阅读说明：本技术 一种混合动力汽车串联工况控制系统及方法 (Series working condition control system and method for hybrid electric vehicle ) 是由 陈孔武 许朋涛 解鹏 左茂良 杨楠 于 2021-08-16 设计创作，主要内容包括：本发明公开了一种混合动力汽车串联工况控制系统及方法,属于混合动力技术领域,通过设计混联式混合动力汽车串联模式控制,控制串联模式发动机运行目标怠速、转速上升和下降梯度及发动机起动和停机条件,及噪声声压级报警逻辑,可使混联式混合动力汽车串联模式经济性和NVH性能达到最优。通过本发明同时兼顾考虑了经济性与NVH性能,能够有效指导混连式混合动力汽车串联模式开发。(The invention discloses a series working condition control system and method for a hybrid electric vehicle, belonging to the technical field of hybrid power. According to the invention, the economy and the NVH performance are considered at the same time, and the series mode development of the hybrid electric vehicle can be effectively guided.)

1. A series working condition control method of a hybrid electric vehicle is characterized by comprising the following steps:

according to the universal characteristic diagram of the engine, under the current power demand request of the engine, selecting the idle speed with the minimum oil consumption rate as a target idle speed, and taking the target idle speed as an initial target idle speed;

measuring a first sound pressure level signal of an initial target idle speed and a torque point corresponding to the initial target idle speed, if the first sound pressure level signal is greater than a first standard sound pressure level, adjusting the initial target idle speed, continuously calculating the first sound pressure level signal, and taking the corresponding target idle speed when the first sound pressure level signal is less than the first standard sound pressure level as a final target idle speed;

respectively testing oil consumption rates and second sound pressure level signals under different engine speed gradients and different high-voltage battery electric quantities, and taking the engine speed gradient with the minimum oil consumption rate and the second sound pressure level signal being smaller than a second standard sound pressure level as corresponding speed gradient points under the current engine speed and the current high-voltage battery electric quantity;

calibrating the starting and stopping power limit value of the series mode engine, the starting and stopping delay time of the engine and the electric quantity limit value of the high-voltage battery, so that the starting times of the engine under the low-speed working condition are less than the first preset times, and the stopping times of the engine in the medium-speed stage are not more than the second preset times.

2. The method of claim 1, wherein the current engine demand power request is obtained by:

calibrating the required power of the generator under different difference values of the actual electric quantity and the target electric quantity of the high-voltage battery and different required powers of the driving motor, and determining the required power of the electrical accessories according to the power of each electric load;

calibrating a compensation coefficient of the series mode electrical appliance accessory under the difference value of the actual electric quantity and the target electric quantity of different high-voltage batteries;

calibrating power transfer efficiency under different generator rotating speeds and different generator torques;

and the required power of the electric appliance accessories is multiplied by the compensation coefficient of the series-connected electric appliance accessories, then the multiplied power is added with the required power of the generator, then the addition result is divided by the power transfer efficiency to obtain the required power request of the engine, and then the required power request of the engine is determined according to the difference value of the actual electric quantity of the current high-voltage battery and the target electric quantity, the required power of the current driving motor, the required power of the current electric appliance accessories, the rotating speed of the current generator and the torque of the current generator.

3. The method of claim 2, wherein selecting the idle speed with the lowest fuel consumption rate as the target idle speed and the target idle speed as the initial target idle speed according to the engine universal characteristic map at the current engine power demand request comprises:

calibrating the ascending speed gradient and the descending speed gradient of the engine speed under different high-voltage battery electric quantities and different engine speeds;

calibrating the target idle speed of the series mode engine under different power requirements of different engines based on the difference value between the actual electric quantity and the target electric quantity of different high-voltage batteries;

according to the universal characteristic diagram of the engine, under the current power demand request of the engine, the idling speed with the minimum oil consumption rate is selected as the target idling speed, and the target idling speed is used as the initial target idling speed.

4. The method of claim 3, wherein adjusting the initial target idle speed, continuing to calculate the first sound pressure level signal, and using the target idle speed corresponding to the first sound pressure level signal being less than the first standard sound pressure level as the final target idle speed comprises:

under the current power demand request of the engine, adjusting according to a preset amplitude each time within a preset range of an initial target idle speed, wherein the adjusted target idle speed cannot exceed a contour region of a current oil consumption rate, then measuring a first sound pressure level signal corresponding to the adjusted target idle speed, and selecting the corresponding target idle speed as a final target idle speed until the first sound pressure level signal is smaller than a first standard sound pressure level.

5. The method of any of claims 1 to 4, wherein calibrating the series mode engine start and stop power limit, the engine start and stop delay time, and the high voltage battery charge limit to allow the engine to start less than a first predetermined number of times at low speed and stop no more than a second predetermined number of times during a medium speed phase comprises:

calibrating an engine starting power limit value and an engine stopping power limit value under different vehicle speeds according to the difference value between the actual electric quantity and the target electric quantity of different high-voltage batteries;

when the engine required power request is larger than or equal to the engine starting power limit value, sending an engine starting request; when the engine demand power request is less than the engine starting power limit, the engine is shut down; when the engine demand power request is greater than or equal to the engine stop power limit value, stopping the engine; when the engine demand power request is smaller than the engine stop power limit value, sending an engine start request;

when the difference value between the actual electric quantity and the target electric quantity of the high-voltage battery is less than or equal to the electric quantity limit value of the engine starting high-voltage battery, sending an engine starting request; when the difference value between the actual electric quantity and the target electric quantity of the high-voltage battery is larger than the electric quantity limit value of the high-voltage battery for starting the engine, stopping the engine; when the difference value between the actual electric quantity and the target electric quantity of the high-voltage battery is less than or equal to the electric quantity limit value of the high-voltage battery when the engine is stopped, stopping the engine; when the difference value between the actual electric quantity and the target electric quantity of the high-voltage battery is larger than the electric quantity limit value of the high-voltage battery when the engine is stopped, sending an engine starting request; wherein a preset delay time is met between the issuance of a start or stop request and the actual start or stop.

