CN114123378A

CN114123378A - Power-taking control method of electric automobile

Info

Publication number: CN114123378A
Application number: CN202111193593.4A
Authority: CN
Inventors: 王建平; 郑凯; 徐凯; 於家华; 金力; 徐远; 程尧; 周剑兵; 汪斌; 刘新; 郭良华; 李燕; 成凯; 肖恩
Original assignee: Dongfeng Automobile Co Ltd
Current assignee: Dongfeng Automobile Co Ltd
Priority date: 2021-10-13
Filing date: 2021-10-13
Publication date: 2022-03-01
Anticipated expiration: 2041-10-13
Also published as: CN114123378B

Abstract

A power taking control method of an electric automobile is based on a vehicle power taking system, wherein the power taking system comprises a Vehicle Control Unit (VCU), a power battery pack assembly, a bidirectional vehicle-mounted charger and an alternating current charging and discharging interface; the power taking control method comprises access signal judgment, system awakening and self-checking, high-voltage control on the system and high-voltage control under the system, when the equipment of the alternating current charging and discharging interface is an alternating current power taking gun, a power taking program is entered, the power taking system is awakened and self-checking is completed, and then the high-voltage control on the system is entered to enable the bidirectional vehicle-mounted charger to discharge and output to the alternating current power taking gun through the alternating current charging and discharging interface; when the electricity taking is finished, the system enters a low-voltage control mode to enable the bidirectional vehicle-mounted charger to stop discharging, and then the electricity taking system enters a dormant state. The design utilizes the complete electrical appliance framework of the electric automobile to take electricity, not only can the electricity be taken without additionally increasing conversion equipment or starting the automobile, but also the electricity taking safety can be ensured.

Description

Power-taking control method of electric automobile

Technical Field

The invention relates to a control method of an electric automobile, in particular to a power-taking control method of the electric automobile, which is particularly suitable for supplying power to electric equipment through a new energy automobile.

Background

Many mobile electrical devices in life require an ac power source, for example: engineering operation equipment, large-scale movable electrical equipment and self-driving tourism living equipment, and the equipment supplies power by an alternating current power supply and is commonly used as a wire network power supply, a generator or inversion of a low-voltage storage battery on a traditional vehicle. The power supply of the methods has different defects, the power supply of a wire network is not available everywhere, and needs a long cable for connection, and the power generation of a generator has the problems of large pollution, large noise and the like. If the storage battery on the vehicle is used for inversion to provide electric energy, the power of the storage battery is low, the power requirement of high-power equipment cannot be met, the storage battery can be used after the vehicle is started, and the electricity taking method needs conversion equipment and occupies corresponding space.

In recent years, with the continuous development of new energy electric vehicles, the advantages of environmental protection, operation comfort, application diversity and the like are more and more favored by consumers, the electric vehicle can be used as a vehicle and also can be used as a mobile energy storage station, and the electric vehicle can meet the electricity taking requirement by utilizing the advantages of large capacity, large discharge power and the like of a power battery, so that the living and working requirements of the consumers are met. Therefore, the invention provides a power-taking method for an electric automobile, which utilizes the electric energy of a power battery to be inverted into household alternating current through a bidirectional vehicle-mounted charger OBC arranged on the automobile, and the household alternating current is supplied to required power-using equipment through an alternating current charging port and a power-taking gun.

Disclosure of Invention

The invention aims to solve the problem that power cannot be obtained by electric equipment under the condition of no alternating current power supply in the prior art, and provides a power obtaining control method of an electric automobile.

In order to achieve the above purpose, the technical solution of the invention is as follows:

an electric automobile power taking control method is based on a vehicle power taking system, and the power taking system comprises: the system comprises a vehicle control unit VCU, a power battery pack assembly, a bidirectional vehicle-mounted charger OBC and an alternating current charging and discharging interface, wherein a direct current terminal of the bidirectional vehicle-mounted charger OBC is electrically connected with the power battery pack assembly, an alternating current terminal of the bidirectional vehicle-mounted charger OBC3 is electrically connected with the alternating current charging and discharging interface through a high voltage wire harness, the alternating current charging and discharging interface is in insertion fit with an alternating current power taking gun, and the alternating current charging and discharging interface is electrically connected with electric equipment through the alternating current power taking gun;

and CAN signal interfaces of the VCU, the power battery pack assembly and the OBC are in signal connection with a CAN bus of the whole vehicle.

The electricity taking method comprises the following steps:

step one, access signal judgment:

when the device is inserted into the alternating current charging and discharging interface, entering a power taking process if the access device is an alternating current power taking gun, and entering a charging process if the access device is an alternating current charging gun;

step two, a power taking process:

if the equipment accessed to the alternating current charging and discharging interface is an alternating current power taking gun, entering a power taking process, wherein the power taking process comprises the following steps:

s1, system awakening and self-checking:

after the OBC detects a power-taking signal through the AC charging and discharging interface, the vehicle power-taking system is awakened and self-checking is completed, and then S2 is carried out, and high-voltage control is carried out on the system;

s2, high-voltage control on the system:

after the OBC detects a power getting signal, if the power getting signal is normal, the VCU sends a high-voltage command to the power battery pack assembly, the power battery pack assembly receives the high-voltage command, meanwhile, the power battery pack assembly detects whether the current state allows the actuation of a main contactor and a negative contactor, and if the current state allows the actuation of the main contactor and the negative contactor in the power battery pack assembly, the main contactor and the negative contactor in the power battery pack assembly are actuated;

the bidirectional vehicle-mounted charger OBC judges whether the current state allows the power-taking instruction to be sent or not, if the current state allows the power-taking instruction to be sent, the power-taking instruction is sent to the power battery pack assembly by the bidirectional vehicle-mounted charger OBC, the power battery pack assembly receives the power-taking instruction after the main contactor and the negative contactor are attracted, then the slow charging contactor in the power battery pack assembly is attracted, the power battery pack assembly starts to discharge to the bidirectional vehicle-mounted charger OBC, and the bidirectional vehicle-mounted charger OBC discharges and outputs to the alternating current power-taking gun through the alternating current charging and discharging interface;

s3, high-pressure control under the system:

when the bidirectional vehicle-mounted charger OBC discharges and outputs to the alternating current power taking gun through the alternating current charging and discharging interface, if the current state does not accord with the discharging condition, the bidirectional vehicle-mounted charger OBC stops discharging, simultaneously sends a power taking stopping instruction to the power battery pack assembly, and enters a dormant state after the power battery pack assembly stops discharging to the bidirectional vehicle-mounted charger OBC;

the power battery pack assembly disconnects the slow charging contactor after receiving the power-taking stopping instruction, the power battery pack assembly stops discharging to the OBC, then the VCU sends a high-voltage instruction to the power battery pack assembly and enters a dormant state, and the power battery pack assembly disconnects the main negative contactor and enters the dormant state after receiving the high-voltage instruction.

