CN115782853A - Control method and control system of extended range vehicle - Google Patents

Abstract

The present application discloses a control method for a range-extender vehicle, which includes obtaining the vehicle speed of the range-extender vehicle and the SOC of the power battery, and if the range-extender vehicle is in the first operating state, starting the range extender and controlling the range extender Running at the highest efficiency point, the first running state refers to: the vehicle speed is greater than or equal to the first preset speed, the state of charge SOC is less than or equal to the first threshold S1, and the range-extender vehicle is in the constant-speed cruise state. If the range-extender is at the highest efficiency After running at the power point, the state of charge SOC is reduced to the lower limit of the target SOC, and the range extender is controlled to run at the first constant speed power point. The application also discloses a control system of the extended-range vehicle. According to the control method of the present application, the range extender operates at the highest efficiency point in the first operating state to improve fuel economy, and if it does not meet the SOC requirements of the state of charge, it operates at the first constant speed power point to increase the power generation and avoid Exiting the cruise control state will affect the driving experience, and then take into account the fuel economy and power generation.

Description

A control method and control system for an extended-range vehicle

technical field

The present application relates to the technical field of electric vehicles, and in particular, relates to a control method and a control system for an extended-range vehicle.

Background technique

The range extender is usually composed of a small engine, a generator integrating power generation/drive, an engine controller, a generator controller, etc., which can supply power to the vehicle power battery or directly to the drive motor, thereby increasing the cruising range of the vehicle. In related technologies, the vehicle controls the range extender under high-speed conditions, and the range extender is usually activated when the SOC of the on-vehicle power battery is less than a certain value.

The power following strategy of the range extender is often adopted now, and the operating point of the range extender changes with the power demand of the vehicle. Hours, the range extender starts and generates electricity. At this time, the engine is in the high-speed and high-torque working area. On the one hand, it is easy to generate large ground vibration noise; on the other hand, according to the power following strategy, the range extender is in the low-efficiency area, and it is difficult to balance fuel economy and power generation. Especially, in the high-speed cruise state, the problem of balancing fuel economy and generating power is extremely acute, so it is extremely necessary to solve the problem of balancing fuel economy and generating power.

Contents of the invention

The purpose of the embodiments of the present application is to provide a control method and a control system for an extended-range vehicle to solve the problem that it is difficult to balance fuel economy and power generation in a high-speed constant speed cruise state.

In order to solve the above problems, the application adopts the following technical solutions to achieve:

The application provides a control method for an extended-range vehicle, including:

Obtain the vehicle speed of the extended-range vehicle and the SOC of the power battery;

If the range-extender vehicle is in the first operating state, start the range extender and control the range extender to operate at the highest efficiency point, wherein the first operating state refers to: the vehicle speed is greater than or equal to the first preset The vehicle speed, the state of charge SOC is less than or equal to the first threshold S1, and the extended-range vehicle is in a constant speed cruise state;

If the state of charge SOC is reduced to the lower limit of the target SOC after the range extender operates at the highest efficiency point, then the range extender is controlled to operate at the first fixed speed power point to increase the range extender The power generation power of the first constant speed power point is greater than the power generation power of the highest efficiency point, and the power generation efficiency of the first constant speed power point is smaller than the power generation efficiency of the highest efficiency point.

Further, after the step of starting the range extender and controlling the range extender to operate at the highest efficiency point, the control method further includes:

If the state of charge SOC increases to a target threshold value, the range extender is controlled to be turned off, and the range extender vehicle enters into an EV mode of operation.

Further, after the step of controlling the range extender to run at the first constant speed power point, the control method further includes:

If the state-of-charge SOC increases to the target SOC upper limit value, the range extender is controlled to operate at the highest efficiency point from the first constant-speed power point.

Further, after the step of obtaining the vehicle speed of the extended-range vehicle and the SOC of the power battery, the control method further includes:

If the range-extended vehicle is in the second running state, start the range extender and control the range extender to run at the first power point, the second running state means: the vehicle speed is less than the first preset speed, And the state of charge SOC is less than or equal to the second threshold S2, wherein the second threshold S2 is smaller than the first threshold S1, and the first power point and the highest efficiency point are respectively at different vehicle speeds The operating point of the range extender.

Further, after the step of starting the range extender and controlling the range extender to operate at the first power point, the control method further includes:

If the state of charge SOC decreases to the third threshold S3 after the range extender operates at the first power point, the range extender is controlled to operate at the second power point, wherein the second The generated power of the power point is greater than the generated power of the first power point.

Further, after the step of controlling the range extender to operate at the second efficiency point, the control method further includes:

If the state of charge SOC decreases to the fourth threshold S4 after the range extender operates at the second power point, the range extender is controlled to operate at the maximum power point, wherein the maximum power point The generated power of is greater than the generated power of the second power point.

Further, after the step of controlling the range extender to operate at the maximum power point, the control method further includes:

If the state of charge SOC increases to the second threshold S2 after the range extender operates at the maximum power point, the range extender is controlled to switch from the maximum power point to the first power point.

Further, after the step of starting the range extender and controlling the range extender to operate at the first power point, the control method further includes:

If the state of charge SOC increases to a target threshold after the range extender operates at the first power point, the range extender is turned off.

The present application also provides a control system of an extended-range vehicle, the control system is used to execute the above control method, the control system includes a detection module and a control module, wherein,

The detection module is used to detect the vehicle speed, state of charge SOC and running state of the extended-range vehicle;

The control module is configured to control the range extender to operate at the highest efficiency point when the range extender vehicle is in the first operating state, and after the range extender operates at the highest efficiency point, the charging When the state SOC decreases to the lower limit of the target SOC, the range extender is controlled to operate at the first fixed speed power point, wherein the first operating state refers to: the vehicle speed is greater than or equal to the first preset vehicle speed, the load The electric state SOC is less than or equal to the first threshold S1, and the range-extended vehicle is in a constant speed cruise state.

