阅读说明：本技术 一种发动机起动及能量回收系统及其控制方法 (Engine starting and energy recovery system and control method thereof ) 是由 韩雷 于 2019-08-22 设计创作，主要内容包括：本发明涉及汽车技术领域,具体公开了一种发动机起动及能量回收系统,包括发电机、蓄电池、起动机、超级电容、双向DC/DC变换器、电控开关和系统控制器,发电机与发动机传动连接,且与整车用电负载并联并与蓄电池并联,蓄电池与整车用电负载并联,超级电容与起动机并联,双向DC/DC变换器的两端分别与超级电容的正极端和发电机的正极端连接,电控开关的两端分别与超级电容的正极端和发电机的正极端连接；系统控制器分别与发动机的控制单元、发电机、超级电容、蓄电池、双向DC/DC变换器以及电控开关连接。可通过超级电容带动起动机起动发动机,并可通过电控开关将超级电容和蓄电池、发电机以及整车用电负载连接,用于回收车辆势能。(The invention relates to the technical field of automobiles, and particularly discloses an engine starting and energy recovery system which comprises a generator, a storage battery, a starter, a super capacitor, a bidirectional DC/DC converter, an electric control switch and a system controller, wherein the generator is in transmission connection with the engine and is connected with an electric load of a whole automobile in parallel and is connected with the storage battery in parallel; the system controller is respectively connected with the control unit of the engine, the generator, the super capacitor, the storage battery, the bidirectional DC/DC converter and the electric control switch. The starter can be driven by the super capacitor to start the engine, and the super capacitor can be connected with the storage battery, the generator and the electric load of the whole vehicle by the electric control switch for recovering the potential energy of the vehicle.)

1. An engine starting and energy recovery system, comprising:

the generator (1) is in transmission connection with the engine (10), and the generator (1) is connected with the electric load (8) of the whole vehicle in parallel;

the storage battery (2) is connected with the generator (1) in parallel and is connected with an electric load (8) for the whole vehicle in parallel;

a starter (3) for starting the engine (10);

the super capacitor (4), the super capacitor (4) is connected with the starter (3) in parallel;

a bidirectional DC/DC converter (5) having a first end connected to the positive terminal of the supercapacitor (4) and a second end connected to the positive terminal of the generator (1);

one end of the electric control switch (6) is connected with the positive electrode end of the super capacitor (4), and the other end of the electric control switch is connected with the positive electrode end of the generator (1);

and the system controller (7) is electrically connected with a control unit (9) of the engine (10), the generator (1), the super capacitor (4), the storage battery (2), the bidirectional DC/DC converter (5) and the electric control switch (6) respectively.

2. A control method of an engine starting and energy recovery system as set forth in claim 1, comprising:

the system controller (7) judges that the engine (10) is in a cold start state through the control unit (9), after the system controller (7) collects an instruction for starting the engine (10), the system controller (7) controls the electric control switch (6) to be switched off, the system controller (7) collects the real-time voltage V of the super capacitor (4), and when the voltage V is not less than a first threshold value V1, the control unit (9) controls the starter (3) to start the engine (10).

3. The control method of an engine starting and energy recovery system according to claim 2, characterized in that if V < V1, the system controller (7) collects the real-time electric quantity E of the storage battery (2), and when E is not less than a second threshold value E1, the system controller (7) controls the storage battery (2) to charge the super capacitor (4) through the bidirectional DC/DC converter (5), the system controller (7) collects the real-time voltage V of the super capacitor (4), and when V ≧ V1, the system controller (7) controls the storage battery (2) to stop charging the super capacitor (4), and the control unit (9) controls the starter (3) to start the engine (10).

4. The control method of an engine starting and energy recovery system according to claim 3, characterized in that if V < V1 and E ≧ E1, the system controller (7) issues a first prompt through an output device during the process in which the system controller (7) controls the battery (2) to charge the supercapacitor (4) through the bidirectional DC/DC converter (5), and when the system controller (7) controls the battery (2) to stop charging the supercapacitor (4), the system controller (7) issues a second prompt through the output device.

