阅读说明：本技术 一种车对车充电系统及其控制方法 (Vehicle-to-vehicle charging system and control method thereof ) 是由 肖波 刘杰 彭政瑜 张旭云 翟钧 李宗华 于 2021-10-27 设计创作，主要内容包括：本发明提供一种车对车充电系统及方法,包括充电连接装置、充电车辆以及配备增程器的放电车辆。通过放电车辆自身搭载的增程器发电,逆变器将三相交流电转换为直流电,通过直流充电口、充电连接装置将直流电直接输送给充电车辆,拥有充电速率快,充电效率高以及不受放电车辆自身动力电池电量限制的优点,并且充、放电车辆本身均无需额外增加其它硬件系统,在不额外增加车辆成本的基础上即可实现本技术方案,极大提升市场救援响应能力和客户用车体验。(The invention provides a vehicle-to-vehicle charging system and method. Generating electricity through the range extender carried by the discharging vehicle, converting three-phase alternating current into direct current by the inverter, charging the port through direct current, charging the connecting device and directly delivering the direct current to the charging vehicle, and having the advantages of high charging efficiency and no limitation of the electric quantity of the power battery of the discharging vehicle, and charging, discharging the vehicle and not needing to additionally increase other hardware systems, can realize the technical scheme on the basis of not additionally increasing the vehicle cost, and greatly improve the market rescue response capability and the customer vehicle experience.)

1. A vehicle-to-vehicle charging system is characterized by comprising a charging connecting device, a range extender, a vehicle control unit A, an inverter A, a direct-current charging port A and a power battery A which are arranged on a discharging vehicle, and a vehicle control unit B, an inverter B, a direct-current charging port B and a power battery B which are arranged on a charging vehicle;

the charging connection device comprises a discharging gun head used for connecting a direct-current charging port A of a discharging vehicle, a charging gun head used for connecting a direct-current charging port B of the charging vehicle, high-voltage and low-voltage cables used for connecting the direct-current charging port A and the direct-current charging port B, a power supply module used for providing low-voltage auxiliary power supply for the charging and discharging vehicle, and a charging connection control device used for detecting the connection state of the charging and discharging gun, collecting the temperature of the gun head of the charging and discharging gun and controlling the unlocking and locking of the charging and discharging vehicle charging electronic lock;

firstly, the charging connecting device completes the connection of a discharging vehicle and a charging vehicle, completes the starting of a range extender, awakens the charging vehicle, controls the locking of an electronic lock of a charging gun and a discharging gun, completes the charging handshake and the charging parameter configuration of the power battery B and the discharging vehicle, and sends a charging ready message to the discharging vehicle after judging the charging ready of the power battery B;

then, the vehicle control unit A controls the range extender to regulate the voltage, controls the output voltage of the range extender by taking the current voltage of the power battery B of the charging vehicle as a target, controls the direct-current charging relays K1 and K2 to be closed after the power battery A judges that the absolute value of the difference value between the output voltage of the range extender and the current voltage of the power battery B is lower than a set value x, and sends a charging preparation message to the charging vehicle; after receiving the message, the power battery B of the charging vehicle sends battery charging state information such as required voltage, required current, charging mode and the like to the discharging vehicle, and the discharging vehicle feeds the battery charging state information such as output voltage/current, accumulated charging time and the like back to the charging vehicle;

then, the vehicle control unit A of the discharging vehicle controls the range extender to enter a motor rotating speed closed-loop control working mode; the discharging vehicle comprehensively calculates the target generating power of the range extender according to the required current and the total voltage of the battery sent by the power battery B, the actual consumed power of the high-voltage load of the discharging vehicle, the temperature of the direct-current charging seat, the temperature of the gun head of the charging gun, the temperature of the gun head of the discharging gun and the generating capacity of the range extender, and controls the range extender to generate power;

and finally, entering a direct current charging state until the charging is finished or the charging is terminated, and finishing the power-off and dormancy of the charging and discharging vehicles respectively.

2. The vehicle-to-vehicle charging system according to claim 1, wherein when the charging connection device is connected to the charging vehicle, the power battery A of the discharging vehicle simulates a charging pile to send a direct current charging related message to the charging vehicle after detecting the connection of a discharging gun.

3. The vehicle-to-vehicle charging system according to claim 1, wherein after the charging connection device completes the connection between the discharging vehicle and the charging vehicle, the discharging vehicle is awakened by a power supply (a +, a-) which provides low-voltage auxiliary power supply for the discharging vehicle, after the discharging vehicle is awakened, the discharging vehicle is identified to enter a direct-current discharging state according to the detected CC2 resistance, and a vehicle controller A of the discharging vehicle controls the vehicle to complete high-voltage power-on; meanwhile, the discharging vehicle communicates with the charging connecting device to confirm whether the charging vehicle is connected or not, if so, the vehicle controller A of the discharging vehicle controls the range extender to start, and the working mode is the engine rotating speed closed-loop control mode after the range extender is started successfully.

4. The vehicle-to-vehicle charging system according to claim 1, wherein after the range extender is started successfully, the power battery A of the discharging vehicle controls to cut off the main relays K3 and K4 of the discharging vehicle, the vehicle control unit A controls the range extender to enter a voltage closed-loop control working mode, the range extender is responsible for maintaining the voltage of the high-voltage system at the current voltage level of the power battery A so as to maintain the self high-voltage load electricity utilization of the vehicle, and the power battery A simulates the charging pile to send a handshake message to the charging vehicle.

