阅读说明：本技术 一种直流v2v电动汽车充放电装置及其方法 (Direct-current V2V electric vehicle charging and discharging device and method thereof ) 是由 何开堤 柳永旭 夏涛 苏明明 于 2021-08-14 设计创作，主要内容包括：本发明公开了一种直流V2V电动汽车充放电装置及其方法,包括与直流放电车相连的直流放电接头、V2V转换设备和与直流充电车辆相连的直流充电转换接头,所述直流放电接头包括CC1电阻检测电路、CC2电阻检测电路、DC+/DC-回路、A+/A-回路、S+/S-回路、电阻R2、电阻R3、电阻R4,所述V2V转换设备包括V2V控制器和用于升压/降压的DC/DC变换器、电阻R1、电阻R1’,采用上述技术方案,通过对充放电车辆的数据参数监控,并通过对升压、降压的调整,从而可进行任意两辆电动车之间的直流充放电；在直流充放电时,对升压、降压的调控,从而不受蓄电池电池参数的影响。(The invention discloses a charging and discharging device and a charging and discharging method for a direct current V2V electric vehicle, which comprises a direct current discharging joint connected with a direct current discharging vehicle, a V2V conversion device and a direct current charging conversion joint connected with the direct current charging vehicle, wherein the direct current discharging joint comprises a CC1 resistance detection circuit, a CC2 resistance detection circuit, a DC +/DC-loop, an A +/A-loop, an S +/S-loop, a resistor R2, a resistor R3 and a resistor R4, the V2V conversion device comprises a V2V controller, a DC/DC converter used for boosting/reducing voltage, a resistor R1 and a resistor R1', and by adopting the technical scheme, through monitoring data parameters of the charging and discharging vehicle and through adjustment of boosting and reducing voltage, direct current charging and discharging between any two electric vehicles can be carried out; during direct current charging and discharging, the regulation and control of voltage boosting and voltage reducing are carried out, so that the influence of battery parameters of the storage battery is avoided.)

1. A charging and discharging device of a direct current V2V electric automobile is characterized by comprising a direct current discharging joint connected with a direct current discharging vehicle, a V2V conversion device and a direct current charging conversion joint connected with a direct current charging vehicle, the direct current discharge joint comprises a CC1 resistance detection circuit, a CC2 resistance detection circuit, a DC +/DC-loop, an A +/A-loop, an S +/S-loop, a resistor R2, a resistor R3 and a resistor R4, the V2V conversion device comprises a V2V controller, a DC/DC converter for voltage boosting/reducing and isolation, a resistor R1, a resistor R1', the V2V controller comprises a low-voltage power supply port A +, a low-voltage power supply port A-, a CC1 detection port, a CC1 ' detection port, a communication port S +, a communication port S-, a communication port S + ', and a communication port S- '; the direct-current charging connector comprises a CC1 ' resistance detection circuit, a CC2 ' resistance detection circuit, a DC + '/DC- ' circuit, an A + '/A- ' circuit, an S + '/S- ' circuit, a resistor R2 ', a resistor R3 ', a resistor R4 ', a CC2 resistance detection circuit is connected with one end of a resistor R3, the CC1 resistance detection circuit divides voltage through a resistor R2 and a resistor R4, a sampling port of the CC1 resistance detection circuit is connected with a CC1 detection port, a CC1 detection port is connected with one end of a resistor R1, the DC +/DC-circuit is connected to the input end of a DC/DC converter, the A +/A-circuit is respectively connected with a low-voltage power supply port A + and a low-voltage power supply port A-, and the S +/S-circuit is respectively connected with a communication port S + and a communication port S-, the data acquisition unit is used for acquiring data parameters of the direct current discharge vehicle; the CC2 ' resistance detection circuit is connected with one end of a resistor R3 ', the CC1 ' resistance detection circuit divides voltage through a resistor R2 ' and a resistor R4 ', a sampling port of the CC1 ' resistance detection circuit is connected with a CC1 ' detection port, a CC1 ' detection port is connected with one end of a resistor R1 ', the DC + '/DC- ' loop is connected to the input end of the DC/DC converter, the A + '/A- ' loop is respectively connected with a low-voltage power supply port A + ' and a low-voltage power supply port A- ', and the S + '/S- ' loop is respectively connected with a communication port S + ' and a communication port S- ' and used for obtaining data parameters of the direct-current charging electric vehicle.