In the second step, in the S1 of the power taking program, the system awakening and self-checking, the bidirectional vehicle-mounted charger OBC is awakened after detecting the power taking signal through the alternating-current charging and discharging interface, then the bidirectional vehicle-mounted charger OBC sends a VCU awakening signal to the vehicle control unit VCU and completes the self-checking, the vehicle control unit VCU is awakened and completes the self-checking after receiving the VCU awakening signal, then the vehicle control unit VCU sends a BMS awakening signal to the power battery pack assembly, the power battery pack assembly is awakened and completes the self-checking after receiving the BMS awakening signal, and at this time, the vehicle power taking system is awakened and completes the self-checking.

Step two, S2 in the power taking program and high-voltage control on the system, wherein the power battery pack assembly detects that the main negative contactor, the main drive contactor, the auxiliary drive contactor, the quick charge contactor and the slow charge contactor are not adhered, and the current state allows the main negative contactor to be attracted;

the power battery pack assembly detects that any relay in the main negative contactor, the main drive contactor, the auxiliary drive contactor, the quick charge contactor and the slow charge contactor is adhered, the current state does not allow the main negative contactor to be attracted, and the power battery pack assembly reports a fault to a VCU (vehicle control unit).

In the step two, in the power-taking program of S2 and the system high-voltage control, the process of sending the high-voltage command to the power battery pack assembly by the vehicle control unit VCU1 is as follows:

after the OBC detects the power taking signal, if the power taking signal is normal, the OBC sends the power taking signal to the power battery pack assembly, the power battery pack assembly receives the power taking signal sent by the OBC, converts the power taking signal into an alternating current charging signal and forwards the alternating current charging signal to the VCU, and the VCU sends a high voltage instruction to the VCU and controls the vehicle not to allow driving;

if the power-taking signal is abnormal, the power-taking program is terminated.

An electronic lock is arranged at the connection position of the alternating current charging and discharging interface and the alternating current power taking gun, a control end of the electronic lock is in signal connection with an electronic lock control signal output end of the bidirectional vehicle-mounted charger OBC, and the electronic lock is used for locking the alternating current power taking gun on the alternating current charging and discharging interface;

the power-taking control signal input end of the bidirectional vehicle-mounted charger OBC is in signal connection with the power-taking switch through a hard wire;

step two, in S2 in the power taking program and high-voltage control on the system, the step of judging whether the current state allows to send the power taking instruction by the OBC comprises the following steps:

a1, after the OBC detects a power getting signal, if the power getting signal is normal, the OBC controls the electronic lock to be closed, if the electronic lock is successfully closed, the next step is carried out, and if the electronic lock is not successfully closed, the OBC delays for 500ms and reports an electronic lock fault to a VCU (vehicle control unit);

a2, after the electronic lock is successfully closed, if the power taking switch is opened and the allowable discharge current of the power battery pack assembly is larger than 30A, judging that the current state is allowed to send a power taking instruction by the bidirectional vehicle-mounted charger OBC 3;

if the power taking switch is not turned on or the discharging current allowed by the power battery pack assembly is less than or equal to 30A, the OBC judges that the current state does not allow sending a power taking instruction, the OBC3 controls the electronic lock to unlock after 3min, meanwhile, the OBC stops sending a VCU awakening signal to the VCU of the vehicle control unit, and then the OBC delays for 2S to enter a sleeping state.

Step two, S2 in the power taking program and high-voltage control on the system, when the power battery pack assembly receives the power taking instruction and closes the slow charging contactor, if the slow charging contactor is not closed after time out for 3S, the power battery pack assembly reports a pull-in fault of the slow charging contactor to the vehicle control unit VCU 1;

the slow charging contactor is closed, the power battery pack assembly starts to discharge to the OBC, the OBC detects whether input voltage is normal or not, if the input voltage is normal, the OBC discharges and outputs to the AC power taking gun through the AC charging and discharging interface, and if the input voltage is abnormal, the OBC reports voltage abnormity to the VCU after overtime for 3 s.

In the step two, S3 in the power-taking program and the high-voltage control under the system, the fact that the current state does not meet the discharge condition means that any one of the following conditions exists:

a. the power switch is not turned on;

b. the VCU of the vehicle controller sends a high-voltage command;

c. serious faults occur inside the OBC;

d. the allowable discharge current of the power battery pack assembly is less than or equal to 30A.

Step two, in S3 in the power taking program and the high-voltage control under the system, the step that the bidirectional vehicle-mounted charger OBC stops sending a VCU awakening signal to the vehicle control unit VCU and enters the sleeping state comprises the following steps:

after the OBC sends an electricity-taking stopping instruction to the power battery pack assembly, the OBC detects whether the power battery pack assembly stops discharging:

when the power battery pack assembly stops discharging, the OBC controls the electronic lock to unlock after the power battery pack assembly stops discharging, the OBC stops sending a VCU awakening signal to the VCU1 of the vehicle control unit after the electronic lock is unlocked, and enters a dormant state after the OBC stops sending the VCU awakening signal to the VCU of the vehicle control unit for 2 seconds;

when the power battery pack assembly does not stop discharging, the OBC controls the electronic lock to unlock after 3s of time out, the OBC stops sending a VCU awakening signal to the VCU of the vehicle control unit after the electronic lock is unlocked, and the OBC enters a dormant state after stopping sending the VCU awakening signal to the VCU of the vehicle control unit for 2 s;

and step two, S3 in the power taking program and in the high-voltage control under the system, when the power battery pack assembly receives the power taking stopping instruction and controls the slow charging contactor to be disconnected, if the slow charging contactor is not successfully disconnected, the power battery pack assembly reports the disconnection fault of the slow charging contactor to the vehicle control unit VCU after time out is 3S.

The alternating current power taking gun is internally provided with a first resistor and a power taking confirmation resistor, a connection confirmation switch is arranged on a shell of the alternating current power taking gun, one end of the first resistor is connected with a grounding end on the alternating current power taking gun, the other end of the first resistor is connected with one end of the power taking confirmation resistor, the other end of the power taking confirmation resistor is connected with a power taking confirmation interface end on the alternating current power taking gun, and the connection confirmation switch is connected with the first resistor in parallel;

when the alternating current electricity taking gun is inserted into the alternating current charge and discharge interface, the electricity taking confirmation interface end on the alternating current electricity taking gun is connected with the charge and discharge connection confirmation interface end on the alternating current charge and discharge interface, and the grounding end on the alternating current electricity taking gun is connected with the vehicle body ground interface end on the alternating current charge and discharge interface;

in the step two, S1 in the power taking program, system awakening and self-checking, the bidirectional vehicle-mounted charger OBC detects a power taking signal on a charging and discharging connection confirmation interface end through an alternating current charging and discharging interface;

and step two, S2 in the power taking program, and in the high-voltage control on the system, when the resistance value between the charging and discharging connection confirmation interface end on the alternating current charging and discharging interface and the ground interface end of the vehicle body is equal to the resistance value of the power taking confirmation resistor, the power taking signal is normal.