Further, the control module is also used for:

When the range-extender vehicle is in the second operating state, start the range extender and control the range extender to operate at the first power point, wherein the second operating state refers to: the vehicle speed is less than the first preset The vehicle speed, and the state of charge SOC is less than or equal to the second threshold S2.

The control method and control system of the range-extended vehicle of the embodiment of the present application, wherein the control method includes obtaining the vehicle speed of the range-extended vehicle and the SOC of the power battery, and if the range-extended vehicle is in the first operating state, start the range extender , and control the range extender to operate at the highest efficiency point, the first operating state refers to: the vehicle speed is greater than or equal to the first preset vehicle speed, the state of charge SOC is less than or equal to the first threshold S1, and the range extender vehicle is in the constant speed cruise state. If the state of charge SOC decreases to the lower limit of the target SOC after the range extender operates at the highest efficiency point, then the range extender is controlled to operate at the first constant speed power point. In the control method of the present application, when the range extender vehicle is in the first operating state, the range extender operates at the highest efficiency point to improve fuel economy. If the range extender operates at the highest efficiency point, the state of charge SOC is reduced to If the lower limit of the target SOC is difficult to meet the requirements of the SOC of the state of charge, then the operation is transferred from the highest efficiency point to the first constant speed power point to increase the power generation to meet the requirements of the SOC of the state of charge and reduce the , the risk of exiting the cruise control state will affect the driving experience. Since the operating state of the extended-range vehicle is judged first, the range extender operates at the highest efficiency point and the first constant-speed power point in the case of high-speed constant-speed cruise. Choose, and then take into account fuel economy and power generation.

Description of drawings

FIG. 1 is a schematic flowchart of a first control method for an extended-range vehicle provided in an embodiment of the present application;

FIG. 2 is a schematic flowchart of a second control method for an extended-range vehicle provided in an embodiment of the present application;

FIG. 3 is a schematic flowchart of a third control method for an extended-range vehicle provided in an embodiment of the present application;

FIG. 4 is a schematic flowchart of a fourth control method for an extended-range vehicle provided in an embodiment of the present application;

FIG. 5 is a schematic flowchart of a fifth control method for an extended-range vehicle provided in an embodiment of the present application;

Fig. 6 is a system block diagram of a control system of a range-extending vehicle provided by an embodiment of the present application;

Fig. 7 is an optimization strategy diagram in a control method of a range-extended vehicle provided in an embodiment of the present application, wherein the operating condition points of the range-extender at different rotational speeds are displayed;

FIG. 8 is a control strategy diagram of a control method for an extended-range vehicle provided in an embodiment of the present application;

FIG. 9 is a control strategy diagram of another control method for an extended-range vehicle provided by an embodiment of the present application; and

Fig. 10 is a logic control diagram of a range extender in the prior art.

Detailed ways

Specific embodiments of the present application will be described in detail below in conjunction with the accompanying drawings.

It should be noted that, in the case of no conflict, the embodiments in the application and the technical features in the embodiments can be combined with each other. Undue Limitation of This Application.

It should be understood that the orientation or positional relationship is based on the orientation or positional relationship shown in the drawings. These orientation terms are only for the convenience of describing the application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the application.

In the description of this application, the term "first/second" is only used to distinguish similar objects, and does not represent a specific order for objects. It is understandable that "first/second" can be The specific order or sequencing is interchanged such that the embodiments of the application described herein can be practiced in other sequences than illustrated or described herein.

The hybrid system is currently the most promising model in the market, among which the range-extended power system is becoming more and more popular. Compared with traditional vehicles, it matches the high-efficiency operating point of the engine, greatly reduces the fuel consumption and emissions of the vehicle, and reaches the National VI/National 7. Emission regulations. Compared with HEV (Hybrid Electric Vehicle, hybrid electric vehicle) and PHEV (Plug-inhybrid electric vehicle, plug-in hybrid electric vehicle) hybrid models, the range extender minimizes the mileage anxiety problem and realizes the mileage of traditional vehicles. The driving experience of the vehicle.

In the hybrid architecture, the range extender is only used to provide electric power, and the engine does not participate in the direct drive of the vehicle. The range extender is completely decoupled from the work of the entire vehicle, and the operating point of the range extender has no direct relationship with the vehicle speed. Therefore, from the perspective of vehicle performance, it is extremely important to maximize the performance potential of the range extender, reasonably match the operating point of the range extender, and optimize the control strategy.

However, as shown in Figure 10, based on the working efficiency of the range extender, there are two existing control strategies for the range extender: 1—fixed-point strategy (multi-point working conditions), according to the power requirements of the common working conditions of the vehicle, select multiple Different power matching points of a range extender; 2—power following strategy, based on the best efficiency point under different range extender powers, the range extender matching point follows the change of vehicle power demand. Compared with traditional cars, the weight of hybrid models is increased, especially PHEV models, which usually have the phenomenon of "small horses and large carts" in the state of power loss. Due to the high power demand, when the whole vehicle is in a state of power loss, there are problems such as abnormally high fuel consumption in high-speed working conditions and poor user experience. At the same time, the speed of the range extender is high in the power loss mode, and the NVH is insufficient. For example, high-speed working conditions of the whole vehicle require high power. According to the existing strategy, the matching point of the range extender works under high-speed and high-load conditions, and is in the low-efficiency area of the range extender (refer to the high-speed working condition matching point in Figure 10). The consumption rate is high and the fuel economy is poor. Especially when the vehicle is at high speed and cruise at a constant speed, the insufficient power generation will further reduce the SOC of the state of charge, affecting the mileage, and the fuel economy is poor under high power generation, and the working efficiency of the Zengcheng device is low. Therefore, under high-speed and constant-speed cruise, in order to meet the needs of high-speed and constant-speed cruise, it is necessary to balance the relationship between the state of charge SOC and the power generation and working efficiency of the range extender. For example, when selecting the appropriate power generation to ensure fuel economy, the power generation of the range extender is reduced, and because the vehicle is in a stage of high power demand and the SOC of the power battery is already relatively low, in order to maintain the power demand, the power The battery also needs to provide part of the electric energy for the drive motor, resulting in a short cruising range of the vehicle, which cannot meet the mileage requirement.