2. The DC V2V electric vehicle charging and discharging device according to claim 1, the V2V conversion equipment also comprises a high-voltage relay K1, a high-voltage relay K2, a high-voltage relay K1 'and a high-voltage relay K2', two ends of the high-voltage relay K1 are respectively connected with the DC + output end of the DC +/DC-loop and the input end of the DC/DC converter, two ends of the high-voltage relay K2 are respectively connected with the DC-output end of the DC +/DC-loop and the input end of the DC/DC converter, two ends of the high-voltage relay K1 'are respectively connected with the DC +' input end of the DC + '/DC-' loop and the output end of the DC/DC converter, the two ends of the high-voltage relay K2 'are respectively connected with the DC-' input end of the DC + '/DC-' loop and the output end of the DC/DC converter.

3. The direct-current V2V electric vehicle charging and discharging device according to claim 2, wherein the DC +/DC-loop and the DC/DC converter are connected with each other by: the direct-current discharge side IMD circuit is used for measuring insulation resistance values between a DC + port and a grounding terminal of the direct-current discharge side and between the DC-port and the grounding terminal; the direct current discharge side bleeder circuit is used for ensuring that the voltage of a DC +/DC-port is not high by 60V when the direct current discharge side is separated from a direct current discharge vehicle; FUSE for ensuring that the discharge loop of the direct current discharge side can be cut off in time when short-circuit fault occurs during discharge; the direct current discharge side current measuring circuit is used for detecting the discharge current of the direct current discharge side in real time; and the direct current discharge side current measuring circuit is used for detecting the direct current discharge side discharge current in real time.

4. The charging and discharging device for the direct current V2V electric vehicle according to claim 3, wherein a DC/DC converter is connected between the DC + '/DC-' loop and the DC/DC converter: the direct-current charging side IMD circuit is used for measuring insulation resistance values between a DC + 'port and a grounding terminal of the direct-current charging side and between the DC-' port and the grounding terminal; a DC charging side bleeder circuit for ensuring that the voltage at the DC + '/DC-' port is not 60V higher when the DC charging side is separated from the DC charging vehicle; FUSE for ensuring that the direct current charging side can cut off the discharging loop of the direct current charging side in time when short-circuit fault occurs during discharging; the direct current charging side current measuring circuit is used for detecting the charging current of the direct current charging side in real time; and the direct current charging side current measuring circuit is used for detecting the discharge current of the direct current charging side in real time.

5. The charging and discharging device for the direct current V2V electric vehicle as recited in claim 4, wherein a direct current discharging side voltage measuring circuit is connected between said DC +/DC-circuit and said DC/DC converter, a direct current charging side voltage measuring circuit is connected between said DC + '/DC-circuit and said DC/DC converter, a high voltage relay K1 ' is connected between a DC + ' input end of said DC + '/DC-circuit and an output end of said DC/DC converter, and a high voltage relay K2 ' is connected between a DC- ' input end of said DC + '/DC-circuit and an output end of said DC/DC converter.

6. The dc V2V electric vehicle charge-discharge device according to claim 1, wherein the dc discharge electric vehicle data parameters include minimum allowed discharge current, maximum allowed discharge current, minimum allowed discharge voltage, maximum allowed discharge voltage, and minimum allowed discharge SOC; the data parameters of the dc charging electric vehicle include a minimum allowed charging current, a maximum allowed charging current, a minimum allowed charging voltage, a maximum allowed charging voltage, a minimum allowed charging SOC, a charging voltage of a currently requested charging, a currently requested charging current, and a current SOC.

7. The DC V2V electric vehicle charging and discharging device according to claim 1, wherein the V2V controller communicates with the DC/DC converter via CAN, and the V2V controller communicates with the communication port S +, the communication port S-, the communication port S + 'and the communication port S-'.

8. The DC V2V electric vehicle charging and discharging device according to claim 6, wherein the DC/DC converter output voltage and current should not exceed the requested voltage and current of the DC charging vehicle, and the DC/DC converter operating power is the smaller of the DC discharging vehicle and the DC charging vehicle.

9. The charging and discharging method for the direct current V2V electric vehicle according to any one of claims 1-8, characterized by comprising the following steps:

s1, acquiring data parameters of the direct current discharging vehicle and data parameters of the direct current charging vehicle;

s2, performing voltage boosting/reducing adjustment on the DC/DC converter according to the acquired data parameters;

s3, charging and discharging;

and S4, monitoring and adjusting the charge and discharge state in real time.