5. The vehicle-to-vehicle charging system according to claim 1, wherein after the charging vehicle is awakened, the charging vehicle is identified to enter a direct current charging state according to the detected resistance CC2, a vehicle controller B of the charging vehicle controls the vehicle to complete high-voltage power-on, then a power battery B and the discharging vehicle complete charging handshake and charging parameter configuration, and the maximum allowable charging total voltage/current/temperature, total energy, state of charge, current voltage and other information of the power battery B are sent to the discharging vehicle; and meanwhile, the power battery B of the discharging vehicle sends information such as the maximum/minimum output voltage, the maximum/minimum output current and the like of the discharging vehicle to the charging vehicle, the power battery B of the charging vehicle judges whether the charging vehicle is matched with the self state or not according to the received charging parameters and judges whether the charging vehicle is ready or not, if so, the power battery B controls to close the direct current charging relays K5 and K6 and sends a charging ready message to the discharging vehicle.

6. The vehicle-to-vehicle charging system according to claim 1, wherein after entering the dc charging state, if the charging is completed, the user actively terminates the charging, or the charging and discharging vehicle has a fault requiring termination of the charging, the vehicle controller a of the discharging vehicle controls to shut down the range extender and other vehicle high voltage loads, after the range extender is shut down, the power battery a controls the dc charging relays K1 and K2 to be disconnected, and after the charging vehicle judges that the charging current is lower than a certain value, the power battery B controls the dc charging relays K5 and K6 to be disconnected; after the charging connecting device confirms that the direct-current charging relays K1 and K2 are disconnected, the charging connecting device controls the electronic locks of the charging guns and the discharging guns to be unlocked, the power supply for supplying low-voltage auxiliary power to the charging vehicles and the discharging vehicles is stopped, and the charging vehicles and the discharging vehicles respectively finish power-off and dormancy.

7. The vehicle-to-vehicle charging system according to claim 1, wherein the resistance value of CC2 of the discharging gun head is self-defined by a host factory and is greatly different from the resistance value of DC charging CC2 recommended by the national standard so that the discharging vehicle can be identified to enter a DC discharging state; the resistance value of CC2 of rifle head that charges is unanimous with the DC CC2 resistance value of charging that national standard recommends.

8. A vehicle-to-vehicle charging system control method is characterized by comprising the following steps:

step 1, a charging connection device completes connection of a discharging vehicle and a charging vehicle;

step 2, the vehicle control unit A of the discharging vehicle controls the range extender to start, and the main relays K3 and K4 are switched off to prepare for external power generation of the range extender;

step 3, the vehicle control unit A controls the range extender to enter a voltage closed-loop control working mode, a charging vehicle is awakened, the electronic lock of the charging gun and the discharging gun is controlled to be locked, the charging vehicle is identified to enter a direct-current charging state, and the vehicle control unit B controls the charging vehicle to complete high-voltage electrification;

step 4, entering a direct current charging process to prepare for charging;

step 5, the vehicle control unit A controls the range extender to regulate the voltage, so that the voltage difference between two ends of the direct-current charging relays K1 and K2 is in a certain range;

step 6, controlling the direct-current charging relays K1 and K2 to be closed, and enabling the charging vehicle and the discharging vehicle to mutually send battery charging state information;

step 7, entering a motor rotating speed closed-loop control working mode;

step 8, entering direct current charging control, calculating target generating power of the range extender, and controlling the range extender to generate power according to the target generating power;

step 9, judging the charging stop condition, and turning off the range extender;

step 10, controlling the direct current charging relays K1, K2, K5 and K6 to be disconnected, controlling the electronic locks of the charging guns and the discharging guns to be unlocked, and stopping providing a power supply (A +, A-) of low-voltage auxiliary power supply for the charging vehicles and the discharging vehicles;

and 11, completing power-off and dormancy of the charging and discharging vehicles respectively.

9. The vehicle-to-vehicle charging system control method according to claim 8, wherein the step 1 includes:

step A01, completing the connection of the discharging vehicle and the charging vehicle through the charging connection device;

step A02, detecting whether the charging and discharging gun is in a complete connection state, if yes, entering step A03, if no, returning to step A01;

step A03, the charging connection device provides a power supply (A +, A-) of low-voltage auxiliary power supply for the discharging vehicle to wake up the discharging vehicle;

step A04, recognizing that the discharging vehicle enters a direct current discharging state according to the detected CC2 resistance, and controlling the vehicle to finish high-voltage electrification by the vehicle controller A of the discharging vehicle;

step a05, the discharging vehicle communicates with the charging connection device, and confirms whether the charging vehicle is connected, and step 2 is entered, no, and the process returns to step a 01.

10. The vehicle-to-vehicle charging system control method according to claim 8, wherein the step 2 includes:

step A06, the vehicle control unit A of the discharging vehicle controls the range extender to start, and the working mode of the range extender is controlled to be an engine rotating speed closed-loop control mode after the range extender is successfully started;

step A07, the vehicle control unit A judges whether the range extender is started successfully, if yes, the step A08 is entered, if no, the step A06 is returned;

step A08, controlling and cutting off main relays K3 and K4 of a power battery A of the discharging vehicle to prepare for external power generation of the range extender;

in the step A09, the power battery A needs to judge whether the main relays K3 and K4 are successfully cut off, if yes, the step 3 is executed, and if no, the step A08 is returned.