5. The control method of an engine starting and energy recovery system according to claim 4, characterized in that the system controller (7) issues a third prompt through the output device if V < V1 and E < E1.

6. The control method of an engine starting and energy recovery system according to claim 2, characterized in that the system controller (7) controls the electrically controlled switch (6) to be closed after the engine (10) is started.

7. The control method of the engine starting and energy recovery system according to claim 6, characterized in that after the engine (10) is started, the system controller (7) collects the speed of the whole vehicle, the position of an accelerator pedal and the position of a brake pedal through the control unit (9), and when the speed of the whole vehicle is greater than or equal to 25km/h and the accelerator pedal is not pressed or the brake pedal is pressed, the system controller (7) controls the generator (1) to increase the output voltage.

8. The method for controlling an engine starting and energy recovery system according to claim 6, characterized in that after the engine (10) is started, if the system controller (7) collects a stop command through the control unit (9), the system controller (7) controls the electric switch (6) to be turned off, and the system controller (7) collects the real-time voltage V of the super capacitor (4), when V is between the second threshold value V2 and the first threshold value V1, the control unit (9) controls the engine (10) to be shut down, V2 < V1.

9. The control method of an engine starting and energy recovering system according to claim 8, characterized in that when the system controller (7) collects a stop command through the control unit (9), if V > V1, the system controller (7) controls the super capacitor (4) to charge the battery (2) through the bidirectional DC/DC converter (5) until V ≦ V1.

10. The control method of the engine starting and energy recovery system according to claim 1, characterized in that after the system controller (7) collects a stop command through the control unit (9), if V < V2, the system controller (7) controls the storage battery (2) to charge the super capacitor (4) through the bidirectional DC/DC converter (5) until V is greater than or equal to V1.

Technical Field

The invention relates to the technical field of engines, in particular to an engine starting and energy recovery system and a control method thereof.

Background

At present, storage batteries are basically used as power supplies for starting engines, but when the engines are started in a cold state, particularly under a low-temperature condition, the viscosity of engine oil of the engines is increased, so that the starting resistance of the engines is increased, on the other hand, the internal resistance of the storage batteries is increased at a low temperature, the activity of active substances is reduced, and further the discharge capacity is reduced, and the low-temperature starting of the engines is difficult due to two reasons; on the other hand, the storage battery is often discharged by large current, and particularly under the starting and stopping working conditions, the storage battery can reach the service life limit earlier. And at low temperatures, if the battery SOC is low, it is substantially difficult to start the vehicle.

In this regard, a previous patent application No. cn201710287550.x discloses a starting system based on a fuel engine, including a super capacitor, a unidirectional DC/DC converter, a generator, a starter, and a starting system controller, wherein: the first end of the super capacitor is connected with the first end of the starter, the second end of the super capacitor is connected with the first end of the unidirectional DC/DC converter, and the second end of the unidirectional DC/DC converter is connected with the second end of the starter; the generator is connected with the super capacitor in parallel and is suitable for charging the super capacitor; the starting system controller is respectively connected with the super capacitor and the unidirectional DC/DC converter, the unidirectional DC/DC converter is controlled to be switched on or switched off according to a starting signal for starting the starter and the output voltage of the super capacitor, and when the unidirectional DC/DC converter is switched on, the unidirectional DC/DC converter performs voltage conversion on the output voltage of the super capacitor and supplies power to the starter. However, the super capacitor is only used for starting the engine and cannot be used for potential energy recovery, so that fuel efficiency of the whole vehicle is reduced.

Disclosure of Invention

The invention aims to: the utility model provides an engine starting and energy recovery system and a control method thereof, which aims to solve the problem of low fuel efficiency of a starting system based on a fuel engine in the prior art.

