg of the shaft generator 22 is increased in proportion to the power consumption Pd, and when the power consumption Pd is greater than the power consumption reference value Pdr, the power generation amount Psg of the shaft generator 22 is calculated to set the power generation amount Psg of the shaft generator 22 to a constant value (maximum value). Also, when the power consumption Pd is equal to or less than the power consumption reference value Pdr, the discharge amount Pb of the battery 44 is set to 0 to prevent discharge, and when the power consumption Pd is greater than the power consumption reference value Pdr, the discharge amount Pb of the battery 44 is calculated to increase in proportion to the power consumption Pd.

After step S410, step S204 proceeds to step S408 described above.

Returning to step S409, if the SOC is smaller than the high SOC reference value _EH (Y in S409), step S204 proceeds to step S411. In step S411, the calculation unit 120 determines whether the required propeller torque Tp is smaller than the best fuel economy torque Tm best of the main engine 21. The best fuel economy torque Tm best of the main engine 21 is the torque at which the fuel economy of the main engine 21 is optimal, and is determined in advance based on the specifications of the main engine 21. If the required propeller torque Tp is smaller than the best fuel economy torque Tm best of the main engine 21 (Y in S411), step S204 proceeds to step S412.

In step S412, the calculation unit 120 calculates the torque of the main engine 21, the charge amount Pc of the battery 44, the torque Tm of the main engine, and the power generation amount Psg of the shaft generator 22 using the following equations (29) to (31).
Pc=Psg-Pd Formula (29)
Tm=Tmbest Formula (30)
Psg=(Tm-Tp)*ηsg*Ne/C Formula (31)

Returning to step S402, if the power consumption Pd is not smaller than Psm (N in S402), step S204 proceeds to step S413. Also, returning to step S411, if the required propeller torque Tp is not smaller than the best fuel consumption torque Tm best of the main engine 21 (N in S411), step S204 proceeds to step S413. In step S413, the calculation unit 120 calculates the charge amount Pc and discharge amount Pb of the battery 44 and the power generation amount Psg of the shaft generator 22 using the following equations (32) to (34):
Pc=0 Formula (32)
Pb = 0 Equation (33)
Pd=Psg Formula (34)
As shown in equations (32) to (34), the battery 44 is not charged or discharged, and the power consumption Pd is covered by the power generation amount Psg of the shaft generator 22.

After step S413, step S204 proceeds to step S408 described above.

After step S408 or S412, processing of step S204 in the second mode ends.

Next, using Figure 18, we will explain the calculation method when the operating mode in step S204 is the third mode.

In step S501, the calculation unit 120 calculates the maximum torque Tmmax of the main engine 21 based on the current rotation speed Ne of the main engine 21. Step S501 is similar to step S401 described above, and therefore its description will be omitted.

In step S502, the calculation unit 120 determines whether the power consumption Pd is smaller than Pm, where Pm is the amount of power obtained by taking into account a predetermined power generation margin m from the sum of the maximum power generation capacity Psgmax of the shaft generator 22 and the maximum power generation capacity Pdgmax of the auxiliary machine 30, and is expressed by the following equation (35):
Pm=(Psgmax+Pdgmax)/m Formula (35)
The maximum power generation capacity Psgmax of the shaft generator 22 is expressed by the above formula (22), and the maximum power generation capacity Pdgmax of the auxiliary machine 30 is determined in advance as described above. If the power consumption capacity Pd is smaller than Pm (Y in S502), step S204 proceeds to step S503.

In step S503, the calculation unit 120 determines whether the SOC is smaller than the extremely low SOC reference value E _VL . If the SOC is smaller than the extremely low SOC reference value E _VL (Y in S503), step S204 proceeds to step S504.

In step S504, the calculation unit 120 calculates the charge amount Pc of the battery, the power generation amount Pdg of the auxiliary machine 30, and the power generation amount Psg of the shaft generator 22 using the following equations (36) to (38).
Pc=Pm-Pd Formula (36)
Pdg=Pgm Formula (37)
Psg=Psm Formula (38)
Pgm and Psm are as described above in equations (11) and (21), respectively.

