CN105539424B - A kind of energy control method of extended-range electric vehicle - Google Patents

Abstract

The invention belongs to the technical field of electric vehicles, and relates to an energy control method for an extended-range electric vehicle; it overcomes the problems of short service life of a power battery, low working efficiency of an engine, and a single operation mode of a complete vehicle in the prior art, and comprises the following steps: (1) ) to obtain the health status of the power battery; (2) judging whether the health status of the power battery is less than the predetermined value of the health status of the power battery; (3) judging whether the brake pedal is activated; (4) judging whether the power of the power battery is higher (5) The whole vehicle enters the stage of multi-point power recovery; (6) The whole vehicle enters the stage of single-point power consumption; (7) Judging whether the brake pedal is activated; (8) Judging whether the power of the power battery is higher than that of the power The battery is in the lower limit of power in an unhealthy state; (9) the whole vehicle enters the curve power maintenance stage; (10) the whole vehicle enters the curve power consumption stage, and the operation mode of the whole vehicle is controlled by the required power of the whole vehicle.

Description

Energy control method for a range-extended electric vehicle

technical field

The invention belongs to the technical field of electric vehicles, and in particular relates to an energy control method for an extended-range electric vehicle.

Background technique

With the development of low-carbon economy, the demand for energy saving and emission reduction has become the development trend of the automobile industry. The emergence of electric vehicles, especially extended-range electric vehicles, has effectively realized the concept of energy saving and emission reduction while ensuring the mileage of the vehicle. The power battery is the main energy storage component of the extended-range electric vehicle. Due to the limitation of technical conditions, its life will have a serious impact on the performance of the vehicle, the cost of the vehicle, and the environmental pollution after the vehicle is scrapped.

However, the current energy operation methods of extended-range electric vehicles seldom take into account the life of the power battery. How to improve the life of the power battery while ensuring the power and economy of the vehicle is a problem to be solved.

The Chinese patent with application number 201310401309.7 provides a method for operating an extended-range electric vehicle. According to the obtained remaining power of the power battery pack, it is judged whether the remaining power is less than or equal to the predetermined value of power; if not, the pure electric mode operation method is executed; if If yes, it is further judged whether the power battery pack is allowed to be charged, if yes, the operation method of the range-extending mode is executed; if not, the operation method of the power follow mode is executed. When the remaining power is greater than the predetermined value of power, this solution only provides energy through the power battery pack, which increases the discharge power and frequency of the power battery pack. service life.

The Chinese patent application number 201110240225.0 proposes a range-extended electric vehicle control system and its control method. The range-extender is composed of a small engine, a generator integrating power generation/drive, an engine controller, and a generator controller. The range-extender To supply power to the on-board power battery or directly drive the motor, the vehicle controller drives the vehicle and manages the energy of the vehicle according to the driver's needs and the status of each subsystem of the vehicle, and sends various Instructions for working status. The operating conditions of the engine in this scheme are relatively simple. It only works at high idle speed and two controllable economic zones. It cannot make the engine follow the power demanded by the vehicle, and increases the power output of the power battery, especially when the performance of the power battery declines. , affecting the power demand of the vehicle.

Contents of the invention

The technical problem to be solved by the present invention is to provide an energy control method for an extended-range electric vehicle by overcoming the problems of short power battery life, low engine working efficiency and single vehicle operation mode in the prior art.

In order to solve the problems of the technologies described above, the present invention is achieved by adopting the following technical solutions:

An energy control method for an extended-range electric vehicle, comprising the following steps:

(1) Obtain the health status of the power battery;

(2) Judging whether the state of health of the power battery is less than the predetermined value of the state of health of the power battery; if not, execute (3); if yes, execute (7);

(3) Determine whether the brake pedal is activated; if yes, the vehicle enters the braking phase; if not, determine the power of the power battery and execute (4);

(4) Further judge whether the electric quantity of the traction battery is higher than the lower limit value of the electric quantity of the traction battery in a healthy state; if not, enter the stage of multi-point electric quantity recovery, execute (5); if yes, enter the stage of single-point electric quantity consumption, execute (6);

(5) The whole vehicle enters the multi-point power recovery stage, and the operation mode of the whole vehicle is controlled by using the required power of the whole vehicle and the power of the power battery;

(6) The whole vehicle enters the stage of single-point power consumption, and the operation mode of the whole vehicle is controlled by using the required power of the whole vehicle;

(7) Determine whether the brake pedal is activated; if yes, the vehicle enters the braking phase; if not, determine the power of the power battery and execute (8);

(8) Further judge whether the electric quantity of the traction battery is higher than the lower limit value of the electric quantity of the traction battery in an unhealthy state; if not, enter the curve electric quantity maintenance stage and execute (9); if yes, then enter the curve electric quantity consumption stage and execute ( 10);

(9) The whole vehicle enters the curve power maintenance stage, and the operation mode of the whole vehicle is controlled by using the required power of the whole vehicle and the electric power of the power battery;

(10) The whole vehicle enters the curve power consumption stage, and the operation mode of the whole vehicle is controlled by using the required power of the whole vehicle.