In view of this, as shown in Figure 1, the embodiment of the present application provides a control method for an extended-range vehicle, including:

S101. Obtain the vehicle speed of the extended-range vehicle and the SOC of the power battery;

S201. If the range-extended vehicle is in the first operating state, start the range extender and control the range extender to operate at the highest efficiency point, wherein the first operating state refers to: the vehicle speed is greater than the first preset vehicle speed, and the state of charge SOC is less than equal to the first threshold S1, and the range-extended vehicle is in the state of constant speed cruise;

S301. If the state of charge SOC is reduced to the lower limit of the target SOC after the range extender operates at the highest efficiency point, then control the range extender to operate at the first constant speed power point to increase the power generation of the range extender, wherein, The generated power at the first fixed-speed power point is greater than the generated power at the highest efficiency point, and the generated power at the first fixed-speed power point is lower than the generated power at the highest efficiency point.

Specifically, the extended-range vehicle is powered on, and after running, the vehicle speed of the extended-range vehicle and the state of charge SOC of the power battery are obtained. For example, the data of the vehicle speed and the state of charge SOC are read by the controller. SOC, to determine the operating condition of the range extender. When the vehicle speed is greater than the first preset vehicle speed, the state of charge SOC is less than or equal to the first threshold S1, and the range-extending vehicle is in the constant-speed cruising state, it is determined that the range-extending vehicle is in the first operating state. At this time, the range extender is activated. And control the range extender to run at the highest efficiency point.

For example, the range extender has high-speed fixed point 3, high-speed fixed point 4, and high-speed fixed point 5, among which, high-speed fixed point 3 is a common high-speed operating point, and high-speed fixed point 3 represents the highest efficiency point of the range extender, which has the best fuel economy (see Fig. 7) When the vehicle speed is greater than the first preset vehicle speed, the extended-range vehicle is in a high-speed running state, and the state of charge SOC and the current running state of the extended-range vehicle are further judged. If the state of charge SOC is less than or equal to the first threshold S1 and the range-extender vehicle is in the constant speed cruise state, it is determined that the range-extender vehicle is in the first operating state. 3 run.

It should be noted that the first threshold S1 is higher than the threshold value of the SOC of the range extender under normal circumstances. For example, the first threshold S1 is 40%. The threshold value is 30%. When the range-extended vehicle is in the first operating state, the state of charge SOC is less than or equal to 40%, the range-extender starts and runs at high-speed fixed point 3 (the highest efficiency point); when the range-extended vehicle is in normal condition When the state of charge SOC is less than or equal to 30%, the range extender starts to start. Since the range-extender vehicle is in the first running state, the demand for electricity is relatively large. Compared with the start-up threshold of the range extender under normal circumstances, a larger threshold (the first threshold S1) is used to make the range extender start in advance, and Run at high-speed fixed point 3 (the highest efficiency point) to achieve the best operating efficiency and improve fuel economy. It should be understood that in general, the activation of the range extender represents a non-high-speed constant-speed cruise state. For example, when the range-extender vehicle is running at a low speed, at this time, it can be considered as a normal situation. When the state of charge SOC is less than or equal to 30%, The range extender just starts to start.

When the range extender is started and running at the highest efficiency point (refer to the high-speed fixed point 3 in Figure 8), since the range extender vehicle is in the first operating state, if the SOC of the state of charge decreases to the lower limit of the target SOC, the control increase The scheduler operates at the first constant speed power point. For example, the lower limit of the target SOC is 35%. When the range extender is started and runs at the highest efficiency point (refer to high-speed fixed point 3 in Figure 8), the state of charge SOC decreases from 40% to 35%. The power generation of the extended-range vehicle at the highest efficiency point is difficult to meet the power consumption demand of the current first operating state. The extended-range vehicle needs to increase the power generation, and the controller controls the range extender to transfer from the highest efficiency point to the first constant speed power point. .

It should be understood that if the power generation efficiency at the first fixed-speed power point still cannot meet the power consumption demand, that is, the SOC of the range extender is still decreasing when the range extender is running at the first constant-speed power point, then the range extender is controlled at The second constant speed power point operation with higher generating power at high speed. For example, as shown in Figure 7 and Figure 8, the first fixed-speed power point is high-speed fixed point 4, and the second fixed-speed power point is high-speed fixed point 5. When the range extender is started, it is at the highest efficiency point (high-speed fixed point 3) After running, the state of charge SOC decreases from 40% to 35%. At this time, it shows that the power generation of the extended-range vehicle at the highest efficiency point cannot meet the power consumption demand of the current first operating state. The extended-range vehicle needs to increase the power generation and control The controller controls the range extender to run from the highest efficiency point to the first constant speed power point. If the state of charge SOC decreases from 35% to 32% at the first fixed-speed power point, it indicates that the power generation of the extended-range vehicle at the first fixed-speed power point is still difficult to meet the current power consumption demand. The vehicle needs to further increase the power generation, and the range extender runs from the first constant speed power point to the second constant speed power point. Extending along this strategy, it can be seen that if the second constant speed power point cannot meet the power consumption demand of constant speed cruise at high speed, it can further jump to the next constant speed power point, or even reach the maximum power point at high speed.