The resistance value of the power-taking confirmation resistor is 2K omega;

and step two, S2 in the power taking program, and in the high-voltage control on the system, when detecting the charging and discharging connection on the alternating current charging and discharging interface, the OBC confirms that the resistance value between the interface end and the ground interface end of the vehicle body is 2K omega, and the power taking signal is normal.

Compared with the prior art, the invention has the beneficial effects that:

1. according to the power taking control method of the electric automobile, the OBC is directly connected with the power battery pack assembly, when the access device is an AC power taking gun, the OBC is used for detecting a power taking signal through the AC charging and discharging interface and then automatically awakening the power taking system of the electric automobile and completing self-detection, and the automobile does not need to be started; and the bidirectional vehicle-mounted charger OBC3 sends the electricity taking signal to the power battery pack assembly after detecting that the electricity taking signal is normal, the power battery pack assembly converts the electricity taking signal into an alternating current charging signal and forwards the alternating current charging signal to the vehicle control unit VCU, and the vehicle control unit VCU controls the vehicle not to allow the vehicle to drive after receiving the alternating current charging signal, so that the electricity taking safety is ensured. Therefore, in the design, the system is automatically awakened after the AC charging and discharging gun is connected, and the vehicle can be powered without starting; and meanwhile, the VCU of the vehicle control unit does not allow the vehicle to drive in the power taking process, so that the power taking safety is ensured.

2. According to the power-taking control method of the electric automobile, the power battery pack assembly is allowed to pull in the main and negative contactors only when detecting the main and negative contactors, the main drive contactor, the auxiliary drive contactor, the quick charging contactor and the slow charging contactor; the bidirectional vehicle-mounted charger OBC sends a power getting instruction to the power battery pack assembly only when the electronic lock is closed and has no fault, the power getting switch is opened and the power battery pack assembly allows the discharging current to be larger than 30A, and then the slow charging contactor is closed to enable the power battery pack assembly to discharge to the bidirectional vehicle-mounted charger OBC; after the power battery pack assembly starts to discharge to the OBC, the OBC detects that the input voltage is normal, and then discharges and outputs to the AC power taking gun through the AC charging and discharging interface, so that the power taking safety is ensured. Therefore, the OBC of the bidirectional vehicle-mounted charger discharges electricity only under the condition of meeting the safety setting condition in the design, and electricity taking safety is guaranteed.

3. According to the power-taking control method of the electric automobile, the characteristic that the bidirectional vehicle-mounted charger OBC can invert direct current from the power battery into alternating current is utilized, the power battery pack assembly directly discharges and outputs to the alternating current power-taking gun through the bidirectional vehicle-mounted charger OBC, the control method is based on the charging system architecture of the electric automobile, power can be taken without additionally adding conversion equipment, the power taking is safe and convenient, no noise and no pollution exist, the power-taking requirement of a consumer is met, and meanwhile the use scene of the electric automobile is expanded. Therefore, the charging system framework of the electric automobile is fully utilized, electricity can be obtained without additionally adding conversion equipment, electricity obtaining is safe and convenient, and the use scene of the electric automobile is expanded while the electricity utilization requirements of consumers are met.

4. According to the power-taking control method of the electric automobile, the OBC detects the power-taking signal on the charging and discharging connection confirmation interface through the AC charging and discharging interface, and when the resistance value between the charging and discharging connection confirmation interface CC on the AC charging and discharging interface and the resistance value between the PE interface on the AC charging and discharging interface are equal to the resistance value of the power-taking confirmation resistor, the OBC detects that the power-taking signal is normal, so that the power-taking signal can be controlled by controlling the on-off of the connection confirmation switch S3 on the AC power-taking gun, and then the charging is controlled after the AC power-taking gun is inserted into the AC charging and discharging interface. Therefore, in the design, the power taking signal is controlled through the connection confirmation switch S3, so that the charging can be controlled.

Drawings

Fig. 1 is a schematic structural diagram of a vehicle power-taking system.

Fig. 2 is a flow chart of high pressure control on the system.

Fig. 3 is a flow chart of high pressure control under the system.

Fig. 4 is a schematic diagram of the connection of the ac charging and discharging interface and the ac power-taking gun.

In the figure: the vehicle-mounted power supply control system comprises a vehicle control unit VCU1, a power battery pack assembly 2, a bidirectional vehicle-mounted charger OBC3, an alternating current charging and discharging interface 5, an alternating current power taking gun 6, a grounding terminal 61, a power taking confirmation interface terminal 62, an electronic lock 7, an electric device 8, a first resistor R1, a power taking confirmation resistor R2, a connection confirmation switch S3, a charging and discharging connection confirmation interface CC and a vehicle body ground interface terminal PE.

Detailed Description

The present invention will be described in further detail with reference to the following description and embodiments in conjunction with the accompanying drawings.

Referring to fig. 1 to 4, a power-taking control method for an electric vehicle is based on a vehicle power-taking system, and the power-taking system includes: the vehicle charging system comprises a vehicle control unit VCU1, a power battery pack assembly 2, a bidirectional vehicle-mounted charger OBC3 and an alternating current charging and discharging interface 5, wherein a direct current terminal of the bidirectional vehicle-mounted charger OBC3 is electrically connected with the power battery pack assembly 2, an alternating current terminal of the bidirectional vehicle-mounted charger OBC3 is electrically connected with the alternating current charging and discharging interface 5 through a high voltage wire harness, the alternating current charging and discharging interface 5 is in insertion fit with an alternating current power taking gun 6, and the alternating current charging and discharging interface 5 is electrically connected with an electric device 8 through the alternating current power taking gun 6;

and CAN signal interfaces of the VCU1 of the whole vehicle controller, the power battery pack assembly 2 and the bidirectional vehicle-mounted charger OBC3 are in signal connection with a whole vehicle CAN bus.