6. A series operating condition control system of a hybrid electric vehicle is characterized by comprising: the device comprises a noise sensor, a high-voltage battery electric quantity sensor, an engine rotating speed sensor, a vehicle speed sensor and a VECU controller, wherein the VECU controller is respectively connected with the noise sensor, the high-voltage battery electric quantity sensor, the engine rotating speed sensor and the vehicle speed sensor;

wherein the noise sensor is used for measuring noise in the cab; the high-voltage battery electric quantity sensor is used for measuring the electric quantity of the high-voltage battery; the engine speed sensor is used for measuring the engine speed; the vehicle speed sensor is used for measuring vehicle speed; the VECU controller is used for executing the following operations:

according to the universal characteristic diagram of the engine, under the current power demand request of the engine, selecting the idle speed with the minimum oil consumption rate as a target idle speed, and taking the target idle speed as an initial target idle speed;

measuring a first sound pressure level signal of an initial target idle speed and a torque point corresponding to the initial target idle speed, if the first sound pressure level signal is greater than a first standard sound pressure level, adjusting the initial target idle speed, continuously calculating the first sound pressure level signal, and taking the corresponding target idle speed when the first sound pressure level signal is less than the first standard sound pressure level as a final target idle speed;

respectively testing oil consumption rates and second sound pressure level signals under different engine speed gradients and different high-voltage battery electric quantities, and taking the engine speed gradient with the minimum oil consumption rate and the second sound pressure level signal being smaller than a second standard sound pressure level as corresponding speed gradient points under the current engine speed and the current high-voltage battery electric quantity;

calibrating the starting and stopping power limit value of the series mode engine, the starting and stopping delay time of the engine and the electric quantity limit value of the high-voltage battery, so that the starting times of the engine under the low-speed working condition are less than the first preset times, and the stopping times of the engine in the medium-speed stage are not more than the second preset times.

7. The system of claim 6, wherein the current engine demand power request is obtained by:

calibrating the required power of the generator under different difference values of the actual electric quantity and the target electric quantity of the high-voltage battery and different required powers of the driving motor, and determining the required power of the electrical accessories according to the power of each electric load;

calibrating a compensation coefficient of the series mode electrical appliance accessory under the difference value of the actual electric quantity and the target electric quantity of different high-voltage batteries;

calibrating power transfer efficiency under different generator rotating speeds and different generator torques;

and the required power of the electric appliance accessories is multiplied by the compensation coefficient of the series-connected electric appliance accessories, then the multiplied power is added with the required power of the generator, then the addition result is divided by the power transfer efficiency to obtain the required power request of the engine, and then the required power request of the engine is determined according to the difference value of the actual electric quantity of the current high-voltage battery and the target electric quantity, the required power of the current driving motor, the required power of the current electric appliance accessories, the rotating speed of the current generator and the torque of the current generator.

8. The system of claim 7, wherein the step of selecting the idle speed with the lowest fuel consumption rate as the target idle speed and taking the target idle speed as the initial target idle speed according to the universal characteristic diagram of the engine under the current power demand request of the engine comprises the following steps:

calibrating the ascending speed gradient and the descending speed gradient of the engine speed under different high-voltage battery electric quantities and different engine speeds;

calibrating the target idle speed of the series mode engine under different power requirements of different engines based on the difference value between the actual electric quantity and the target electric quantity of different high-voltage batteries;

according to the universal characteristic diagram of the engine, under the current power demand request of the engine, the idling speed with the minimum oil consumption rate is selected as the target idling speed, and the target idling speed is used as the initial target idling speed.

9. The system of claim 8, wherein adjusting the initial target idle speed, continuing to calculate the first sound pressure level signal, and using the target idle speed corresponding to the first sound pressure level signal being less than the first standard sound pressure level as the final target idle speed comprises:

under the current power demand request of the engine, adjusting according to a preset amplitude each time within a preset range of an initial target idle speed, wherein the adjusted target idle speed cannot exceed a contour region of a current oil consumption rate, then measuring a first sound pressure level signal corresponding to the adjusted target idle speed, and selecting the corresponding target idle speed as a final target idle speed until the first sound pressure level signal is smaller than a first standard sound pressure level.

10. The system of any one of claims 6 to 9, wherein calibrating the series mode engine start and stop power limit, the engine start and stop delay time, and the high voltage battery charge limit to allow the engine to start less than a first predetermined number of times at low speed and stop no more than a second predetermined number of times during a medium speed phase comprises:

calibrating an engine starting power limit value and an engine stopping power limit value under different vehicle speeds according to the difference value between the actual electric quantity and the target electric quantity of different high-voltage batteries;

when the engine required power request is larger than or equal to the engine starting power limit value, sending an engine starting request; when the engine demand power request is less than the engine starting power limit, the engine is shut down; when the engine demand power request is greater than or equal to the engine stop power limit value, stopping the engine; when the engine demand power request is smaller than the engine stop power limit value, sending an engine start request;

when the difference value between the actual electric quantity and the target electric quantity of the high-voltage battery is less than or equal to the electric quantity limit value of the engine starting high-voltage battery, sending an engine starting request; when the difference value between the actual electric quantity and the target electric quantity of the high-voltage battery is larger than the electric quantity limit value of the high-voltage battery for starting the engine, stopping the engine; when the difference value between the actual electric quantity and the target electric quantity of the high-voltage battery is less than or equal to the electric quantity limit value of the high-voltage battery when the engine is stopped, stopping the engine; when the difference value between the actual electric quantity and the target electric quantity of the high-voltage battery is larger than the electric quantity limit value of the high-voltage battery when the engine is stopped, sending an engine starting request; wherein a preset delay time is met between the issuance of a start or stop request and the actual start or stop.

