CN109515429B - Control method of tandem type gas-electricity hybrid power system of commercial vehicle - Google Patents

Abstract

The invention provides a control method of a tandem type gas-electricity hybrid power system of a commercial vehicle, which is based on the tandem type gas-electricity hybrid power system, and is fed back from all components, a driving system and a preset control strategy according to a traction power instruction of a driver, and a vehicle controller selects a specific working mode from seven modes of pure electric driving, pure gas driving, hybrid driving, a driving charging mode, a parking charging mode, regenerative braking and a hybrid charging mode according to the control method, so that the energy which cannot be utilized in the traditional vehicle is fully utilized, the energy utilization rate of the whole vehicle is improved, and the driving range of the vehicle is increased.

Description

Control method of tandem type gas-electricity hybrid power system of commercial vehicle

Technical Field

The invention belongs to the field of new energy automobile design, and relates to a control method of a series gas-electricity hybrid power system of a commercial vehicle.

Background

The series gas-electric hybrid power system can prolong the driving range of the vehicle and relieve the driving anxiety of the new energy vehicle. Because the series hybrid power system has a plurality of working modes, the optimal working mode is selected according to different driving requirements and vehicle states, and the driving range of the vehicle can be increased to the maximum extent. The operating mode of the electric drive system is closely related to the control method, and the vehicle controller receives operating commands from the driver, as well as feedback from the various components and drive train, and makes decisions based on the preset control method to apply the particular operating mode. The performance of the drive system depends mainly on the quality of the control, wherein the control method plays a decisive role.

Disclosure of Invention

The invention provides a control method of a tandem type gas-electricity hybrid power system of a commercial vehicle, which is based on the tandem type gas-electricity hybrid power system, and is fed back from all components, a driving system and a preset control strategy according to a traction power instruction of a driver, and a vehicle controller selects a specific working mode from seven modes of pure electric driving, pure gas driving, hybrid driving, a driving charging mode, a parking charging mode, regenerative braking, a hybrid charging mode and the like according to the control method, so that the energy which cannot be utilized in the traditional vehicle is fully utilized, the energy utilization rate of the whole vehicle is improved, and the driving mileage of the vehicle is improved.

In order to achieve the purpose, the invention is realized by the following technical scheme:

a control method of a series gas-electric hybrid power system of a commercial vehicle is characterized in that the system comprises a power battery, an electric coupling device, a motor controller, a motor, a transmission device and tires which are sequentially connected and form an energy transfer channel; the system also comprises an inflator pump, a compressed gas cylinder, a pneumatic generator and a vehicle control unit, wherein the inflator pump drives the inflator pump to work by utilizing vibration and impact of a vehicle and inflates the compressed gas cylinder on the vehicle, and the pneumatic generator drives the inflator pump to work by utilizing air pressure in the compressed gas cylinder and outputs electric energy to the electric coupling device; the method comprises the following steps:

the vehicle control unit monitors the air pressure value of the compressed air cylinder and the vehicle state in real time, and controls the working state of the pneumatic generator and the working mode of the vehicle according to the air pressure value of the compressed air cylinder and the vehicle state, wherein the working mode comprises the steps of monitoring the air pressure value of the compressed air cylinder, monitoring the vehicle speed, calculating the required power of the vehicle, calculating the maximum generating power of the motor, and determining the working mode of the vehicle according to the monitored and calculated values.