10. The method for charging and discharging the direct current V2V electric vehicle of claim 9, wherein the step S4 comprises: detecting whether an auxiliary power supply is needed; detecting insulation resistance values between DC + and DC-on the direct current discharge side and grounding ends respectively, and ensuring that the insulation performance of the direct current discharge side is good; detecting the redundant energy release of the DC + and the DC-bus at the direct current discharge side, and ensuring that the voltage of a DC + DC-port is not higher than 60V when the direct current discharge side is separated from a direct current discharge vehicle; detecting the protection of the direct current discharge side, ensuring that the direct current discharge side has short-circuit fault during discharging and cutting off a discharge loop of the direct current discharge side in time; detecting the current output by the direct current discharging vehicle; measuring the voltage of the battery at the direct current charging side to ensure the consistency of the parameters of the battery at the direct current discharging side; measuring the insulation resistance between the DC + '/DC-' of the direct current charging side and a grounding end to ensure that the insulation performance of the direct current charging side is good; detecting the discharge of the direct current charging side between the direct current charging vehicle and the direct current charging vehicle, and ensuring that the voltage of a DC + 'DC-' port is not higher than 60V when the direct current charging side is disconnected; the short-circuit fault of the direct-current charging side during charging is ensured through FUSE, and a discharging loop of the direct-current charging side can be cut off in time; and detecting the charging current of the direct current charging side in real time.

Technical Field

The invention relates to the technical field of charging and discharging of new energy automobiles, in particular to a charging and discharging device and method for a direct-current V2V electric automobile.

Background

The electric vehicle is taken as an outstanding representative of new energy, has the advantages of environmental protection, energy conservation and the like, and is replacing the traditional fuel oil vehicle.

At present, in order to meet the requirements of charging and discharging of an electric automobile, the electric automobile has an alternating current vehicle-to-vehicle charging and discharging function at present, but the application of the direct current vehicle-to-vehicle charging and discharging is relatively less. The vehicle-to-vehicle charging and discharging scheme is widely applied to the field of electric vehicles, a direct current V2V device in the current market is in a form of a cable, two ends of the cable are respectively connected with a charging gun head, one end of the gun head is connected into a charging vehicle, the other end of the gun head is connected into a discharging vehicle, vehicle-to-vehicle charging and discharging are directly achieved, and other power converter circuits are not arranged in the middle of the gun head.

In the implementation process, the inventor finds that at least the following problems exist in the conventional technology:

in the traditional scheme, a direct current vehicle charges and discharges the vehicle, energy can be transmitted only from a direction with higher battery voltage to a direction with lower battery voltage, and the energy transmission from the direction with higher battery energy to the direction with lower battery energy cannot be realized;

according to the traditional scheme, a direct current vehicle charges and discharges the vehicle, and charging and discharging voltage and current are influenced by parameters of a battery of the charging and discharging vehicle, wherein the parameters mainly comprise battery open-circuit voltage, battery internal resistance and the like;

according to the traditional scheme, the direct current vehicle charges and discharges the vehicle, and large potential safety hazards exist because the discharged vehicle battery and the charged vehicle battery are not electrically isolated.

Disclosure of Invention

The invention provides a direct current V2V electric vehicle charging and discharging device and a method thereof according to the defects of the prior art, which can realize direct current charging and discharging between any two electric vehicles.

In order to solve the technical problems, the technical scheme of the invention is as follows:

a direct current V2V electric vehicle charging and discharging device comprises a direct current discharging joint connected with a direct current discharging vehicle, a V2V conversion device and a direct current charging conversion joint connected with a direct current charging vehicle, wherein the direct current discharging joint comprises a CC1 resistance detection circuit, a CC2 resistance detection circuit, a DC +/DC loop, an A +/A loop, an S +/S loop, a resistor R2, a resistor R3 and a resistor R4, the V2V conversion device comprises a V2V controller, a DC/DC converter with boosting/reducing voltage and isolation functions, a resistor R1 and a resistor R1 ', the V2V controller comprises a low-voltage power supply port A +, a low-voltage power supply port A-, a CC1 detection port, a CC 1' detection port, a communication port S + ', and a communication port S'; the direct-current charging connector comprises a CC1 ' resistance detection circuit, a CC2 ' resistance detection circuit, a DC + '/DC- ' circuit, an A + '/A- ' circuit, an S + '/S- ' circuit, a resistor R2 ', a resistor R3 ', a resistor R4 ', a CC2 resistance detection circuit is connected with one end of a resistor R3, the CC1 resistance detection circuit divides voltage through a resistor R2 and a resistor R4, a sampling port of the CC1 resistance detection circuit is connected with a CC1 detection port, a CC1 detection port is connected with one end of a resistor R1, the DC +/DC-circuit is connected to the input end of a DC/DC converter, the A +/A-circuit is respectively connected with a low-voltage power supply port A + and a low-voltage power supply port A-, and the S +/S-circuit is respectively connected with a communication port S + and a communication port S-, the data acquisition unit is used for acquiring data parameters of the direct current discharge vehicle; the CC2 ' resistance detection circuit is connected with one end of a resistor R3 ', the CC1 ' resistance detection circuit divides voltage through a resistor R2 ' and a resistor R4 ', a sampling port of the CC1 ' resistance detection circuit is connected with a CC1 ' detection port, a CC1 ' detection port is connected with one end of a resistor R1 ', the DC + '/DC- ' loop is connected to the input end of the DC/DC converter, the A + '/A- ' loop is respectively connected with a low-voltage power supply port A + ' and a low-voltage power supply port A- ', and the S + '/S- ' loop is respectively connected with a communication port S + ' and a communication port S- ' and used for obtaining data parameters of the direct-current charging electric vehicle.

Preferably, the V2V switching device further includes a high voltage relay K1, a high voltage relay K2, a high voltage relay K1 'and a high voltage relay K2', wherein two ends of the high voltage relay K1 are respectively connected to a DC + output terminal of the DC +/DC-circuit and an input terminal of the DC/DC converter, two ends of the high voltage relay K2 are respectively connected to a DC-output terminal of the DC +/DC-circuit and an input terminal of the DC/DC converter, two ends of the high voltage relay K1 'are respectively connected to a DC +' input terminal of the DC + '/DC-circuit and an output terminal of the DC/DC converter, and two ends of the high voltage relay K2' are respectively connected to a DC- 'input terminal of the DC +'/DC-circuit and an output terminal of the DC/DC converter.

Preferably, the DC +/DC-circuit and the DC/DC converter are connected by: the direct-current discharge side IMD circuit is used for measuring insulation resistance values between a DC + port and a grounding terminal of the direct-current discharge side and between the DC-port and the grounding terminal; the direct current discharge side bleeder circuit is used for ensuring that the voltage of a DC +/DC-port is not high by 60V when the direct current discharge side is separated from a direct current discharge vehicle; FUSE for ensuring that the discharge loop of the direct current discharge side can be cut off in time when short-circuit fault occurs during discharge; the direct current discharge side current measuring circuit is used for detecting the discharge current of the direct current discharge side in real time; and the direct current discharge side current measuring circuit is used for detecting the direct current discharge side discharge current in real time.

Preferably, the DC +'/DC-loop and the DC/DC converter are connected by: the direct-current charging side IMD circuit is used for measuring insulation resistance values between a DC + 'port and a grounding terminal of the direct-current charging side and between the DC-' port and the grounding terminal; a DC charging side bleeder circuit for ensuring that the voltage at the DC + '/DC-' port is not 60V higher when the DC charging side is separated from the DC charging vehicle; FUSE for ensuring that the direct current charging side can cut off the discharging loop of the direct current charging side in time when short-circuit fault occurs during discharging; the direct current charging side current measuring circuit is used for detecting the charging current of the direct current charging side in real time; and the direct current charging side current measuring circuit is used for detecting the discharge current of the direct current charging side in real time.

Preferably, a DC discharge side voltage measuring circuit is connected between the DC +/DC-circuit and the DC/DC converter, and a DC charge side voltage measuring circuit is connected between the DC +'/DC-circuit and the DC/DC converter.

Preferably, the data parameters of the dc discharge electric vehicle include a minimum allowable discharge current, a maximum allowable discharge current, a minimum allowable discharge voltage, a maximum allowable discharge voltage, and a minimum allowable discharge SOC; the data parameters of the dc charging electric vehicle include a minimum allowed charging current, a maximum allowed charging current, a minimum allowed charging voltage, a maximum allowed charging voltage, a minimum allowed charging SOC, a charging voltage of a currently requested charging, a currently requested charging current, and a current SOC.

Preferably, the V2V controller communicates with the DC/DC converter through CAN, and the V2V controller communicates with the DC discharging vehicle through a communication port S +, a communication port S-and BMS; the communication port S + 'and the communication port S-' communicate with the DC charging vehicle in BMS communication.