Technical Field

The invention belongs to the technical field of hybrid power, and particularly relates to a series working condition control system and method for a hybrid electric vehicle.

Background

The series-parallel hybrid electric vehicle has the advantages that the traditional internal combustion engine and the pure electric vehicle motor are used for driving the vehicle, the demand for petroleum fuel is reduced, the fuel economy of the vehicle is improved, the fuel consumption of the whole vehicle can be effectively reduced, and the energy crisis problem is relieved. A typical series-parallel hybrid vehicle has two drive modes: series mode (whether the engine is started or not is determined according to the high-voltage battery amount and the driving power demand); a parallel mode (if the required driving power is smaller, the automobile is driven by the engine, and if the required driving power is larger, the automobile is driven by the combination of the driving motor and the engine); the target idling of the series mode engine, the gradient selection of speed change and the start and stop of the engine become key and difficult points for reducing the oil consumption. The series mode control takes into account the following difficulties: how to operate the engine in the current optimal oil consumption area under the condition of ensuring Noise, Vibration and Harshness (NVH) performance; how to control the start-stop conditions of the series mode engine to ensure that the oil consumption under the specific working condition is optimal. The series mode relates to the matching of an engine, a driving motor, a generator and a high-voltage battery multi-system, so that the oil consumption and the NVH performance are optimal, and the control difficulty is high.

With reference to patent application CN112590528A, a hybrid system, a hybrid vehicle, a control method thereof, and a vehicle control unit are disclosed. The system comprises: the engine is used for selectively outputting power to the wheel end; a drive motor; a generator; the capacity of the power battery is greater than or equal to a first preset capacity; the controller is configured to acquire driving parameters of the hybrid vehicle, control the engine, the driving motor and the generator according to the driving parameters, enable the engine to work in an economic area by performing charge and discharge control on the power battery, and select a working mode with the lowest equivalent oil consumption as a current working mode of the hybrid vehicle by comparing equivalent oil consumptions of the hybrid vehicle in a series mode, a parallel mode and an EV mode, so that the hybrid vehicle works in the working mode with the lowest equivalent oil consumption according to the driving parameters, the energy consumption is low, the economy of the hybrid vehicle is effectively improved, and the use expectation of a user is met. The scheme comprehensively considers the hybrid vehicle mechanism and the control under each mode, but does not separately consider the performance development (such as NVH) problem except the economic development under the series mode.

Disclosure of Invention

Aiming at the defects or improvement requirements in the prior art, the invention provides a hybrid electric vehicle series working condition control system and method, which can give consideration to both the economy and the NVH performance in the development process of a hybrid electric vehicle series mode.

To achieve the above object, according to one aspect of the present invention, there is provided a series operating condition control method for a hybrid vehicle, including:

according to the universal characteristic diagram of the engine, under the current power demand request of the engine, selecting the idle speed with the minimum oil consumption rate as a target idle speed, and taking the target idle speed as an initial target idle speed;

measuring a first sound pressure level signal of an initial target idle speed and a torque point corresponding to the initial target idle speed, if the first sound pressure level signal is greater than a first standard sound pressure level, adjusting the initial target idle speed, continuously calculating the first sound pressure level signal, and taking the corresponding target idle speed when the first sound pressure level signal is less than the first standard sound pressure level as a final target idle speed;

respectively testing oil consumption rates and second sound pressure level signals under different engine speed gradients and different high-voltage battery electric quantities, and taking the engine speed gradient with the minimum oil consumption rate and the second sound pressure level signal being smaller than a second standard sound pressure level as corresponding speed gradient points under the current engine speed and the current high-voltage battery electric quantity;

calibrating the starting and stopping power limit value of the series mode engine, the starting and stopping delay time of the engine and the electric quantity limit value of the high-voltage battery, so that the starting times of the engine under the low-speed working condition are less than the first preset times, and the stopping times of the engine in the medium-speed stage are not more than the second preset times.

In some alternative embodiments, the current engine demand power request is obtained by:

calibrating the required power of the generator under different difference values of the actual electric quantity and the target electric quantity of the high-voltage battery and different required powers of the driving motor, and determining the required power of the electrical accessories according to the power of each electric load;

calibrating a compensation coefficient of the series mode electrical appliance accessory under the difference value of the actual electric quantity and the target electric quantity of different high-voltage batteries;

calibrating power transfer efficiency under different generator rotating speeds and different generator torques;

and the required power of the electric appliance accessories is multiplied by the compensation coefficient of the series-connected electric appliance accessories, then the multiplied power is added with the required power of the generator, then the addition result is divided by the power transfer efficiency to obtain the required power request of the engine, and then the required power request of the engine is determined according to the difference value of the actual electric quantity of the current high-voltage battery and the target electric quantity, the required power of the current driving motor, the required power of the current electric appliance accessories, the rotating speed of the current generator and the torque of the current generator.

In some optional embodiments, according to the engine universal characteristic map, under the current engine demand power request, selecting the idle speed with the minimum fuel consumption rate as the target idle speed, and taking the target idle speed as the initial target idle speed, includes:

calibrating the ascending speed gradient and the descending speed gradient of the engine speed under different high-voltage battery electric quantities and different engine speeds;

calibrating the target idle speed of the series mode engine under different power requirements of different engines based on the difference value between the actual electric quantity and the target electric quantity of different high-voltage batteries;

according to the universal characteristic diagram of the engine, under the current power demand request of the engine, the idling speed with the minimum oil consumption rate is selected as the target idling speed, and the target idling speed is used as the initial target idling speed.

