阅读说明：本技术 一种电动汽车供电系统及其控制方法、增程电动汽车 (Electric automobile power supply system, control method thereof and range-extended electric automobile ) 是由 凌飞 于 2019-11-07 设计创作，主要内容包括：本发明公开了一种电动汽车供电系统及控制方法、增程电动汽车。其供电系统电池组包括多个并联电池包,车载控制器监测电池包电压并控制与汽车直流总线的接通与断开,智能控制器判断车辆运行状态并控制变速离合器接通或断开和直流电动机启动或停止,增速器Ⅰ低速轴与电动汽车轮轴连接且高速轴与变速离合器输入端连接,变速离合器输出端与增程发电机转子轴连接,直流电动机输出轴通过增速器Ⅱ与储能飞轮连接,储能飞轮与增程发电机转子轴连接。所述控制方法包括电池组及车辆运动监控、发电控制步骤。所述电动汽车包括电动汽车供电系统。智能控制器控制两套发电驱动系统对电池组电池包的充放电进行均衡管理,有效增加续航里程,提高纯电动车的使用效能。(The invention discloses an electric automobile power supply system, a control method and a range-extended electric automobile. The battery pack of the power supply system comprises a plurality of battery packs connected in parallel, a vehicle-mounted controller monitors the voltage of the battery packs and controls the connection and disconnection with a vehicle direct current bus, an intelligent controller judges the running state of a vehicle and controls the connection or disconnection of a speed change clutch and the start or stop of a direct current motor, a low-speed shaft of a speed increaser I is connected with a wheel shaft of the electric vehicle, a high-speed shaft of the speed increaser I is connected with the input end of the speed change clutch, the output end of the speed change clutch is connected with a rotor shaft of a range-increasing generator, an output shaft of the direct current motor is connected with an energy storage flywheel. The control method comprises the steps of monitoring the motion of the battery pack and the vehicle and controlling the power generation. The electric automobile comprises an electric automobile power supply system. The intelligent controller controls the two sets of power generation driving systems to carry out balanced management on charging and discharging of the battery pack, so that the endurance mileage is effectively increased, and the use efficiency of the pure electric vehicle is improved.)

1. A power supply system of an electric automobile comprises a battery pack (1), an on-board controller (2), an intelligent controller (3), a range-increasing generator (4), a speed-changing clutch (5), a speed-increasing device I (6), a speed-increasing device II (7), a direct current motor (8) and an energy-storing flywheel (9), and is characterized in that the battery pack (1) comprises a plurality of battery packs connected in parallel, the on-board controller (2) is used for monitoring the voltage of each battery pack of the battery pack (1) and controlling the connection and disconnection of each battery pack and a high-voltage direct current bus of the electric automobile, the intelligent controller (3) is in signal connection with a vehicle speed sensor and the on-board controller (2) of the automobile and is used for judging the running state of the automobile according to the speed of the automobile and the current of a wheel driving motor, the intelligent controller (3) is also used for controlling the connection or disconnection of the speed-changing clutch (5) and the starting or stopping of the direct current motor, the low-speed shaft of speed increaser I (6) is connected with the wheel axle of electric automobile and the high-speed shaft of the other end is connected with the input of speed change clutch (5), the output of speed change clutch (5) is connected with the rotor shaft of range-increasing generator (4), the output shaft of DC motor (8) is connected with energy storage flywheel (9) through speed increaser II (7), energy storage flywheel (9) is connected with the rotor shaft of range-increasing generator (4).

2. The electric vehicle power supply system according to claim 1, further comprising a plurality of control switches, wherein the intelligent controller (3) is respectively connected with the speed change clutch (5) and the direct current motor (8) through the control switches to control a power source of the range-extended generator (4), a first control switch connected with the vehicle-mounted controller (2) is arranged between each battery pack of the battery pack (1) and the electric vehicle high-voltage direct current bus, and a second control switch connected with the intelligent controller (3) is communicated with the range-extended generator (4) and the electric vehicle high-voltage direct current bus.

3. The power supply system for the electric vehicle according to claim 2, wherein the on-board controller (2) is configured to control the first control switch to connect the battery pack with the highest voltage to the high-voltage dc bus for entering the power supply mode, and/or to connect the battery pack with the lowest voltage to the dc motor (8) via the high-voltage dc bus for entering the charging mode.