In step S505, the calculation unit 120 calculates the torque Tm of the main engine 21 using the following equation (39).
Tm=Tp+Psg/ηsg/Ne*C Formula (39)

Returning to step S503, if the SOC is not smaller than the extremely low SOC reference value _EVL (N in S503), step S204 proceeds to step S506.

In step S506, calculation unit 120 determines whether or not the SOC is smaller than the low SOC reference value _EL . If the SOC is smaller than the low SOC reference value _EL (Y in S506), step S204 proceeds to step S507.

In step S507, the calculation unit 120 calculates a provisional value Pc1 of the charge amount of the battery 44 based on the SOC. Step S507 is similar to step S303 described above, and therefore its description will be omitted.

In step S508, the calculation unit 120 determines whether (Pc1 + Pd) is greater than Pm. If (Pc1 + Pd) is greater than Pm (Y in S508), step S204 proceeds to step S504. If (Pc1 + Pd) is not greater than Pm (N in S508), step S204 proceeds to step S509.

In step S509, the calculation unit 120 calculates the charge amount Pc of the battery, the power generation amount Psg of the shaft generator 22, and the power generation amount Pdg of the auxiliary machine 30 using the following equations (40) and (41).
Pc=Pc1 Formula (40)
Pc+Pd=Psg+Pdg Formula (41)
Here, the power generation amount Psg of the shaft generator 22 and the power generation amount Pdg of the auxiliary machine 30 are calculated. For example, using the map of Figure 6 in which the parameter Pd in the graph is replaced with Pd + Pc, Psg and Pdg are calculated with the power generation ratio optimized based on (Pd + Pc) and the required propeller torque. After step S509, step S204 proceeds to the above-mentioned step S505.

Returning to step S506, if the SOC is not smaller than the low SOC reference value _EL (N in S506), step S204 proceeds to step S510. In step S510, calculation unit 120 determines whether the SOC is smaller than the high SOC reference value _EH . Step S510 is the same as step S307 described above. If the SOC is not smaller than the high SOC reference value _EH (N in S510), step S204 proceeds to step S511.

In step S511, the calculation unit 120 calculates the discharge amount Pb of the battery 44, the power generation amount Psg of the shaft generator 22, and the power generation amount Pdg of the auxiliary machine 30 using the following equations (42) and (43).
Pd=Psg+P' Formula (42)
P'=Pb+Pdg Formula (43)
Here, P' is the total amount of power discharged Pb and the amount of power generated Pdg by the auxiliary 30. In equation (42), the power generation ratio between the amount of power generated Psg of the shaft generator 22 and the total amount of power P' is optimized using the map of FIG. 6 in which the amount of power generated Pdg of the auxiliary 30 on the vertical axis is replaced with the total amount of power P'. Furthermore, the allocation of the amount of power discharged Pb and the amount of power generated Pdg by the auxiliary 30 in the total amount of power P' is determined as described above using FIG. 14 in which the amount of power consumed Pd on the horizontal axis is replaced with P'. After step S511, step S204 proceeds to the above-mentioned step S505.

Returning to step S502 or S510, if the power consumption Pd is not less than Pm (N in S502) or if the SOC is less than the high SOC reference value _EH (Y in S510), step S204 proceeds to step S512. In step S512, the calculation unit 120 calculates the charge amount Pc and discharge amount Pb of the battery 44, the power generation amount Psg of the shaft generator 22, and the power generation amount Pdg of the auxiliary machine 30 using the following equations (44) to (46).
Pc=0 Formula (44)
Pb = 0 Equation (45)
Pd=Psg+Pdg Formula (46)
As shown in equations (44) to (46), the battery 44 is not charged or discharged, and the power consumption Pd is covered by the power generation amount Psg of the shaft generator 22 and the power generation amount Pdg of the auxiliary machine 30. Here, the power generation ratio between the power generation amount Psg of the shaft generator 22 and the power generation amount Pdg of the auxiliary machine 30 is optimized as described above using the map of Figure 6.