The invention provides an engine starting and energy recovery system, comprising:

the generator is in transmission connection with the engine and is connected with the electric load of the whole vehicle in parallel;

the storage battery is connected with the generator in parallel and is connected with the electric load of the whole vehicle in parallel;

a starter for starting the engine;

the super capacitor is connected with the starter in parallel;

a bidirectional DC/DC converter, the first end of which is connected with the positive terminal of the super capacitor, and the second end of which is connected with the positive terminal of the generator;

one end of the electric control switch is connected with the positive electrode end of the super capacitor, and the other end of the electric control switch is connected with the positive electrode end of the generator;

and the system controller is electrically connected with the control unit of the engine, the generator, the super capacitor, the storage battery, the bidirectional DC/DC converter and the electric control switch respectively.

On the other hand, the present embodiment provides a method for controlling an engine starting and energy recovery system according to the above-mentioned aspect, including: the system controller judges that the engine is in a cold engine starting state through the control unit, after the system controller collects an engine starting instruction, the system controller controls the electric control switch to be switched off, the system controller collects the real-time voltage V of the super capacitor, and when the voltage V is not less than a first threshold value V1, the control unit controls the starter to start the engine.

As a preferable scheme of the control method of the engine starting and energy recovery system, if V is less than V1, the system controller collects real-time electric quantity E of the storage battery, and when E is not less than a second threshold value E1, the system controller controls the storage battery to charge the super capacitor through the bidirectional DC/DC converter, the system controller collects real-time voltage V of the super capacitor, and when V is greater than or equal to V1, the system controller controls the storage battery to stop charging the super capacitor, and the control unit controls the starter to start the engine.

As a preferable scheme of the control method of the engine starting and energy recovery system, if V is less than V1 and E is more than or equal to E1, the system controller sends a first prompt through an output device in the process that the system controller controls the storage battery to charge the super capacitor through the bidirectional DC/DC converter, and when the system controller controls the storage battery to stop charging the super capacitor, the system controller sends a second prompt through the output device.

As a preferable scheme of the control method of the engine starting and energy recovery system, if V < V1 and E < E1, the system controller sends out a third prompt through the output device.

As a preferable scheme of the control method of the engine starting and energy recovery system, after the engine is started, the system controller controls the electric control switch to be closed.

As a preferred scheme of a control method of an engine starting and energy recovery system, after the engine is started, the system controller acquires the speed of the whole vehicle, the position of an accelerator pedal and the position of a brake pedal through the control unit, and when the speed of the whole vehicle is greater than or equal to 25km/h, and the accelerator pedal is not stepped on or the brake pedal is stepped on, the system controller controls the generator to increase the output voltage.

As a preferable scheme of the control method of the engine starting and energy recovery system, after the engine is started, if the system controller acquires a stop command through the control unit, the system controller controls the electric control switch to be switched off, and the system controller acquires the real-time voltage V of the super capacitor, when V is between the second threshold value V2 and the first threshold value V1, the control unit controls the engine to be shut down, and V2 is less than V1.

As a preferable scheme of the control method of the engine starting and energy recovery system, after the system controller collects a parking instruction through the control unit, if V is larger than V1, the system controller controls the super capacitor to charge the storage battery through the bidirectional DC/DC converter until V is smaller than or equal to V1.

As a preferable scheme of the control method of the engine starting and energy recovery system, after the system controller acquires a stop command through the control unit, if V is less than V2, the system controller controls the storage battery to charge the super capacitor through the bidirectional DC/DC converter until V is more than or equal to V1.

The invention has the beneficial effects that:

the invention provides an engine starting and energy recovery system which comprises a generator, a storage battery, a starter, a super capacitor, a bidirectional DC/DC converter, an electric control switch and a system controller. The generator is in transmission connection with the engine, the generator is connected with the electric load of the whole vehicle in parallel and is connected with the storage battery in parallel, the storage battery is connected with the electric load of the whole vehicle in parallel, the super capacitor is connected with the starter in parallel, the first end of the bidirectional DC/DC converter is connected with the positive end of the super capacitor, the second end of the bidirectional DC/DC converter is connected with the positive end of the generator, one end of the electric control switch is connected with the positive end of the super capacitor, and the other end of the electric control switch is; the system controller is respectively and electrically connected with a control unit of the engine, the generator, the super capacitor, the storage battery, the bidirectional DC/DC converter and the electric control switch. The starter can be driven by the super capacitor to start the engine, and the super capacitor can be connected with the storage battery, the generator and the electric load of the whole vehicle by the electric control switch for recovering the potential energy of the vehicle.