Preferably, the method comprises the following steps:

s1: judging the air pressure value P of the compressed air bottle_{Gas cylinder}Whether it is greater than the minimum threshold value P of the output power of the driving pneumatic generator_minIf yes, go to step S6; if not, go to step S2;

s2: judging the running state of the vehicle according to the vehicle speed, if the vehicle speed V is greater than 0, executing step S3, if the vehicle speed V is equal to 0, the vehicle enters a parking mode, and the pneumatic generator and the motor are both in an OFF state;

s3: calculating the required power P of the vehicle_comIf P is_comIf the power is more than 0, the vehicle is in a driving state, the vehicle enters a pure electric driving mode, the pneumatic generator is in an OFF state, the motor works in a motor state, and the output power P is_M＝P_com(ii) a If P_comIf the vehicle is in the braking state, executing step S4;

s4: judging the SOC of the battery, if the SOC of the battery is more than the SOC_maxIf the vehicle is in the OFF state, the vehicle enters a mechanical braking mode, the energy required by the braking of the vehicle is completely provided by a mechanical braking system, and the pneumatic generator and the motor are both in the OFF state; if the SOC of the battery is less than or equal to the SOC_maxThen step S5 is executed, the above SOC_maxStopping SOC for charging the battery;

s5: obtaining the maximum generating power P which can be provided when the motor is in the working state of the generator according to the motor characteristic MAP_{Power generation max}If P is_com<P_{Power generation max}The vehicle enters a regenerative braking mode, the pneumatic generator is in an OFF state, the motor operates in a generator state, and the output power P is_M＝P_{Power generation max}(ii) a If P_com≥P_{Power generation max}The vehicle enters a regenerative braking mode, the pneumatic generator is in an OFF state, the motor operates in a generator state, and the output power P is_M＝P_com；

S6: judging the running state of the vehicle according to the vehicle speed, if the vehicle speed V is greater than 0, executing step S8, if the vehicle speed V is equal to 0, entering the parking mode, and executing step S7;

s7: judging the SOC of the battery, if the SOC of the battery is more than the SOC_maxIf the vehicle is in the parking mode, the pneumatic generator and the motor are both in an OFF state; if the SOC of the battery is less than or equal to the SOC_maxIf the vehicle enters a parking charging mode, the pneumatic generator works to charge the power battery with the maximum power until the SOC is reached>SOC_maxOr P_{Gas cylinder}<P_minAt the moment, the output power P of the pneumatic generator_{Pneumatic power}＝P_{Pneumatic max}(ii) a The motor is in an OFF state;

s8: calculating the required power P of the vehicle_comIf P is_com<0, vehicleIf the brake state is reached, step S9 is executed; if P_com>0, the vehicle is in a driving state, step S11 is executed.

S9: judging the SOC of the battery, if the SOC of the battery is more than the SOC_maxWhen the vehicle enters a mechanical braking mode, the pneumatic generator and the motor do not work and are in an OFF state; if the SOC of the battery is less than or equal to the SOC_maxThen step S10 is executed.

S10: obtaining the maximum generating power P which can be provided when the motor is in the working state of the generator according to the motor characteristic MAP_{Power generation max}If P is_com<P_{Power generation max}Then the vehicle enters a hybrid charging mode, the pneumatic generator is operated, and P_{Pneumatic power}＝P_{Pneumatic max}The motor works in a generator state and outputs power P_M＝P_{Power generation max}(ii) a If P_com≥P_{Power generation max}Then enter a hybrid charging mode, the pneumatic generator is operated, and P_{Pneumatic power}＝P_{Pneumatic max}The motor works in a generator state and outputs power P_M＝P_com；

S11: if the required power P of the whole vehicle_com>P_{Pneumatic max}·η₁The vehicle enters a hybrid driving mode, the pneumatic generator and the motor are both operated, and the pneumatic generator outputs power P_{Pneumatic power}＝P_{Pneumatic max}Output power P of the motor_M＝P_com(ii) a If P_com≤P_{Pneumatic max}·η₁Then step S12 is executed, where eta₁The working efficiency of the motor and the electric coupler is improved;

s12: judging the SOC of the battery, if the SOC of the battery is more than the SOC_maxThen the air-driven generator enters a pure air driving mode, the air-driven generator is in a working state, and the output power P is output_{Pneumatic power}＝P_com/η₁The motor is in the motor working state and outputs power P_M＝P_com(ii) a If the SOC of the battery is less than or equal to the SOC_maxThen entering a charging mode of driving, the pneumatic engine is in a working state and outputs power P_{Pneumatic power}＝P_{Pneumatic max}The motor is in the motor working state and outputs power P_M＝P_com。