The electricity taking method comprises the following steps:

step one, access signal judgment:

when a device is inserted into the alternating current charging and discharging interface 5, if the access device is an alternating current power taking gun 6, entering a power taking process, and if the access device is an alternating current charging gun, entering a charging process;

step two, a power taking process:

if the equipment accessed to the alternating current charging and discharging interface 5 is an alternating current power taking gun 6, entering a power taking process, wherein the power taking process comprises the following steps:

s1, system awakening and self-checking:

after the bidirectional vehicle-mounted charger OBC3 detects a power-taking signal through the alternating-current charging and discharging interface 5, a vehicle power-taking system is awakened and self-checking is completed, and then the system enters S2 and high-voltage control is carried out;

s2, high-voltage control on the system:

after the bidirectional vehicle-mounted charger OBC3 detects a power getting signal, if the power getting signal is normal, the vehicle control unit VCU1 sends a high voltage instruction to the power battery pack assembly 2, the power battery pack assembly 2 receives the high voltage instruction, meanwhile, the power battery pack assembly 2 detects whether the current state allows to pull in a main contactor and a negative contactor, and if the current state allows to pull in the main contactor and the negative contactor in the power battery pack assembly 2;

the bidirectional vehicle-mounted charger OBC3 judges whether the current state allows the sending of a power-taking instruction, if the current state allows the sending of the power-taking instruction, the bidirectional vehicle-mounted charger OBC3 sends the power-taking instruction to the power battery pack assembly 2, after the attraction of the main contactor and the negative contactor, the power battery pack assembly 2 receives the power-taking instruction, then the slow charging contactor in the power battery pack assembly 2 is attracted, the power battery pack assembly 2 starts to discharge to the bidirectional vehicle-mounted charger OBC3, and the bidirectional vehicle-mounted charger OBC3 discharges and outputs to the alternating current power-taking gun 6 through the alternating current charging and discharging interface 5;

s3, high-pressure control under the system:

when the bidirectional vehicle-mounted charger OBC3 discharges and outputs to the alternating current power taking gun 6 through the alternating current charging and discharging interface 5, if the current state does not accord with the discharging condition, the bidirectional vehicle-mounted charger OBC3 stops discharging and sends a power taking stopping instruction to the power battery pack assembly 2, and then the bidirectional vehicle-mounted charger OBC3 stops sending a VCU awakening signal to the vehicle control unit VCU1 and enters a dormant state;

after the bidirectional vehicle-mounted charger OBC3 stops sending a VCU wake-up signal to the vehicle control unit VCU1, the vehicle control unit VCU1 sends a high voltage command to the power battery pack assembly 2, and then the vehicle control unit VCU1 enters a sleep state;

and the power battery pack assembly 2 disconnects the slow charging contactor after receiving the power-taking stopping instruction, the power battery pack assembly 2 stops discharging to the bidirectional vehicle-mounted charger OBC3, and the power battery pack assembly 2 disconnects the main negative contactor and enters a dormant state after receiving the low-voltage instruction.

In the second step, in the S1 and system awakening and self-checking in the power taking program, the bidirectional vehicle-mounted charger OBC3 is awakened after detecting the power taking signal through the alternating-current charging and discharging interface 5, then the bidirectional vehicle-mounted charger OBC3 completes self-checking and sends a VCU awakening signal to the vehicle controller VCU1, the vehicle controller VCU1 is awakened and completes self-checking after receiving the VCU awakening signal, then the vehicle controller VCU1 sends a BMS awakening signal to the power battery pack assembly 2, the power battery pack assembly 2 is awakened and completes self-checking after receiving the BMS awakening signal, and at this time, the vehicle power taking system is awakened and completes self-checking.

In the step two, S2 in the power-taking program and the high-voltage control on the system, the process that the vehicle control unit VCU1 sends the high-voltage command to the power battery pack assembly 2 is as follows:

after the bidirectional vehicle-mounted charger OBC3 detects a power getting signal, if the power getting signal is normal, the bidirectional vehicle-mounted charger OBC3 sends the power getting signal to the power battery pack assembly 2, the power battery pack assembly 2 receives the power getting signal sent by the bidirectional vehicle-mounted charger OBC3, converts the power getting signal into an alternating current charging signal and forwards the alternating current charging signal to the vehicle control unit VCU1, and the vehicle control unit VCU1 sends a high voltage instruction to the power battery pack assembly 2 after receiving the alternating current charging signal and controls the vehicle not to allow driving;

if the power-taking signal is abnormal, the power-taking program is terminated.

Step two, S2 in the power taking program and high-voltage control on the system, when the power battery pack assembly 2 detects that the main negative contactor, the main drive contactor, the auxiliary drive contactor, the quick charge contactor and the slow charge contactor are not adhered, the current state allows the main negative contactor to be attracted;

when the power battery pack assembly 2 detects that any one of the main negative contactor, the main drive contactor, the auxiliary drive contactor, the quick charge contactor and the slow charge contactor is adhered, the current state does not allow the main negative contactor to be attracted, and at the moment, the power battery pack assembly 2 reports a fault to the VCU1 of the vehicle control unit.

An electronic lock 7 is arranged at the connection position of the alternating current charging and discharging interface 5 and the alternating current power taking gun 6, the control end of the electronic lock 7 is in signal connection with the electronic lock control signal output end of the bidirectional vehicle-mounted charger OBC3, and the electronic lock 7 is used for locking the alternating current power taking gun 6 inserted into the alternating current charging and discharging interface 5;

the power-taking control signal input end of the bidirectional vehicle-mounted charger OBC3 is in signal connection with the power-taking switch 4 through a hard wire, and the power-taking switch 4 is used for controlling power taking;

step two, in S2 in the power-taking program and high-voltage control on the system, the step of judging whether the current state allows the power-taking instruction to be sent by the bidirectional vehicle-mounted charger OBC3 comprises the following steps:

a1, after the bidirectional vehicle-mounted charger OBC3 detects a power-taking signal, if the power-taking signal is normal, the bidirectional vehicle-mounted charger OBC3 controls the electronic lock 7 to be closed, if the electronic lock is successfully closed, the next step is carried out, and if the electronic lock is not successfully closed, the bidirectional vehicle-mounted charger OBC3 delays for 500ms and reports an electronic lock fault to a vehicle control unit VCU 1;

a2, after the electronic lock is successfully closed, if the power taking switch 4 is opened and the power battery pack assembly 2 allows the discharging current to be larger than 30A, the OBC3 of the bidirectional vehicle-mounted charger judges that the current state allows the power taking instruction to be sent;

if the power taking switch 4 is not turned on or the discharging current allowed by the power battery pack assembly 2 is less than or equal to 30A, the OBC3 judges that the power taking instruction is not allowed to be sent in the current state, the bidirectional vehicle-mounted charger OBC3 controls the electronic lock 7 to be unlocked after 3min, meanwhile, the bidirectional vehicle-mounted charger OBC3 stops sending a VCU awakening signal to the VCU1 of the vehicle control unit, and then the bidirectional vehicle-mounted charger OBC3 delays for 2S to enter the sleeping state.