4. The power supply system of the electric automobile according to claim 2, characterized in that the intelligent controller (3) is used for obtaining the vehicle speed, the braking state and the current of the wheel driving motor and comparing the current with a preset threshold value to control a third control switch to separate or engage the speed change clutch (5) and control a fourth control switch to start or stop the direct current motor (8).

5. The electric vehicle power supply system according to any one of claims 1 to 4, wherein a large gear (10) and a small gear (11) are disposed between the low-speed shaft of the speed increaser I (6) and the wheel axle of the electric vehicle, the large gear (10) is coaxially connected with the wheel axle, and the small gear (11) is coaxially connected with the low-speed shaft of the speed increaser I (6).

6. The power supply system of the electric automobile according to claim 5, characterized in that an accelerating gear is arranged between the energy storage flywheel (9) and the rotor shaft of the range-extended generator (4), the accelerating gear is engaged with an inner gear ring or an outer gear ring at the outer edge of the energy storage flywheel (9), and the accelerating gear is coaxially connected with the rotor shaft of the range-extended generator (4).

7. A control method of a power supply system of an electric vehicle as claimed in claim 4, 5 or 6, characterized by comprising the steps of battery pack monitoring, vehicle motion monitoring, and power generation mode control, specifically comprising:

A. battery pack monitoring: the vehicle-mounted controller (2) monitors the voltage of each battery pack of the battery pack (1) and switches on the battery pack with the highest voltage and the high-voltage direct-current bus to enter a power supply mode by controlling the first control switch, and/or switches on the battery pack with the lowest voltage and the direct-current motor (8) to enter a charging mode by controlling the high-voltage direct-current bus;

B. vehicle motion monitoring: the intelligent controller (3) acquires the vehicle speed, the brake state and the current of the wheel driving motor and compares the current with a preset threshold value to judge that the vehicle is in a downhill, brake, idle or normal driving state;

C. and (3) power generation mode control: the intelligent controller (3) controls the third control switch to enable the speed change clutch (5) to be separated or connected according to the vehicle state, and controls the fourth control switch to enable the direct current motor (8) to be started or stopped.

8. The control method of the power supply system of the electric vehicle according to claim 7, wherein in the step B, if the vehicle speed and the current of the wheel driving motor both obtained by the intelligent controller (3) are lower than the preset threshold, the vehicle is determined as idling, if the vehicle speed is higher than the preset threshold, the current of the wheel driving motor is lower than the preset threshold and no braking signal is generated, the vehicle is determined as downhill, if the braking signal is obtained, the vehicle is determined as braking, otherwise, the vehicle is normally driven.

9. The control method of the power supply system of the electric automobile according to claim 8, wherein in the step C, if the intelligent controller (3) judges that the vehicle is idling and the vehicle-mounted controller (2) monitors that the voltage of the battery pack is lower than the preset threshold, the intelligent controller controls the third control switch to separate the clutch (5) and controls the fourth control switch to enable the starting of the direct current motor (8) to drive the range-extended generator (4) to generate power; if the vehicle is judged to be downhill or braked, controlling a third control switch to engage a clutch (5) and controlling a fourth control switch to close a direct current motor (8) so that a wheel shaft of the electric vehicle drives a range-extending generator (4) to generate electricity; and if the vehicle is judged to run normally, controlling the third control switch to separate the clutch (5) and controlling the fourth control switch to turn off the direct current motor (8).

10. An extended-range electric vehicle, characterized by comprising the electric vehicle power supply system according to any one of claims 1 to 6.

Technical Field

The invention belongs to the technical field of electric automobiles, and particularly relates to an electric automobile power supply system, a control method thereof and a range-extended electric automobile, wherein the electric automobile power supply system can monitor the working state of each battery pack in real time and immediately supply electric energy to the corresponding battery pack so as to effectively increase the driving mileage of the automobile.

Background

With the introduction of human society into the industrialized era, fuel automobiles become basic consumer goods for daily life of people, and the automobile keeping quantity is increasing day by day. However, the environmental problems caused by fuel oil automobiles are more and more serious, the greenhouse effect is caused by the discharged carbon dioxide, natural disasters caused by global warming frequently occur, and the great influence is caused on the production and the life of human beings. Meanwhile, excessive mineral energy consumption brings great trouble to human society. The climate change caused by the greenhouse effect is emphasized by various countries all over the world, global advocates are sent out, multi-side cooperation agreements among governments are signed, and the climate change problem is coped with together. China is a responsible large country, actively responds to initiatives and puts into practice. The development and utilization of green energy resources are increased for years, and the electric automobile is vigorously developed. Governments of various countries also actively act to promote global automobile industry structure upgrading and power system electromotion strategy transformation by pushing new energy vehicles, particularly pure electric vehicles, organize and guarantee system construction by policy driving, promote the formation of social basic industry structures of electric automobiles in multiple levels and boost sustainable electric automobile development strategies.

