CN111976458B - Series type severe hybrid power engineering machinery transmission system and control method thereof - Google Patents

Abstract

The invention relates to the field of new energy construction machinery, in particular to a series-type heavy hybrid construction machinery transmission system and a control method thereof. The system includes a mechanical transmission system, an electrical connection system and a control system, an engine output shaft is connected to a clutch, and an ECU system It is respectively connected with the engine, clutch, hydraulic system, motor generator, motor controller, power battery, electric motor, gearbox and other systems. The ECU system collects signals in real time for data analysis and processing. Combined with the characteristics of the construction machinery's own working conditions, it formulates a fuzzy logic control strategy to plan the working modes of the engine, motor generator and motor, and solves the problem of online real-time adaptive and robust control.

Description

A series heavy hybrid construction machinery transmission system and its control method

technical field

The invention relates to the field of new energy construction machinery, in particular to a series-type heavy hybrid construction machinery transmission system and a control method thereof, which are suitable for scraper construction machinery with multiple power outputs.

Background technique

Construction machinery has the shortcomings of high energy consumption, poor emissions, low engine efficiency and high noise, and energy conservation issues have received more and more attention. Therefore, related new technologies such as hybrid technology, new transmission technology, and intelligent control technology need to be widely promoted and applied. .

The working environment of construction machinery is complex and changeable, and it is often necessary to work in special conditions such as underground mines, flammable and explosive areas, low-noise areas, thin air areas, and indoor operations.

Hybrid power systems can achieve energy conservation and emission reduction, but the system power and energy flow have become more complex. New ideas are urgently needed to solve the multi-mode energy distribution relationship, and efficient and reasonable energy management and optimization strategies can be formulated to give full play to the performance of composite energy storage systems. It is also the key to breaking the bottleneck of on-board energy storage technology.

SUMMARY OF THE INVENTION

In order to solve the above problems, the present invention provides a series-type heavy hybrid construction machinery transmission system and a control method thereof. The structure is simple, and the system transmission efficiency is improved while braking energy recovery. The hybrid control strategy needs to solve the complex nonlinear system. Energy distribution problem, combined with the characteristics of series heavy hybrid construction machinery, fuzzy logic has better adaptability and robustness, and can solve the problem of online real-time control.

In order to achieve the above object, the present invention adopts the following technical solutions:

The invention provides a series-type heavy hybrid construction machinery transmission system, which includes a mechanical transmission system, an electrical connection system and a control system.

The mechanical transmission system includes an engine, a clutch, a transfer case, a hydraulic system, a motor generator, an electric motor, a gearbox, a main reducer and a differential, wherein the output shaft of the engine is connected to one end of the clutch, and the other end of the clutch is connected to the transfer case. The input I shaft is connected, the transfer case input II shaft is connected with the motor generator output shaft, the transfer case output shaft is connected with the hydraulic system, the electric motor is used as the power element of the driving system, and the motor output shaft is coaxially connected with the input shaft of the gearbox. The output shaft of the gearbox is connected to the main reducer and the differential;

The clutch controls the on-off of engine power;

The transfer case adjusts the power synthesis and distribution of the power system;

The hydraulic system provides hydraulic power for the working system and the steering system of the hybrid construction machinery transmission system;

the controller controls the work of the motor generator and the motor;

The power battery is the second energy system of the whole vehicle, which is responsible for the storage and release of electric energy, and adjusts the power distribution of the power system through the SOC value of the power battery to improve the fuel economy of the engine and the efficiency of the whole vehicle;

The transmission realizes the function of speed reduction and distance increase, and improves the efficiency of the transmission system and the working efficiency of the electric motor;

The main reducer and the differential realize the speed reduction and differential functions of the transmission system;

The ECU system collects working condition signals, analyzes and processes the data, inputs the data signals into the fuzzy logic controller, formulates a reasonable control scheme according to the control rules, and plans the working modes of the engine, the motor generator and the electric motor.

The electrical connection system includes an engine, a clutch, a hydraulic system, a motor generator, a motor controller, a power battery, an electric motor, a gearbox and an ECU system, wherein the power battery is used as the energy source of the electrical system and is connected to the input end of the motor controller, The output terminals of the motor controller are respectively connected to the motor generator and the motor, and the ECU system is respectively connected to the engine, clutch, hydraulic system, motor generator, motor controller, power battery, motor and gearbox. Control the working mode of each component.