11. The vehicle-to-vehicle charging system control method according to claim 8, wherein the step 3 includes:

step A10, the vehicle control unit A controls the range extender to enter a voltage closed-loop control working mode, and the range extender is responsible for maintaining the voltage of the high-voltage system at the current voltage level of the power battery A so as to maintain the self high-voltage load electricity utilization of the discharging vehicle; meanwhile, the power battery A sends a handshake message to the charging vehicle;

step A11, the vehicle control unit A judges whether the range extender has entered the voltage closed-loop control working mode, if yes, the vehicle control unit enters step A12, if no, the vehicle control unit returns to step A10;

step A12, the charging connection device provides a power supply (A +, A-) of low-voltage auxiliary power supply for the charging vehicle to wake up the charging vehicle, and controls the electronic lock of the charging and discharging gun to be locked;

and step A13, recognizing that the vehicle enters a direct current charging state according to the detected CC2 resistance after the vehicle is awakened, and controlling the vehicle to finish high-voltage electrification by the vehicle controller B of the vehicle to be charged.

12. The vehicle-to-vehicle charging system control method according to claim 8, wherein the step 4 includes:

step A14, the power battery B and the discharging vehicle complete charging handshake and charging parameter configuration, and the maximum allowable charging total voltage/current/temperature, total energy, state of charge, current voltage and other information of the power battery B are sent to the discharging vehicle; meanwhile, the power battery A of the discharging vehicle sends information such as the maximum/minimum output voltage, the maximum/minimum output current and the like of the discharging vehicle to the charging vehicle;

step A15, the power battery 2 of the charging vehicle judges whether to match with the self state according to the received charging parameters, and judges whether to charge the vehicle ready, if yes, the step A16 is entered, if no, the step A15 is returned, and the charging is ready;

and step A16, the power battery B controls to close the direct current charging relays K5 and K6 and sends a charging ready message to the discharging vehicle.

13. The vehicle-to-vehicle charging system control method according to claim 8, wherein the step 5 includes:

step A17, after the discharging vehicle receives the charging ready message, the vehicle controller A controls the range extender to regulate the voltage, the current voltage of the power battery B of the charging vehicle is used as the target to regulate the output voltage of the range extender, and the voltage difference between the two ends of the direct-current charging relays K1 and K2 is in a certain range;

step A18, the power battery A judges whether the absolute value of the difference value between the output voltage of the range extender and the current voltage of the power battery 2 is lower than a certain value, if yes, the step 6 is entered, if no, the step A17 is returned, the step A17 is waited for completing the pressure difference adjustment, if the pressure difference adjustment at the two ends of the direct current charging relays K1 and K2 is not completed within a certain time, the charging is finished.

14. The vehicle-to-vehicle charging system control method according to claim 8, wherein the step 6 includes:

step A19, the power battery A controls the direct current charging relays K1 and K2 to be closed and sends a charging ready message to the charging vehicle, the power battery B of the charging vehicle sends battery charging state information such as required voltage, required current and charging mode to the discharging vehicle after receiving the charging ready message, and the discharging vehicle feeds the battery charging state information such as output voltage/current and accumulated charging time back to the charging vehicle;

in the step a20, the power battery 1 detects and judges whether the direct current charging relays K1 and K2 are closed, if yes, the step 7 is executed, if no, the step a19 is returned.

15. The vehicle-to-vehicle charging system control method according to claim 8, wherein the step 7 includes:

step A21, controlling the range extender to exit a voltage and rotating speed closed-loop control working mode by a vehicle control unit A of the discharging vehicle, entering a motor rotating speed closed-loop control working mode and preparing for generating power regulation;

and step A22, the vehicle control unit 1 detects and judges whether the range extender enters the motor rotating speed closed-loop control working mode, if yes, the vehicle control unit enters step 8, and if no, the vehicle control unit returns to step A21.

16. The vehicle-to-vehicle charging system control method according to claim 8, wherein the step 8 includes:

step A23, the discharging vehicle calculates the current required power generation power of the charging vehicle according to the required current and the total battery voltage sent by the power battery B, and the current self high-voltage load actual power consumption of the discharging vehicle is added to be used as the target power generation power of the range extender; the range extender target generated power also takes the following dimensional correction limit into consideration: and finally, comprehensively calculating the target power generation power of the range extender, and controlling the range extender to generate power according to the target power generation power.

17. The vehicle-to-vehicle charging system control method according to claim 8, wherein the step 9 includes:

step A24, judging the charging stop condition, including that the charging vehicle judges that the charging is finished, the charging connection device detects that the user pulls out the gun to actively stop the charging or the charging and discharging vehicle has the fault of requiring to stop the charging, if yes, the step A25 is entered, if no, the step A23 is returned;

step A25, controlling a vehicle controller A of the discharging vehicle to close the range extender and other high-voltage loads of the vehicle;

and step A26, judging whether the range extender is stopped completely, if yes, entering step 10, and if no, returning to step A25.

18. The vehicle-to-vehicle charging system control method according to claim 8, wherein the step 10 includes:

step A27, the power battery A controls the direct current charging relays K1 and K2 to be disconnected, and meanwhile, after the charging vehicle judges that the charging current is lower than a certain value, the power battery B controls the direct current charging relays K5 and K6 to be disconnected;

step A28, the charging connection device judges whether the direct current charging relays K1 and K2 are disconnected, if yes, the step A29 is entered, if no, the step A27 is returned, and the direct current charging relays K1 and K2 are waited to be disconnected;

in step a29, the charging connection device controls the electronic lock of the charging and discharging gun to unlock, stops providing the power supply (a +, a-) of the low-voltage auxiliary power supply for the charging and discharging vehicle, and proceeds to step 11.