Although an electric vehicle, particularly a pure electric vehicle, has the advantages of energy conservation, environmental protection and zero emission, the driving mileage is short due to the limited energy storage capacity of the power battery in the prior art, and in addition, a fixed charging pile is required to supply electric energy, and the required charging time is long. Before the charging facilities are not sound and the performance of the battery is substantially improved, the performance of the power battery based on the prior art is still difficult to be compared with that of a fuel automobile in popularization and application. Therefore, the cruising ability of the electric automobile is an important factor which hinders the popularization and the use of the electric automobile at present. Based on the above, in the prior art, a generator set, i.e., a range extender, which is formed by integrating a high-efficiency and low-emission engine and a generator is added in the electric vehicle, so as to quickly supplement electric energy to a power battery and solve the problem of short driving range of the pure electric vehicle. However, the generator used with the range extender at present generally has the disadvantages of low output power and low generating efficiency, and cannot meet the use requirements of users. And power battery is charged through the (fuel oil) engine consuming energy, the secondary pollution problem of engine emission can be caused, and the environment-friendly and energy-saving original purpose of the electric automobile is deviated. In addition, more domestic pure electric vehicles are provided with an energy secondary recycling system for supplying brake feedback electric energy to the battery, but the brake time is relatively short compared with the whole driving process, and the electric energy supplied to the battery pack is limited. In addition, in the prior art, most of power systems used by electric vehicles adopt a single battery pack or a plurality of battery packs connected in series, so that the charging state and the high balance of battery characteristics are required to be kept among the battery packs, and thus new and old batteries, batteries with different capacities or battery packs with different characteristics cannot be used together; and the failure of a certain battery cell or battery pack can cause the failure of the whole battery system. Not only greatly improves the production and screening cost of the battery system, but also has great difficulty in secondary use of the old battery. Therefore, how to effectively utilize the energy in the motion of the vehicle to supply the electric energy to the battery pack in real time, the development and the application of the secondary energy increasing system are key measures and effective methods for solving the endurance mileage of the electric vehicle.

Disclosure of Invention

The invention aims to provide an electric automobile power supply system which can monitor the working state of each battery pack in real time and immediately supply electric energy for the corresponding battery pack so as to effectively increase the endurance mileage of a vehicle;

the invention also aims to provide a control method of the electric automobile power supply system;

the invention further aims to provide an extended-range electric automobile.

The first object of the invention is realized by that the electric vehicle power supply system comprises a battery pack, an on-board controller, an intelligent controller, a range-increasing generator, a speed-changing clutch, a speed-increasing I, a speed-increasing II, a direct current motor and an energy-storing flywheel, wherein the battery pack comprises a plurality of battery packs connected in parallel, the on-board controller is used for monitoring the voltage of each battery pack of the battery pack and controlling the connection and disconnection of each battery pack and a high-voltage direct current bus of the electric vehicle, the intelligent controller is in signal connection with a vehicle speed sensor and the on-board controller of the vehicle and is used for judging the running state of the vehicle according to the vehicle speed and the current of a wheel driving motor, the intelligent controller is also used for controlling the connection or disconnection of the speed-changing clutch and the starting or stopping of the direct current motor to change the power source of the range-increasing generator, the low-speed shaft of the speed-increasing I is connected with a wheel shaft, the output end of the speed change clutch is connected with a rotor shaft of the range-increasing generator, the output shaft of the direct current motor is connected with the energy storage flywheel through the speed increasing device II, and the energy storage flywheel is connected with the rotor shaft of the range-increasing generator.