The vehicle demand power described in the step (5) in the technical solution is used for judging the size relationship with the power of the first economic point of the engine, the power of the optimal operating point of the engine, and the power of the second economic point of the engine;

The electric power of the power battery is used to judge the relationship with the safe electric power in the multi-point power recovery stage, and then determine the operating state of the power components;

The specific judgment steps are as follows:

1) If the required power of the whole vehicle is less than or equal to the power of the first economic point of the engine, judge whether the electric power of the power battery is lower than the safe electric power of the multi-point electric power recovery stage; ; If so, the engine works at the power of the first economic point of the engine, and the remaining power is used to charge the power battery.

2) If the power at the first economic point of the engine < the required power of the vehicle ≤ the power at the best working point of the engine, the engine works at the power at the best working point, and the remaining power is used to charge the power battery;

3) If the power at the best operating point of the engine < the required power of the vehicle ≤ the power at the second economic point of the engine, the engine works at the power at the second economic point, and the remaining power is used to charge the power battery;

4) If the power at the second economic point of the engine is less than the required power of the vehicle, it is judged whether the power of the power battery is lower than the safe power in the multi-point power recovery stage; Compensation; if it is, the engine works at the second economic point power, the power battery has no energy change, and a reminder signal is sent to the driver.

The safe power in the multi-point power recovery stage described in the technical solution is the minimum discharge value of the power battery. In order to protect the power battery, when the power battery power is lower than the safe power in the multi-point power recovery stage, the discharge of the power battery is terminated;

The safety power in the multi-point power recovery stage is <the lower limit value of the power battery in a healthy state;

The power at the first economic point of the engine<the power at the best operating point of the engine<the power at the second economic point of the engine.

The vehicle demand power described in the step (9) in the technical solution is used to judge the size relationship with the first economic point power of the engine, the second economic point power of the engine, and the maximum power of the engine;

The electric quantity of the power battery is used to judge the relationship with the safe electric quantity in the curve electric quantity maintenance stage, and then determine the running state of the power components;

The specific judgment steps are as follows:

1) If the required power of the whole vehicle is less than or equal to the power of the first economic point of the engine, judge whether the electric power of the power battery is lower than the safe electric power of the curve electric power maintenance stage; If yes, the engine works at the power of the first economic point of the engine, and the remaining power is used to charge the power battery;

2) If the power of the first economic point of the engine < the required power of the vehicle ≤ the power of the second economic point of the engine, the engine follows the required power of the vehicle along the optimal fuel consumption rate curve, and there is no energy change of the power battery at this time;

3) If the power of the second economic point of the engine < the required power of the whole vehicle ≤ the maximum power of the engine, judge whether the electric power of the power battery is lower than the safe electric power of the curve power maintenance stage; if not, the engine works at the second economic point, and the remaining demanded power of the whole vehicle is Power battery compensation; if yes, the engine works at maximum power, and the remaining power is used to charge the power battery;

4) If the maximum power of the engine is less than the required power of the vehicle, it is judged whether the power of the power battery is lower than the safe power of the curve power maintenance stage; if not, the engine works at the maximum power, and the remaining required power of the vehicle is compensated by the power battery; if so, the engine works At maximum power, the power battery has no energy change, and a reminder signal is sent to the driver.

The safe power in the curve power maintenance stage described in the technical solution is the lowest discharge value of the power battery in an unhealthy state. To protect the power battery, when the power battery power is lower than the safe power in the curve power maintenance stage, the discharge of the power battery is terminated;

The safe power in the curve power maintenance stage <the lower limit value of the power battery in an unhealthy state;

The power of the first economic point of the engine<the power of the second economic point of the engine<the maximum power of the engine.