Step two, S2 in the power getting program, and in high-voltage control on the system, when the power battery pack assembly 2 receives the power getting instruction and closes the slow charging contactor, if the slow charging contactor does not complete pull-in after time out for 3S, the power battery pack assembly 2 reports the pull-in fault of the slow charging contactor to the vehicle control unit VCU 1;

the contactor that charges slowly is closed, and power battery package assembly 2 begins to discharge the back to two-way vehicle-mounted charger OBC3, and two-way vehicle-mounted charger OBC3 detects whether power battery package assembly 2's discharge voltage is normal, if power battery package assembly 2's discharge voltage is normal then two-way vehicle-mounted charger OBC3 through alternating current charge and discharge interface 5 to the output of discharging of alternating current power taking gun 6, if power battery package assembly 2's discharge voltage is abnormal then two-way vehicle-mounted charger OBC3 reports voltage anomaly to vehicle control unit VCU1 after overtime-out 3 s.

a. the electricity taking switch 4 is not turned on;

b. the VCU1 sends out a high voltage command;

c. serious faults occur inside the bidirectional vehicle-mounted charger OBC 3;

d. the allowable discharge current of the power battery pack assembly 2 is less than or equal to 30A.

Step two, in the step of S3 in the power taking program and the high-voltage control under the system, the step of stopping sending the VCU awakening signal to the vehicle control unit VCU1 by the bidirectional vehicle-mounted charger OBC3 and entering the sleeping state comprises the following steps:

after the bidirectional vehicle-mounted charger OBC3 sends an electricity-taking termination instruction to the power battery pack assembly 2, the bidirectional vehicle-mounted charger OBC3 detects whether the power battery pack assembly 2 stops discharging:

when the power battery pack assembly 2 stops discharging, the two-way vehicle-mounted charger OBC3 controls the electronic lock 7 to unlock after the power battery pack assembly 2 stops discharging, the two-way vehicle-mounted charger OBC3 stops sending VCU awakening signals to the vehicle control unit VCU1 after the electronic lock 7 is unlocked, and the two-way vehicle-mounted charger OBC3 enters a dormant state after sending VCU awakening signals 2s to the vehicle control unit VCU 1;

when the power battery pack assembly 2 does not stop discharging, the two-way vehicle-mounted charger OBC3 controls the electronic lock 7 to unlock after overtime for 3s, the two-way vehicle-mounted charger OBC3 stops sending VCU awakening signals to the vehicle control unit VCU1 after the electronic lock 7 is unlocked, and the two-way vehicle-mounted charger OBC3 enters a dormant state after stopping sending VCU awakening signals to the vehicle control unit VCU1 for 2 s;

and step two, S3 in the power taking program and during high-voltage control under the system, when the power battery pack assembly 2 receives the power taking termination instruction and controls the slow charging contactor to be disconnected, if the slow charging contactor is not successfully disconnected, the power battery pack assembly 2 reports the disconnection fault of the slow charging contactor to the vehicle control unit VCU1 after time out is 3S.

A first resistor R1 and a power-taking confirmation resistor R2 are arranged inside the alternating current power-taking gun 6, a connection confirmation switch S3 is arranged on a shell of the alternating current power-taking gun 6, one end of the first resistor R1 is connected with a grounding terminal 61 on the alternating current power-taking gun 6, the other end of the first resistor R1 is connected with one end of a power-taking confirmation resistor R2, the other end of the power-taking confirmation resistor R2 is connected with a power-taking confirmation interface terminal 62 on the alternating current power-taking gun 6, and the connection confirmation switch S3 is connected with the first resistor R1 in parallel;

when the alternating current electricity taking gun 6 is inserted into the alternating current charge and discharge interface 5, the electricity taking confirmation interface end 62 on the alternating current electricity taking gun 6 is connected with the charge and discharge connection confirmation interface end CC on the alternating current charge and discharge interface 5, and the grounding end 61 on the alternating current electricity taking gun 6 is connected with the vehicle body ground interface end PE on the alternating current charge and discharge interface 5;

in the step two, in S1 and system awakening and self-checking in the power taking program, the bidirectional vehicle-mounted charger OBC3 detects a power taking signal on the charging and discharging connection confirmation interface end CC through the alternating current charging and discharging interface 5;

and step two, in the power taking program S2 and the system high-voltage control, when the resistance value between the charging and discharging connection confirmation interface end CC on the alternating current charging and discharging interface 5 and the vehicle body ground interface end PE is equal to the resistance value of the power taking confirmation resistor R2, the power taking signal is normal.

The resistance value of the power taking confirmation resistor R2 is 2K omega;

and step two, S2 in the power taking program and high-voltage control on the system, when detecting that the charging and discharging connection on the alternating current charging and discharging interface 5 confirms that the resistance value between the interface end CC and the vehicle body ground interface end PE is 2K omega, the bidirectional vehicle-mounted charger OBC3 obtains a normal power taking signal.

The principle of the invention is illustrated as follows:

the OBC can work in the forward direction to realize AC-DC, converts the alternating current of a power grid into direct current to charge a power battery of the electric automobile, and can also work in the reverse direction to realize DC-AC, and inverts the electric energy of a power battery pack into household alternating current; when the electric automobile is in the charging process, the OBC works in the forward direction, and when the electric automobile is in the power taking process, the OBC works in the reverse direction.

Including power battery, battery management system BMS and each contactor by battery management system BMS control in power battery assembly 2, if main negative contactor, fill contactor slowly, main contactor of driving, assist and drive contactor, fill contactor etc. soon, after power battery package assembly 2 received BMS wake-up signal, the inside battery management system BMS of power battery package assembly 2 was awaken up and is accomplished the self-checking, and power battery package assembly 2 is awaken up and accomplishes the self-checking promptly.

The alternating current charging and discharging interface 5 can be inserted with an alternating current power taking gun 6 or an alternating current charging gun, and the bidirectional vehicle-mounted charger OBC3 judges whether the insertion device is the alternating current power taking gun 6 or the charging gun according to a signal received by a charging and discharging connection confirmation interface CC in the alternating current charging and discharging interface 5.

The electronic lock 7 is used for locking the alternating current charging and discharging interface 5 and the alternating current power taking gun 6, and the alternating current power taking gun 6 is prevented from falling off the alternating current charging and discharging interface 5 in the power taking process; similarly, the electronic lock 7 can also be used for locking the alternating current charging and discharging interface 5 and the charging gun.

The power battery pack assembly 2 is awakened and completes self-checking after receiving the BMS awakening signal, the awakening of the power battery pack assembly 2 indicates that the power battery pack assembly 2 is awakened, the completion of the self-checking of the power battery pack assembly 2 indicates that the self-checking of the power battery pack assembly 2 is successful and the power battery pack assembly 2 does not have a fault requiring high voltage, if the power battery pack assembly 2 has the fault requiring high voltage, the self-checking is unsuccessful, at the moment, the power taking program is terminated, and meanwhile, the power battery pack assembly 2 reports the fault to the vehicle control unit VCU 1.