The other purpose of the invention is realized in such a way that the control method of the electric automobile power supply system comprises the steps of battery pack monitoring, vehicle motion monitoring and power generation mode control, and specifically comprises the following steps:

A. battery pack monitoring: the vehicle-mounted controller monitors the voltage of each battery pack of the battery pack and switches on the battery pack with the highest voltage and the high-voltage direct-current bus to enter a power supply mode by controlling the first control switch, and/or switches on the battery pack with the lowest voltage and the direct-current motor to enter a charging mode by the high-voltage direct-current bus;

B. vehicle motion monitoring: the intelligent controller obtains the vehicle speed, the braking state and the current of the wheel driving motor and compares the current with a preset threshold value to judge that the vehicle is in a downhill state, a braking state, an idling state or a normal driving state;

C. and (3) power generation mode control: the intelligent controller controls the third control switch to disengage or engage the transmission clutch and controls the fourth control switch to start or stop the direct current motor according to the vehicle state.

The invention further aims to realize that the range-extended electric automobile is a pure electric automobile which comprises any one of the electric automobile power supply systems and can effectively increase the endurance mileage of the electric automobile.

Based on the common participation of the speed increasing system and the energy storage flywheel system, the invention forms an efficient and sustainable electric automobile power supply system, and has the following beneficial effects:

1. the battery pack is modularized and connected in parallel to form the combined battery pack, the battery pack can work independently and can also be combined to operate, the integration effect is good, safety and reliability are realized, and the maintenance is simple and convenient; the battery pack can be flexibly arranged on the vehicle, and the system design of the whole vehicle is simplified. The vehicle-mounted controller detects the voltage of each battery pack and preferentially controls the battery pack with higher voltage to output to drive the automobile according to the electric quantity change of each battery pack, and the battery pack with the lowest preferential control voltage is charged, so that the charging state and the battery characteristic balance among the battery packs are kept, the operation of the electric automobile is not influenced by the fault of a single battery pack, the battery pack is easy to replace, and the new and old battery packs and the battery packs with different materials and different capacities are allowed to be connected in parallel for use.

2. The intelligent controller is arranged to control the two sets of power generation driving systems to carry out balanced management on charging and discharging of the battery pack. The running state of the vehicle can be judged according to signals of a vehicle speed sensor and a vehicle-mounted controller, and then the starting and stopping of a direct current motor or a speed change clutch are automatically controlled, namely, mechanical energy is obtained from a wheel shaft of the electric vehicle through switching or electric energy is obtained from a battery pack through the direct current motor, so that a range-extended generator is driven to generate electricity to charge the battery pack, the problem that the engine in the range extender in the prior art needs to consume energy is solved, the electric vehicle can charge the battery pack without external consumption or with low energy consumption in downhill, braking and even idle states, the cruising mileage is effectively increased, and the use efficiency of the pure electric vehicle is improved.

3. The invention is provided with the range-extended generator, the system is connected with the wheel axle of the electric automobile or the output shaft of the direct-current motor through the speed increaser, the purpose of increasing the rotating speed of the wheel axle of the electric automobile and the rotating speed of the output shaft of the direct-current motor so as to increase the rotating speed of the rotor of the range-extended generator is realized, the efficiency of the range-extended generator is improved, and the charging voltage of the battery pack is stable and the current is large.

4. The speed control threshold is preset, when the vehicle idles and the voltage of the battery pack is detected to be lower than the preset threshold, the vehicle-mounted controller and the intelligent controller are matched, the speed change clutch is controlled to be separated, the direct current motor is started to operate by the battery pack with higher voltage, the speed is increased by the speed increaser II to drive the energy storage flywheel to rotate the range-increasing direct current generator to generate electricity, so that the current and the voltage suitable for the load are output to charge the battery pack with the lowest voltage, the balance of the charging state and the battery characteristics among the battery packs is realized, and the service life of the battery pack is effectively prolonged. And the hybrid use of new and old battery packs, battery packs with different capacities or battery packs with different characteristics can be realized, and the use cost of the battery is obviously lower.

Drawings

FIG. 1 is a schematic diagram of the principle structure of the range-extended electric vehicle according to the present invention;

FIG. 2 is a logic diagram of an intelligent controller of the power supply system of an electric vehicle according to the present invention;

in the figure: 1~ group battery, 2~ vehicle-mounted controller, 3~ intelligent control ware, 4~ increase journey generators, 5~ speed change clutch, 6~ speed increaser I, 7~ speed increaser II, 8~ DC motor, 9~ energy storage flywheel, 10~ gear wheel, 11~ pinion, 12~ driving motor, 13~ wheel I, 14~ wheel II.