It should be understood that the range-extender vehicle can perform constant-speed cruise at different vehicle speeds, especially at high-speed constant-speed cruises with different high-speed values. Make the vehicle quit high-speed cruise control, thereby affecting the driving experience. For example, the constant speed cruise at a speed of 90km/h is different from the constant speed cruise at a speed of 120km/h. The SOC requirements of the two are different, and the constant speed at 90km/h can be satisfied at high-speed fixed point 3 Cruise demand (state of charge SOC increases from 40%), in the case of high-speed fixed point 3, it may be difficult to meet the demand for constant speed cruise at 120km/h (state of charge SOC decreases from 40%), at this time, the range extender Jump to high-speed fixed point 4 for more power generation.

In the control method of the present application, when the range extender vehicle is in the first operating state, the range extender operates at the highest efficiency point to improve fuel economy. If the range extender operates at the highest efficiency point, the state of charge SOC is reduced to If the lower limit of the target SOC is difficult to meet the requirements of the SOC of the state of charge, then the operation is transferred from the highest efficiency point to the first constant speed power point to increase the power generation to meet the requirements of the SOC of the state of charge and reduce the , the risk of exiting the cruise control state will affect the driving experience. Since the operating state of the extended-range vehicle is judged first, the range extender operates at the highest efficiency point and the first constant-speed power point in the case of high-speed constant-speed cruise. Choose, and then take into account fuel economy and power generation.

In one embodiment, as shown in FIG. 2, after S201, starting the range extender and controlling the range extender to operate at the highest efficiency point, the control method further includes:

S202. If the state of charge SOC increases to the target threshold value, the range extender is controlled to be turned off, and the range extender vehicle enters the EV mode of operation.

Specifically, when the range extender is started and running at the highest efficiency point, if the state of charge SOC starts to increase and increases to the target threshold over time, the range extender is controlled to be turned off, and the range extender vehicle enters EV mode operation. For example, the target threshold value is 90%. When the range extender is started and runs at the highest efficiency point (high-speed fixed point 3), if the state of charge SOC starts to increase and increases to 90% over time, the range extender will be controlled. Closed, the extended-range vehicle enters the EV mode.

It should be understood that when the range extender is started and running at the highest efficiency point, if the state of charge SOC starts to increase, it means that the power generation of the range extender vehicle running at the highest efficiency point can meet the current power consumption of the first operating state The range-extended vehicle does not need to increase the power generation, and can obtain the best work efficiency and the best fuel economy by running at the highest efficiency point.

In one embodiment, as shown in Figure 2 and Figure 8, after S301, the step of controlling the range extender to operate at the first constant speed power point, the control method further includes:

S302. If the state of charge SOC increases to the target SOC upper limit value, control the range extender to switch from the first constant speed power point to the highest efficiency point.

Specifically, when the range extender is started and runs at the first constant speed power point, if the state of charge SOC starts to increase and increases to the upper limit of the target SOC over time, the range extender is controlled to start from the first constant speed The power point is transferred to the highest efficiency point for operation. For example, the upper limit of the target SOC is 60%. When the range extender is started and runs at the first constant speed power point (high speed fixed point 4), if the state of charge SOC starts to increase and increases to 60% over time, Then control the range extender to turn off, and control the range extender to run from the first constant speed power point to the highest efficiency point (high speed fixed point 3) (see Figure 8).

It should be understood that when the range extender is started and runs at the first constant speed power point, if the state of charge SOC starts to increase, it means that the power generation of the range extender vehicle running at the first constant speed power point can meet the current requirements. The power consumption demand of the first operating state, the extended-range vehicle does not need to increase the power generation again, and the current SOC power consumption demand can be met by running at the first constant speed power point. If the SOC of the state of charge increases to the upper limit of the target SOC, Control the range extender from the first fixed-speed power point to the highest efficiency point, through the above-mentioned "reciprocating" conversion of the operating point of the range extender, so as to effectively take into account the best work efficiency, the best fuel economy and Cruise control driving experience at the current speed.

In one embodiment, as shown in FIG. 3, after S101, the step of obtaining the vehicle speed of the extended-range vehicle and the SOC of the power battery, the control method further includes:

S102. If the range-extended vehicle is in the second operating state, start the range extender and control the range extender to operate at the first power point. The second operating state means: the vehicle speed is less than the first preset vehicle speed, and the state of charge SOC is less than It is equal to the second threshold S2, wherein the second threshold S2 is smaller than the first threshold S1, and the first power point and the highest efficiency point are the operating conditions of the range extender at different vehicle speeds.

Specifically, if the vehicle speed is less than the first preset vehicle speed, and the state of charge SOC is less than or equal to the second threshold value S2, it is determined that the range-extender vehicle is in the second operating state. At this time, the range extender is activated and controlled to operate at the first power point operation. For example, as shown in Figure 9, the second threshold S2 is a percentage A (30%), the vehicle speed is less than the first preset vehicle speed, and the state of charge SOC is less than or equal to A, at this time it is determined that the extended-range vehicle is in the second operating state, Then start the range extender, and control the range extender to run at the first power point. In particular, fixed point 1 (first power point) is the highest efficiency operating point of the range extender at low vehicle speeds, and the highest efficiency point (high-speed fixed point 3) is the highest efficiency operating point of the range extender at high vehicle speeds.