In some optional embodiments, adjusting the initial target idle speed, continuing to calculate the first sound pressure level signal, and regarding the target idle speed corresponding to the first sound pressure level signal being less than the first standard sound pressure level as the final target idle speed includes:

under the current power demand request of the engine, adjusting according to a preset amplitude each time within a preset range of an initial target idle speed, wherein the adjusted target idle speed cannot exceed a contour region of a current oil consumption rate, then measuring a first sound pressure level signal corresponding to the adjusted target idle speed, and selecting the corresponding target idle speed as a final target idle speed until the first sound pressure level signal is smaller than a first standard sound pressure level.

In some alternative embodiments, calibrating the series mode engine start and stop power limit, the engine start and stop delay time, and the high voltage battery charge limit to cause the engine to start less than a first predetermined number of times at low speed and stop no more than a second predetermined number of times at intermediate speed comprises:

calibrating an engine starting power limit value and an engine stopping power limit value under different vehicle speeds according to the difference value between the actual electric quantity and the target electric quantity of different high-voltage batteries;

when the engine required power request is larger than or equal to the engine starting power limit value, sending an engine starting request; when the engine demand power request is less than the engine starting power limit, the engine is shut down; when the engine demand power request is greater than or equal to the engine stop power limit value, stopping the engine; when the engine demand power request is smaller than the engine stop power limit value, sending an engine start request;

when the difference value between the actual electric quantity and the target electric quantity of the high-voltage battery is less than or equal to the electric quantity limit value of the engine starting high-voltage battery, sending an engine starting request; when the difference value between the actual electric quantity and the target electric quantity of the high-voltage battery is larger than the electric quantity limit value of the high-voltage battery for starting the engine, stopping the engine; when the difference value between the actual electric quantity and the target electric quantity of the high-voltage battery is less than or equal to the electric quantity limit value of the high-voltage battery when the engine is stopped, stopping the engine; when the difference value between the actual electric quantity and the target electric quantity of the high-voltage battery is larger than the electric quantity limit value of the high-voltage battery when the engine is stopped, sending an engine starting request; wherein a preset delay time is met between the issuance of a start or stop request and the actual start or stop.

According to another aspect of the present invention, there is provided a series operating condition control system for a hybrid vehicle, comprising: the device comprises a noise sensor, a high-voltage battery electric quantity sensor, an engine rotating speed sensor, a vehicle speed sensor and a VECU controller, wherein the VECU controller is respectively connected with the noise sensor, the high-voltage battery electric quantity sensor, the engine rotating speed sensor and the vehicle speed sensor;

wherein the noise sensor is used for measuring noise in the cab; the high-voltage battery electric quantity sensor is used for measuring the electric quantity of the high-voltage battery; the engine speed sensor is used for measuring the engine speed; the vehicle speed sensor is used for measuring vehicle speed; the VECU controller is used for executing the following operations:

according to the universal characteristic diagram of the engine, under the current power demand request of the engine, selecting the idle speed with the minimum oil consumption rate as a target idle speed, and taking the target idle speed as an initial target idle speed;

measuring a first sound pressure level signal of an initial target idle speed and a torque point corresponding to the initial target idle speed, if the first sound pressure level signal is greater than a first standard sound pressure level, adjusting the initial target idle speed, continuously calculating the first sound pressure level signal, and taking the corresponding target idle speed when the first sound pressure level signal is less than the first standard sound pressure level as a final target idle speed;

respectively testing oil consumption rates and second sound pressure level signals under different engine speed gradients and different high-voltage battery electric quantities, and taking the engine speed gradient with the minimum oil consumption rate and the second sound pressure level signal being smaller than a second standard sound pressure level as corresponding speed gradient points under the current engine speed and the current high-voltage battery electric quantity;

calibrating the starting and stopping power limit value of the series mode engine, the starting and stopping delay time of the engine and the electric quantity limit value of the high-voltage battery, so that the starting times of the engine under the low-speed working condition are less than the first preset times, and the stopping times of the engine in the medium-speed stage are not more than the second preset times.

In some alternative embodiments, the current engine demand power request is obtained by:

calibrating the required power of the generator under different difference values of the actual electric quantity and the target electric quantity of the high-voltage battery and different required powers of the driving motor, and determining the required power of the electrical accessories according to the power of each electric load;

calibrating a compensation coefficient of the series mode electrical appliance accessory under the difference value of the actual electric quantity and the target electric quantity of different high-voltage batteries;

calibrating power transfer efficiency under different generator rotating speeds and different generator torques;

and the required power of the electric appliance accessories is multiplied by the compensation coefficient of the series-connected electric appliance accessories, then the multiplied power is added with the required power of the generator, then the addition result is divided by the power transfer efficiency to obtain the required power request of the engine, and then the required power request of the engine is determined according to the difference value of the actual electric quantity of the current high-voltage battery and the target electric quantity, the required power of the current driving motor, the required power of the current electric appliance accessories, the rotating speed of the current generator and the torque of the current generator.

In some optional embodiments, according to the engine universal characteristic map, under the current engine demand power request, selecting the idle speed with the minimum fuel consumption rate as the target idle speed, and taking the target idle speed as the initial target idle speed, includes:

calibrating the ascending speed gradient and the descending speed gradient of the engine speed under different high-voltage battery electric quantities and different engine speeds;

calibrating the target idle speed of the series mode engine under different power requirements of different engines based on the difference value between the actual electric quantity and the target electric quantity of different high-voltage batteries;

according to the universal characteristic diagram of the engine, under the current power demand request of the engine, the idling speed with the minimum oil consumption rate is selected as the target idling speed, and the target idling speed is used as the initial target idling speed.

In some optional embodiments, adjusting the initial target idle speed, continuing to calculate the first sound pressure level signal, and regarding the target idle speed corresponding to the first sound pressure level signal being less than the first standard sound pressure level as the final target idle speed includes:

under the current power demand request of the engine, adjusting according to a preset amplitude each time within a preset range of an initial target idle speed, wherein the adjusted target idle speed cannot exceed a contour region of a current oil consumption rate, then measuring a first sound pressure level signal corresponding to the adjusted target idle speed, and selecting the corresponding target idle speed as a final target idle speed until the first sound pressure level signal is smaller than a first standard sound pressure level.