Detailed Description

The invention is further illustrated by the following figures and examples, which are not intended to limit the invention in any way, and any variations or modifications which are based on the teachings of the invention are intended to be within the scope of the invention.

As shown in fig. 1 and 2, the power supply system for an electric vehicle of the present invention includes a battery pack 1, an onboard controller 2, an intelligent controller 3, a range-increasing generator 4, a speed-changing clutch 5, a speed-increasing unit i 6, a speed-increasing unit ii 7, a dc motor 8, and an energy-storing flywheel 9, wherein the battery pack 1 includes a plurality of battery packs connected in parallel, the onboard controller 2 is configured to monitor the voltage of each battery pack of the battery pack 1 and control the connection and disconnection between each battery pack and a high-voltage dc bus of the electric vehicle, the intelligent controller 3 is in signal connection with a vehicle speed sensor of the vehicle and the onboard controller 2 and is configured to determine a vehicle operating state according to a vehicle speed and a current of a wheel driving motor, the intelligent controller 3 is further configured to control the connection or disconnection of the speed-changing clutch 5 and the start or stop of the dc motor 8 to change a power source of the range-increasing generator 4, a low-speed shaft of the speed-increasing unit i 6 is connected with a wheel The input end of the speed changing clutch 5 is connected, the output end of the speed changing clutch 5 is connected with a rotor shaft of the range-extended generator 4, the output shaft of the direct current motor 8 is connected with an energy storage flywheel 9 through a speed increasing gear II 7, and the energy storage flywheel 9 is connected with the rotor shaft of the range-extended generator 4.

The invention also comprises a plurality of control switches, the intelligent controller 3 is respectively connected with the speed change clutch 5 and the direct current motor 8 through the control switches to control the power source of the range-extended generator 4, a first control switch connected with the vehicle-mounted controller 2 is arranged between each battery pack of the battery pack 1 and the high-voltage direct current bus of the electric vehicle, and a second control switch connected with the intelligent controller 3 is communicated with the range-extended generator 4 and the high-voltage direct current bus of the electric vehicle.

The vehicle-mounted controller 2 is used for controlling the first control switch to connect the battery pack with the highest voltage with the high-voltage direct-current bus to enter a power supply mode, and/or to connect the battery pack with the lowest voltage with the direct-current motor 8 through the high-voltage direct-current bus to enter a charging mode.

The intelligent controller 3 is used for acquiring the vehicle speed, the braking state and the current of the wheel driving motor, comparing and judging with a preset threshold value to control the third control switch to separate or connect the speed change clutch 5 and control the fourth control switch to start or stop the direct current motor 8.

The battery pack 1 is a solid-state power battery pack, the range-extended generator 4 is a low-rotating-speed, low-torque and low-friction permanent magnet direct current generator, and the vehicle-mounted controller 2 is provided with a phase-loss protection circuit, a high-temperature protection circuit, an overvoltage protection circuit, an overcurrent protection circuit, an undervoltage protection circuit, a short-circuit protection circuit, a reverse connection protection circuit, a ground protection circuit, an insulation protection circuit and/or a lightning protection circuit.

The intelligent controller 3 is provided with a voltage current monitor and a voltage current compensator, wherein the voltage current compensator is arranged between the range-extended generator 4 and the battery pack 1 and used for compensating unstable electric quantity according to the monitoring value of the voltage current monitor to the charging voltage current when the range-extended generator 4 charges the battery pack in the battery pack 1 so as to keep stable charging voltage and charging current.

A large gear 10 and a small gear 11 which are meshed with each other are arranged between the low-speed shaft of the speed increaser I6 and a wheel shaft of the electric automobile, the large gear 10 is coaxially connected with the wheel shaft, and the small gear 11 is coaxially connected with the low-speed shaft of the speed increaser I6.

An accelerating gear is arranged between the energy storage flywheel 9 and the rotor shaft of the range-extended generator 4, the accelerating gear is meshed with an inner gear ring or an outer gear ring at the outer edge of the energy storage flywheel 9, and the accelerating gear is coaxially connected with the rotor shaft of the range-extended generator 4.

The onboard controller 2 is a BMS (Battery management system).