It should be understood that since the vehicle speed is less than the first preset vehicle speed, it indicates that the current vehicle speed is relatively low and is not in a high-speed situation, and its power consumption is far lower than the demand in the first operating state, so start the range extender and control the range extender If the inverter operates at the first power point, it can meet the power consumption demand at the current vehicle speed.

In one embodiment, as shown in FIG. 3 , after S102, starting the range extender and controlling the range extender to operate at the first power point, the control method further includes:

S103. If the state of charge SOC decreases to the third threshold S3 after the range extender operates at the first power point, then control the range extender to operate at the second power point, wherein the generated power of the second power point is greater than the first Generating power at the power point.

Specifically, when the vehicle speed is lower than the first preset vehicle speed, the range extender is activated, and the range extender is controlled to operate at the first power point, if the state of charge SOC decreases, it indicates that when the range extender operates at the first power point, The power generation is difficult to meet the current power consumption demand, and the power generation needs to be increased. At this time, the state of charge SOC is reduced to the third threshold S3, and the range extender is controlled to switch from the first power point to the second power point, thereby increasing the power generation. For example, the third threshold value is A-b, as shown in Figure 9, the vehicle speed is less than the first preset vehicle speed, the state of charge SOC is less than or equal to A, start the range extender, and control the range extender to run at fixed point 1, if the range extender After running at fixed point 1, the SOC of the state of charge decreases, and the SOC of the state of charge decreases to A-b, and the range extender changes from fixed point 1 to fixed point 2 operation.

It should be noted that the generated power of the second power point is greater than that of the first power point, but the fuel economy and work efficiency of the second power point are both lower than those of the first power point.

In an embodiment, as shown in FIG. 4 , after S103, the step of controlling the range extender to operate at the second efficiency point, the control method further includes:

S104. If the state of charge SOC decreases to the fourth threshold S4 after the range extender operates at the second power point, control the range extender to operate at the maximum power point, wherein the power generated at the maximum power point is greater than the second power point of power generation.

Specifically, when the vehicle speed is less than the first preset vehicle speed, and the range extender vehicle is in the second operating state, after the range extender operates at the second power point, the state of charge SOC decreases, indicating that when the range extender operates at the second power point, The power generation is difficult to meet the current power consumption demand, and the power generation needs to be further increased. At this time, the state of charge SOC is reduced to the fourth threshold S4, and the range extender is controlled to operate at the maximum power point from the second power point, thereby increasing the power generation. For example, the fourth threshold value is A-b-c-d, as shown in Figure 9, the vehicle speed is less than the first preset vehicle speed, and the state of charge SOC is less than or equal to A, start the range extender, and control the range extender to run at fixed point 1, if the range extender After running at fixed point 1, the SOC of the state of charge decreases, and the SOC of the state of charge decreases to A-b. The range extender is transferred from fixed point 1 to fixed point 2. If the power consumption at the current speed cannot be met under the condition of fixed point 2, then Control the range extender to run at the maximum power point, so as to maximize power generation and avoid vehicle power-off.

It should be noted that the above is only described with the second power point, the first power point and the maximum power point. In other practical situations, the third power point, the fourth power point, the fifth power point, etc. can be added until The maximum power point, the number from the first power point to the maximum power point can be determined according to the actual situation. In the embodiment of this application, only the first power point, the second power point and the maximum power point are used as examples, and it should not be understood For the limitation of this application. For example, as shown in FIG. 9 , when the vehicle speed is less than the first preset vehicle speed and the state of charge SOC is less than or equal to A, the range extender is controlled through fixed point 1, fixed point 2, fixed point 3 and maximum power point.

In one embodiment, as shown in FIG. 4, after S104, the step of controlling the range extender to operate at the maximum power point, the control method further includes:

S105. If the state of charge SOC increases to the second threshold S2 after the range extender operates at the maximum power point, control the range extender to switch from the maximum power point to the first power point operation.

Specifically, the vehicle speed is less than the first preset vehicle speed, and the range extender vehicle is in the second operating state. After the range extender operates at the maximum power point, the state of charge SOC increases. When the state of charge SOC increases to the second threshold S2 , to control the range extender to run from the maximum power point to the first power point. At this time, it shows that after the range extender has been running at the maximum power point for a period of time, the range extender can satisfy the vehicle operation, and the accumulated power during this period meets the corresponding threshold value. After jumping to fixed point 1, the vehicle can run at low speed. The fuel economy is also in the best state, improving the working efficiency of the range extender.

It should be noted that the above is only exemplified by the increase of the state of charge SOC after the maximum power point operation, and should not be construed as a limitation of the application. In the case of a certain point, if the range extender works at one of the points, and the state of charge SOC increases to a certain threshold, the range extender will jump to the next level in turn until it returns to fixed point 1. For example, the range extender works at fixed point 3, the SOC increases, and the SOC is greater than A-b-c+k2. At this time, the range extender switches from fixed point 3 to fixed point 2 to work. Correspondingly, after fixed point 2 satisfies the corresponding condition, jump to fixed point 1.

In one embodiment, as shown in FIG. 5, after S102, starting the range extender and controlling the range extender to operate at the first power point, the control method further includes:

S112. If the state of charge SOC increases to the target threshold after the range extender operates at the first power point, turn off the range extender.

Specifically, when the vehicle speed is less than the first preset vehicle speed, and the range-extender vehicle is in the second operating state, the range extender is controlled to operate at the first power point. After the range extender operates at the first power point for a certain period of time, the state of charge SOC increase, and reach the target threshold, the range extender is turned off, and the range extender vehicle enters EV mode.