In some alternative embodiments, calibrating the series mode engine start and stop power limit, the engine start and stop delay time, and the high voltage battery charge limit to cause the engine to start less than a first predetermined number of times at low speed and stop no more than a second predetermined number of times at intermediate speed comprises:

calibrating an engine starting power limit value and an engine stopping power limit value under different vehicle speeds according to the difference value between the actual electric quantity and the target electric quantity of different high-voltage batteries;

when the engine required power request is larger than or equal to the engine starting power limit value, sending an engine starting request; when the engine demand power request is less than the engine starting power limit, the engine is shut down; when the engine demand power request is greater than or equal to the engine stop power limit value, stopping the engine; when the engine demand power request is smaller than the engine stop power limit value, sending an engine start request;

when the difference value between the actual electric quantity and the target electric quantity of the high-voltage battery is less than or equal to the electric quantity limit value of the engine starting high-voltage battery, sending an engine starting request; when the difference value between the actual electric quantity and the target electric quantity of the high-voltage battery is larger than the electric quantity limit value of the high-voltage battery for starting the engine, stopping the engine; when the difference value between the actual electric quantity and the target electric quantity of the high-voltage battery is less than or equal to the electric quantity limit value of the high-voltage battery when the engine is stopped, stopping the engine; when the difference value between the actual electric quantity and the target electric quantity of the high-voltage battery is larger than the electric quantity limit value of the high-voltage battery when the engine is stopped, sending an engine starting request; wherein a preset delay time is met between the issuance of a start or stop request and the actual start or stop.

In general, compared with the prior art, the above technical solution contemplated by the present invention can achieve the following beneficial effects:

by designing the series mode control of the series hybrid electric vehicle, controlling the running target idle speed, the rotating speed rising and falling gradient of the series mode engine, the starting and stopping conditions of the engine and the noise sound pressure level alarm logic, the series mode economy and the NVH performance of the series hybrid electric vehicle can be optimized. According to the invention, the economy and the NVH performance are considered at the same time, and the series mode development of the hybrid electric vehicle can be effectively guided.

Drawings

Fig. 1 is a structural diagram of a series-parallel hybrid electric vehicle according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a series mode control system according to an embodiment of the present invention;

FIG. 3 is a schematic flow chart of a method for controlling a series operating condition of a hybrid electric vehicle according to an embodiment of the present invention;

FIG. 4 is a diagram illustrating the universal characteristics of an engine provided by an embodiment of the present invention;

FIG. 5 is a series mode engine power demand control map provided by an embodiment of the present invention;

FIG. 6 is a series mode speed control map provided by an embodiment of the present invention;

FIG. 7 is a diagram of a noise alarm control provided by an embodiment of the present invention;

FIG. 8 is a series mode engine start-stop control map provided by an embodiment of the present invention;

FIG. 9 is a schematic diagram of an engine start-stop control provided by an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

In the present examples, "first", "second", etc. are used for distinguishing different objects, and are not used for describing a specific order or sequence.

The structure of the series-parallel hybrid electric vehicle related to the invention is shown in fig. 1. In fig. 1, the engine is a gasoline engine, the black line connection is mechanical connection, the dotted line connection is electrical connection, in the series mode, the clutch is in a disconnected state, the automobile drives the vehicle by the driving motor, and the engine starts or stops according to the driving power required by the driving motor and the electric quantity of the high-voltage battery, wherein the electric quantity of the high-voltage battery refers to the electric quantity percentage of the high-voltage battery.

The series mode control system of the present invention is shown in fig. 2. A noise signal measured by a noise sensor inside a cab is transmitted to a controller (VECU) as one of conditions of engine speed Control, starting and stopping Control so as to meet the NVH development requirement; the high-voltage battery electric quantity sensor feeds back the measured electric quantity percentage signal to the VECU, and the measured electric quantity percentage signal is used as one of control conditions of engine torque control, rotating speed control and starting or stopping; the engine intake flow sensor and the rotating speed sensor send measured flow and rotating speed signals to the VECU, the VECU obtains output torque and rotating speed of the engine through calculation (the rotating speed signals measured by the sensors are filtered in the VECU through a relevant filtering method), and whether the output torque and the rotating speed of the engine are in an optimal economic area under the current working condition is judged so as to reduce oil consumption.

Example one

Fig. 3 is a schematic flow chart of a method for controlling a series operating condition of a hybrid electric vehicle according to an embodiment of the present invention, where the method shown in fig. 3 includes the following steps:

s1: according to the universal characteristic diagram of the engine, under the current power demand request of the engine, selecting the idle speed with the minimum oil consumption rate as a target idle speed, and taking the target idle speed as an initial target idle speed;

FIG. 4 is a characteristic diagram of the engine in which the horizontal axis represents the engine speed; the longitudinal axis is the output torque of the engine; the black contour line in the graph is an oil consumption rate curve; the thick dashed line is the generator efficiency (representing the generator input power to output power efficiency); the black dashed line represents the engine power curve; the black thick solid line represents an engine optimal oil consumption curve, the oil consumption rate of the engine, the efficiency of the generator and the control dispersion difference are comprehensively considered (namely, a current optimal oil consumption intermediate point is selected), and the series mode engine target idling speed is selected as an initial target idling speed according to the engine optimal oil consumption curve and the current engine power demand request, so that the oil consumption rate under the current engine power demand is optimal.