Preferably, the vehicle required power P is calculated according to the following formula_com：

In the formula: p_com-vehicle power demand, kW; v is vehicle speed, km/h; eta-transmission system efficiency; m is the whole vehicle weight, kg; g-acceleration of gravity, m/s²(ii) a f-rolling resistance coefficient; α -slope angle, °; rho-air Density, kg/m³；C_d-coefficient of air resistance; a-area of the vehicle facing the wind, m²(ii) a -a coefficient of moment of inertia; dv/dt-vehicle acceleration, m/s²。

Compared with the prior art, the invention has the following advantages:

1. on the premise of meeting the driving requirements of the vehicle, the invention can maintain the state of charge of the power battery to the maximum extent and ensure the acceleration performance and the climbing performance of the vehicle;

2. the gas energy related by the invention is from vibration energy and impact energy generated in the running process of the vehicle, external energy supply is not needed, and the cost is saved.

Drawings

FIG. 1 is a schematic structural diagram of a series gas-electric hybrid power system of a commercial vehicle.

FIG. 2 is a flow chart of a control method of a series gas-electric hybrid power system of a commercial vehicle.

Detailed Description

The invention discloses a control method of a tandem type gas-electricity hybrid power system of a commercial vehicle, wherein the tandem type hybrid power system mainly comprises a power battery, an electric coupling device, a motor controller, a motor, a transmission device, tires, an inflator pump arranged in a cab suspension, the inflator pump arranged in a chassis suspension, a compressed gas cylinder, a vehicle control unit and a pneumatic generator, and the control method is shown in figure 1. The power battery, the electric coupling device, the motor controller, the motor, the transmission device and the tire form an energy transmission channel, and the transmission device comprises a gearbox, a transmission shaft and a rear drive axle. The inflator pump drives the inflator pump to work by utilizing vibration and impact of a vehicle and inflates the compressed gas cylinder on the vehicle, and the pneumatic generator drives the inflator pump to work by utilizing air pressure in the compressed gas cylinder and outputs electric energy to the electric coupling device. The system can recover the vibration and impact energy of the suspension system, store the energy in the compressed gas cylinder, complete the self-inflating process, and then release the energy to the power system through the pneumatic generator to drive the vehicle to run, so that the energy which cannot be utilized in the traditional vehicle is fully utilized, the energy utilization rate of the whole vehicle is improved, and the driving range of the vehicle is increased. The hybrid power transmission system can realize that the vehicle works in seven modes of pure electric drive, pure gas drive, hybrid drive, a driving charging mode, a parking charging mode, a regenerative braking mode and a hybrid charging mode.

The control method in the embodiment of the present invention will be further described below with reference to the drawings in the embodiment of the present invention.

The invention provides a control method of a tandem type gas-electricity hybrid power system of a commercial vehicle, which is characterized in that a vehicle control unit monitors the air pressure value and the vehicle state of a compressed air cylinder in real time and controls the working state of a pneumatic generator and the working mode of a vehicle according to the air pressure value and the vehicle state of the compressed air cylinder, wherein the control method comprises the steps of monitoring the air pressure value of the compressed air cylinder, monitoring the vehicle speed, calculating the required power of the vehicle, calculating the maximum power generation power of a motor and determining the working mode of the vehicle according to the monitored and calculated values. The method specifically comprises the following steps:

s1: judging the air pressure value P of the compressed air bottle_{Gas cylinder}Whether it is greater than the minimum threshold value P of the output power of the driving pneumatic generator_minIf yes, go to step S6; if not, go to step S2;