The control system includes an ECU system and a fuzzy logic controller, wherein the ECU system is connected with the fuzzy logic controller, the ECU system collects working condition signals, performs data analysis and processing, and inputs the data signals into the fuzzy logic controller, according to the control rules. Formulate a reasonable control scheme and plan the working mode of the engine, motor generator and electric motor.

The present invention also provides a control method for a series-type heavy hybrid construction machinery transmission system, the steps of which are as follows:

(1) 125 control rules are listed, a fuzzy logic intelligent control strategy is proposed, and a fuzzy logic controller is designed;

(2) The fuzzy logic controller collects the control signal data in real time, the required power _PL of the driving system, the required power PP of the working hydraulic system and the _SOC value of the power battery, and the signal data is divided into 5 segments and fuzzified .

(3) Output the fuzzy signal of the control variable according to the control rules, and then process the data clearly, the motor output power P _M , the _{engine output power PE} and the motor generator output power _PG . The size and the SOC value of the power battery control the operating points of the corresponding motor, engine and motor generator, and solve the energy management problem of the nonlinear complex system through the fuzzy controller.

①In the process of pure electric operation of the construction machinery system, the output power PE of the engine is 0, the output power _PG of the motor generator meets the power demand of the working hydraulic system, and the output power P _M of the _motor meets the power demand of the driving system .

② During the braking energy recovery process, the engine and motor generator do not output power, and the motor output power value P _M ≤- P _L (- P _L represents the braking power value of the driving system), and the recovery strategy is formulated in combination with the SOC state parameters; When the SOC value is low SOC∈(0,0.5], if the motor peak power P _Mmax ≥- P _L , the motor output power value P _M =- P _L , if the motor peak power P _Mmax <- P _L , the motor output Power value P _M = P _Mmax ; when the SOC value is in the median SOC ∈ (0.5, 0.8], if the motor rated power P _Me ≥- P _L , the motor output power value P _M =- P _L , if the motor rated power P When _Me <- P _L , the motor output power value P _M = P _Me ; when the SOC value is higher, SOC∈(0.8, 1.0], the motor output power value P _M =5(1-SOC)*min( P _Me ,- PL ₎ .

③In the process of hybrid drive, establish a fuzzy logic controller, collect PL , PP and _SOC values in real time, and output _PG and _PE values ; among them, the size of _{PM value} is determined by PL ; PL _takes a _positive value When _{PG is positive, it represents the driving state of the whole vehicle; when PL} is negative, it represents the braking state of the whole vehicle ; when _PG is positive, it means that the generator and the motor _{-generator jointly drive the hydraulic system to work; when PG} is 0, the It means that the output power of the motor generator is 0. When PG _takes a negative value, it means that the SOC value is low or the power required by the driving system is large, and the motor generator is in a power generation state.

Among them, the fuzzy logic controller of the series heavy hybrid construction machinery transmission system in the hybrid drive process is shown in the attached drawing, and the control rules are as follows:

Table 1 Fuzzy logic rule base

"——" means that the engine does not work, and the system is in a pure electric working state.

The invention provides a series heavy hybrid construction machinery transmission system, which can realize four working modes, mainly including: engine independent driving mode, pure electric driving mode, hybrid driving mode and braking energy recovery mode.

When the series-type heavy hybrid construction machinery transmission system enters the engine independent drive mode, the working principle: the engine inputs the power to the transfer case through the clutch, a part of the power of the transfer case drives the load hydraulic system to work, and the remaining power drives the motor generator Work, the generated electric energy is used for the electric motor to drive the driving system to work, and the excess energy can be stored in the power battery;

The series-type heavy hybrid construction machinery transmission system enters the pure electric drive mode, and the working principle: in the case of special working conditions or engine failure, the power battery drives two motors to work at the same time, the motor drives the driving system to work, and the motor generator passes through. The transfer case drives the hydraulic system to work;

The series heavy hybrid construction machinery transmission system enters the hybrid drive mode, and the working principle is as follows:

①The engine drives the hydraulic system alone, and the electric motor drives the driving system alone;

②The electric motor drives the driving system alone, and the engine and the motor-generator jointly drive the hydraulic system;

③ Part of the power of the engine drives the hydraulic system, and the remaining power drives the motor-generator to work, and the generated electric energy and the power battery jointly drive the motor to work.