For example, when the vehicle speed is 20km/h and the SOC is less than or equal to 30%, the range extender is activated and runs at fixed point 1. When the state of charge SOC increases and reaches 90%, the range extender is turned off. Correspondingly, if the vehicle speed is 50km/h and the SOC is less than or equal to 30%, the range extender starts and runs at fixed point 1. At this time, after running at fixed point 1, the state of charge SOC drops, and when the SOC is less than or equal to A-b, the range extender The inverter is transferred from fixed point 1 to fixed point 2 to increase power generation.

As shown in FIG. 6 , the embodiment of the present application also provides a control system 100 for an extended-range vehicle. The control system is used to execute the above-mentioned control method. The control system 100 includes a detection module 110 and a control module 120, wherein the detection module 110 For detecting the vehicle speed, state of charge SOC and running state of the range-extending vehicle, the control module 120 is used for controlling the range extender to operate at the highest efficiency point when the range-extending vehicle is in the first operating state, and when the range extender is at the highest After running at the efficiency point, when the state of charge SOC is reduced to the lower limit of the target SOC, the range extender is controlled to run at the first constant speed power point, where the first running state refers to: the vehicle speed is greater than or equal to the first preset The state SOC is less than or equal to the first threshold S1, and the range-extended vehicle is in a constant speed cruise state.

Specifically, the detection module 110 detects the vehicle speed and the state of charge SOC of the extended-range vehicle. For example, the detection module 110 is provided with a plurality of sensors, and the vehicle speed and the state of charge SOC are acquired through the sensors. At the same time, the detection module 110 can also detect the current running state of the vehicle, for example, the detection module 110 detects that the vehicle is in EV mode or constant speed cruise state. After passing through the detection module 110, if the vehicle speed is greater than or equal to the first preset vehicle speed, the state of charge SOC is less than or equal to the first threshold value S1, and the extended-range vehicle is in the constant speed cruise state, it is determined that the current extended-range vehicle is in the first running state , the control module 120 controls the range extender to run at the highest efficiency point.

In particular, as shown in FIG. 9 , it is known from the detection module 110 that the vehicle speed is greater than or equal to the first preset vehicle speed, which indicates that the vehicle is at a high speed. If the SOC is less than or equal to 40%, and the detection module 110 detects that the vehicle is in a constant speed cruise state, the control module 120 controls the range extender to operate at the highest efficiency point (high speed fixed point 3).

Through the detection module 110 and the control module 120, when the range extender vehicle is in the first operating state, the range extender operates at the highest efficiency point to improve fuel economy. If the range extender operates at the highest efficiency point, the state of charge SOC decreases When it reaches the lower limit of the target SOC, it is difficult to meet the requirements of the SOC of the state of charge, then the operation is transferred from the highest efficiency point to the first constant speed power point, and the power generation is increased to meet the requirements of the SOC of the state of charge, and the SOC caused by the state of charge is reduced. Insufficient, the risk of exiting the constant speed cruise state will affect the driving experience. Since the operating state of the extended-range vehicle is judged first, the range extender is at the highest efficiency point and the first constant-speed power point in the case of high-speed constant-speed cruise. Choose between fuel economy and power generation.

In one embodiment, the control module 120 is also used for: when the range-extender vehicle is in the second operating state, start the range extender, and control the range extender to operate at the first power point, wherein the second operating state refers to: vehicle speed is less than the first preset vehicle speed, and the state of charge SOC is less than or equal to the second threshold S2.

Specifically, after the detection module 110 detects the vehicle speed and state of charge SOC of the extended-range vehicle, if the vehicle speed is less than the first preset vehicle speed and the state of charge SOC is less than or equal to the second threshold S2, it is determined that the current extended-range vehicle is in the second operation In the state, the control module 120 controls the range extender to run at the first power point.

For example, as shown in FIG. 9 , it is known from the detection module 110 that the vehicle speed is less than the first preset vehicle speed, which indicates that the vehicle is at a medium or low speed. If the SOC is less than or equal to 30%, and the detection module 110 detects that the vehicle is in a non-cruising state, the control module 120 controls the range extender to operate at the first power point (fixed point 1).

In order to better understand the control method of the range-extended vehicle in the embodiment of the present application, the control logic of the range-extended vehicle will be described below with reference to FIG. 8 and FIG. 9 .

When the range-extended vehicle is at a low speed (lower than the first preset vehicle speed), the control of the range extender is performed based on the state of charge SOC of the power battery. , the range extender starts.

When the range-extended vehicle is in the high-speed constant-speed cruising condition, the control logic of the range extender is as follows: when the state of charge SOC drops to a low battery level, at the same time, it is judged whether the vehicle speed reaches the target high speed (vehicle speed is greater than or equal to the first preset speed), The range extender enters the high-speed fixed-point working condition. For example, the high-speed fixed-point working condition has high-speed fixed-point 3, high-speed fixed-point 4, and high-speed fixed-point 5. Among them, high-speed fixed-point 3 is a common high-speed working condition point, which represents the highest efficiency point of the range extender. Optimum fuel economy. When the range-extender vehicle is in the high-speed constant-speed cruising condition, and the state of charge SOC is less than or equal to the first threshold S1, the range-extender is activated, and the range-extender is controlled to run at high-speed fixed point 3 (highest efficiency point). It should be noted that the first threshold S1 is higher than the second threshold S2 of the SOC of the range extender activated at low speed, for example, the first threshold S1 is 40%, and the second threshold S2 is 30%. When the range-extended vehicle is in the high-speed constant-speed cruising condition, the state of charge SOC is less than or equal to 40%, the range extender starts and runs at the high-speed fixed point 3 (the highest efficiency point); when the range-extended vehicle is in the low-speed condition, the load The range extender will start only when the battery state SOC is less than or equal to 30%. Since the range-extended vehicle is in the high-speed constant-speed cruising condition, the demand for electricity is relatively large. Compared with the start-up threshold of the range extender under low-speed conditions, a larger threshold (the first threshold S1) is used to make the range extender start in advance. , and run at high-speed fixed point 3 (highest efficiency point) to achieve the best operating efficiency and improve fuel economy.