After step S512, step S204 proceeds to step S505 described above.

After step S505, processing of step S204 in the third mode ends.

In the second embodiment, there is a margin for the storage/discharge capacity of the battery 44, as well as for the amount of power generated by the shaft generator 22 and the increase/decrease in torque. This makes it possible to more effectively suppress deterioration in fuel economy.

In the second embodiment, the control unit 140 controls at least one of the charge amount Pc or discharge amount Pb of the battery 44 and the power generation amount of the auxiliary machinery 30 and the shaft generator 22 based on the current power consumption amount Pd and the SOC of the battery 44. This configuration makes it possible to appropriately control the power supply within the vessel from the battery 44, the auxiliary machinery 30, and the shaft generator 22, thereby improving fuel efficiency.

In the second embodiment, when the operating point D is within the extremely low torque extremely low power consumption region R2C and the SOC of the battery 44 is greater than the threshold value, the control unit 140 puts the main engine 21 into an idling state, the auxiliary engine 30 into a stopped state, and the shaft generator 22 into a torque output state. With this configuration, the propulsive force of the vessel 1 is generated by the power supply from the battery 44 to the shaft generator 22, and the power consumption Pd, including the power supply from the battery 44 to the shaft generator 22, is entirely covered by the battery 44, thereby reducing fuel consumption and improving fuel efficiency. Furthermore, since the main engine 21 and auxiliary engine 30 can be stopped, extremely quiet operation is possible.

As a modification of the second embodiment, when the shaft generator 22 is controlled using the above-described computational model (trained model), this model may further include the SOC of the battery 44 as input data, and may further include the charge amount Pc or discharge amount Pb of the battery 44 as output data.

In the embodiment, the number of auxiliary devices 30 was not taken into consideration, but if multiple auxiliary devices 30 are provided, the power generation ratio of each auxiliary device 30 may be determined. An example of a method for determining the power generation ratio of each auxiliary device will be described using Figure 19. Figure 19 illustrates an example in which three auxiliary devices 30A, 30B, and 30C are used. If the power consumption Pd is small enough to be covered by the power generation capacity of a single auxiliary device, the power generation capacity of only auxiliary device 30A is increased in proportion to the power consumption Pd. If the power consumption Pd exceeds, for example, 33% of the total power that can be generated by each auxiliary device 30 and cannot be covered by the power generation capacity of a single auxiliary device, auxiliary device 30B is made to generate power in addition to auxiliary device 30A, and auxiliary device 30A is made to generate power at 100% output, while the power generation capacity of the second auxiliary device 30B is increased in proportion to the power consumption Pd. If the power consumption Pd exceeds, for example, 66% of the total power that can be generated by each auxiliary device 30 and the power generation capacity of two auxiliary devices is insufficient, auxiliary device 30C is further made to generate power, auxiliary devices 30A and 30B are made to generate power at 100% output, and the power generation capacity of the third auxiliary device 30C is increased in proportion to the power consumption Pd. Here, when multiple auxiliary devices 30 are installed, fuel efficiency is improved if the outputs of each auxiliary device 30 are approximately the same. In this way, by sequentially generating power in this way, multiple auxiliary devices 30 can be operated at approximately the same output using 100% output, while the power generation capacity of the other auxiliary devices 30 can be adjusted according to the power consumption Pd, thereby improving fuel efficiency.

The graphs and maps in Figures 4, 6, 7, 11, 13, 14, 16, 17, and 19 are merely examples and may be set appropriately through experiments, etc., taking into account the specifications and usage of the main engine 21, etc.

Any combination of the above-described embodiments and variations is also useful as an embodiment of the present invention. New embodiments resulting from such combinations combine the effects of the combined embodiments and variations.