The series-type heavy hybrid construction machinery transmission system enters the braking energy recovery mode. The working principle is as follows: when the whole vehicle is braking, the driving motor generates braking force for braking energy recovery, and the recovered energy is used to charge the power battery.

When the system works purely electrically, the clutch is disconnected, and the clutch is closed under other working conditions;

In the pure electric mode of the system, the motor-generator works as an electric motor to drive the hydraulic system, and in the hybrid mode, it can also act as an engine to provide electric power for the electric motor or to charge the power battery.

The electric motor is the power element of the drive system, and its electric energy comes from the power battery or the motor generator. At the same time, the electric motor is in the state of generating electricity during the braking process of the system to recover the braking energy.

Compared with the prior art, the present invention has the beneficial effects that the motor-driven driving system is adopted, the hydraulic torque converter is eliminated, the transmission efficiency of the system is improved, and the braking energy can be recovered at the same time; It can ensure that the engine works stably in the high-efficiency and low-fuel consumption area; the pure electric working mode is suitable for special working conditions such as flammable and explosive areas, low-noise areas, thin air areas, and indoor operations. Control strategy: The hybrid control strategy needs to solve the energy distribution problem of complex nonlinear systems, while the traditional control mode that relies on accurate models needs to be improved. Intelligent control simulates human reasoning to achieve optimal control of objects to a certain extent. Combined with hybrid construction machinery Due to the characteristics of the transmission system, fuzzy logic has better adaptability and robustness, and can solve the problem of online real-time control.

Description of drawings

The following drawings are only some typical working mode cases of the present invention. The control scheme diagrams are some example diagrams obtained by combining the control rules in Table 1, and other control scheme diagrams can also be obtained according to relevant information.

Figure 1 is a schematic diagram of the overall structure of the present invention.

FIG. 2 is a schematic diagram of the pure electric drive mode of the present invention.

FIG. 3 is a schematic diagram of the pure engine driving mode of the present invention.

FIG. 4 is a schematic diagram of the independent driving mode of the engine and the motor according to the present invention.

FIG. 5 is a schematic diagram of the hydraulic system mode of the combined driving of the engine and the generator according to the present invention.

FIG. 6 is a schematic diagram of the mode of the combined driving system of the engine and the electric motor of the present invention.

FIG. 7 is a schematic diagram of the charging mode of the engine of the present invention for the power battery.

FIG. 8 is a schematic diagram of the braking energy recovery mode of the present invention.

FIG. 9 is a schematic structural diagram of the fuzzy logic control mode of the present invention.

FIG. 10 is a schematic diagram of the control rules of the fuzzy logic part of the present invention.

1. Engine; 2. Clutch; 3. Transfer case; 4. Hydraulic system; 5. Motor generator; 6. Motor controller; 7. Power battery; 8. Electric motor; 9. Gearbox; 10. Main reducer and differential; 11. ECU system.

Detailed ways

In order to more clearly express the embodiments of the present invention, the system working mode and the control method, the working mode and control scheme of the series heavy hybrid construction machinery transmission system will be briefly introduced below with reference to the accompanying drawings. System working mode diagram, Figure 9 and Figure 10 show the control scheme diagram, the thin line in the figure represents the electrical connection, the thick line represents the mechanical connection, and the direction of the arrow represents the direction of energy flow.

As shown in FIG. 1 , the present invention discloses a structural scheme of a series-type heavy hybrid construction machinery transmission system, including a mechanical transmission, an electrical connection system and a control system. The mechanical transmission system includes an engine 1, a clutch 2, a transfer case 3, The hydraulic system 4, the motor generator 5, the electric motor 8, the gearbox 9, the main reducer and the differential 10, the output shaft of the engine 1 is connected to one end of the clutch 2, the other end of the clutch 2 is connected to the input shaft of the transfer case 3, and the split The input shaft of the transmission case 3 is connected to the output shaft of the motor generator 5, the output shaft of the transfer case 3 is connected to the hydraulic system 4, the electric motor 8 is used as the power element of the driving system, and the output shaft of the electric motor 8 is coaxially connected to the input shaft 9 of the gearbox. , the output shaft of the gearbox 9 is connected to the main reducer and the differential 10;