Preferably, the DC/DC converter outputs a voltage and a current that do not exceed a requested voltage and a requested current of the DC charging vehicle, and the DC/DC converter operates at a lower power than the DC discharging vehicle and the DC charging vehicle.

A charging and discharging method for a direct current V2V electric automobile is characterized by comprising the following steps:

s1, acquiring BMS data parameters of the direct current discharging vehicle and BMS data parameters of the direct current charging vehicle;

s2, performing voltage boosting/reducing adjustment on the DC/DC converter according to the acquired BMS data parameters;

s3, charging and discharging;

and S4, monitoring and adjusting the charge and discharge state in real time.

Preferably, the step S4 includes: detecting whether an auxiliary power supply is needed; detecting insulation resistance values between DC + and DC-on the direct current discharge side and grounding ends respectively, and ensuring that the insulation performance of the direct current discharge side is good; detecting the redundant energy release of the DC + and the DC-bus at the direct current discharge side, and ensuring that the voltage of a DC + DC-port is not higher than 60V when the direct current discharge side is separated from a direct current discharge vehicle; detecting the protection of the direct current discharge side, ensuring that the direct current discharge side has short-circuit fault during discharging and cutting off a discharge loop of the direct current discharge side in time; detecting the current output by the direct current discharging vehicle; measuring the voltage of the battery at the direct current charging side to ensure the consistency of the parameters of the battery at the direct current discharging side; measuring the insulation resistance between the DC + '/DC-' of the direct current charging side and a grounding end to ensure that the insulation performance of the direct current charging side is good; detecting the discharge of the direct current charging side between the direct current charging vehicle and the direct current charging vehicle, and ensuring that the voltage of a DC + 'DC-' port is not higher than 60V when the direct current charging side is disconnected; the short-circuit fault of the direct-current charging side during charging is ensured through FUSE, and a discharging loop of the direct-current charging side can be cut off in time; and detecting the charging current of the direct current charging side in real time.

The invention has the following characteristics and beneficial effects:

by adopting the technical scheme, the BMS data parameters of the charging and discharging vehicles are monitored, and the DC/DC converter is subjected to voltage boosting/reducing control, so that direct current charging and discharging between any two electric vehicles can be carried out; when charging and discharging the direct current, the DC/DC converter is subjected to voltage boosting/reducing control, so that the influence of battery parameters of the storage battery is avoided.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic diagram of the principle of the embodiment of the present invention.

Fig. 2 is a schematic circuit diagram of the voltage measuring circuit of fig. 1.

Fig. 3 is a schematic circuit diagram of the current measuring circuit of fig. 1.

Fig. 4 is a schematic diagram of the bleeder circuit of fig. 1.

FIG. 5 is a schematic diagram of the CC1 detection port circuit of FIG. 1

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention. Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

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 meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.

The invention provides a direct current V2V electric vehicle charging and discharging device, which comprises a direct current discharging joint connected with a direct current discharging vehicle, a V2V conversion device and a direct current charging conversion joint connected with the direct current charging vehicle, wherein the direct current discharging joint comprises a CC1 resistance detection circuit, a CC2 resistance detection circuit, a DC +/DC-loop, an A +/A-loop, an S +/S-loop, a resistor R2, a resistor R3 and a resistor R4, the V2V conversion device comprises a V2V controller, a DC/DC converter used for boosting/reducing voltage, a resistor R1 and a resistor R1 ', the V2V controller comprises a low-voltage power supply port A +, a low-voltage power supply port A-, a CC1 detection port, a CC 1' detection port, a communication port S + ', and a communication port S'; the direct-current charging connector comprises a CC1 ' resistance detection circuit, a CC2 ' resistance detection circuit, a DC + '/DC- ' circuit, an A + '/A- ' circuit, an S + '/S- ' circuit, a resistor R2 ', a resistor R3 ', a resistor R4 ', a CC2 resistance detection circuit is connected with one end of a resistor R3, the CC1 resistance detection circuit divides voltage through a resistor R2 and a resistor R4, a sampling port of the CC1 resistance detection circuit is connected with a CC1 detection port, a CC1 detection port is connected with one end of a resistor R1, the DC +/DC-circuit is connected to the input end of a DC/DC converter, the A +/A-circuit is respectively connected with a low-voltage power supply port A + and a low-voltage power supply port A-, and the S +/S-circuit is respectively connected with a communication port S + and a communication port S-, the data acquisition unit is used for acquiring data parameters of the direct current discharge vehicle; the CC2 ' resistance detection circuit is connected with one end of a resistor R3 ', the CC1 ' resistance detection circuit divides voltage through a resistor R2 ' and a resistor R4 ', a sampling port of the CC1 ' resistance detection circuit is connected with a CC1 ' detection port, a CC1 ' detection port is connected with one end of a resistor R1 ', the DC + '/DC- ' loop is connected to the input end of the DC/DC converter, the A + '/A- ' loop is respectively connected with a low-voltage power supply port A + ' and a low-voltage power supply port A- ', and the S + '/S- ' loop is respectively connected with a communication port S + ' and a communication port S- ' and used for obtaining data parameters of the direct-current charging electric vehicle.