In the present embodiment, as shown in fig. 5, the current engine required power request is obtained in the following manner:

at different high-voltage battery actual electric quantity and target electric quantity difference, under different driving motor required power, mark generator required power, wherein, when the calibration, generator required power is 10s power under the room temperature that driving motor required power + different high-voltage battery actual electric quantity and target electric quantity difference correspond, so that the high-voltage battery electric quantity does not reduce (satisfy 1% error range), show as table 1 and mark the table for generator required power, wherein, the abscissa is driving motor required power, it is calculated by accelerator pedal required torque, the speed of a motor vehicle and current driving motor transmission efficiency, the computational formula is as follows:

the required power of the driving motor is equal to the required torque of an accelerator pedal multiplied by vehicle speed/(2 multiplied by the rolling radius of the wheel)/30000/the transmission efficiency of the current driving motor, wherein the transmission efficiency of the driving motor can be obtained through a driving motor bench test.

And the ordinate is the difference value between the current high-voltage battery electric quantity and the target electric quantity. The negative values in table 1 indicate the required charging power, and when the values in table 1 are positive, it indicates that the present generator is used as a driver to drive the engine, and the series mode in this embodiment does not involve.

Determining the required power of the electrical appliance accessories according to the power of each electrical load;

the power required by the electrical accessories is a fixed calibration value, and is the sum of power required by electrical loads such as lamps, wipers, electric air conditioners, windows of vehicles, which are powered by the target high-voltage battery under the electric quantity, and the calculation formula is as follows:

the power demand of the electrical equipment accessories is equal to the power demand of the lamp, the power demand of the windscreen wiper, the power demand of the electric air conditioner, the power demand of the opening and closing of the vehicle window and the power demand of other electric loads.

Calibrating a compensation coefficient of the series-connected mode electrical accessories under the difference value between the actual electric quantity and the target electric quantity of different high-voltage batteries, wherein during calibration, the required power of the electrical accessories plus the power of 10s at room temperature corresponding to the difference value between the actual electric quantity and the target electric quantity of different high-voltage batteries so as to ensure that the electric quantity of the high-voltage batteries is not reduced (the error range of +/-1 percent is met);

the series mode electrical accessory compensation coefficient calibration table is a compensation coefficient for power required by electrical accessories under different high-voltage battery electric quantities, and is shown in table 2.

Calibrating power transfer efficiency under different generator rotating speeds and different generator torques, wherein the power transfer efficiency can be obtained through a bench test, and is the power of an output shaft/input electric power of the generator;

the power transfer efficiency calibration table, which represents the transfer efficiency from the engine input power received by the generator to the actual output power, can be obtained through a generator bench test, as shown in table 3.

And the required power of the electric appliance accessories is multiplied by the compensation coefficient of the series-connected electric appliance accessories, then the multiplied power is added with the required power of the generator, then the addition result is divided by the power transfer efficiency to obtain the required power request of the engine, and then the required power request of the engine is determined according to the difference value of the actual electric quantity of the current high-voltage battery and the target electric quantity, the required power of the current driving motor, the required power of the current electric appliance accessories, the rotating speed of the current generator and the torque of the current generator.

TABLE 1

TABLE 2

Difference value (%) between actual electric quantity and target electric quantity of high-voltage battery	-20	-15	-10	-5	0
						Series mode electrical accessory compensation factor	1.2	1.15	1.1	1.05	1

TABLE 3

In the present embodiment, step S1 can be implemented by:

as shown in fig. 6, the engine speed ascending speed gradient and the engine speed descending speed gradient are calibrated under different high-voltage battery capacities and different engine speeds, wherein, when the rotating speed is changed during calibration, the battery capacity error is kept at +/-1%, in fig. 6, LU/LD respectively represents limit up and limit down, which represent the limit value of the speed gradient, and the speed gradient is limited during the process of changing from one target idle speed to the other target idle speed;

the engine speed rising speed gradient calibration meter is shown in table 4, the horizontal axis represents the electric quantity of the high-voltage battery measured by the high-voltage battery sensor, and the vertical axis represents the engine speed; the engine speed reduction gradient calibration table is shown in table 5, the horizontal axis represents the high-voltage battery power measured by the high-voltage battery sensor, and the vertical axis represents the engine speed.

Calibrating the target idle speed of the series mode engine under different power requirements of different engines based on the difference value between the actual electric quantity and the target electric quantity of different high-voltage batteries;

under the current demand power request of the engine, according to the universal characteristic diagram of the engine, selecting the idle speed with the minimum oil consumption rate as a target idle speed, and taking the target idle speed as an initial target idle speed.

The series mode engine target idle speed calibration table is shown in table 6, wherein the horizontal axis represents the difference between the actual electric quantity and the target electric quantity of the high-voltage battery, and the vertical axis represents the engine power demand request, and the idle speed with the minimum oil consumption rate can be selected as the target idle speed according to the universal characteristic diagram of the engine under the current engine power demand request.

TABLE 4

TABLE 5

TABLE 6

S2: measuring a first sound pressure level signal of an initial target idle speed and a torque point corresponding to the initial target idle speed, if the first sound pressure level signal is greater than a first standard sound pressure level, adjusting the initial target idle speed, continuously calculating the first sound pressure level signal, and taking the corresponding target idle speed when the first sound pressure level signal is less than the first standard sound pressure level as a final target idle speed;

in this embodiment, as shown in fig. 7, adjusting the initial target idle speed, continuing to calculate the first sound pressure level signal, and taking the target idle speed corresponding to the first sound pressure level signal being less than the first standard sound pressure level as the final target idle speed includes:

under the current power demand request of the engine, adjusting according to a preset amplitude each time within a preset range of an initial target idle speed, wherein the adjusted target idle speed cannot exceed a contour region of a current oil consumption rate, then measuring a first sound pressure level signal corresponding to the adjusted target idle speed, and selecting the corresponding target idle speed as a final target idle speed until the first sound pressure level signal is smaller than a first standard sound pressure level.