The control method of the power supply system of the electric automobile comprises the steps of battery pack monitoring, vehicle motion monitoring and power generation mode control, and specifically comprises the following steps:

A. battery pack monitoring: the battery pack 1 comprises a plurality of battery packs connected in parallel, the vehicle-mounted controller 2 monitors the voltage of each battery pack of the battery pack 1 and switches on the battery pack with the highest voltage and the high-voltage direct-current bus to enter a power supply mode by controlling the first control switch, and/or switches on the battery pack with the lowest voltage and the direct-current motor 8 to enter a charging mode through the high-voltage direct-current bus;

B. vehicle motion monitoring: the intelligent controller 3 acquires the vehicle speed, the braking state and the current of the wheel driving motor and compares the current with a preset threshold value to judge that the vehicle is in a downhill, braking, idling or normal driving state;

C. and (3) power generation mode control: the intelligent controller 3 controls the third control switch to disengage or engage the transmission clutch 5 and controls the fourth control switch to start or stop the dc motor 8 according to the vehicle state.

And in the step B, if the vehicle speed acquired by the intelligent controller 3 and the current of the wheel driving motor are both lower than a preset threshold value, the vehicle is judged to be idling, if the acquired vehicle speed is higher than the preset threshold value, the current of the wheel driving motor is lower than the preset threshold value and no braking signal exists, the vehicle is judged to be downhill, if the acquired braking signal exists, the vehicle is judged to be braking, and if the acquired braking signal does not exist, the vehicle is judged to be normally running.

In the step C, if the intelligent controller 3 judges that the vehicle idles and the vehicle-mounted controller 2 monitors that the voltage of the battery pack is lower than a preset threshold value, the intelligent controller controls the third control switch to separate the clutch 5 and controls the fourth control switch to enable the starting of the direct current motor 8 to drive the range-extended generator 4 to generate electricity; if the vehicle is judged to be downhill or braked, controlling a third control switch to engage the clutch 5 and controlling a fourth control switch to close a direct current motor 8 so that a wheel shaft of the electric vehicle drives the range-extending generator 4 to generate electricity; if the vehicle is judged to be normally running, the third control switch is controlled to separate the clutch 5, and the fourth control switch is controlled to turn off the direct current motor 8.

The working principle of the invention is as follows:

the battery pack adopts a plurality of battery packs connected in parallel, has the characteristics of modularization, integration/maintenance simplicity and high reliability, the vehicle-mounted controller detects the voltage of each battery pack and preferentially controls the battery pack with higher voltage to output to drive the automobile according to the electric quantity change of each battery pack, and preferentially controls the battery pack with the lowest voltage to charge, so that the balance of the charging state and the battery characteristics among the battery packs is kept, the battery pack is flexibly arranged on the electric automobile, and the integrated design of the whole automobile is simplified; the operation of the electric automobile is not influenced by the fault of the single battery pack, the battery pack is easy to replace, and the new and old battery packs and the battery packs made of different materials and different capacities are allowed to be used in parallel; the intelligent controller judges the running state of the vehicle according to signals of a vehicle speed sensor and a vehicle-mounted controller, and then automatically controls the starting and stopping of a direct current motor or a speed change clutch, namely mechanical energy is obtained from a wheel axle of the electric vehicle through switching or electric energy is obtained from a battery pack by the direct current motor, so that an extended range generator is driven to generate electricity to charge the battery pack, the problem that the engine in the extended range device in the prior art needs to consume energy is solved, the electric vehicle can charge the battery pack without external consumption or low energy consumption in downhill, braking and even idle states, the cruising mileage of the electric vehicle can be effectively increased, and the charging difficulty effect of the electric vehicle is solved; the range-extending generator is connected with a wheel axle of the electric automobile or an output shaft of the direct-current motor through the speed increaser, so that the purpose of increasing the rotating speed of the wheel axle of the electric automobile and the rotating speed of the output shaft of the direct-current motor to increase the rotating speed of a rotor of the range-extending generator is achieved, the efficiency of the range-extending generator is improved, and the charging voltage of the battery pack is stable and the current is large; when the vehicle is idling and the voltage of the battery pack is detected to be lower than the preset threshold value, the vehicle-mounted controller and the intelligent controller are matched, the speed change clutch is controlled to be separated, the direct current motor is started to operate by the battery pack with higher voltage, the energy storage flywheel is driven to rotate by the speed increaser II to increase the range of the direct current generator to generate electricity, so that the current and the voltage suitable for the load are output to charge the battery pack with the lowest voltage, the charging state and the battery characteristic among the battery packs are balanced, the service life of the battery pack is effectively prolonged, the mixed use of the new and old battery packs, the battery packs with different capacities or the battery packs with different characteristics can be realized, and the use cost of the battery is obviously lower. Furthermore, the intelligent controller and the vehicle-mounted controller can switch the power source of the range-extended generator according to the battery and the vehicle running state through controlling each control switch, so that the electric automobile can charge the battery pack without external consumption or low energy consumption in downhill, braking and even idling states, and the cruising mileage of the electric automobile can be effectively increased. Furthermore, the intelligent controller provided by the invention can compensate and keep the charging voltage and the charging current of the battery pack stable when the charging circuit generates high-voltage feedback electromotive force due to braking and the power supply voltage and current of the range-extended generator change due to the vehicle speed change, and can ensure that the range-extended generator does not generate high-voltage feedback electromotive force disconnection due to braking, so that the charging process of the battery pack is balanced and continuous, and the service life of the battery pack is prolonged. Furthermore, the inner gear ring or the outer gear ring of the energy storage flywheel is coaxially connected with the rotor shaft of the range-extended generator through the accelerating gear, the rotor speed of the range-extended generator can be effectively increased to achieve the purpose of improving the generating efficiency, and larger torque can be obtained to drive the range-extended generator to rotate, so that the stability of the operation of the range-extended generator, namely the stability of charging voltage and current, can be ensured. Therefore, the power supply system of the electric automobile can effectively increase the endurance mileage of the electric automobile, the battery pack in the battery pack can be used in a mixed manner, the cost is low, the service life is long, and the battery pack is flexibly arranged on the electric automobile.