Drawings

FIG. 1 is a schematic diagram of an engine starting and energy recovery system according to an embodiment of the present invention.

In the figure:

1. a generator; 2. a storage battery; 3. a starter; 4. a super capacitor; 5. a bidirectional DC/DC converter; 6. an electric control switch; 7. a system controller; 8. the electric load of the whole vehicle; 9. a control unit; 10. an engine.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Where the terms "first position" and "second position" are two different positions, and where a first feature is "over", "above" and "on" a second feature, it is intended that the first feature is directly over and obliquely above the second feature, or simply means that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

As shown in fig. 1, the present embodiment provides an engine starting and energy recovery system, which includes a generator 1, a storage battery 2, a starter 3, a super capacitor 4, a bidirectional DC/DC converter 5, an electronic control switch 6, and a system controller 7. The generator 1 is connected with the transmission of the engine 10, the generator 1 can be driven to generate electricity through the engine 10, the generator 1 is connected with the electric load 8 of the whole vehicle in parallel and is connected with the storage battery 2 in parallel, the storage battery 2 is connected with the electric load 8 of the whole vehicle in parallel, therefore, the electricity generated by the generator 1 can be used for directly using the electric load 8 of the whole vehicle and can also be stored in the storage battery 2, and when the generated energy of the generator 1 cannot support the electric load 8 of the whole vehicle, the storage battery 2 can provide electric energy for the electric load 8. The super capacitor 4 is connected in parallel with the starter motor 3, and the super capacitor 4 is used for starting the starter motor 3, so that the engine 10 is started through the starter motor 3. The bidirectional DC/DC converter 5 has a first terminal connected to the positive terminal of the super capacitor 4 and a second terminal connected to the positive terminal of the generator 1, so that the electricity generated by the engine 10 can be supplied to the super capacitor 4 through the bidirectional DC/DC converter 5. One end of the electric control switch 6 is connected with the positive pole end of the super capacitor 4, and the other end of the electric control switch is connected with the positive pole end of the generator 1; the system controller 7 is electrically connected to the control unit 9 of the engine 10, the generator 1, the supercapacitor 4, the battery 2, the bidirectional DC/DC converter 5, and the electric control switch 6, respectively. The control unit 9 is an EMS, and is configured to control the starter 3 to start, and feed back parameters such as a vehicle speed, a pedal position, and an accelerator position to the system controller 7 when the engine 10 is running.

The bidirectional DC/DC converter 5 is in the prior art, has a boost mode and a buck mode, and when the voltage of the super capacitor 4 is too low, the voltage of the storage battery 2 can be increased through the boost mode so as to charge the super capacitor 4, and when the voltage of the super capacitor 4 is too high, the redundant electric quantity of the super capacitor 4 can be output to the storage battery 2 through the buck mode. In the present embodiment, the engine 10 and the super capacitor 4 constitute a starting circuit, the generator 1, the battery 2, and the electric load 8 for the vehicle constitute a load circuit, and the bidirectional DC/DC converter 5 is located between the starting circuit and the load circuit. When the starting circuit is in operation, the bidirectional DC/DC converter 5 may be used to isolate the starting circuit from the load circuit, so that the starting circuit and the load circuit do not affect each other. The system controller 7 can control the current flowing direction and power between the super capacitor 4 and the storage battery 2 through the DC/DC converter 5, and avoid direct connection to generate overcurrent.

The electric control switch 6 is used for communicating the starting loop and the load loop, and when the starting loop is communicated with the load loop, the generator 1 can charge the super capacitor 4 and the storage battery 2 simultaneously. Particularly, when the whole vehicle brakes or slides, the generator 1 can increase the generating voltage to convert the potential energy of the whole vehicle into electric energy as much as possible, at the moment, the super capacitor 4 can be used for storing the electric energy, and when the vehicle runs through fuel, the stored electric energy is charged into the storage battery 2 or is supplied to the electric load 8 of the whole vehicle for use, so that the energy waste can be avoided.