As can be understood, the dc discharging connector is connected to the dc discharging vehicle, the dc charging connector is connected to the dc charging vehicle, and the electric energy of the dc discharging vehicle is transmitted to the dc charging vehicle through the V2V conversion device.

In the technical scheme, whether the auxiliary power supplies of A + and A-need to be output externally is judged by detecting the resistance value of R3 in the resistance detection circuit of the CC2, so that the auxiliary power supply of 12V10A is provided for the V2V conversion equipment; the V2V controller determines whether the V2V controller and the DC discharging vehicle are well connected through the voltage of the detection port in the CC1 resistance detection circuit; the V2V controller transmits energy through DC +, DC-and DC-discharging vehicles, the V2V controller communicates with the DC-discharging vehicles through S +, S-, acquires battery parameter information of the DC-discharging vehicles through S +, S-, and sets the maximum power point of the V2V conversion equipment through BMS communication. The V2V controller determines whether the V2V conversion device and the charging electric vehicle are reliably connected through the CC1 ' resistance detection circuit, the V2V controller obtains battery parameter information of the direct current charging electric vehicle through S + ' S- ', wherein a data packet generated when data transmission is carried out by BMS communication contains the discharging voltage and the direct current discharging current of the direct current discharging vehicle, and the V2V conversion device obtains the discharging voltage and the direct current discharging current of the direct current discharging vehicle, and further sets a DC/DC converter, and the maximum power point of the DC/DC converter is not larger than the product of the direct current discharging voltage and the direct current discharging current.

The V2V controller respectively calculates the highest allowable discharging power and the lowest allowable discharging power of the direct-current discharging vehicle and the charging power currently requested by the direct-current charging vehicle; the dedicated V2V controller sets the power of the DC/DC converter to the smaller one of the DC discharging vehicle and the DC charging pile vehicle.

It can be understood that the DC/DC converter needs to have both the voltage boosting and voltage reducing functions, and when the battery voltage of the DC discharging vehicle is higher than the battery voltage of the DC charging vehicle, the DC/DC converter needs to reduce the voltage so that the output voltage of the DC/DC converter is equal to the battery voltage of the DC charging vehicle, thereby avoiding a relatively large charging current caused by the fact that the battery voltage of the discharging vehicle is much higher than the battery voltage of the charging vehicle during the DC charging and discharging of V2V; when the battery voltage of the direct current discharging vehicle is lower than that of the direct current charging vehicle, the DC/DC converter needs to boost the voltage so that the output voltage of the DC/DC converter is equal to that of the direct current charging vehicle, and the problem that the battery voltage of the discharging vehicle is far lower than that of the charging vehicle so as to avoid energy transfer during direct current charging and discharging of V2V is avoided.

Therefore, the data parameters of the charging and discharging vehicles are monitored in real time, and direct-current charging and discharging between any two electric vehicles can be carried out through adjustment of voltage boosting and voltage reducing; during direct current charging and discharging, the regulation and control of voltage boosting and voltage reducing are carried out, so that the influence of battery parameters of the storage battery is avoided.

The acquired data parameters comprise battery information of the direct-current discharging vehicle and the minimum allowable discharging current, the maximum allowable discharging current, the minimum allowable discharging voltage, the maximum allowable discharging voltage and the minimum allowable discharging SOC of the discharging vehicle at the position analyzed from the battery related information; the method comprises the steps of obtaining relevant information of a direct current charging vehicle battery and analyzing minimum allowable charging current, maximum allowable charging current, minimum allowable charging voltage, maximum allowable charging SOC and current request charging voltage, current request charging current and current SOC of a charging vehicle from the relevant information of the battery.