When the range extender starts and runs at the high-speed fixed point 3 (highest efficiency point), since the range-extended vehicle is in the high-speed constant-speed cruising condition, if the state of charge SOC continues to decline, the range extender is controlled to enter the high-power point (high-speed fixed point 4/5). After the battery power rises to the target SOC, it enters the high-speed fixed point 3, and switches between the best efficiency point 3 and the high power point 4/5 to ensure the high-speed fuel consumption of the extended-range hybrid vehicle. It should be noted that high-speed fixed-point 4/5 represents high-speed fixed-point 4 or high-speed fixed-point 5. High-speed fixed-point 5 has higher power generation than high-speed fixed-point 4, but its work efficiency and fuel economy are lower than high-speed fixed-point 4. For example, after the range extender enters the high-speed fixed point 4, it still cannot meet the high-speed constant speed cruising condition and the current state of charge SOC requirements, and the state of charge SOC is still declining, then the range extender is controlled to enter the fixed point 5.

When the range extender enters the high-speed fixed point 4 and the state of charge SOC rises to the upper limit of the target SOC, the range extender transfers from the high-speed fixed point 4 to the high-speed fixed point 3 (the highest efficiency point). According to the specific situation of the state of charge SOC Switch between high-speed fixed point 3 and high-power point 4/5, so as to take into account the fuel economy, driving experience and power generation of extended-range vehicles under high-speed constant-speed cruising conditions, and avoid forced exit from high-speed vehicles due to insufficient SOC. Cruise control conditions affect the driving experience.

For example, identify the driving mode of the whole vehicle, judge the opening of the range extender based on the state of charge SOC of the power battery and the vehicle speed, and determine the operating point of the range extender. When the state of charge SOC≤40% and the vehicle is at a high speed When cruising at high speed, the range extender starts in advance and enters the highest efficiency point of the range extender (high-speed fixed point 3). When running at high-speed fixed point 3, the state of charge SOC continues to decrease and reaches the lower limit of the target SOC, the range extender enters high-speed fixed point 4 or high-speed fixed point 5 (based on the vehicle speed to determine the fixed-point working condition), so that the range extender is at high power In the power generation state, quickly make up for the power loss. When running at high-speed fixed point 4 or high-speed fixed point 5, the state of charge SOC continues to increase, and when the state of charge SOC reaches the upper limit of the target SOC, it enters high-speed fixed point 3. By switching the range extender between high-speed fixed point 3 and high-speed fixed point 4/5, the high-speed fuel economy of the range-extended vehicle is guaranteed. When the state of charge SOC increases to the target threshold at high-speed fixed point 3, the range extender is turned off. At this time, the power of the power battery can meet the needs of high-speed constant-speed cruising conditions, and the range extender is not required to operate.

As shown in Figure 9, when the vehicle speed is less than the first preset vehicle speed, and the state of charge SOC is less than or equal to the second threshold S2, and the second threshold S2 is less than the first threshold S1, the range extender is activated and the range extender is controlled. The range extender operates at the first power point. The first power point is the operating point of the range extender at low speed (the vehicle speed is less than the first preset vehicle speed), and the highest efficiency point is at high speed (the vehicle speed is greater than or equal to the first preset vehicle speed). The operating point of the range extender under certain conditions. For example, the second threshold S2 is 30% (refer to SOC≤A in Figure 9), and the first threshold S1 is 40%. When the vehicle speed is lower than the first preset vehicle speed and the state of charge SOC≤30%, the range extension is activated. and control the range extender to run at fixed point 1.

If the SOC of the state of charge is still decreasing after the range extender operates at fixed point 1 (refer to SOC≤A-b in Figure 9), the range extender is transferred from fixed point 1 to fixed point 2 to meet the SOC requirements of the state of charge. Fixed point 2 has greater generating power than fixed point 1, but fixed point 2 is more efficient than fixed point 1, and its fuel economy is lower.

If the SOC of the state of charge is still decreasing after the range extender is running at fixed point 2 (refer to SOC≤A-b-c in Figure 9), the range extender is transferred from fixed point 2 to fixed point 3 to meet the SOC requirements of the state of charge. Fixed point 3 has greater generating power than fixed point 2, but fixed point 3 is more efficient than fixed point 2, and its fuel economy is lower.

If the state of charge SOC is still decreasing after the range extender is running at fixed point 3 (refer to SOC≤A-b-c-d in Figure 9), the range extender is transferred from fixed point 3 to the maximum power point operation, so that the range extender is in the state of maximum power generation, To increase the state of charge SOC most rapidly, reduce the risk of insufficient state of charge SOC and power off.

Conversely, if the state of charge SOC increases at the corresponding maximum power point, fixed point 3 and fixed point 2, and reaches the corresponding numerical requirements, it will be fed back from the maximum power point to fixed point 3, fixed point 2 and fixed point 1 in sequence.