The system controller 7 can acquire real-time voltages of the super capacitor 4 and the storage battery 2. Specifically, the super capacitor 4 and the storage battery 2 are both provided with a voltage detection module, and the voltage detection module feeds back the real-time electric quantity of the super capacitor 4 to the system controller 7 or feeds back the real-time electric quantity of the storage battery 2 to the system controller 7. Since the characteristics of the super capacitor 4 and the battery 2 are different, when the SOC (State of Charge) of the battery 2 is in the 0-100% period, the voltage is substantially between 12-13V, and the electric quantity and the voltage of the super capacitor 4 are directly related, according to the formula E-1/2C U2, the higher the voltage of the super capacitor 4 is, the higher the energy is, and thus the system controller 7 can obtain the voltage of the super capacitor 4 and the electric quantity of the battery 2.

The embodiment also provides a control method of the engine starting and energy recovery system, which comprises the following steps:

s11: the system controller 7 judges that the engine 10 is in a cold start state through the control unit 9, after the system controller 7 collects an instruction for starting the engine 10, the system controller 7 controls the electric control switch 6 to be switched off, the system controller 7 collects the real-time voltage V of the super capacitor 4, and when the voltage V is not less than a first threshold value V1, the control unit 9 controls the starter 3 to start the engine 10. The first threshold V1 is the minimum voltage at which the super capacitor 4 can start the starter motor 3 in the cold state.

The system controller 7 may collect the rotation speed of the engine 10 through the control unit 9, may indicate that the engine 10 is not started when the rotation speed is zero, and may obtain the oil temperature of the engine 10 and the ambient temperature through the temperature sensor, indicate that the engine 10 is in a cold start state when the oil temperature of the engine 10 is below the thermostat initial start temperature, and indicate that the engine 10 is in an idle start-stop state when the oil temperature of the engine 10 is above the thermostat initial start temperature. Of course, the time of the last stop may be recorded by the system controller 7, and it may be determined that the engine 10 is in the idle start-stop state by the time interval being equal to or smaller than the preset threshold, and it may be determined that the engine 10 is in the cold start state by the time interval being greater than the preset threshold.

S12: if V is less than V1, the system controller 7 collects the real-time electric quantity E of the storage battery 2, when E is not less than a second threshold value E1, the system controller 7 controls the storage battery 2 to charge the super capacitor 4 through the bidirectional DC/DC converter 5, the system controller 7 collects the real-time voltage V of the super capacitor 4, when V is larger than or equal to V1, the system controller 7 controls the storage battery 2 to stop charging the super capacitor 4, and the control unit 9 controls the starter 3 to start the engine 10. The second threshold value E1 is the minimum amount of the battery 2 that can satisfy the requirement of charging the super capacitor 4 through the bidirectional DC/DC converter 5 to the voltage V1 of the super capacitor 4.

S13: if V is less than V1 and E is more than or equal to E1, the system controller 7 sends a first prompt through the output device in the process that the system controller 7 controls the storage battery 2 to charge the super capacitor 4 through the bidirectional DC/DC converter 5, and when the system controller 7 controls the storage battery 2 to stop charging the super capacitor 4, the system controller 7 sends a second prompt through the output device.

The output device may be a meter, a touch screen, or a sound, etc. The first prompt may be used to prompt the user to wait for charging, and the second prompt may be used to prompt the user that charging has been completed and may be initiated.

S14: if V < V1 and E < E1, the system controller 7 issues a third prompt via the output device.

The third prompt may be used to prompt the user that the battery 2 needs to be replaced or to charge the battery 2 and to make the charge of the battery 2 at least reach E1, so that the starter 10 may be started.

S21: after the engine 10 is started, the system controller 7 controls the electronic control switch 6 to be closed so as to conduct the driving circuit and the load circuit.