The electrical connection system includes an engine 1, a clutch 2, a hydraulic system 4, a motor generator 5, a motor controller 6, a power battery 7, an electric motor 8, a gearbox 9 and an ECU system 11, wherein the input end of the motor controller 6 is connected to the power battery 7 is connected, the output end is connected to the motor generator 5 and the motor 8 respectively, the ECU system 11 is respectively connected to the engine 1, the clutch 2, the hydraulic system 4, the motor generator 5, the motor controller 6, the power battery 7, the motor 8 and the gearbox 9 connect;

The control system includes an ECU system 11 and a fuzzy logic controller, wherein the ECU system 11 is connected with the fuzzy logic controller.

The present invention provides a method for controlling the transmission system of a series-type heavy hybrid construction machinery. The steps of the method are as follows:

(1) 125 control rules are listed, a fuzzy logic intelligent control strategy is proposed, and a fuzzy logic controller is designed;

(2) The fuzzy logic controller collects the control signal data in real time, and the system input parameters include the SOC value of the power battery, the required power value P _P of the working hydraulic system, and the required power value P _L of the driving system;

(3) Divide the signal data into 5 segments and fuzzify them, output the control variable fuzzy signal according to the control rules, and then process the data clearly. The output parameters are the motor generator output power value P _G , the motor output power P _M and the engine output power The value P _E , during the working process of the system, through the online real-time sensing of the size of the load and the SOC value of the power battery, the corresponding operating points of the engine, the motor and the motor generator are controlled, and the fuzzy controller is used to solve the energy management problem of the nonlinear complex system.

As shown in Figure 10, a schematic diagram of the fuzzy logic part of the control rules of a series-type heavy hybrid construction machinery transmission system, according to the fuzzy logic control rules, the view surf diagram is drawn, and the real-time collected data signals are processed in segments, and then processed by the fuzzy logic controller. Then output a series of control parameters to control the working mode and working parameters of the system.

In this series-type heavy hybrid construction machinery transmission system scheme, the transmission system is directly driven by the electric motor, which cancels the hydraulic torque converter of the traditional system and improves the transmission efficiency of the system; the engine operating point is not affected by the driving road conditions, and the fuel economy is greatly improved. Improve; the system is suitable for special working conditions such as underground mines, thin air areas, flammable and explosive areas, low-noise areas, and indoor operations in the pure electric working mode, and the braking energy recovery function is realized through the series hybrid structure.

The series heavy hybrid construction machinery transmission system has engine mode, pure electric mode and hybrid drive mode. The energy management system decides the working mode of the system according to the load demand power value and the battery SOC value. The specific motor operating point is determined by the power demand of the driving system. PL determines that the engine and motor generator operating points are formulated by the fuzzy logic controller _.

Specifically, the fuzzy logic control rules shown in Table 1 and Figure 10, Table 1 lists 125 kinds of control rules, the fuzzy logic controller collects the control signal data in real time, processes the signal data in 5 segments and fuzzifies, and outputs according to the control rules The fuzzy signal of the control variable is controlled, and then the data is processed clearly to control the operating points of the corresponding engine and motor generator, and solve the energy management problem of the nonlinear complex system through the fuzzy controller.

Combine the control rules and view surf diagrams to analyze the characteristics of several working conditions . For example, when the input signal of the fuzzy controller is _: the power battery SOC value is too high, the working hydraulic pump PP value is low, the driving system _PL value is positive and small, the output electric The generator P _G value is positive and small, and the engine P _E value is 0. At this time, the engine does not work, the system is in a pure electric working state, part of the electric energy is used for the electric motor to drive the driving system to work, and part of the electric energy is used for the motor generator to drive the hydraulic system to work; As shown in Figure 2, the system is in the pure electric working mode, the power battery 7 transmits electric energy to the motor generator 5 and the motor 8 through the motor controller 6, the motor 8 drives the driving system to work, and the motor generator 5 is in the electric state , drive the working hydraulic system 4 to work.