s2: judging the running state of the vehicle according to the vehicle speed, if the vehicle speed V is greater than 0, executing step S3, if the vehicle speed V is equal to 0, the vehicle enters a parking mode, and the pneumatic generator and the motor are both in an OFF state;

s3: calculating the required power P of the vehicle_comIf P is_comIf the speed is more than 0, the vehicle is in a driving state, the vehicle enters a pure electric driving mode, the pneumatic generator is in an OFF state, and the motorOperating in motor state and outputting power P_M＝P_com(ii) a If P_comIf the vehicle is in the braking state, executing step S4;

s4: judging the SOC of the battery, if the SOC of the battery is more than the SOC_maxIf the vehicle is in the OFF state, the vehicle enters a mechanical braking mode, the energy required by the braking of the vehicle is completely provided by a mechanical braking system, and the pneumatic generator and the motor are both in the OFF state; if the SOC of the battery is less than or equal to the SOC_maxThen step S5 is executed, the above SOC_maxStopping SOC for charging the battery;

s5: obtaining the maximum generating power P which can be provided when the motor is in the working state of the generator according to the motor characteristic MAP_{Power generation max}If P is_com<P_{Power generation max}The vehicle enters a regenerative braking mode, the pneumatic generator is in an OFF state, the motor operates in a generator state, and the output power P is_M＝P_{Power generation max}(ii) a If P_com≥P_{Power generation max}The vehicle enters a regenerative braking mode, the pneumatic generator is in an OFF state, the motor operates in a generator state, and the output power P is_M＝P_com；

S6: judging the running state of the vehicle according to the vehicle speed, if the vehicle speed V is greater than 0, executing step S8, if the vehicle speed V is equal to 0, entering the parking mode, and executing step S7;

s7: judging the SOC of the battery, if the SOC of the battery is more than the SOC_maxIf the vehicle is in the parking mode, the pneumatic generator and the motor are both in an OFF state; if the SOC of the battery is less than or equal to the SOC_maxIf the vehicle enters a parking charging mode, the pneumatic generator works to charge the power battery with the maximum power until the SOC is reached>SOC_maxOr P_{Gas cylinder}<P_minAt the moment, the output power P of the pneumatic generator_{Pneumatic power}＝P_{Pneumatic max}(ii) a The motor is in an OFF state;

s8: calculating the required power P of the vehicle_comIf P is_com<0, if the vehicle is in a braking state, executing step S9; if P_com>0, the vehicle is in a driving state, step S11 is executed.

S9: judging the state of charge (SOC) of the battery if the battery SOC＞SOC_maxWhen the vehicle enters a mechanical braking mode, the pneumatic generator and the motor do not work and are in an OFF state; if the SOC of the battery is less than or equal to the SOC_maxThen step S10 is executed.

S10: obtaining the maximum generating power P which can be provided when the motor is in the working state of the generator according to the motor characteristic MAP_{Power generation max}If P is_com<P_{Power generation max}Then the vehicle enters a hybrid charging mode, the pneumatic generator is operated, and P_{Pneumatic power}＝P_{Pneumatic max}The motor works in a generator state and outputs power P_M＝P_{Power generation max}(ii) a If P_com≥P_{Power generation max}Then enter a hybrid charging mode, the pneumatic generator is operated, and P_{Pneumatic power}＝P_{Pneumatic max}The motor works in a generator state and outputs power P_M＝P_com；

S11: if the required power P of the whole vehicle_com>P_{Pneumatic max}·η₁The vehicle enters a hybrid driving mode, the pneumatic generator and the motor are both operated, and the pneumatic generator outputs power P_{Pneumatic power}＝P_{Pneumatic max}Output power P of the motor_M＝P_com(ii) a If P_com≤P_{Pneumatic max}·η₁Then step S12 is executed, where eta₁The working efficiency of the motor and the electric coupler is improved;

s12: judging the SOC of the battery, if the SOC of the battery is more than the SOC_maxThen the air-driven generator enters a pure air driving mode, the air-driven generator is in a working state, and the output power P is output_{Pneumatic power}＝P_com/η₁The motor is in the motor working state and outputs power P_M＝P_com(ii) a If the SOC of the battery is less than or equal to the SOC_maxThen entering a charging mode of driving, the pneumatic engine is in a working state and outputs power P_{Pneumatic power}＝P_{Pneumatic max}The motor is in the motor working state and outputs power P_M＝P_com。