Technical Field

The invention relates to the technical field of external charging of new energy automobiles, in particular to an automobile-to-automobile charging system and a control method.

Background

At present, energy crisis and environmental deterioration become important factors restricting global economic development, a new energy automobile which is researched to save energy and protect environment is one of effective means for relieving energy pressure and reducing environmental pollution, and the new energy automobile is already listed as a strategic emerging industry of the country. In recent years, new energy automobiles in China show a explosive growth trend, development vision of development plans of new energy automobile industry (2021-2035) is expected, by 2025, the sales volume of new energy automobiles reaches about 20% of the total sales volume of new energy automobiles, and pure electric automobiles, plug-in hybrid power (including extended range) automobiles and fuel cell automobiles are regarded as three vertical under the large environment of industrial development, so that the new energy automobiles are certainly the mainstream of new energy automobile development in the next decade.

However, due to the concern of charging convenience, the enthusiasm of potential consumer groups for purchasing new energy automobiles is greatly influenced, and meanwhile, the problem that the vehicles are stranded due to the fact that the electric quantity of the power battery is exhausted is also frequently worried about in the daily vehicle using process of pure electric vehicles.

In order to avoid the problem that the use experience of a vehicle user on the pure electric vehicle is influenced, and even the use and popularization of the pure electric vehicle are influenced, a plurality of new energy vehicles capable of being charged and discharged are already provided in the market, and the new energy vehicles are provided with a bidirectional vehicle-mounted bidirectional charger capable of being charged and discharged, so that the vehicle can be anchored due to the fact that the electric quantity of a power battery is exhausted in emergency rescue to a certain extent.

For example, chinese patent documents with patent application No. 201720999147.5, entitled "a new energy vehicle-to-vehicle charging system" and patent application No. 201810260158.0, entitled "a vehicle-to-vehicle charging device and method" disclose some solutions for vehicle-to-vehicle charging, but the technical solutions have the following disadvantages: 1. the rescue capability is limited by the electric quantity of a power battery of a discharged vehicle, the risk of re-anchoring the rescue vehicle after the anchored vehicle is charged exists, and the rescue scene is limited; 2. the charging and discharging scheme that direct current is converted into alternating current and alternating current is converted into direct current is adopted in the prior art, and the problems of low electric energy conversion efficiency and low charging rate exist.

Disclosure of Invention

The invention provides a vehicle-to-vehicle charging system of a new energy vehicle and a control method thereof.

The technical scheme of the invention is as follows:

the invention provides a vehicle-to-vehicle charging system, which mainly comprises a discharging vehicle, a charging connecting device and a charging vehicle.

Specifically, the discharging vehicle is a range extending vehicle with a direct-current charging function (a range extender does not directly participate in vehicle driving, and the range extender is only used for generating power for a vehicle power system), and a key subsystem of the discharging vehicle mainly comprises the range extender (integrating a gasoline engine and a generator), a vehicle control unit a, an inverter a, a direct-current charging port a and a power battery a.

The charging vehicle is an electric vehicle with a direct-current charging function, and key subsystems of the charging vehicle mainly comprise a vehicle control unit B, an inverter B, a direct-current charging port B and a power battery B.

The charging connecting device mainly comprises a discharging gun head used for connecting a direct current charging port A of a discharging vehicle, wherein the resistance value of CC2 of the discharging gun head is self-defined by a host factory and is greatly different from the resistance value of direct current charging CC2 recommended by the national standard so that the discharging vehicle can be identified to enter a direct current discharging state. And the resistance value of the charging gun head CC2 is consistent with the resistance value of the national standard recommended DC charging CC2, so that the charging vehicle can be identified to enter a DC charging state. The charging connection control device is used for detecting the connection state of a charging gun and a discharging gun, acquiring the temperature of the gun head of the charging gun and the gun head of the discharging gun and controlling the charging and the discharging of the vehicle through locking and unlocking electronic locks, and meanwhile, the charging connection control device also comprises a communication module which has the capability of communicating with the discharging vehicle. The charging connecting device is only responsible for communicating with the discharging vehicle, and the charging and discharging vehicle completes the connection of the CAN communication interfaces S & lt + & gt and S & lt- & gt through a low-voltage cable and a direct-current charging port of the charging connecting device, so that the communication between the charging and discharging vehicles is realized.

After a power battery A of a discharging vehicle detects that a discharging gun is connected, a charging pile can be simulated according to GB/T27930 direct current charging communication protocol to send a direct current charging related message to the charging vehicle, and the charging vehicle only needs to have a direct current charging function according to national standard requirements without additional change. The discharging vehicle can meet the charging requirement of the charging vehicle and the limiting requirements of charging port over-temperature protection and the like by adjusting the power generation power of the range extender.

The related interaction and flow of the charging vehicle and the discharging vehicle are completely consistent with the direct current pile charging, and no additional modification is needed.

The charging connecting device is mainly used for realizing charging and discharging high-voltage and low-voltage cable connection (including a communication circuit), detecting the connection state of a charging gun and a discharging gun, acquiring the temperature of the gun head of the charging gun and the discharging gun, providing a power supply (A +, A-) for low-voltage auxiliary power supply for the charging vehicle and the discharging vehicle, and waking up the charging vehicle and the discharging vehicle.