Among the embodiments disclosed herein, those comprised of multiple objects may have the multiple objects integrated, and conversely, those comprised of a single object may be separated into multiple objects. Regardless of whether they are integrated, it is sufficient that they are configured in a way that enables the purpose of the invention to be achieved. Among the embodiments disclosed herein, those comprised of multiple distributed functions may have some or all of those functions integrated, and conversely, those comprised of multiple distributed functions may have some or all of those functions integrated. Regardless of whether the functions are integrated or distributed, it is sufficient that they are configured in a way that enables the purpose of the invention to be achieved.

1 Ship, 10 Telegraph, 20 Propulsion generating device, 21 Main engine, 22 Shaft generator, 23 Propeller, 30 Auxiliary engine, 40 AC grid, 44 Battery, 60 Inboard busbar, 80 Inboard load, 100 ECU, 110 Acquisition unit, 111 Rotational speed acquisition unit, 112 Power consumption acquisition unit, 113 SOC acquisition unit, 120 Calculation unit, 130 Operation mode determination unit, 140 Control unit, 150 Memory unit.

Claims (11)

a main engine for generating a thrust for propulsion of the ship;
an auxiliary machine that generates power to be supplied to the onboard bus;
a shaft generator connected to an output shaft of the main engine, capable of selectively performing a function of generating electric power to be supplied to the inboard busbar by rotation of the output shaft, and a function of generating a propulsive force for propelling the ship by outputting torque using electric power supplied via the inboard busbar;
a rotation speed acquisition unit that acquires a current rotation speed of the main engine and a target rotation speed of the main engine;
a power consumption amount acquiring unit that acquires a current power consumption amount in the ship;
a calculation unit that calculates a required propeller torque, which is a torque required in a propeller of the ship in order to make the rotational speed of the main engine the target rotational speed, based on the current rotational speed and the target rotational speed;
a control unit that controls the main engine, the auxiliary engine, and the shaft generator based on the current required propeller torque and the amount of power consumption;
A control device for a ship comprising: when an operating point of the ship determined by the required propeller torque and the amount of power consumption is included in a second operating region outside a first operating region, the control unit sets the main engine and the auxiliary engine to an operating state and the shaft generator to an idling state,
the required propeller torque and the range of the power consumption amount in the first operating region are set so that the fuel efficiency of the main engine is better than a predetermined fuel efficiency standard,
the first operating region includes a low power consumption region in which the range of power consumption is set below a first power consumption reference value, and a high power consumption region in which the range of power consumption is set equal to or above the first power consumption reference value;
When the operating point is included in the low power consumption region, the control unit sets the main engine in an operating state, the auxiliary engine in a stopped state, and the shaft generator in a power generating state,
When the operating point is included in the high power consumption region, the main engine and the auxiliary engine are in an operating state and the shaft generator is in a power generating state.
The control device for a vessel according to claim 1. the ranges of the required propeller torque and the power consumption amount in the first operating region are set so that the fuel efficiency of the main engine is better than a predetermined fuel efficiency standard,
a second operating region outside the first operating region includes a low-torque, low-power-consumption region in which the range of the required propeller torque is set below a first torque reference value and the range of the power consumption is set below a second power consumption reference value;
when an operating point of the ship determined by the required propeller torque and the amount of power consumption is included in the low torque, low power consumption region, the control unit puts the main engine into an idling state, the auxiliary engine into an operating state, and the shaft generator into a torque output state in which torque is output to the shaft generator.
The control device for a ship according to claim 1 or 2. a battery connected to the inboard busbar and configured to be chargeable and dischargeable;
the second operating region includes an extremely low torque, extremely low power consumption region in which the range of the required propeller torque is set below a lower limit value of the required propeller torque in the low torque, low power consumption region, and the range of the power consumption is set below an extremely low power consumption reference value that is smaller than the second power consumption reference value,