Combine the control rules and view surf diagrams to analyze the characteristics of several working conditions . For example, when the input signal of the fuzzy controller is _: the power battery SOC value is moderate, the working hydraulic pump PP value is moderate, the driving system _PL value is small, and the output motor generator The PG value is negative and the engine _{PE value} is moderate. At this time, the engine alone drives the system to work, a part of the energy drives the hydraulic system to work, the remaining energy drives the motor generator to generate electricity, and the electric energy supplies the motor to drive the driving system to work; as shown in Figure 3, the system is in the engine independent drive mode, The engine 1 divides the power into two paths through the transfer case 3, one part drives the hydraulic system 4 to work, and part of the energy drives the motor generator 5 to work, and the generated electric energy is used by the motor 8 to drive the driving system to work.

Combine the control rules and view surf diagrams to analyze the characteristics of several working conditions . For example, when the input signal of the fuzzy controller is _: the power battery SOC value is high, the working hydraulic pump PP value is low, the driving system _PL value is positive, and the output electric The generator PG value is 0, and the engine _{PE value} is low. At this time, the system is in the independent driving state of the engine and the electric motor, the motor generator does not work, the engine drives the hydraulic system to work, and the power battery supplies the electric motor to drive the driving system to work; as shown in Figure 4, the system is in the independent driving mode of the engine and the electric motor. , the engine 1 drives the hydraulic system 4 to work through the transfer case 3; the power battery 7 transmits the electric energy to the electric motor 8 through the motor controller 6 to drive the driving system to work.

When the construction machinery system is braking, the motor can generate braking torque to assist braking. At this time, the driving motor is in the power generation state, and the value of PL is negative _. If the output parameter PG of the control strategy is negative, it indicates that the motor _- generator is in In the power generation state, the SOC value of the power battery is low, and the engine has excess energy. The engine and the braking system jointly charge the power battery; if the control strategy output parameter P _G value is 0, it indicates that the motor generator does not work, and the braking system alone provides power to the power battery. The power battery is charged; if the control strategy output parameter PG is a positive value, it indicates that the motor _- generator is in an electric state, and the electric energy recovered by the braking system must be used to drive the hydraulic system to work; as shown in Figure 8, the system is in In the braking energy recovery working mode, during the whole vehicle braking process, the electric motor 8 performs auxiliary braking and works in a power generation state, and the electric energy generated during the braking process is stored in the power battery 7 system.

As shown in Figure 5, the system is in the working mode of the hydraulic system jointly driven by the electric motor and the engine. In this mode, the hydraulic system is in a heavy load condition. Part of the energy of the power battery 7 is distributed to the electric motor 8 to drive the driving system to work, and the other part of the energy drives the driving system. The motor generator 5 operates, and the motor generator and the engine 1 jointly drive the working hydraulic system 4 to operate.

As shown in Figure 6, the system is in the working mode of the electric motor and the engine jointly driving the driving system. A part of the energy of the engine 1 drives the working hydraulic system 4 to work, and the remaining energy drives the motor generator 5 to generate electricity. The electric energy and power generated by the motor generator 5 The battery 7 together drives the electric motor 8 for the driving system to work.

As shown in Figure 7, the system is in the power battery charging mode, a part of the energy of the engine 1 drives the working hydraulic system 4 to work, the remaining energy drives the motor generator 5 to generate electricity, and the electric energy generated by the motor generator supplements the power battery 7.

As shown in Figure 9, a series-type heavy hybrid construction machinery transmission system fuzzy logic control mode structure diagram, the system input parameters include the power battery SOC value, the working hydraulic system demand power value P _P , the driving system demand power value P _L , The output parameters are the motor-generator output power value _PG and the engine output power value PE . _During the system operation, by sensing the size of the load load and the SOC value of the power battery in real time online, the operating point of the motor-generator and the engine and the system work are controlled. model.