In the technical solution, the lower limit value of the power battery in the healthy state in step (4) and the lower limit value of the power battery in the unhealthy state in step (8) are selected as follows:

The lower limit value of the power battery in a healthy state is selected for making full use of the electric energy of the power battery when the health state of the power battery is higher than the preset value of the power battery health state; the lower limit value of the power battery in an unhealthy state is When the state of health of the power battery is lower than the predetermined value of the state of health of the power battery, it is selected by fully exerting the role of the engine to prolong the life of the power battery; therefore, the lower limit value of the power of the power battery in a healthy state is required < the power of the power battery in an unhealthy state lower limit.

In step (6) of the technical solution, the specific steps for determining the operating mode of the vehicle using the required power of the vehicle are as follows:

Determine whether the required power of the vehicle is greater than or equal to the power at the optimum operating point of the engine; if not, the engine cannot work at the optimum operating point, and the power battery is sufficient, the power battery alone provides energy for the vehicle, and the vehicle is in pure electric mode mode; if so, the engine works at the optimum operating point power, and at the same time, the remaining required power of the vehicle is compensated by the power battery.

The specific steps for determining the operating mode of the vehicle using the required power of the vehicle as described in step (10) of the technical solution are as follows:

Judging the relationship between the required power of the vehicle and the power at the best operating point of the engine and the power at the second economic point of the engine; mode; if the power at the best working point of the engine < the required power of the vehicle ≤ the power at the second economic point of the engine, the engine will follow the required power of the vehicle along the optimal fuel consumption rate curve, and there will be no energy change in the power battery; if the required power of the vehicle > the second engine power The power of the second economic point, the engine works at the second economic point, and the remaining required power of the vehicle is compensated by the power battery.

The power at the first economic point of the engine, the power at the best operating point of the engine, and the power at the second economic point of the engine are located on the best fuel consumption rate curve of the engine; the best fuel consumption rate curve of the engine can be obtained by the engine bench test. The characteristic curve, according to the fuel consumption rate in the universal characteristic curve of the engine, marks the corresponding minimum fuel consumption rate points under different output powers of the engine, and connects the marked minimum fuel consumption rate points to form the best fuel consumption rate curve of the engine; The power at the best operating point of the engine is selected as the engine output power corresponding to the lowest point of the fuel consumption rate on the engine's best fuel consumption rate curve.

Compared with prior art, the beneficial effects of the present invention are:

(1) The energy control method involved in the patent of the present invention judges the state of health of the power battery and the power of the power battery, and adjusts the working mode of the engine, so that while ensuring the power and economy of the vehicle, the energy consumption of the power battery can be improved. service life.

(2) The vehicle fully takes into account the health status of the power battery and the power condition of the power battery in the process of controlling the operation of the power components. In particular, by considering the health status of the power battery, the operating status of the power components of the vehicle is generally separated, that is, when the health status of the power battery is greater than the predetermined value of the health status of the power battery, the performance of the power battery is fully utilized; when the power battery is healthy When the state is less than the predetermined value of the state of health of the power battery, the performance of the engine is fully exerted.

(3) The engine can work on a single-point, multi-point or optimal fuel consumption rate curve. The single working mode of the engine in the more commonly used range-extending electric vehicle can fully exert the engine performance. While satisfying the driving demand, the engine changes the operating conditions to improve the economy of the vehicle.

(4) Set the safe power in the multi-point power recovery stage and the safe power in the curve power maintenance stage, fully considering the discharge capacity of the power battery, thereby avoiding the over-discharge of the power battery and prolonging the life of the power battery.

Description of drawings

Below in conjunction with accompanying drawing, the present invention will be further described:

Fig. 1 is the structural representation of the range-extended electric vehicle of the present invention;

Fig. 2 is the logical control diagram of the energy control method of the extended-range electric vehicle of the present invention;

Fig. 3 is a logic control diagram of the multi-point power recovery stage in the energy control method of the extended-range electric vehicle of the present invention;

Fig. 4 is a logic control diagram of the single-point power consumption stage in the energy control method of the extended-range electric vehicle of the present invention;

Fig. 5 is a logic control diagram of the curve power maintenance stage in the energy control method of the extended-range electric vehicle of the present invention;

Fig. 6 is a logic control diagram of the curve electricity consumption stage in the energy control method of the extended-range electric vehicle of the present invention.

detailed description

The present invention is described in detail below in conjunction with accompanying drawing:

Referring to FIG. 1 , the range-extended electric vehicle includes a vehicle controller, a battery management system, a range extender controller, and a motor controller connected by signals, and a power battery, a range extender, and a motor connected by electricity. The range extender includes an engine, a generator and its inverter, and the range extender is directly connected to the DC bus through the inverter. The range-extended electric vehicle utilizes the mechanical output of the electric motor to be connected to the transmission device to drive the driving wheels to rotate. The electric energy consumed by the electric motor is converted by the inverter, or comes from the power battery alone, or comes from the range extender alone, or is jointly provided by the power battery and the range extender. Under certain working conditions, the range extender can supplement power for the power battery to meet the driving needs of the entire vehicle in the future.