After a user finishes connection of a discharging vehicle and a charging vehicle through the charging connection device, the charging connection device firstly provides a power supply (A +, A-) for low-voltage auxiliary power supply for the discharging vehicle to wake up the discharging vehicle, the discharging vehicle recognizes to enter a direct-current discharging state according to the detected CC2 resistance after being woken up, and the vehicle controller 1 of the discharging vehicle controls the vehicle to finish high-voltage electrification. Meanwhile, the discharging vehicle communicates with the charging connecting device to confirm whether the charging vehicle is connected or not, if so, the vehicle controller A of the discharging vehicle controls the range extender to start, and the working mode is the engine rotating speed closed-loop control mode after the range extender is started successfully. After the range extender is started successfully, the power battery A of the discharging vehicle controls and cuts off the main relays K3 and K4 of the discharging vehicle, after the main relays K3 and K4 are cut off, the vehicle control unit A controls the range extender to enter a voltage closed-loop control working mode, the range extender is responsible for maintaining the voltage of a high-voltage system at the current voltage level of the power battery A so as to maintain the power consumption of the high-voltage load of the vehicle, and the power battery 1 simulates a charging pile to send a handshake message to the charging vehicle according to GB/T27930 electric vehicle direct current charging communication protocol.

After the range extender of the discharging vehicle enters a voltage closed-loop control working mode, the charging connecting device provides a power supply with low-voltage auxiliary power supply for the charging vehicle to wake up the charging vehicle and simultaneously controls the electronic lock of the charging gun and the discharging gun to be locked. After the charging vehicle is awakened, the charging vehicle is identified to enter a direct current charging state according to the detected CC2 resistance, and the vehicle controller B of the charging vehicle controls the vehicle to complete high-voltage electrification. And then, the power battery B finishes charging handshake and charging parameter configuration with the discharging vehicle according to GB/T27930 direct current charging communication protocol, and sends the maximum allowable charging total voltage/current/temperature, total energy, state of charge, current voltage and other information of the power battery B to the discharging vehicle. And the power battery B of the charging vehicle judges whether the power battery B is matched with the self state or not according to the received charging parameters and judges whether the power battery B is ready for charging or not, and if the judgment is yes, the power battery B controls to close the direct current charging relays K5 and K6 and sends a message of ready for charging to the discharging vehicle.

After the discharging vehicle receives a charging readiness message of the charging vehicle, the vehicle control unit A controls the range extender to carry out voltage regulation, the current voltage of the power battery B of the charging vehicle is taken as a target to control the output voltage of the range extender, and after the power battery A judges that the absolute value of the difference value between the output voltage of the range extender and the current voltage of the power battery B is lower than a certain value, the direct current charging relays K1 and K2 are controlled to be closed, and the charging readiness message is sent to the charging vehicle. After receiving the charge ready message sent by the discharging vehicle, the power battery B of the charging vehicle starts to send battery charge state information such as required voltage, required current, charge mode and the like to the discharging vehicle, and the discharging vehicle feeds back the battery charge state information such as output voltage/current, accumulated charge time and the like to the charging vehicle.

After the direct-current charging relays K1 and K2 are closed, the vehicle control unit A of the discharging vehicle controls the range extender to exit the voltage and rotating speed closed-loop control working mode and enter the motor rotating speed closed-loop control working mode. And then, the discharging vehicle comprehensively calculates the target generating power of the range extender according to the required current and the total battery voltage sent by the power battery B, the actual consumed power of the high-voltage load of the discharging vehicle, the temperature of the direct-current charging seat, the temperature of the charging gun head, the temperature of the discharging gun head and the generating capacity of the range extender, and controls the range extender to generate power.

After the vehicle enters the direct-current charging state, if the charging is finished and the user actively stops the charging or the charging and discharging vehicle has a fault requiring the stopping of the charging, the vehicle controller A of the discharging vehicle controls the stopping of the range extender and other high-voltage loads of the vehicle, and after the range extender is stopped, the power battery A controls the direct-current charging relays K1 and K2 to be disconnected. And after the charging vehicle judges that the charging current is lower than a certain value, the power battery B controls the direct current charging relays K5 and K6 to be disconnected.

After the charging connecting device confirms that the direct-current charging relays K1 and K2 are disconnected, the charging connecting device controls the electronic locks of the charging guns and the discharging guns to be unlocked, the power supply for supplying low-voltage auxiliary power to the charging vehicles and the discharging vehicles is stopped, and the charging vehicles and the discharging vehicles respectively finish power-off and dormancy.

Another object of the present invention is to provide a method for controlling a vehicle-to-vehicle charging system, which includes the steps of:

step 1, a charging connection device completes connection A of a discharging vehicle and a charging vehicle;

step 2, the vehicle control unit A of the discharging vehicle controls the range extender to start, and the main relays K3 and K4 are switched off to prepare for external power generation of the range extender;

step 3, the vehicle control unit A controls the range extender to enter a voltage closed-loop control working mode, a charging vehicle is awakened, the electronic lock of the charging gun and the discharging gun is controlled to be locked, the charging vehicle is identified to enter a direct-current charging state, and the vehicle control unit B controls the charging vehicle to complete high-voltage electrification;

step 4, entering a direct current charging process to prepare for charging;

step 5, the vehicle control unit A controls the range extender to regulate the voltage, so that the voltage difference between two ends of the direct-current charging relays K1 and K2 is in a certain range;

step 6, controlling the direct-current charging relays K1 and K2 to be closed, and enabling the charging vehicle and the discharging vehicle to mutually send battery charging state information;

step 7, entering a motor rotating speed closed-loop control working mode;

step 8, entering direct current charging control, calculating target generating power of the range extender, and controlling the range extender to generate power according to the target generating power;

step 9, judging the charging stop condition, and turning off the range extender;

step 10, controlling the direct current charging relays K1, K2, K5 and K6 to be disconnected, controlling the electronic locks of the charging guns and the discharging guns to be unlocked, and stopping providing a power supply (A +, A-) of low-voltage auxiliary power supply for the charging vehicles and the discharging vehicles;

and 11, completing power-off and dormancy of the charging and discharging vehicles respectively.