When the slow charging contactor or the main negative contactor is disconnected, the power battery in the power battery pack assembly 2 is disconnected with the bidirectional vehicle-mounted charger OBC3, the power battery pack assembly 2 does not discharge to the bidirectional vehicle-mounted charger OBC3, when the slow charging contactor and the main negative contactor are both in a closed state, the power battery in the power battery pack assembly 2 is electrically connected with the bidirectional vehicle-mounted charger OBC, the power battery pack assembly 2 outputs direct current to the bidirectional vehicle-mounted charger OBC, and the bidirectional vehicle-mounted charger OBC inverts the direct current output by the power battery into alternating current and then provides the alternating current to the electric equipment 8 through the alternating current charging and discharging interface 5.

After the power battery pack assembly 2 starts to discharge to the bidirectional vehicle-mounted charger OBC3, because the power battery in the power battery pack assembly 2 is electrically connected with the bidirectional vehicle-mounted charger OBC3, the bidirectional vehicle-mounted charger OBC3 detects whether the input voltage of the power battery is normal, if the input voltage is normal, the bidirectional vehicle-mounted charger OBC3 discharges and outputs to the alternating current power taking gun 6 through the alternating current charging and discharging interface 5, and if the input voltage is abnormal, the bidirectional vehicle-mounted charger OBC3 reports voltage abnormality to the vehicle control unit VCU1 after time out for 3 s.

The power battery pack assembly 2 allows discharge current, namely the maximum discharge current allowed by the power battery system in real time; the power battery pack assembly 2 looks up a table according to the current SOC (battery state of charge) and the cell temperature, and then the current allowable discharge current of the power battery pack assembly 2 can be obtained.

The electronic lock 7 is used for locking the alternating current charging and discharging interface 5 and the alternating current power taking gun 6, and when the electronic lock 7 is closed, the alternating current charging and discharging interface 5 and the alternating current power taking gun 6 are locked; when the electronic lock 7 is unlocked, the AC power-taking gun 6 can be pulled out from the AC charging and discharging interface 5.

The connection confirmation switch S3 is used to determine the connection state between the ac charging/discharging interface 5 and the ac charging gun 6.

When the charging gun is inserted into the alternating current charging and discharging interface 5, the charging and discharging connection confirmation interface end CC receives a charging signal, when the alternating current power taking gun 6 is inserted into the alternating current charging and discharging interface 5, the charging and discharging connection confirmation interface end CC receives a power taking signal, and when the power taking signal meets a certain condition, the power taking signal is effective.

Example 1:

an electric automobile power taking control method is based on a vehicle power taking system, and the power taking system comprises: the vehicle charging system comprises a vehicle control unit VCU1, a power battery pack assembly 2, a bidirectional vehicle-mounted charger OBC3 and an alternating current charging and discharging interface 5, wherein a direct current terminal of the bidirectional vehicle-mounted charger OBC3 is electrically connected with the power battery pack assembly 2, an alternating current terminal of the bidirectional vehicle-mounted charger OBC3 is electrically connected with the alternating current charging and discharging interface 5 through a high-voltage wire harness, the alternating current charging and discharging interface 5 is in insertion fit with an alternating current power taking gun 6, the alternating current charging and discharging interface 5 is electrically connected with an electric device 8 through the alternating current power taking gun 6, an electronic lock 7 is arranged at the connection position of the alternating current charging and discharging interface 5 and the alternating current power taking gun 6, and the electronic lock 7 is used for locking the alternating current power taking gun 6 on the alternating current charging and discharging interface 5;

the whole vehicle controller VCU1, power battery package assembly 2 and two-way vehicle carry charger OBC 3's CAN signal interface all with whole vehicle CAN bus signal connection, two-way vehicle carry charger OBC3 get the electric control signal input end and be connected with getting electric switch 4 through the hardwire, the control end of electronic lock 7 and two-way vehicle carry charger OBC 3's electronic lock control signal output phase number is connected.

The electricity taking method comprises the following steps:

step one, access signal judgment:

step two, a power taking process:

s1, system awakening and self-checking:

because the alternating current power taking gun 6 is inserted into the alternating current charging and discharging interface 5, the bidirectional vehicle-mounted charger OBC3 detects a power taking signal (namely a CC3 signal in the attached figure 2) through the alternating current charging and discharging interface 5, and the vehicle power taking system is awakened and completes self-detection according to the following flow: the bidirectional vehicle-mounted charger OBC3 is awakened after detecting a power taking signal through the alternating current charging and discharging interface 5, then the bidirectional vehicle-mounted charger OBC3 completes self-checking and sends a VCU awakening signal to the vehicle control unit VCU1, the vehicle control unit VCU1 is awakened and completes self-checking after receiving the VCU awakening signal, then the vehicle control unit VCU1 sends a BMS awakening signal to the power battery pack assembly 2, the power battery pack assembly 2 is awakened and completes self-checking after receiving the BMS awakening signal, at the moment, a vehicle power taking system is awakened and completes self-checking, and then the vehicle enters S2 and high-voltage control on the system.

S2, high-voltage control on the system:

if the power-taking signal is abnormal, the power-taking program is terminated.

After the power battery pack assembly 2 receives the high-voltage instruction, the power battery pack assembly 2 detects whether the current state allows the actuation of the main and negative contactors: if the main negative contactor, the main drive contactor, the auxiliary drive contactor, the quick charging contactor and the slow charging contactor are not adhered, the current state allows the main negative contactor to be attracted, and the main negative contactor is attracted at the moment;

if any one of the main negative contactor, the main drive contactor, the auxiliary drive contactor, the quick charge contactor and the slow charge contactor is adhered at the moment, the main negative contactor is not allowed to be attracted in the current state, and the power battery pack assembly 2 reports a fault to the VCU1 of the vehicle control unit at the moment;

meanwhile, after the bidirectional vehicle-mounted charger OBC3 detects a normal power taking signal, the bidirectional vehicle-mounted charger OBC3 controls the electronic lock 7 to be closed, if the electronic lock is not closed successfully, the bidirectional vehicle-mounted charger OBC3 delays for 500ms and reports the fault of the electronic lock to the vehicle control unit VCU1, and if the electronic lock is closed successfully, the next step is carried out:

after the electronic lock is successfully closed, if the power taking switch 4 is opened and the discharging current allowed by the power battery pack assembly 2 is greater than 30A, the two-way vehicle-mounted charger OBC3 sends a power taking instruction to the power battery pack assembly 2; if the power-taking switch 4 is not turned on or the discharging current allowed by the power battery pack assembly 2 is less than or equal to 30A, the bidirectional vehicle-mounted charger OBC3 controls the electronic lock 7 to unlock after 3min, meanwhile, the bidirectional vehicle-mounted charger OBC3 stops sending a VCU awakening signal to the vehicle control unit VCU1, and then the bidirectional vehicle-mounted charger OBC3 delays 2S to enter a sleep state;