According to the state of health (SOH) of the power battery and the power of the power battery (SOC), the engine is controlled to work at the economical point or power follow, so as to ensure the power and economy of the vehicle while improving the service life of the power battery. Based on this, the working mode of the extended-range electric vehicle is designed. For the specific operation method, please refer to the flowcharts in Fig. 2, Fig. 3, Fig. 4, Fig. 5, and Fig. 6.

Referring to Fig. 2, the steps of the energy control method of the extended-range electric vehicle according to the present invention are as follows:

(1) Obtain the state of health (SOH) of the power battery; the battery management system indirectly obtains the internal resistance value of the battery by detecting data such as voltage, current, and temperature, and according to the experimental relationship between the internal resistance value of the battery and the state of health of the battery, The health status of the power battery is obtained, and fed back to the vehicle controller through the CAN (Controller Area Network) bus to judge the vehicle status.

(2) Judging whether the state of health of the power battery is less than a predetermined value (SOH_pre) of the state of health of the power battery; if not, execute (3); if yes, execute (7).

(3) Determine whether the brake pedal is activated; if yes, the vehicle enters the braking phase; if not, determine the power of the power battery and execute (4);

(4) Further judge whether the electric quantity of the traction battery is higher than the electric quantity lower limit (SOC_low1) of the traction battery in a healthy state; if not, enter the stage of multi-point electric quantity recovery, execute (5); if yes, enter the stage of single-point electric quantity consumption, execute(6);

(5) Referring to Figure 3, the whole vehicle enters the multi-point power recovery stage, and uses the vehicle demand power (P_req) and power battery power to control the operation mode of the whole vehicle. Among them, the required power of the whole vehicle is used to judge the relationship between the power of the first economic point of the engine (P_en_lo), the power of the optimal operating point of the engine (P_en_op), and the power of the second economic point of the engine (P_en_hi); The relationship between the safety power (SOC_safe1) in the point power recovery stage, and then determine the operating status of the power components. The specific judgment steps are as follows:

1) If the required power of the vehicle (P_req) ≤ the power of the first economic point of the engine (P_en_lo), determine whether the power battery power (SOC) is lower than the safe power level (SOC_safe1) in the multi-point power recovery stage; if not, the vehicle demand at this time If the power is low, the power battery can be used to drive the whole vehicle alone; if it is, the engine works at the engine's first economic point power (P_en_lo), and the remaining power is used to charge the power battery.

2) If the power of the first economic point of the engine (P_en_lo) < the required power of the vehicle (P_req) ≤ the power of the optimal operating point of the engine (P_en_op), the engine works at the power of the optimal operating point (P_en_op), and the remaining power is used to charge the power battery;

3) If the power at the best operating point of the engine (P_en_lo) < the required power of the vehicle (P_req) ≤ the power of the second economic point of the engine (P_en_hi), the engine works at the power of the second economic point (P_en_hi), and the remaining power is used to charge the power battery;

4) If the power of the second economic point of the engine (P_en_hi) < the required power of the vehicle (P_req), determine whether the power battery (SOC) is lower than the safe power (SOC_safe1) of the multi-point power recovery stage; if not, the engine works at the second Economic point power (P_en_hi), the remaining required power of the vehicle is compensated by the power battery; if so, the engine works at the second economic point power (P_en_hi), the power battery has no energy change, and a reminder signal is sent to the driver.

Wherein, the safe power level (SOC_safe1) in the multi-point power recovery stage is the minimum discharge value of the power battery. To protect the power battery, when the power battery power (SOC) is lower than the safe power level (SOC_safe1) in the multi-point power recovery phase, the power battery discharge is terminated. Therefore, the safety power level (SOC_safe1) in the multi-point power recovery stage <the lower limit value (SOC_low1) of the power battery in a healthy state; at the same time, the power of the first economic point of the engine (P_en_lo)<the power of the best operating point of the engine (P_en_op) <Engine second economy point power (P_en_hi).

(6) Referring to Figure 4, the whole vehicle enters the stage of single-point power consumption, and the operation mode of the whole vehicle is controlled by using the required power of the whole vehicle (P_req). Determine whether the required power of the vehicle (P_req) is greater than or equal to the power of the optimal operating point of the engine (P_en_op); if not, the engine cannot work at the optimal operating point, and the power battery is sufficient, and the power battery can provide the vehicle alone energy, the vehicle is in pure electric mode; if it is, the engine works at the optimum operating point power (P_en_op), and the remaining required power of the vehicle is compensated by the power battery.