Specifically, as shown in fig. 5, in the CC1 resistance detection circuit, the CC1 divides voltage through the resistance R3 of the dc charge-discharge terminal, isolates and discharges through the operation discharger LM358 and the optical coupler isolation HCNR201, and then accesses the AD sampling port to perform sampling detection, and sends the sampling detection to the V2V controller.

Wherein the V2V controller is an MCU controller.

It should be noted that the resistance detection circuit is a conventional detection circuit, and therefore, the connection of the circuit is not specifically described in this application.

According to a further arrangement of the invention, the V2V switching device further comprises a high-voltage relay K1, a high-voltage relay K2, a high-voltage relay K1 ', a high-voltage relay K2', wherein two ends of the high-voltage relay K1 are respectively connected with a DC + output end of the DC +/DC-circuit and an input end of the DC/DC converter, two ends of the high-voltage relay K2 are respectively connected with a DC-output end of the DC +/DC-circuit and an input end of the DC/DC converter, two ends of the high-voltage relay K1 'are respectively connected with a DC +' input end of the DC + '/DC-circuit and an output end of the DC/DC converter, and two ends of the high-voltage relay K2' are respectively connected with a DC- 'input end of the DC +'/DC-circuit and an output end of the DC/DC converter.

In the technical scheme, the energy controllable transmission of the direct current discharging side is realized through the high-voltage relay K1 and the high-voltage relay K2, and the energy controllable transmission of the direct current charging side is realized through the high-voltage relay K1 'and the high-voltage relay K2'.

Furthermore, the DC +/DC-loop and the DC/DC converter are connected with each other by: the direct-current discharge side IMD circuit is used for measuring insulation resistance values between a DC + port and a grounding terminal of the direct-current discharge side and between a DC-port and the grounding terminal, so that the good insulation performance of the direct-current discharge side is ensured; the direct current discharging side discharging circuit is used for ensuring that the voltage of a DC +/DC-port is not high by 60V when the direct current discharging side is separated from a direct current discharging vehicle, and detecting the discharging current of the direct current discharging side in real time through the current measurement of the direct current discharging side; FUSE for ensuring that the discharge loop of the direct current discharge side can be cut off in time when short-circuit fault occurs during discharge; the direct current discharge side current measuring circuit is used for detecting the discharge current of the direct current discharge side in real time; and the direct current discharge side current measuring circuit is used for detecting the direct current discharge side discharge current in real time.

Further, a DC + '/DC-loop is connected with the DC/DC converter, and the DC +'/DC-loop comprises: the direct-current charging side IMD circuit is used for measuring insulation resistance values between a DC + 'port and a grounding terminal of the direct-current charging side and between a DC-' port and the grounding terminal, and the insulation resistance values between the DC + 'and PE of the direct-current charging side and between the DC-' and PE are measured through the direct-current charging side IMD to ensure that the insulation performance of the direct-current charging side is good; a DC charging side bleeder circuit for ensuring that the voltage at the DC + '/DC-' port is not 60V higher when the DC charging side is separated from the DC charging vehicle; FUSE for ensuring that the direct current charging side can cut off the discharging loop of the direct current charging side in time when short-circuit fault occurs during discharging; the direct current charging side current measuring circuit is used for detecting the charging current of the direct current charging side in real time; and the direct current charging side current measuring circuit is used for detecting the discharge current of the direct current charging side in real time.

In addition, a direct current discharge side voltage measuring circuit is connected between the DC +/DC-loop and the DC/DC converter, a direct current charge side voltage measuring circuit is connected between the DC + '/DC-loop and the DC/DC converter, the voltage of the direct current discharge side battery is measured through the direct current discharge side voltage measuring circuit to ensure the consistency of the parameters of the direct current discharge side battery, the direct current discharge side energy controllable transmission is realized through a high-voltage relay K1K 2, the direct current charge side battery voltage is measured through the direct current charge side voltage measuring circuit to ensure the consistency of the parameters of the direct current discharge side battery, and the direct current charge side energy controllable transmission is realized through a high-voltage relay K1 ' K2 '.

Specifically, as shown in fig. 2, the voltage measurement circuit includes a resistor R165, a resistor R166, an isolation operational amplifier ACPL-C87B and a TLV271, the dc bus voltage is subjected to resistance voltage division through the resistor R165 and the resistor R166, then the isolation dc bus voltage is sampled through the isolation operational amplifier ACPL-C87B and the TLV271, and the sampled data is sent to the V2V controller.