after the main negative contactor is actuated, the power battery pack assembly 2 receives a power getting instruction sent by an OBC3, the power battery pack assembly 2 controls the slow charging contactor inside the power battery pack assembly to be actuated, and if the slow charging contactor is not closed after being overtime for 3 seconds, the power battery pack assembly 2 reports the actuation fault of the slow charging contactor to a VCU1 of a vehicle control unit;

if the slow charging contactor is successfully attracted, the power battery pack assembly 2 starts to discharge to the bidirectional vehicle-mounted charger OBC3, at the moment, the bidirectional vehicle-mounted charger OBC3 detects whether the discharge voltage of the power battery pack assembly 2 is normal or not, if the discharge voltage of the power battery pack assembly 2 is normal, the bidirectional vehicle-mounted charger OBC3 discharges and outputs to the alternating current power taking gun 6 through the alternating current charge-discharge interface 5, and if the discharge voltage of the power battery pack assembly 2 is abnormal, the bidirectional vehicle-mounted charger OBC3 reports voltage abnormality to the vehicle control unit VCU1 after time-out for 3 s.

S3, high-pressure control under the system:

when the bidirectional vehicle-mounted charger OBC3 discharges and outputs to the alternating current power taking gun 6 through the alternating current charging and discharging interface 5, if any one of the following conditions exists, the current state does not meet the discharging condition:

a. the electricity taking switch 4 is not turned on;

b. the VCU1 sends out a high voltage command;

c. serious faults occur inside the bidirectional vehicle-mounted charger OBC 3;

d. the allowable discharge current of the power battery pack assembly 2 is less than or equal to 30A;

the serious fault inside the OBC3 refers to a hardware fault or communication loss fault inside the OBC.

If the current state does not meet the discharging condition, the two-way vehicle-mounted charger OBC3 stops discharging, meanwhile, the two-way vehicle-mounted charger OBC3 sends a power-taking stopping instruction to the power battery pack assembly 2, the power battery pack assembly 2 disconnects the slow charging contactor after receiving the power-taking stopping instruction, the power battery pack assembly 2 stops discharging to the two-way vehicle-mounted charger OBC3, and if the slow charging contactor is not disconnected at the moment, the power battery pack assembly 2 reports the disconnection fault of the slow charging contactor to the vehicle control unit VCU1 after 3s of time out;

when the slow charging contactor is normally disconnected and the power battery pack assembly 2 stops discharging, the two-way vehicle-mounted charger OBC3 controls the electronic lock 7 to unlock after the power battery pack assembly 2 stops discharging, the two-way vehicle-mounted charger OBC3 stops sending a VCU awakening signal to the vehicle control unit VCU1 after the electronic lock 7 is unlocked, and the two-way vehicle-mounted charger OBC3 enters a dormant state after stopping sending the VCU awakening signal 2s to the vehicle control unit VCU 1;

when the slow charging contactor is not normally disconnected, the power battery pack assembly 2 does not stop discharging, the bidirectional vehicle-mounted charger OBC3 controls the electronic lock 7 to unlock after overtime for 3s, the bidirectional vehicle-mounted charger OBC3 stops sending VCU awakening signals to the vehicle control unit VCU1 after the electronic lock 7 is unlocked, and the bidirectional vehicle-mounted charger OBC3 enters a dormant state after stopping sending VCU awakening signals 2s to the vehicle control unit VCU 1;

and the power battery pack assembly 2 disconnects the main negative contactor and enters a dormant state after receiving the high-voltage command.

Example 2:

example 2 is substantially the same as example 1 except that:

Example 3:

example 3 is substantially the same as example 2 except that:

the resistance value of the power taking confirmation resistor R2 is 2K omega;

Claims

1. An electric automobile power-taking control method is characterized in that:

the electricity taking control method is based on a vehicle electricity taking system, and the electricity taking system comprises: the vehicle-mounted charging system comprises a vehicle control unit VCU (1), a power battery pack assembly (2), a bidirectional vehicle-mounted charger OBC (3) and an alternating current charging and discharging interface (5), wherein a direct current terminal of the bidirectional vehicle-mounted charger OBC (3) is electrically connected with the power battery pack assembly (2), an alternating current terminal of the bidirectional vehicle-mounted charger OBC (3) is electrically connected with the alternating current charging and discharging interface (5) through a high-voltage wire harness, the alternating current charging and discharging interface (5) is in insertion fit with an alternating current power taking gun (6), and the alternating current charging and discharging interface (5) is electrically connected with electric equipment (8) through the alternating current power taking gun (6);

CAN signal interfaces of the VCU (1), the power battery pack assembly (2) and the OBC (3) are in signal connection with a CAN bus of the whole vehicle;

the power taking control method comprises the following steps:

step one, access signal judgment:

when a device is inserted into the alternating current charging and discharging interface (5), entering a power taking process if the access device is an alternating current power taking gun (6), and entering a charging process if the access device is an alternating current charging gun;

step two, a power taking process:

if the equipment accessed to the alternating current charging and discharging interface (5) is an alternating current power taking gun (6), entering a power taking process, wherein the power taking process comprises the following steps:

s1, system awakening and self-checking:

after the bidirectional vehicle-mounted charger OBC (3) detects a power-taking signal through the alternating current charging and discharging interface (5), a vehicle power-taking system is awakened and self-checking is completed, and then S2 is carried out, and high-voltage control is carried out on the system;

s2, high-voltage control on the system:

after the OBC (3) of the bidirectional vehicle-mounted charger detects a power-taking signal, if the power-taking signal is normal, the VCU (1) of the vehicle control unit sends a high-voltage instruction to the power battery pack assembly (2), the power battery pack assembly (2) receives the high-voltage instruction, meanwhile, the power battery pack assembly (2) detects whether the current state allows the actuation of a main contactor and a negative contactor, and if the current state allows the actuation of the main contactor and the negative contactor in the power battery pack assembly (2);

the bidirectional vehicle-mounted charger OBC (3) judges whether the current state allows the power-taking instruction to be sent, if the current state allows the power-taking instruction to be sent, the bidirectional vehicle-mounted charger OBC (3) sends the power-taking instruction to the power battery pack assembly (2), after the main contactor and the negative contactor are attracted, the power battery pack assembly (2) receives the power-taking instruction, then the slow charging contactor in the power battery pack assembly (2) is attracted, the power battery pack assembly (2) starts to discharge to the bidirectional vehicle-mounted charger OBC (3), and the bidirectional vehicle-mounted charger OBC (3) discharges and outputs to the alternating current power-taking gun (6) through the alternating current charging and discharging interface (5);