The above-mentioned single-point power consumption stage and multi-point power recovery stage are both mode switching under the condition that the power battery is in good health. In the power maintenance stage, the two modes are switched to adapt to the changes in the state of the power components of the vehicle, thereby improving the performance of the vehicle.

(7) Determine whether the brake pedal is activated; if so, the vehicle enters the braking phase; if not, perform power battery power (SOC) determination and execute (8);

(8) Further judge whether the electric power of the power battery is higher than the power lower limit (SOC_low2) of the power battery in an unhealthy state; if not, enter the curve power maintenance stage and execute (9); if yes, enter the curve power consumption stage , execute (10);

(9) Referring to Figure 5, the whole vehicle enters the curve power maintenance stage, and uses the vehicle demand power (P_req) and power battery power (SOC) to control the operation mode of the whole vehicle. Among them, the required power of the vehicle is used to judge the relationship with the first economic point power of the engine (P_en_lo), the second economic point power of the engine (P_en_hi), and the maximum power of the engine (P_en_max); the power battery power (SOC) is used to judge the relationship with the curve The power maintains the relationship with the safe power (SOC_safe2), and then determines the running state of the power components. The specific judgment steps are as follows:

1) If the required power of the whole vehicle (P_req) ≤ the power of the first economic point of the engine (P_en_lo), determine whether the power battery power (SOC) is lower than the safe power level (SOC_safe2) of the curve power maintenance stage; if not, the power required by the whole vehicle at this time (P_req) is low, use the power battery to drive the vehicle alone; if it is, the engine works at the engine's first economic point power (P_en_lo), and the remaining power is used to charge the power battery.

2) If the power of the first economic point of the engine (P_en_lo)<required power of the vehicle (P_req)≤the power of the second economic point of the engine (P_en_hi), the engine follows the required power of the vehicle (P_req) along the optimal fuel consumption rate curve, at this time The power battery has no energy change.

3) If the power of the second economic point of the engine (P_en_hi) < the vehicle demand power (P_req) ≤ the maximum power of the engine (P_en_max), determine whether the power battery power (SOC) is lower than the safe power level (SOC_safe2) of the curve power maintenance stage; if not , the engine works at the second economic point (P_en_hi), and the remaining required power of the vehicle is compensated by the power battery; if so, the engine works at the maximum power (P_en_max), and the remaining power is used to charge the power battery.

4) If the maximum power of the engine (P_en_max) < the required power of the vehicle (P_req), determine whether the power battery power (SOC) is lower than the safe power level (SOC_safe2) of the curve power maintenance stage; if not, the engine works at the maximum power (P_en_max), The remaining required power of the vehicle is compensated by the power battery; if it is, the engine works at the maximum power (P_en_max), the power battery has no energy change, and a reminder signal is sent to the driver.

Wherein, the safe electric quantity (SOC_safe2) in the curve power maintenance stage is the lowest discharge value of the power battery in an unhealthy state. In order to protect the power battery, when the power battery power (SOC) is lower than the safe power quantity (SOC_safe2) in the curve power maintenance stage, the power battery is terminated. Discharge, so there is a curve for the safe power level (SOC_safe2) in the power maintenance stage <the lower limit value of the power battery in an unhealthy state (SOC_low2). At the same time, the first economic point power of the engine (P_en_lo)<the second economic point power of the engine (P_en_hi)<the maximum power of the engine (P_en_max).

(10) Referring to Fig. 6, the whole vehicle enters the curve power consumption stage, and the operation mode of the whole vehicle is controlled by using the required power of the whole vehicle (P_req). Determine the relationship between the required power of the vehicle (P_req), the engine's best operating point power (P_en_op), and the engine's second economic point power (P_en_hi). If the required power of the vehicle (P_req) ≤ the power of the optimal operating point of the engine (P_en_op), the power battery alone provides energy for the vehicle, and the vehicle is in pure electric mode; if the power of the optimal operating point of the engine (P_en_op) < the required power of the vehicle (P_req)≤Engine second economic point power (P_en_hi), the engine follows the vehicle demand power along the optimal fuel consumption rate curve, and the power battery has no energy change; if the vehicle demand power (P_req)＞Engine second economic point power ( P_en_hi), the engine works at the second economic point (P_en_hi), and the remaining required power of the vehicle is compensated by the power battery.