By adopting the technical scheme, the invention can realize that the range extender carried by the discharging vehicle is started to generate power after the discharging vehicle arrives at a rescue site, the inverter carried by the discharging vehicle converts three-phase alternating current into direct current, and the direct current is directly transmitted to the charging vehicle through the direct current charging port and the charging connecting device.

The charging connection device is used as key equipment for connecting charging and discharging vehicles, so that real-time communication between the charging and discharging vehicles is realized, the generated power of the discharging vehicle is adjusted in real time according to the charging requirement and the receiving capacity of the charging vehicle, and the state monitoring of a charging and discharging connection loop is realized. And this charging connection device can realize the effect that the simulation was filled electric pile, and the vehicle that charges only need be according to the national standard design of direct current charging, need not other improvements for the vehicle that discharges can be towards all electric automobile that possess the direct current function of charging on the market, but the rescue scope is showing and is widening.

The invention is simple, reliable and feasible, the rescue function is arranged in the extended-range automobile, other hardware systems are not required to be additionally arranged on the charging and discharging automobiles, the automobile cost is not increased, the rescue can be implemented for other electric automobiles with the power battery exhausted at any time, the rescue capability is not limited by the power battery of the discharging automobile, and the rescue range can be remarkably widened. Meanwhile, the invention directly adopts a charging and discharging scheme of converting alternating current into direct current, thereby improving the electric energy conversion efficiency and obviously improving the rescue charging rate. By applying the technical scheme, the market rescue response capability and the customer vehicle using experience can be greatly improved.

Drawings

FIG. 1 is a schematic diagram of a vehicle-to-vehicle charging system for a new energy vehicle according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a vehicle-to-vehicle charging control flow of a new energy vehicle according to an embodiment of the invention;

in the figure, 1-range extender; 2-vehicle controller A; 3-inverter a; 4-direct current charging port A; 5-power battery A; 6-charging connection means; 7-inverter B; 8-direct current charging port B; 9-power battery B; 10-vehicle controller B; 51-direct current charging relays K1, K2 of the power battery A; 52-main relays K3, K4 of power battery A; 91-direct current charging relays K5, K6 of power battery B; 92-main relays K7, K8 of power battery B.

Detailed Description

The invention is further described with reference to the accompanying drawings in which:

the first embodiment is as follows:

as shown in fig. 1, the present embodiment is a vehicle-to-vehicle charging system, which mainly includes a discharging vehicle, a charging connection device, and a charging vehicle.

Specifically, the discharging vehicle is a range extending vehicle with a direct-current charging function (a range extender of the discharging vehicle does not directly participate in vehicle driving, and the range extender is only used for generating power for a vehicle power system), and a key subsystem of the discharging vehicle mainly comprises the range extender (integrating a gasoline engine and a generator), a vehicle control unit A, an inverter A, a direct-current charging port A and a power battery A (including a battery control unit), and information interaction is performed among all the control units through a CAN network. When the vehicle runs normally, the alternating current three-phase power generated by the range extender is subjected to alternating current-direct current conversion through the inverter A and then is charged into the power battery A, and the alternating current three-phase power can also be directly used for driving the motor to drive; when the emergency vehicle is used as a rescue vehicle, after the power battery A of the discharging vehicle detects that a discharging gun is connected, a direct-current charging related message can be sent to the charging vehicle by a simulation charging pile according to GB/T27930 direct-current charging communication protocol of the electric vehicle, after direct-current charging of the charging vehicle and the discharging vehicle is ready, alternating-current three-phase power sent by a range extender can be directly used for charging the power battery of the anchoring vehicle after alternating-current three-phase power is subjected to alternating-current-direct-current conversion through an inverter A, and the discharging vehicle can meet the charging requirement of the charging vehicle and the limiting requirements of over-temperature protection of a charging port and the like by adjusting the power generation of the range extender.

The charging vehicle is an electric vehicle with a direct-current charging function, key subsystems of the charging vehicle mainly comprise a vehicle control unit B, an inverter B, a direct-current charging port B and a power battery B (comprising a battery control unit), the charging vehicle needs to have the direct-current charging function meeting national standard requirements, and relevant interaction and flow of the charging vehicle and a discharging vehicle are completely consistent with that of direct-current pile charging without other additional changes.

The charging connecting device mainly comprises a discharging gun head used for connecting a direct current charging port A of a discharging vehicle, wherein the resistance value of CC2 of the discharging gun head is self-defined by a host factory and is greatly different from the resistance value of direct current charging CC2 recommended by the national standard so that the discharging vehicle can be identified to enter a direct current discharging state. And the resistance value of the charging gun head CC2 is consistent with the resistance value of the national standard recommended DC charging CC2, so that the charging vehicle can be identified to enter a DC charging state. The charging connection control device is used for detecting the connection state of a charging gun and a discharging gun, acquiring the temperature of the gun head of the charging gun and the discharging gun and controlling the charging and discharging vehicle charging electronic lock release and locking, and meanwhile, the charging connection control device also has the capability of communicating with the discharging vehicle.