The working process of the invention is as follows:

as shown in fig. 1 and 2, when the electric vehicle turns on a power switch, the vehicle-mounted controller 2 detects the voltage of each battery pack in the battery pack 1, and then controls the battery pack with the highest voltage to be connected with the high-voltage direct-current bus to supply power to the vehicle motor, and the driving motor 12 of the electric vehicle drives the wheels i 13 of the vehicle to run. A large gear 10 coaxial with the wheel II 14 is meshed with a small gear 11 coaxial with the low-speed shaft of the speed increaser I6, a spline on the high-speed shaft at the other end of the speed increaser I6 is sleeved in a sleeve opening on the left side of the speed change clutch 5, and a sleeve opening on the right side of the speed change clutch 5 is sleeved in a spline shaft of the range-increasing generator 4. When the electric automobile runs, the intelligent controller 3 acquires signals of a speed sensor and an on-board controller 2 of the automobile so as to judge that the automobile is in a downhill, braking, idling or normal running state.

If the intelligent controller 3 judges that the vehicle idles and the vehicle-mounted controller 2 monitors that the voltage of a battery pack is lower than a preset threshold value, the third control switch is controlled to separate the clutch 5 and control the fourth control switch to start the direct current motor 8, the direct current motor 8 drives the speed increaser II 7 to accelerate and then drives the energy storage flywheel 9 to rotate through the transmission shaft, the energy storage flywheel 9 does work to send the rotating speed and the torque into the range-increasing generator 4 through the transmission shaft to generate electricity, the range-increasing generator 4 generates electricity and is connected with a high-voltage direct-current bus through a buffer and a control switch of the intelligent controller 3, and the vehicle-mounted controller 2 controls the battery pack with the lowest voltage to be connected with the high-voltage direct; if the vehicle is judged to be downhill or braked, the third control switch is controlled to enable the clutch 5 to be connected, the fourth control switch is controlled to enable the direct current motor 8 to be switched off, a large gear 10 on a wheel II 14 of the electric vehicle drives a small gear 11 to rotate, a shaft on the small gear 11 accelerates the speed through a speed increaser I6, the intelligent controller 3 controls the speed change clutch 5 to be connected, the rotating speed accelerated by the speed increaser I6 is transmitted to the range increaser 4, the range increaser 4 generates electricity and is connected with a high-voltage direct current bus through a buffer and a control switch of the intelligent controller 3, and the vehicle-mounted controller 2 controls a battery pack with the lowest voltage to be connected with the high-; if the vehicle is judged to be normally running, the third control switch is controlled to separate the clutch 5, the fourth control switch is controlled to close the direct current motor 8, and the range-extended generator 4 stops running to avoid electric energy loss.