In particular, in the above operation method, the selection principles of the power lower limit value (SOC_low1) of the power battery in a healthy state and the power lower limit value (SOC_low2) of the power battery in an unhealthy state are as follows:

The power lower limit (SOC_low1) of the power battery in the state of health is selected for making full use of the electric energy of the power battery when the state of health (SOH) of the power battery is higher than the predetermined value (SOH_pre) of the state of health of the power battery; The lower limit value (SOC_low2) of the state of health is selected for fully exerting the role of the engine and prolonging the life of the power battery when the state of health (SOH) of the power battery is lower than the predetermined value of the state of health of the power battery (SOH_pre). The lower limit value (SOC_low1) of the battery in a healthy state < the lower limit value (SOC_low2) of the power battery in an unhealthy state.

Particularly, in the above-mentioned operation method, the first economic point power of the engine (P_en_lo), the optimal operating point power of the engine (P_en_op), and the second economical point power of the engine (P_en_hi) are located on the optimal fuel consumption rate curve of the engine; The optimal fuel consumption rate curve of the engine can be obtained from the engine bench test to obtain the universal characteristic curve of the engine. According to the fuel consumption rate in the universal characteristic curve of the engine, the corresponding minimum fuel consumption rate points under different output powers of the engine are marked and connected to The marked minimum fuel consumption rate points form the engine's best fuel consumption rate curve; the engine's best operating point power (P_en_op) is selected as the engine output power corresponding to the lowest point of the engine's best fuel consumption rate curve.

Compared with the single-point power consumption stage when the power battery is in good health, the curve power consumption stage enables the engine to follow the vehicle's required power (P_req), reduces the frequency of use of the power battery, and also works on the best fuel during the engine operation. On the consumption rate curve, it not only prolongs the service life of the power battery, but also improves the economy of the vehicle.

Compared with the multi-point power recovery stage when the power battery is in good health, the curve power maintenance stage enables the engine to follow the vehicle's required power (P_req), and at the same time expands the engine's working range to the engine's maximum power (P_en_max), reducing the use of power batteries In the case of frequency, the engine operation process should try to work on the best fuel consumption rate curve.

Specific examples:

The energy control method of the extended-range electric vehicle is further specified in detail, and two groups of examples are taken for energy control. Refer to Table 1, the preset control parameters of power components are shown in the table:

Table 1 Preset control parameters of power components

Example Assumed Parameters value Battery state of health preset value (SOH_pre) 0.4 Safe power in multi-point power recovery phase (SOC_safe1) 0.1 Curve power maintenance stage safe power (SOC_safe2) 0.15 The lower limit value of power battery health state (SOC_low1) 0.2 The power lower limit of the unhealthy state of the power battery (SOC_low2) 0.25 Engine first economic point power (P_en_lo) 10Kw Engine optimum operating point power (P_en_op) 20Kw Engine second economy point power (P_en_hi) 30Kw Maximum engine power (P_en_max) 50kw

Example 1:

Vehicle status data at the current moment:

The state of health (SOH) of the power battery is 0.6, the power of the power battery (SOC) is 0.18, the required power of the vehicle (P_req) is 15Kw, and the brake pedal is not actuated.

The judgment steps are as follows:

S1: Obtain the health status of the power battery, and the value provided by the battery management system to the vehicle controller through the CAN bus is 0.6;

S2: Judging the health status of the power battery, the health status of the power battery is 0.6 > the predetermined value of the battery health status is 0.4, and it is judged that the power battery is in a healthy state;

S3: Judging whether the brake pedal is activated, according to the current state data of the vehicle, the brake pedal is not activated at this time;

S4: Judgment on the power state of the power battery, the power of the power battery is 0.18 < the lower limit of the power of the power battery in a healthy state is 0.2, and the vehicle enters the stage of multi-point power consumption;

S5: In the stage of multi-point power consumption, since the power of the first economic point of the engine is 10kw<the required power of the whole vehicle is 15Kw<the power of the optimal operating point of the engine is 20Kw, so the power of the engine at the optimal operating point of the engine is 20kw. The remaining power is used to charge the power battery.

Example 2:

Vehicle status data at the current moment:

The power battery state of health (SOH) is 0.2, the power battery power (SOC) is 0.23, the vehicle demand power (P_req) is 45Kw, and the brake pedal is not activated.