The charging connecting device is mainly used for realizing charging and discharging high-voltage and low-voltage cable connection (including a communication circuit), detecting the connection state of a charging gun and a discharging gun, acquiring the temperature of the gun head of the charging gun and the discharging gun, providing a power supply (A +, A-) for low-voltage auxiliary power supply for the charging vehicle and the discharging vehicle, and waking up the charging vehicle and the discharging vehicle.

Example two:

on the basis of the first embodiment, the present embodiment provides a vehicle-to-vehicle charging control method for a new energy vehicle, which generally includes the following steps:

step 1, the charging connection device completes the connection of the discharging vehicle and the charging vehicle.

And step 2, controlling the range extender to start by the vehicle control unit A of the discharging vehicle, and cutting off the main relays K3 and K4 to prepare for external power generation of the range extender.

And 3, controlling the range extender to enter a voltage closed-loop control working mode by the vehicle control unit A, awakening the charging vehicle, controlling the electronic lock of the charging gun and the discharging gun to be locked, identifying that the charging vehicle enters a direct-current charging state, and controlling the charging vehicle to finish high-voltage electrification by the vehicle control unit B.

And 4, entering a direct current charging process to prepare for charging.

And 5, controlling the range extender to regulate the voltage by the vehicle control unit A, so that the voltage difference between two ends of the direct-current charging relays K1 and K2 is within a certain range.

And 6, controlling the direct current charging relays K1 and K2 to be closed, and enabling the charging vehicle and the discharging vehicle to mutually send the battery charging state information.

And 7, entering a motor rotating speed closed-loop control working mode.

And 8, performing direct current charging control, calculating the target generating power of the range extender, and controlling the range extender to generate power according to the target generating power.

And 9, judging the charging stop condition and turning off the range extender.

And step 10, controlling the direct current charging relays K1, K2, K5 and K6 to be disconnected, controlling the electronic locks of the charging guns and the discharging guns to be unlocked, and stopping providing a power supply (A + and A-) of low-voltage auxiliary power supply for the charging vehicles and the discharging vehicles.

And 11, completing power-off and dormancy of the charging and discharging vehicles respectively.

Logic steps of the above method in more detail are shown in fig. 2, and include:

in step a01, the user completes the connection of the discharging vehicle and the charging vehicle through the charging connection device. Step a01 may be directly proceeded to step a02, where in step a02, the charging connection device performs detection and determination of the connection state of the charging and discharging guns, confirms whether the charging and discharging guns are in the complete connection state, and if yes, proceeds to step a03, and if no, returns to step a01 to continue to wait for the user to complete the connection between the discharging vehicle and the charging vehicle.

In step a03, the charging interface wakes up the discharging vehicle from the power supply (a +, a-) that provides low-voltage auxiliary power to the discharging vehicle. Step a03 may directly enter step a04, in step a04, the discharging vehicle is waken up and then recognizes that the vehicle enters a dc discharging state according to the detected CC2 resistance, and the vehicle controller a of the discharging vehicle controls the vehicle to complete high-voltage power-on. Step a04 may be directly proceeded to step a05, where in step a05, the discharging vehicle communicates with the charging connection device to confirm whether the charging vehicle has completed connection, and if yes, step a06 is proceeded, and if no, step a05 is proceeded to wait for the charging vehicle to complete connection.

In step a06, the vehicle control unit a of the discharging vehicle controls the range extender to start, and after the range extender is successfully started, the operating mode of the range extender is controlled to be the engine speed closed-loop control mode. Step a06 may directly enter step a07, in step a07, the vehicle control unit a needs to determine whether the range extender is started successfully, if yes, step a08 is entered, if no, step a06 is returned, the attempt to start the range extender is made again, and if the number of times of the start of the range extender is exceeded, the current charging is ended.

In step a08, the power battery a of the discharging vehicle controls to cut off the main relays K3 and K4 thereof in preparation for the range extender to generate electricity externally. Step a08 may directly proceed to step a09, in step a09, the power battery a needs to determine whether the main relays K3, K4 are successfully cut off, if yes, step a10 is performed, if no, step a08 is performed, and the main relays K3, K4 are waited to be cut off.

In step a10, the vehicle control unit a controls the range extender to enter a voltage closed-loop control mode, and the range extender is responsible for maintaining the voltage of the high-voltage system at the current voltage level of the power battery a so as to maintain the high-voltage load power utilization of the discharging vehicle. Meanwhile, the power battery A simulates a charging pile to send a handshake message to a charging vehicle according to GB/T27930 direct current charging communication protocol of the electric vehicle. Step a10 may directly enter step a11, in step a11, the vehicle control unit a needs to determine whether the range extender has entered the voltage closed-loop control operating mode, if yes, step a12 is entered, if no, step a10 is returned, and the vehicle control unit waits for the range extender to enter the voltage closed-loop control operating mode.

In step A12, the charging connection device provides a power supply (A +, A-) of low-voltage auxiliary power supply for the charging vehicle to wake up the charging vehicle and simultaneously control the locking of the electronic lock of the charging and discharging gun. Step a12 may directly enter step a13, in step a13, the charging vehicle wakes up and recognizes that the vehicle enters a dc charging state according to the detected CC2 resistance, and the vehicle controller a of the charging vehicle controls the vehicle to complete high-voltage power-on.