Wherein the required power P of the vehicle is calculated according to the following formula_com：

In the formula: p_com-vehicle power demand, kW; v is vehicle speed, km/h; eta-transmission system efficiency; m is the whole vehicle weight, kg; g-acceleration of gravity, m/s²(ii) a f-rolling resistance coefficient; α -slope angle, °; rho-air Density, kg/m³；C_d-coefficient of air resistance; a-area of the vehicle facing the wind, m²(ii) a -a coefficient of moment of inertia; dv/dt-vehicle acceleration (deceleration) speed, m/s²And is negative in the deceleration state.

Finally, it should be noted that: the above embodiment only illustrates one technical solution of the present disclosure, and although the present disclosure is described in detail by the accompanying drawings and the like, it should be understood by those of ordinary skill in the art that: modifications of some embodiments or equivalents of some of the technical features of the present disclosure may be made without departing from the design concept of the present disclosure, and similar solutions may still fall within the scope of the present disclosure.

Claims (2)

1. A control method of a series gas-electric hybrid power system of a commercial vehicle is characterized in that the system comprises a power battery, an electric coupling device, a motor controller, a motor, a transmission device and tires which are sequentially connected and form an energy transfer channel; the system also comprises an inflator pump, a compressed gas cylinder, a pneumatic generator and a vehicle control unit, wherein the inflator pump drives the inflator pump to work by utilizing vibration and impact of a vehicle and inflates the compressed gas cylinder on the vehicle, and the pneumatic generator drives the inflator pump to work by utilizing air pressure in the compressed gas cylinder and outputs electric energy to the electric coupling device; the method comprises the following steps:

the vehicle control unit monitors the air pressure value of the compressed air cylinder and the vehicle state in real time, and controls the working state of the pneumatic generator and the working mode of the vehicle according to the air pressure value of the compressed air cylinder and the vehicle state, wherein the working state comprises the steps of monitoring the air pressure value of the compressed air cylinder, monitoring the vehicle speed, calculating the required power of the vehicle, calculating the maximum power generation power of the motor, and determining the working mode of the vehicle according to the monitored and calculated values;

the method comprises the following steps:

s1: judging the air pressure value P of the compressed air bottle_{Gas cylinder}Whether it is greater than the minimum threshold value P of the output power of the driving pneumatic generator_minIf yes, go to step S6; if not, go to step S2;

s2: judging the running state of the vehicle according to the vehicle speed, if the vehicle speed V is greater than 0, executing step S3, if the vehicle speed V is equal to 0, the vehicle enters a parking mode, and the pneumatic generator and the motor are both in an OFF state;

s3: calculating the required power P of the vehicle_comIf P is_comIf the power is more than 0, the vehicle is in a driving state, the vehicle enters a pure electric driving mode, the pneumatic generator is in an OFF state, the motor works in a motor state, and the output power P is_M＝P_com(ii) a If P_comIf the vehicle is in the braking state, executing step S4;

s4: judging the SOC of the battery, if the SOC of the battery is more than the SOC_maxIf the vehicle is in the OFF state, the vehicle enters a mechanical braking mode, the energy required by the braking of the vehicle is completely provided by a mechanical braking system, and the pneumatic generator and the motor are both in the OFF state; if the SOC of the battery is less than or equal to the SOC_maxThen step S5 is executed, the above SOC_maxStopping SOC for charging the battery;

s5: obtaining the maximum generating power P which can be provided when the motor is in the working state of the generator according to the motor characteristic MAP_{Power generation max}If P is_com<P_{Power generation max}The vehicle enters a regenerative braking mode, the pneumatic generator is in an OFF state, the motor operates in a generator state, and the output power P is_M＝P_{Power generation max}(ii) a If P_com≥P_{Power generation max}The vehicle enters a regenerative braking mode, the pneumatic generator is in an OFF state, the motor operates in a generator state, and the output power P is_M＝P_com；