Such as: measuring a first sound pressure level of the initial target idle speed and a torque point corresponding to the initial target idle speed (which can be obtained by calculating current engine required power and the initial target idle speed), and if the first sound pressure level is greater than a first standard sound pressure level, adjusting the initial target idle speed, wherein the adjusting method comprises the following steps: within the range of +/-100 r/min of the initial target idle speed (at the moment, the current required power of the engine is fixed), adjusting +/-10 r/min each time (and the current required power cannot exceed the contour region of the current oil consumption rate), measuring a first sound pressure level until the first sound pressure level is smaller than a first standard sound pressure level, and selecting the corresponding target idle speed as the final target idle speed.

The difference value between the initial target idle speed and the initial target idle speed is within a preset range, for example, the difference value between the initial target idle speed and the initial target idle speed is represented within a range of +/-100 r/min, and the difference value between the initial target idle speed and the initial target idle speed is within a range of-100 r/min.

The adjustment according to the preset amplitude means that the preset amplitude is added or subtracted on the basis of the current idle speed every time, for example, the adjustment is performed at the speed of +/-10 r/min every time, and means that the preset amplitude is added or subtracted on the basis of the current idle speed every time when the adjustment is performed, and in the adjustment process, the idle speed which is already calculated is not repeatedly calculated.

S3: respectively testing oil consumption rates and second sound pressure level signals under different engine speed gradients and different high-voltage battery electric quantities, and taking the engine speed gradient with the minimum oil consumption rate and the second sound pressure level signal being smaller than a second standard sound pressure level as corresponding speed gradient points under the current engine speed and the current high-voltage battery electric quantity;

specifically, table 4 and table 5 are selected as an initial engine speed gradient table, speed gradient points are selected at intervals of ± 1r/min within ± 10r/min gradients of the gradient points of table 4 and table 5, the oil consumption rate a and the second sound pressure level are respectively tested under different engine speeds and different high-voltage battery electric quantities, and the speed gradient with the minimum a and the second sound pressure level smaller than the second standard sound pressure level is the corresponding speed gradient point under the current engine speed and the current high-voltage battery electric quantity.

In this embodiment, by setting the first standard sound pressure level in the series mode and the second standard sound pressure level in the series mode according to the noise sound pressure level alarm logic in steps S2 and S3, it is evaluated whether the sound pressure levels meet the standard requirements under different engine speeds, torques, and speed gradients, and the economy is optimized under the condition of ensuring the NVH performance.

Wherein the first standard sound pressure level is a fixed value indicating the maximum acceptable noise sound pressure level at different engine speeds and different engine torques; the second standard sound pressure level is a fixed value and indicates the maximum acceptable noise sound pressure level under different engine speeds and different engine speed gradients (including ascending and descending speed gradients); and if the sound pressure level signal under the current working condition is greater than the first standard sound pressure level signal or the second standard sound pressure level signal, the VECU sends out a sound pressure level alarm signal.

S4: the starting and stopping power limit value, the starting and stopping delay time and the high-voltage battery capacity limit value of the series mode engine are calibrated, so that the starting times of the engine under the low-speed working condition are less than the first preset times (in the VI wltc cycle, P1 is a low-speed stage, P2 is a medium-speed stage), and the stopping times of the engine under the P2 stage do not exceed the second preset times.

In the present embodiment, as shown in fig. 8, step S4 can be implemented by:

calibrating an engine starting power limit value and an engine stopping power limit value under different vehicle speeds according to the difference value between the actual electric quantity and the target electric quantity of different high-voltage batteries, and enabling the stopping number to be less than a certain number of times by combining working conditions and specific vehicles during calibration;

the engine starting power limit is shown in table 7, the engine stopping power limit is shown in table 8, the abscissa is the difference between the actual electric quantity and the target electric quantity of the high-voltage battery, and the ordinate is the vehicle speed.

When the engine required power request is larger than or equal to the engine starting power limit value, sending an engine starting request; when the engine demand power request is less than the engine starting power limit, the engine is shut down; when the engine demand power request is greater than or equal to the engine stop power limit value, stopping the engine; when the engine demand power request is smaller than the engine stop power limit value, sending an engine start request;

when the difference value between the actual electric quantity and the target electric quantity of the high-voltage battery is less than or equal to the electric quantity limit value of the engine starting high-voltage battery, sending an engine starting request; when the difference value between the actual electric quantity and the target electric quantity of the high-voltage battery is larger than the electric quantity limit value of the high-voltage battery for starting the engine, stopping the engine; when the difference value between the actual electric quantity and the target electric quantity of the high-voltage battery is less than or equal to the electric quantity limit value of the high-voltage battery when the engine is stopped, stopping the engine; when the difference value between the actual electric quantity and the target electric quantity of the high-voltage battery is larger than the electric quantity limit value of the high-voltage battery when the engine is stopped, sending an engine starting request; wherein a preset delay time is met between the issuance of a start or stop request and the actual start or stop.

The electric quantity limit value of the high-voltage battery for starting the engine and the electric quantity limit value of the high-voltage battery for stopping the engine are fixed values and can be determined by the difference value between the current electric quantity of the high-voltage battery and the target electric quantity, and the embodiment is not limited uniquely.

The preset delay time from the sending of the start or stop request to the actual start or stop may be determined according to actual needs, and this embodiment is not limited uniquely.

TABLE 7

TABLE 8

As shown in fig. 9, the series mode engine start and stop power limits, engine start and stop delay times, and high voltage battery charge limits are calibrated for specific fuel consumption test cycles (e.g., wltc cycles P1 and P2 stages in fig. 9). The calibration principle is as follows: the starting times of the engine under the low-speed working condition (the P1 stage) are less than a first preset time (for example, the starting times are not more than 1 time), and the stopping times of the engine under the P2 stage are not more than a second preset time (for example, not more than 2 times). Since frequent starting is economically disadvantageous.

The first preset times and the second preset times can also be determined according to actual needs, and the embodiment is not limited uniquely.