It should be understood that the above description only takes the maximum power point, fixed point 3, fixed point 2 and fixed point 1 as examples, and is not limited to the fact that the operation of the range extender needs to be transferred to the maximum power point, which satisfies the When the conditions are met, you can "return" to the next level to improve fuel economy and work efficiency at the current speed. For example, if the state of charge SOC is increasing after the range extender runs at fixed point 2, and its increase meets the threshold k3 (refer to SOC>A-b+k3 in Figure 9), the range extender will turn from fixed point 2 to Enter fixed point 1 to run. Correspondingly, in Fig. 9, the threshold value of the state of charge SOC when switching from the maximum power point, fixed point 3, fixed point 2 and fixed point 1 is expressed adaptively, and should not be understood as other meanings, for example, A, b, c, d, e, K1, K2 and K3 are all numerical values, and all are greater than zero, A<40%.

It should be noted that in the embodiment of this application, only the maximum power point, fixed point 3, fixed point 2, and fixed point 1 are used as examples for illustration, and they are not characterized as four working condition points. In the actual application process, there can be multiple For example, the range extender has 3 or 5 operating condition points, or even more operating condition points, the range extender is at SOC≤A, and the vehicle speed is less than the first preset vehicle speed (low speed ), the range extender with 3 operating points switches between the 3 operating points. In the high-speed constant-speed cruising condition, only the high-speed fixed point 3, the high-speed fixed point 4, and the high-speed fixed point 5 are used as examples for illustration in the embodiment of the present application, which should not be interpreted as an improper limitation of the present application. At the same time, for the sake of simplicity and readability, fixed point 4/5, high-speed fixed point 4, and high-speed fixed point 5 in Figure 9 are different expressions with the same meaning, and should not be understood as different phrases.

The above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit them; although the application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still describe the contents of the foregoing embodiments Modifications to the technical solutions, or equivalent replacement of some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions claimed in this application.

Claims (10)

1. A control method for an extended-range vehicle, comprising: Obtain the vehicle speed of the extended-range vehicle and the SOC of the power battery; If the range-extender vehicle is in the first operating state, start the range extender and control the range extender to operate at the highest efficiency point, wherein the first operating state refers to: the vehicle speed is greater than or equal to the first preset The vehicle speed, the state of charge SOC is less than or equal to the first threshold S1, and the extended-range vehicle is in a constant speed cruise state; If the state of charge SOC is reduced to the lower limit of the target SOC after the range extender operates at the highest efficiency point, then the range extender is controlled to operate at the first fixed speed power point to increase the range extender The power generation power of the first constant speed power point is greater than the power generation power of the highest efficiency point, and the power generation efficiency of the first constant speed power point is smaller than the power generation efficiency of the highest efficiency point. 2. The control method according to claim 1, characterized in that, after the step of starting the range extender and controlling the range extender to operate at the highest efficiency point, the control method further comprises: If the state of charge SOC increases to a target threshold value, the range extender is controlled to be turned off, and the range extender vehicle enters into an EV mode of operation. 3. The control method according to claim 1, characterized in that, after the step of controlling the range extender to run at the first constant speed power point, the control method further comprises: If the state-of-charge SOC increases to the target SOC upper limit value, the range extender is controlled to operate at the highest efficiency point from the first constant-speed power point. 4. The control method according to claim 1, characterized in that, after the step of obtaining the vehicle speed of the extended-range vehicle and the SOC of the power battery, the control method further comprises: If the range-extended vehicle is in the second running state, start the range extender and control the range extender to run at the first power point, the second running state means: the vehicle speed is less than the first preset speed, And the state of charge SOC is less than or equal to the second threshold S2, wherein the second threshold S2 is smaller than the first threshold S1, and the first power point and the highest efficiency point are respectively at different vehicle speeds The operating point of the range extender. 5. The control method according to claim 4, characterized in that, after the step of starting the range extender and controlling the range extender to operate at the first power point, the control method further comprises: If the state of charge SOC decreases to the third threshold S3 after the range extender operates at the first power point, the range extender is controlled to operate at the second power point, wherein the second The generated power of the power point is greater than the generated power of the first power point. 6. The control method according to claim 5, wherein after the step of controlling the range extender to operate at the second efficiency point, the control method further comprises: If the state of charge SOC decreases to the fourth threshold S4 after the range extender operates at the second power point, the range extender is controlled to operate at the maximum power point, wherein the maximum power point The generated power of is greater than the generated power of the second power point. 7. The control method according to claim 6, characterized in that, after the step of controlling the range extender to operate at the maximum power point, the control method further comprises: If the state of charge SOC increases to the second threshold S2 after the range extender operates at the maximum power point, the range extender is controlled to switch from the maximum power point to the first power point. 8. The control method according to claim 4, characterized in that, after the step of starting the range extender and controlling the range extender to operate at the first power point, the control method further comprises: If the state of charge SOC increases to a target threshold after the range extender operates at the first power point, the range extender is turned off. 9. A control system for an extended-range vehicle, characterized in that the control system is used to execute the control method described in any one of claims 1-8, and the control system includes a detection module and a control module, wherein, The detection module is used to detect the vehicle speed, state of charge SOC and running state of the extended-range vehicle; The control module is configured to control the range extender to operate at the highest efficiency point when the range extender vehicle is in the first operating state, and after the range extender operates at the highest efficiency point, the charging When the state SOC decreases to the lower limit of the target SOC, the range extender is controlled to operate at the first fixed speed power point, wherein the first operating state refers to: the vehicle speed is greater than or equal to the first preset vehicle speed, the load The electric state SOC is less than or equal to the first threshold S1, and the range-extended vehicle is in a constant speed cruise state. 10. The control system according to claim 9, wherein the control module is also used for: When the range-extender vehicle is in the second operating state, start the range extender and control the range extender to operate at the first power point, wherein the second operating state refers to: the vehicle speed is less than the first preset The vehicle speed, and the state of charge SOC is less than or equal to the second threshold S2.

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