S31: when the engine 10 is started, the system controller 7 acquires the speed of the whole vehicle, the position of an accelerator pedal and the position of a brake pedal through the control unit 9, and when the speed of the whole vehicle is larger than or equal to 25km/h and the accelerator pedal is not stepped or the brake pedal is stepped, the system controller 7 controls the generator 1 to increase the output voltage.

When the accelerator pedal is not stepped or the brake pedal is stepped, the engine 10 is in a sliding state or a braking state at the moment, and when the speed of the whole vehicle is more than or equal to 25km/h, the potential energy of the vehicle at the moment is high in recovery value, so that the generator 1 is controlled to increase the output voltage at the moment to fully recover the potential energy of the vehicle.

The first output voltage V1 'and the second output voltage V2', V2 '> V1' of the generator 1 can be preset in the system controller 7, when the speed of the whole vehicle is more than or equal to 25km/h and the accelerator pedal is not pressed down or the brake pedal is pressed down, the system controller 7 controls the output voltage of the generator 1 to be V2 ', and when the speed of the whole vehicle is less than 25km/h or the speed of the whole vehicle is more than or equal to 5km/h and the accelerator pedal is pressed down or the brake pedal is not pressed down, the system controller 7 controls the output voltage of the generator 1 to be V1'. And when the output voltage of the generator 1 is adjusted to V1', the voltage of the super capacitor 4 is usually greater than the voltage of the storage battery 2, and the excess voltage of the super capacitor 4 is used for charging the storage battery 2 and for supplying power to the electric load 8 of the whole vehicle.

S32: after the engine 10 is started, if the system controller 7 acquires a parking instruction through the control unit 9, the system controller 7 controls the electric control switch 6 to be switched off, the system controller 7 acquires the real-time voltage V of the super capacitor 4, when the voltage V is between the second threshold value V2 and the first threshold value V1, the control unit 9 controls the engine 10 to be switched off, and V2 is smaller than V1.

S41: after the system controller 7 acquires a parking instruction through the control unit 9, if V is greater than V1, the system controller 7 controls the super capacitor 4 to charge the storage battery 2 through the bidirectional DC/DC converter 5 until V is less than or equal to V1.

S42: after the system controller 7 acquires a parking instruction through the control unit 9, if V is less than V2, the system controller 7 controls the storage battery 2 to charge the super capacitor 4 through the bidirectional DC/DC converter 5 until V is more than or equal to V1.

The second threshold V2 is the minimum voltage at which the super capacitor 4 can start the generator 1 when the engine 10 is in the start-stop state. Since the viscosity of the oil in the engine 10 is high when the engine 10 is in the start-stop state, and the starter 3 can start the engine 10 relatively easily when the engine 10 is cold, V2 is smaller than V1. Also, when the vehicle is in a fuel-powered driving state, although the electronically controlled switch 6 is in a closed state, the voltage of the super capacitor 4 is above V2, that is, when the engine 10 is stopped and then started while the vehicle is in a start-stop state, the super capacitor 4 can directly start the starter motor 3. However, if the voltage of the super capacitor 4 is smaller than V2 or larger than V1 due to a fault, the super capacitor 4 is controlled to be charged and discharged through the bidirectional DC/DC converter 5 and the storage battery 2, so as to adjust the voltage of the super capacitor 4 between V1 and V2, and at this time, it is ensured that the electric quantity of the super capacitor 4 is not wasted.

At the time of the start at-30 ℃, it is generally necessary to calculate the actual remaining capacity of the battery 2 as 80% of the detected capacity of the battery 2, and therefore the actual remaining capacity of the battery 2 is likely to be much lower than the capacity of the lowest starter motor 3 thereof, and it is likely that the vehicle cannot be started, whereas in the engine starting and energy recovery system provided in the present embodiment, the vehicle can be started basically as long as the battery 2 has the discharge capacity. And the super capacitor 4 can be connected with the storage battery 2, the generator 1 and the electric load 8 for the whole vehicle through the electric control switch 6 for recovering the potential energy of the vehicle.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.