The system working mode in the design of the control idea solution proposed by the present invention improves the economy while meeting the power performance requirements of the entire vehicle. The above descriptions are only specific examples of the present invention, and cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims (1)

1. A control method for a series-type heavy hybrid construction machinery transmission system, the involved system includes a mechanical transmission system, an electrical connection system and a control system, and the mechanical transmission system includes an engine (1), a clutch (2), a transfer case ( 3), hydraulic system (4), motor generator (5), electric motor (8), gearbox (9), final gear and differential (10), of which the engine (1) output shaft and clutch (2) One end is connected, the other end of the clutch (2) is connected with the input shaft of the transfer case (3), the input shaft of the transfer case (3) is connected with the output shaft of the motor generator (5), and the output shaft of the transfer case (3) is connected with the output shaft of the motor generator (5). The hydraulic system (4) is connected, the electric motor (8) is used as the power element of the driving system, the output shaft of the electric motor (8) is coaxially connected with the input shaft of the gearbox (9), and the output shaft of the gearbox (9) is connected with the main reducer and Differential (10); The electrical connection system includes an engine (1), a clutch (2), a hydraulic system (4), a motor generator (5), a motor controller (6), a power battery (7), an electric motor (8), and a gearbox (9) and the ECU system (11), wherein the input end of the motor controller (6) is connected to the power battery (7), the output end is connected to the motor generator (5) and the electric motor (8) respectively, and the ECU system (11) is respectively connected to the engine ( 1), clutch (2), hydraulic system (4), motor generator (5), motor controller (6), power battery (7), motor (8) and gearbox (9) are connected; the control system includes ECU A system (11) and a fuzzy logic controller, wherein the ECU system (11) is connected with the fuzzy logic controller; the ECU system collects working condition signals and performs data analysis and processing, and inputs the data signals into the fuzzy logic controller, according to the control rules Formulate a reasonable control scheme, and plan the working mode of the engine, the motor-generator and the electric motor, and it is characterized in that the steps of the method are as follows: (1) 125 control rules are listed, a fuzzy logic intelligent control strategy is proposed, and a fuzzy logic controller is designed; (2) The fuzzy logic controller collects the control signal data in real time, and the system input parameters include the SOC value of the power battery, the required power value P _P of the working hydraulic system, and the required power value P _L of the driving system; (3) Divide the signal data into 5 segments and fuzzify them, output the control variable fuzzy signal according to the control rules, and then process the data clearly. The output parameters are the motor generator output power value P _G , the motor output power P _M and the engine output power value P _E , during the working process of the system, through the online real-time sensing of the size of the load load and the SOC value of the power battery, the corresponding operating points of the engine, the motor and the motor generator are controlled, and the energy management problem of the nonlinear complex system is solved by the fuzzy controller; ①In the process of pure electric operation of the system, the engine output power _PE is 0, the motor generator output power _PG meets the power demand of the working hydraulic system, and the motor output power P _M meets the power demand of the driving system; ② During the braking energy recovery process of the system, the engine and the motor generator do not output power, the motor output power value P _M ≤ -PL _L , _-PL represents the braking power value of the driving system, and the recovery strategy is formulated in combination with the SOC state parameters; When the SOC value is low SOC∈(0,0.5], if the motor peak power P _Mmax ≥- P _L , the motor output power value P _M =- P _L , if the motor peak power P _Mmax <- P _L , the motor output Power value P _M = P _Mmax ; when the SOC value is in the median SOC ∈ (0.5, 0.8], if the motor rated power P _Me ≥- P _L , the motor output power value P _M =- P _L , if the motor rated power P When _Me <- P _L , the motor output power value P _M = P _Me ; when the SOC value is higher, SOC∈(0.8, 1.0], the motor output power value P _M =5(1-SOC)*min( P _Me ,- p _L ); ③In the process of hybrid drive, the system establishes a fuzzy logic controller, collects _PL , _PP and SOC values in real time, and outputs _PG and _PE values; among them, the value of _{PM is determined by PL; PL is positive} When PG is a positive value, it represents the driving state of the whole vehicle; when _PL is a negative value, it represents the braking state of the whole vehicle; when _PG is a positive value, it means that the generator and the motor-generator jointly drive the hydraulic system to work; when _PG is 0 , which means that the output power of the motor generator is 0. When _PG takes a negative value, it means that the SOC value is low or the power required by the driving system is large, and the motor generator is in the power generation state; ④ The system controls the engine and motor working modes and their working points in real time according to the load demand power and the SOC value of the power battery, so as to realize the intelligent control of the vehicle power system and maximize the recovery of braking energy.

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