when the operating point is included in the extremely low torque extremely low power consumption region and the SOC of the battery is greater than a threshold value, the control unit puts the main engine into an idling state, the auxiliary engine into a stopped state, and the shaft generator into a torque output state in which torque is output to the shaft generator.
The control device for a vessel according to claim 3. the ranges of the required propeller torque and the power consumption amount in the first operating region are set so that the fuel efficiency of the main engine is better than a predetermined fuel efficiency standard,
a second operating region outside the first operating region includes a high-torque, low-power consumption region in which the required propeller torque range is set above a second torque reference value and the power consumption range is set below a third power consumption reference value;
when an operating point of the ship determined by the required propeller torque and the amount of power consumption is included in the high-torque, low-power consumption region, the control unit sets the main engine and the auxiliary engine to an operating state and sets the shaft generator to a torque output state in which torque is output to the shaft generator.
The vessel control device according to any one of claims 1 to 4. When the auxiliary machine is in an operating state and the shaft generator is in a power generating state, if the amount of power consumption is relatively large, the control unit increases the proportion of the amount of power generated by the auxiliary machine in the total amount of power generated by the auxiliary machine and the shaft generator compared to when the amount of power consumption is relatively small.
The vessel control device according to any one of claims 1 to 5. a battery connected to the inboard busbar and configured to be chargeable and dischargeable;
the control unit controls at least one of the charge amount or discharge amount of the battery and the power generation amount of the auxiliary machine and the shaft generator based on the power consumption amount and the SOC of the battery.
The control device for a vessel according to any one of claims 1 to 6. the control unit controls the main engine, the auxiliary machine, and the shaft generator based on the output data of a trained model that includes, as input data, the current required propeller torque and the power consumption amount, and includes, as output data, the torque of the main engine, the power generation amount of the auxiliary machine, and the torque of the shaft generator or the power generation amount of the shaft generator.
The control device for a vessel according to claim 1. a battery connected to the inboard busbar and configured to be chargeable and dischargeable;
the input data further includes an SOC of the battery, and the output data further includes an amount of power to be charged to the battery or an amount of power to be discharged from the battery.
The control device for a vessel according to claim 8. a main engine for generating a thrust for propulsion of the ship;
an auxiliary device including an auxiliary engine and an auxiliary generator that is driven by the auxiliary engine to generate electric power to be supplied to an inboard bus;
a shaft generator connected to an output shaft of the main engine, capable of selectively performing a function of generating electric power to be supplied to the inboard busbar by rotation of the output shaft, and a function of generating a propulsive force for propelling the ship by outputting torque using electric power supplied via the inboard busbar;
obtaining a current rotation speed of the main engine and a target rotation speed of the main engine;
obtaining a current amount of power consumption on board the vessel;
calculating a required propeller torque, which is a torque required to make the rotational speed of the main engine the target rotational speed, based on the current rotational speed and the target rotational speed;
controlling the main engine, the auxiliary engine, and the shaft generator based on the current required propeller torque and the amount of power consumption;
A method for controlling a vessel, comprising: a main engine for generating a thrust for propulsion of the ship;
an auxiliary device including an auxiliary engine and an auxiliary generator that is driven by the auxiliary engine to generate electric power to be supplied to an inboard bus;
a shaft generator connected to an output shaft of the main engine, capable of selectively performing a function of generating electric power to be supplied to the inboard busbar by rotation of the output shaft, and a function of generating a propulsive force for propelling the ship by outputting torque using electric power supplied via the inboard busbar;
The control program for the ship includes:
obtaining a current rotation speed of the main engine and a target rotation speed of the main engine;
obtaining a current amount of power consumption on board the vessel;
calculating a required propeller torque, which is a torque required to make the rotational speed of the main engine the target rotational speed, based on the current rotational speed and the target rotational speed;
controlling the main engine, the auxiliary engine, and the shaft generator based on the current required propeller torque and the amount of power consumption;
A ship's control program for executing the above.