The judgment steps are as follows:

S1: Obtain the health status of the power battery, and the value provided by the battery management system to the vehicle controller through the CAN bus is 0.2;

S2: Judging the health status of the power battery, the health status of the power battery is 0.2<the preset value of the battery health status is 0.4, and it is judged that the power battery is in an unhealthy state;

S3: Judging whether the brake pedal is activated, according to the current state data of the vehicle, the brake pedal is not activated at this time;

S4: Judgment of power state of the power battery, the power of the power battery is 0.23 < the lower limit of the power of the power battery in an unhealthy state is 0.25, and the vehicle enters the curve power maintenance stage;

S5: In the curve power maintenance stage, since the power of the second economic point of the engine is 30Kw<the required power of the vehicle is 45Kw<the maximum power of the engine is 50kw, and the power battery power is 0.23>the safety power of the curve power maintenance stage is 0.15, so the engine Working at the second economic point of the engine, the power is 30kw, and the remaining required power of the vehicle is compensated by the power battery.

Claims (8)

1. An energy control method for an extended-range electric vehicle, comprising the following steps: (1) Obtain the health status of the power battery; (2) Judging whether the state of health of the power battery is less than the predetermined value of the state of health of the power battery; if not, execute (3); if yes, execute (7); (3) Determine whether the brake pedal is activated; if yes, the vehicle enters the braking phase; if not, determine the power of the power battery and execute (4); (4) Further judge whether the electric quantity of the traction battery is higher than the lower limit value of the electric quantity of the traction battery in a healthy state; if not, enter the stage of multi-point electric quantity recovery, execute (5); if yes, enter the stage of single-point electric quantity consumption, execute (6); (5) The whole vehicle enters the multi-point power recovery stage, and the operation mode of the whole vehicle is controlled by using the required power of the whole vehicle and the power of the power battery; (6) The whole vehicle enters the stage of single-point power consumption, and the operation mode of the whole vehicle is controlled by using the required power of the whole vehicle; (7) Determine whether the brake pedal is activated; if yes, the vehicle enters the braking phase; if not, determine the power of the power battery and execute (8); (8) Further judge whether the electric quantity of the traction battery is higher than the lower limit value of the electric quantity of the traction battery in an unhealthy state; if not, enter the curve electric quantity maintenance stage and execute (9); if yes, then enter the curve electric quantity consumption stage and execute ( 10); (9) The whole vehicle enters the curve power maintenance stage, and the operation mode of the whole vehicle is controlled by using the required power of the whole vehicle and the electric power of the power battery; (10) The whole vehicle enters the curve power consumption stage, and the operation mode of the whole vehicle is controlled by using the required power of the whole vehicle. The vehicle demand power described in step (5) is used for judging the size relationship with the power of the first economic point of the engine, the power of the best operating point of the engine, and the power of the second economic point of the engine; The electric power of the power battery is used to judge the relationship with the safe electric power in the multi-point power recovery stage, and then determine the operating state of the power components; The specific judgment steps are as follows: 1) If the required power of the whole vehicle is less than or equal to the power of the first economic point of the engine, judge whether the electric power of the power battery is lower than the safe electric power of the multi-point electric power recovery stage; ; If yes, the engine works at the power of the first economic point of the engine, and the remaining power is used to charge the power battery; 2) If the power at the first economic point of the engine < the required power of the vehicle ≤ the power at the best working point of the engine, the engine works at the power at the best working point, and the remaining power is used to charge the power battery; 3) If the power at the best operating point of the engine < the required power of the vehicle ≤ the power at the second economic point of the engine, the engine works at the power at the second economic point, and the remaining power is used to charge the power battery; 4) If the power at the second economic point of the engine is less than the required power of the vehicle, it is judged whether the power of the power battery is lower than the safe power in the multi-point power recovery stage; Compensation; if it is, the engine works at the second economic point power, the power battery has no energy change, and a reminder signal is sent to the driver. 2. According to the energy control method of a kind of extended-range electric vehicle according to claim 1, it is characterized in that: The safe power in the multi-point power recovery stage is the minimum discharge value of the power battery. In order to protect the power battery, when the power battery power is lower than the safe power in the multi-point power recovery stage, the discharge of the power battery is terminated; The safety power in the multi-point power recovery stage is <the lower limit value of the power battery in a healthy state; The power at the first economic point of the engine<the power at the best operating point of the engine<the power at the second economic point of the engine. 