As shown in FIG. 3, the circuit measurement circuit comprises Hall sensor ACS770xCB-100B-PFF and TLV271 amplifiers, the direct current is sampled by the Hall sensor ACS770xCB-100B-PFF and then amplified by the TLV271 for isolated current sampling, and the sampled data is sent to the V2V controller.

As shown in fig. 4, the bleeder circuit comprises an IXTA1N170DHV MOSFET, and the V2V controller performs redundant energy discharge by controlling the IXTA1N170DHV MOSFET to conduct.

Further, the V2V controller and the DC/DC converter realize the voltage of DC + ', DC-' of the direct current charging side and the current of the direct current charging side through CAN communication, so that the requirement of the charging vehicle CAN be met. The V2V controller is in BMS communication with communication port S +, communication port S-, communication port S + 'and communication port S-'.

The invention also discloses a direct current V2V electric vehicle charging and discharging method, which is characterized by comprising the following steps:

s1, acquiring data parameters of the direct current discharging vehicle and data parameters of the direct current charging vehicle;

s2, performing voltage boosting/reducing adjustment on the DC/DC converter according to the acquired data parameters;

s3, charging and discharging;

and S4, monitoring and adjusting the charge and discharge state in real time.

Wherein the step S4 includes: detecting whether an auxiliary power supply is needed; detecting insulation resistance values between DC + and DC-on the direct current discharge side and grounding ends respectively, and ensuring that the insulation performance of the direct current discharge side is good; detecting the redundant energy release of the DC + and the DC-bus at the direct current discharge side, and ensuring that the voltage of a DC + DC-port is not higher than 60V when the direct current discharge side is separated from a direct current discharge vehicle; detecting the protection of the direct current discharge side, ensuring that the direct current discharge side has short-circuit fault during discharging and cutting off a discharge loop of the direct current discharge side in time; detecting the current output by the direct current discharging vehicle; measuring the voltage of the battery at the direct current charging side to ensure the consistency of the parameters of the battery at the direct current discharging side; measuring the insulation resistance between the DC + '/DC-' of the direct current charging side and a grounding end to ensure that the insulation performance of the direct current charging side is good; detecting the discharge of the direct current charging side between the direct current charging vehicle and the direct current charging vehicle, and ensuring that the voltage of a DC + 'DC-' port is not higher than 60V when the direct current charging side is disconnected; the short-circuit fault of the direct-current charging side during charging is ensured through FUSE, and a discharging loop of the direct-current charging side can be cut off in time; and detecting the charging current of the direct current charging side in real time.

In the above technical solution, the acquired data parameters include battery information of the dc discharge vehicle and a minimum allowable discharge current, a maximum allowable discharge current, a minimum allowable discharge voltage, a maximum allowable discharge voltage, and a minimum allowable discharge SOC of the discharge vehicle at the position analyzed from the battery related information; the method comprises the steps of obtaining relevant information of a direct current charging vehicle battery and analyzing minimum allowable charging current, maximum allowable charging current, minimum allowable charging voltage, maximum allowable charging SOC and current request charging voltage, current request charging current and current SOC of a charging vehicle from the relevant information of the battery.

The DC/DC converter needs to have the functions of boosting and reducing voltage, when the battery voltage of the direct-current discharging vehicle is higher than that of the direct-current charging vehicle, the DC/DC converter needs to reduce the voltage so that the output voltage of the DC/DC converter is equal to that of the direct-current charging vehicle, and the situation that when the direct-current charging and discharging of V2V are carried out, the battery voltage of the discharging vehicle is far higher than that of the charging vehicle, so that a relatively large charging current is avoided; when the battery voltage of the direct current discharging vehicle is lower than that of the direct current charging vehicle, the DC/DC converter needs to boost the voltage so that the output voltage of the DC/DC converter is equal to that of the direct current charging vehicle, and the problem that the battery voltage of the discharging vehicle is far lower than that of the charging vehicle so as to avoid energy transfer during direct current charging and discharging of V2V is avoided.

Therefore, the data parameters of the charging and discharging vehicles are monitored in real time, and the DC/DC converter is subjected to voltage boosting/reducing control, so that direct current charging and discharging between any two electric vehicles can be carried out; when charging and discharging the direct current, the DC/DC converter is subjected to voltage boosting/reducing control, so that the influence of battery parameters of the storage battery is avoided.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. It will be apparent to those skilled in the art that various changes, modifications, substitutions and alterations can be made in these embodiments, including the components, without departing from the principles and spirit of the invention, and still fall within the scope of the invention.