S6: judging the running state of the vehicle according to the vehicle speed, if the vehicle speed V is greater than 0, executing step S8, if the vehicle speed V is equal to 0, entering the parking mode, and executing step S7;

s7: judging the state of charge (SOC) of the battery, if soPool SOC > SOC_maxIf the vehicle is in the parking mode, the pneumatic generator and the motor are both in an OFF state; if the SOC of the battery is less than or equal to the SOC_maxIf the vehicle enters a parking charging mode, the pneumatic generator works to charge the power battery with the maximum power until the SOC is reached>SOC_maxOr P_{Gas cylinder}<P_minAt the moment, the output power P of the pneumatic generator_{Pneumatic power}＝P_{Pneumatic max}(ii) a The motor is in an OFF state;

s8: calculating the required power P of the vehicle_comIf P is_com<0, if the vehicle is in a braking state, executing step S9; if P_com>0, the vehicle is in a driving state, and step S11 is executed;

s9: judging the SOC of the battery, if the SOC of the battery is more than the SOC_maxWhen the vehicle enters a mechanical braking mode, the pneumatic generator and the motor do not work and are in an OFF state; if the SOC of the battery is less than or equal to the SOC_maxThen go to step S10;

s10: obtaining the maximum generating power P which can be provided when the motor is in the working state of the generator according to the motor characteristic MAP_{Power generation max}If P is_com<P_{Power generation max}Then the vehicle enters a hybrid charging mode, the pneumatic generator is operated, and P_{Pneumatic power}＝P_{Pneumatic max}The motor works in a generator state and outputs power P_M＝P_{Power generation max}(ii) a If P_com≥P_{Power generation max}Then enter a hybrid charging mode, the pneumatic generator is operated, and P_{Pneumatic power}＝P_{Pneumatic max}The motor works in a generator state and outputs power P_M＝P_com；

S11: if the required power P of the whole vehicle_com>P_{Pneumatic max}·η₁The vehicle enters a hybrid driving mode, the pneumatic generator and the motor are both operated, and the pneumatic generator outputs power P_{Pneumatic power}＝P_{Pneumatic max}Output power P of the motor_M＝P_com(ii) a If P_com≤P _{Pneumatic max}·η₁Then step S12 is executed, where eta₁The working efficiency of the motor and the electric coupler is improved;

s12: state of charge of batterySOC is judged, if the battery SOC is more than SOC_maxThen the air-driven generator enters a pure air driving mode, the air-driven generator is in a working state, and the output power P is output_{Pneumatic power}＝P_com/η₁The motor is in the motor working state and outputs power P_M＝P_com(ii) a If the SOC of the battery is less than or equal to the SOC_maxThen entering a charging mode of driving, the pneumatic engine is in a working state and outputs power P_{Pneumatic power}＝P_{Pneumatic max}The motor is in the motor working state and outputs power P_M＝P_com。

2. The control method of a series gas-electric hybrid system of a commercial vehicle as claimed in claim 1, wherein the required vehicle power P is calculated according to the following formula_com：

In the formula: p_com-vehicle power demand, kW; v is vehicle speed, km/h; eta-transmission system efficiency; m is the whole vehicle weight, kg; g-acceleration of gravity, m/s²(ii) a f-rolling resistance coefficient; α -slope angle, °; rho-air Density, kg/m³；C_d-coefficient of air resistance; a-area of the vehicle facing the wind, m²(ii) a -a coefficient of moment of inertia; dv/dt-vehicle acceleration, m/s²。

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