3. according to the energy control method of a kind of range-extended electric vehicle according to claim 1, it is characterized in that: The vehicle demand power described in step (9) is used for judging the size relationship with the first economic point power of the engine, the second economic point power of the engine, and the maximum power of the engine; The electric quantity of the power battery is used to judge the relationship with the safe electric quantity in the curve electric quantity maintenance stage, and then determine the running state of the power components; The specific judgment steps are as follows: 1) If the required power of the whole vehicle is less than or equal to the power of the first economic point of the engine, judge whether the electric power of the power battery is lower than the safe electric power of the curve electric power maintenance stage; If yes, the engine works at the power of the first economic point of the engine, and the remaining power is used to charge the power battery; 2) If the power of the first economic point of the engine < the required power of the vehicle ≤ the power of the second economic point of the engine, the engine follows the required power of the vehicle along the optimal fuel consumption rate curve, and there is no energy change of the power battery at this time; 3) If the power of the second economic point of the engine < the required power of the whole vehicle ≤ the maximum power of the engine, judge whether the electric power of the power battery is lower than the safe electric power of the curve power maintenance stage; if not, the engine works at the second economic point, and the remaining demanded power of the whole vehicle is Power battery compensation; if yes, the engine works at maximum power, and the remaining power is used to charge the power battery; 4) If the maximum power of the engine is less than the required power of the vehicle, it is judged whether the power of the power battery is lower than the safe power of the curve power maintenance stage; if not, the engine works at the maximum power, and the remaining required power of the vehicle is compensated by the power battery; if so, the engine works At maximum power, the power battery has no energy change, and a reminder signal is sent to the driver. 4. According to the energy control method of a kind of extended-range electric vehicle according to claim 3, it is characterized in that: The safe power in the curve power maintenance stage is the lowest discharge value of the power battery in an unhealthy state. In order to protect the power battery, when the power battery power is lower than the safe power in the curve power maintenance stage, the discharge of the power battery is terminated; The safe power in the curve power maintenance stage <the lower limit value of the power battery in an unhealthy state; The power of the first economic point of the engine<the power of the second economic point of the engine<the maximum power of the engine. 5. According to the energy control method of a kind of extended-range electric vehicle according to claim 1, it is characterized in that: The selection principle of the power lower limit value of the power battery in a healthy state in step (4) and the power lower limit value of the power battery in an unhealthy state in step (8) is as follows: The lower limit value of the power battery in a healthy state is selected for making full use of the electric energy of the power battery when the health state of the power battery is higher than the preset value of the power battery health state; the lower limit value of the power battery in an unhealthy state is When the state of health of the power battery is lower than the predetermined value of the state of health of the power battery, it is selected by fully exerting the role of the engine to prolong the life of the power battery; therefore, the lower limit value of the power of the power battery in a healthy state is required < the power of the power battery in an unhealthy state lower limit. 6. According to the energy control method of a kind of extended-range electric vehicle according to claim 1, it is characterized in that: The specific judgment steps for controlling the operation mode of the vehicle by using the required power of the vehicle described in step (6) are: Determine whether the required power of the vehicle is greater than or equal to the power at the optimum operating point of the engine; if not, the engine cannot work at the optimum operating point, and the power battery is sufficient, the power battery alone provides energy for the vehicle, and the vehicle is in pure electric mode mode; if so, the engine works at the optimum operating point power, and at the same time, the remaining required power of the vehicle is compensated by the power battery. 7. According to the energy control method of a kind of extended-range electric vehicle according to claim 1, it is characterized in that: The specific steps for determining the operating mode of the vehicle using the required power of the vehicle as described in step (10) are as follows: Judging the relationship between the required power of the vehicle and the power at the best operating point of the engine and the power at the second economic point of the engine; mode; if the power at the best working point of the engine < the required power of the vehicle ≤ the power at the second economic point of the engine, the engine will follow the required power of the vehicle along the optimal fuel consumption rate curve, and there will be no energy change in the power battery; if the required power of the vehicle > the second engine power The power of the second economic point, the engine works at the second economic point, and the remaining required power of the vehicle is compensated by the power battery. 8. According to the energy control method of a kind of extended-range electric vehicle according to claim 1, it is characterized in that: The power at the first economic point of the engine, the power at the best operating point of the engine, and the power at the second economic point of the engine are located on the best fuel consumption rate curve of the engine; the best fuel consumption rate curve of the engine can be obtained by the engine bench test. The characteristic curve, according to the fuel consumption rate in the universal characteristic curve of the engine, marks the corresponding minimum fuel consumption rate points under different output powers of the engine, and connects the marked minimum fuel consumption rate points to form the best fuel consumption rate curve of the engine; The power at the best operating point of the engine is selected as the engine output power corresponding to the lowest point of the fuel consumption rate on the engine's best fuel consumption rate curve.