Step a13 may directly enter step a14, and in step a14, the power battery B completes charging handshake and charging parameter configuration with the discharging vehicle according to GB/T27930 "direct current charging communication protocol of electric vehicle", and sends information such as maximum allowable charging total voltage/current/temperature, total energy, state of charge, current voltage, and the like of the power battery B to the discharging vehicle. Meanwhile, the power battery a of the discharging vehicle transmits information of the maximum/minimum output voltage, the maximum/minimum output current, and the like of the discharging vehicle to the charging vehicle.

Step a14 may be directly proceeded to step a15, in step a15, the power battery B of the charging vehicle determines whether to match its own state according to the received charging parameters, and determines whether to be ready to charge itself, if yes, step a16 is proceeded to, if no, step a15 is returned to, waiting for ready to charge, and if not, the charging is ended.

In step a16, the power battery B controls to close the dc charging relays K5, K6 and sends a charge ready message to the discharging vehicle. Step a16 may directly enter step a17, and in step a17, after the discharging vehicle receives the charge readiness message, the vehicle controller a controls the range extender to perform voltage regulation, and regulates the output voltage of the range extender with the current voltage of the charging vehicle power battery B as a target, so that the voltage difference between the two ends of the dc charging relays K1 and K2 is within a certain range. Step a17 may directly enter step a18, in step a18, the power battery a determines whether the absolute value of the difference between the output voltage of the range extender and the current voltage of the power battery B is lower than a certain value, if yes, step a19 is entered, if no, step a17 is returned, the range extender is waited to complete the pressure difference adjustment, and if the pressure difference adjustment at both ends of the dc charging relays K1 and K2 is not completed after a certain time, the charging is finished.

In step a19, the power battery a controls the dc charging relays K1 and K2 to close and send a charging ready message to the charging vehicle, the power battery B of the charging vehicle starts to send battery charging state information such as required voltage, required current, and charging mode to the discharging vehicle after receiving the charging ready message sent by the discharging vehicle, and the discharging vehicle feeds back the battery charging state information such as output voltage/current and accumulated charging time to the charging vehicle. Step a19 may directly enter step a20, in step a20, the power battery a detects and determines whether the dc charging relays K1 and K2 are closed, if yes, step a21 is entered, if no, step a19 is returned, the dc charging relays K1 and K2 are waited for closing, and if the dc charging relays K1 and K2 are not closed for a certain time, the charging is ended.

In step a21, the vehicle control unit a of the discharging vehicle controls the range extender to exit the voltage and rotation speed closed-loop control working mode, and enters the motor rotation speed closed-loop control working mode to prepare for the adjustment of the generated power. Step A21 may directly enter step A22, in step A22, the vehicle control unit A detects and judges whether the range extender has entered the motor speed closed-loop control mode, if yes, step A23 is entered, if no, step A21 is returned, the range extender is waited to enter the motor speed closed-loop control mode, if the range extender has not entered the motor speed closed-loop control mode for a certain time, the charging is ended.

In step a23, the discharging vehicle calculates the current required power generation power of the charging vehicle according to the required current sent by the power battery B and the total battery voltage, and adds the current self actual power consumption of the discharging vehicle to serve as the target power generation power of the range extender. The range extender target generated power also takes the following dimensional correction limit into consideration: and finally, comprehensively calculating the target power generation power of the range extender, and controlling the range extender to generate power according to the target power generation power. Step a23 may be directly proceeded to step a24, and the determination of the charging stop condition is performed in step a24, where the determination includes that the charging is completed by the charging vehicle, the charging connection device detects that the user pulls the gun to actively stop charging, or the charging and discharging vehicle has a fault requiring to stop charging. If yes, the process proceeds to step a25, and if no, the process returns to step a23 to continue charging and wait for the charging stop condition to be satisfied.

In step a25, the vehicle controller a of the discharging vehicle controls the shutdown range extender and other high-voltage loads of the vehicle to prepare for cutting off the dc charging relay. Step a25 may be directly proceeded to step a26, where the determination of completion of the shutdown of the range extender is performed in step a26, if the determination is "yes", step a27 is proceeded, and if the determination is "no", step a25 is returned to wait for completion of the shutdown of the range extender.

In step a27, the power battery a controls the dc charging relays K1, K2 to open. Meanwhile, after the charging vehicle judges that the charging current is lower than a certain value, the power battery B controls the direct-current charging relays K5 and K6 to be disconnected. Step a27 may directly proceed to step a28, where the charging connection device performs disconnection determination of the dc charging relays K1 and K2 in step a28, and if the determination is "yes", step a29 is performed, and if the determination is "no", step a27 is performed, and the dc charging relays K1 and K2 are waited to be disconnected.

In step a29, the charging connection device controls the electronic lock of the charging and discharging gun to unlock, and stops providing the power supply (a +, a-) of the low-voltage auxiliary power supply for the charging and discharging vehicle, so as to prepare for powering off and sleeping the charging and discharging vehicle.

Step a29 may be directed to step a30 where the charging and discharging vehicles are powered down and hibernated at step a30, respectively.

The embodiment shows that the three-phase alternating current is converted into the direct current by the inverter carried by the discharging vehicle, the direct current is directly transmitted to the charging vehicle by the direct current charging port and the charging connecting device, the charging speed is high, the charging efficiency is high, and the charging vehicle is not limited by the electric quantity of the power battery of the discharging vehicle.

The above-described embodiments of the present invention should not be construed as limiting the scope of the present invention. Any other corresponding changes and modifications made according to the technical idea of the present invention should be included in the protection scope of the claims of the present invention.