Example two

As shown in fig. 2, the embodiment provides a series operating condition control system for a hybrid electric vehicle, including: the device comprises a noise sensor, a high-voltage battery electric quantity sensor, an engine rotating speed sensor, a vehicle speed sensor and a VECU controller, wherein the VECU controller is respectively connected with the noise sensor, the high-voltage battery electric quantity sensor, the engine rotating speed sensor and the vehicle speed sensor;

wherein the noise sensor is used for measuring noise in the cab; the high-voltage battery electric quantity sensor is used for measuring the electric quantity of the high-voltage battery; the engine speed sensor is used for measuring the engine speed; the vehicle speed sensor is used for measuring vehicle speed; the VECU controller is used for executing the following operations:

according to the universal characteristic diagram of the engine, under the current power demand request of the engine, selecting the idle speed with the minimum oil consumption rate as a target idle speed, and taking the target idle speed as an initial target idle speed;

measuring a first sound pressure level signal of an initial target idle speed and a torque point corresponding to the initial target idle speed, if the first sound pressure level signal is greater than a first standard sound pressure level, adjusting the initial target idle speed, continuously calculating the first sound pressure level signal, and taking the corresponding target idle speed when the first sound pressure level signal is less than the first standard sound pressure level as a final target idle speed;

respectively testing oil consumption rates and second sound pressure level signals under different engine speed gradients and different high-voltage battery electric quantities, and taking the engine speed gradient with the minimum oil consumption rate and the second sound pressure level signal being smaller than a second standard sound pressure level as corresponding speed gradient points under the current engine speed and the current high-voltage battery electric quantity;

calibrating the starting and stopping power limit value of the series mode engine, the starting and stopping delay time of the engine and the electric quantity limit value of the high-voltage battery, so that the starting times of the engine under the low-speed working condition are less than the first preset times, and the stopping times of the engine in the medium-speed stage are not more than the second preset times.

In some alternative embodiments, the current engine demand power request is obtained by:

calibrating the required power of the generator under different difference values of the actual electric quantity and the target electric quantity of the high-voltage battery and different required powers of the driving motor, and determining the required power of the electrical accessories according to the power of each electric load;

calibrating a compensation coefficient of the series mode electrical appliance accessory under the difference value of the actual electric quantity and the target electric quantity of different high-voltage batteries;

calibrating power transfer efficiency under different generator rotating speeds and different generator torques;

and the required power of the electric appliance accessories is multiplied by the compensation coefficient of the series-connected electric appliance accessories, then the multiplied power is added with the required power of the generator, then the addition result is divided by the power transfer efficiency to obtain the required power request of the engine, and then the required power request of the engine is determined according to the difference value of the actual electric quantity of the current high-voltage battery and the target electric quantity, the required power of the current driving motor, the required power of the current electric appliance accessories, the rotating speed of the current generator and the torque of the current generator.

In some optional embodiments, according to the engine universal characteristic map, under the current engine demand power request, selecting the idle speed with the minimum fuel consumption rate as the target idle speed, and taking the target idle speed as the initial target idle speed, includes:

calibrating the ascending speed gradient and the descending speed gradient of the engine speed under different high-voltage battery electric quantities and different engine speeds;

calibrating the target idle speed of the series mode engine under different power requirements of different engines based on the difference value between the actual electric quantity and the target electric quantity of different high-voltage batteries;

according to the universal characteristic diagram of the engine, under the current power demand request of the engine, the idling speed with the minimum oil consumption rate is selected as the target idling speed, and the target idling speed is used as the initial target idling speed.

In some optional embodiments, adjusting the initial target idle speed, continuing to calculate the first sound pressure level signal, and regarding the target idle speed corresponding to the first sound pressure level signal being less than the first standard sound pressure level as the final target idle speed includes:

under the current power demand request of the engine, adjusting according to a preset amplitude each time within a preset range of an initial target idle speed, wherein the adjusted target idle speed cannot exceed a contour region of a current oil consumption rate, then measuring a first sound pressure level signal corresponding to the adjusted target idle speed, and selecting the corresponding target idle speed as a final target idle speed until the first sound pressure level signal is smaller than a first standard sound pressure level.

In some alternative embodiments, calibrating the series mode engine start and stop power limit, the engine start and stop delay time, and the high voltage battery charge limit to cause the engine to start less than a first predetermined number of times at low speed and stop no more than a second predetermined number of times at intermediate speed comprises:

calibrating an engine starting power limit value and an engine stopping power limit value under different vehicle speeds according to the difference value between the actual electric quantity and the target electric quantity of different high-voltage batteries;

when the engine required power request is larger than or equal to the engine starting power limit value, sending an engine starting request; when the engine demand power request is less than the engine starting power limit, the engine is shut down; when the engine demand power request is greater than or equal to the engine stop power limit value, stopping the engine; when the engine demand power request is smaller than the engine stop power limit value, sending an engine start request;

when the difference value between the actual electric quantity and the target electric quantity of the high-voltage battery is less than or equal to the electric quantity limit value of the engine starting high-voltage battery, sending an engine starting request; when the difference value between the actual electric quantity and the target electric quantity of the high-voltage battery is larger than the electric quantity limit value of the high-voltage battery for starting the engine, stopping the engine; when the difference value between the actual electric quantity and the target electric quantity of the high-voltage battery is less than or equal to the electric quantity limit value of the high-voltage battery when the engine is stopped, stopping the engine; when the difference value between the actual electric quantity and the target electric quantity of the high-voltage battery is larger than the electric quantity limit value of the high-voltage battery when the engine is stopped, sending an engine starting request; wherein a preset delay time is met between the issuance of a start or stop request and the actual start or stop.

It should be noted that, according to the implementation requirement, each step/component described in the present application can be divided into more steps/components, and two or more steps/components or partial operations of the steps/components can be combined into new steps/components to achieve the purpose of the present invention.

It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.