s3, high-pressure control under the system:

when the bidirectional vehicle-mounted charger OBC (3) discharges and outputs to the alternating current power taking gun (6) through the alternating current charging and discharging interface (5), if the current state does not accord with the discharging condition, the bidirectional vehicle-mounted charger OBC (3) stops discharging and sends a power taking stopping instruction to the power battery pack assembly (2), and then the bidirectional vehicle-mounted charger OBC (3) stops sending a VCU awakening signal to the vehicle control unit VCU (1) and enters a dormant state;

after the OBC (3) stops sending a VCU awakening signal to the VCU (1), the VCU (1) sends a high-voltage command to the power battery pack assembly (2), and then the VCU (1) enters a dormant state;

the power battery pack assembly (2) disconnects the slow charging contactor after receiving the power-taking stopping instruction, the power battery pack assembly (2) stops discharging to the bidirectional vehicle-mounted charger OBC (3), and the power battery pack assembly (2) disconnects the main negative contactor and enters a dormant state after receiving the low-voltage instruction.

2. The electric vehicle power-taking control method according to claim 1, characterized in that:

in the second step, in the S1 and system awakening and self-checking in the power taking program, the bidirectional vehicle-mounted charger OBC (3) is awakened after detecting a power taking signal through the alternating-current charging and discharging interface (5), then the bidirectional vehicle-mounted charger OBC (3) completes self-checking and sends a VCU awakening signal to the vehicle control unit VCU (1), the vehicle control unit VCU (1) is awakened and completes self-checking after receiving the VCU awakening signal, then the vehicle control unit VCU (1) sends a BMS awakening signal to the power battery pack assembly (2), the power battery pack assembly (2) is awakened and completes self-checking after receiving the BMS awakening signal, and at the moment, the vehicle power taking system is awakened and completes self-checking.

3. The electric vehicle power-taking control method according to claim 2, characterized in that:

step two, in the step S2 in the power-taking program and the system high-voltage control, the process that the vehicle control unit VCU (1) sends a high-voltage instruction to the power battery pack assembly (2) is as follows:

after the bidirectional vehicle-mounted charger OBC (3) detects a power getting signal, if the power getting signal is normal, the bidirectional vehicle-mounted charger OBC (3) sends the power getting signal to the power battery pack assembly (2), the power battery pack assembly (2) receives the power getting signal sent by the bidirectional vehicle-mounted charger OBC (3), converts the power getting signal into an alternating current charging signal and forwards the alternating current charging signal to the vehicle control unit VCU (1), and the vehicle control unit VCU (1) sends a high voltage instruction to the power battery pack assembly (2) after receiving the alternating current charging signal and controls the vehicle not to allow driving;

if the power-taking signal is abnormal, the power-taking program is terminated.

4. The electric vehicle power-taking control method according to claim 3, characterized in that:

step two, S2 in the power taking program and high-voltage control on the system, wherein the power battery pack assembly (2) detects that the main negative contactor, the main drive contactor, the auxiliary drive contactor, the quick charge contactor and the slow charge contactor are not adhered, and the current state allows the main negative contactor to be attracted;

the power battery pack assembly (2) detects that any one of the main negative contactor, the main drive contactor, the auxiliary drive contactor, the quick charge contactor and the slow charge contactor is adhered, the current state does not allow the main negative contactor to be attracted, and the power battery pack assembly (2) reports a fault to the VCU (vehicle control unit) (1).

5. The electric vehicle power-taking control method according to claim 4, characterized in that:

an electronic lock (7) is arranged at the connection position of the alternating current charging and discharging interface (5) and the alternating current power taking gun (6), the control end of the electronic lock (7) is in signal connection with the electronic lock control signal output end of the bidirectional vehicle-mounted charger OBC (3), and the power taking control signal input end of the bidirectional vehicle-mounted charger OBC (3) is in signal connection with the power taking switch (4) through a hard line;

step two, in S2 in the power taking program and high-voltage control on the system, the step of judging whether the current state allows to send the power taking instruction by the bidirectional vehicle-mounted charger OBC (3) comprises the following steps:

a1, after the bidirectional vehicle-mounted charger OBC (3) detects a power-taking signal, if the power-taking signal is normal, the bidirectional vehicle-mounted charger OBC (3) controls the electronic lock (7) to be closed, if the electronic lock is successfully closed, the next step is carried out, and if the electronic lock is not successfully closed, the bidirectional vehicle-mounted charger OBC (3) reports an electronic lock fault to the vehicle control unit VCU (1) after delaying for 500 ms;

a2, after the electronic lock is successfully closed, if the power taking switch (4) is opened and the discharge current allowed by the power battery pack assembly (2) is greater than 30A, the OBC (3) of the bidirectional vehicle-mounted charger judges that the current state allows the power taking instruction to be sent;

if the power taking switch (4) is not turned on or the discharging current allowed by the power battery pack assembly (2) is less than or equal to 30A, the OBC3 judges that the current state is not allowed to send a power taking instruction, the OBC (3) of the bidirectional vehicle-mounted charger controls the electronic lock (7) to unlock after 3min, meanwhile, the OBC (3) of the bidirectional vehicle-mounted charger stops sending a VCU awakening signal to the VCU (1) of the vehicle control unit, and then the OBC (3) of the bidirectional vehicle-mounted charger delays for 2S to enter a dormant state.

6. The electric vehicle power-taking control method according to claim 5, characterized in that:

step two, S2 in the power getting program and high-voltage control on the system, when the power battery pack assembly (2) receives the power getting instruction and closes the slow charging contactor, if the slow charging contactor still does not finish the pull-in after the time is out for 3S, the power battery pack assembly (2) reports the pull-in fault of the slow charging contactor to the vehicle control unit VCU (1);

the contactor that charges slowly is closed, power battery package assembly (2) begin to discharge the back to two-way on-vehicle machine OBC (3) that charges, two-way on-vehicle machine OBC (3) detect whether discharge voltage of power battery package assembly (2) is normal, if the discharge voltage of power battery package assembly (2) is normal then two-way on-vehicle machine OBC (3) through alternating current charge and discharge interface (5) to the output of discharging of alternating current power taking gun (6), if the discharge voltage of power battery package assembly (2) is unusual then two-way on-vehicle machine OBC (3) after overtime-out 3s report voltage unusual to vehicle control unit VCU (1).

7. The electric vehicle power-taking control method according to claim 6, characterized in that:

a. the power-taking switch (4) is not turned on;

b. the VCU (1) of the vehicle control unit sends a high-voltage command;

c. serious faults occur inside the bidirectional vehicle-mounted charger OBC (3);

d. the allowable discharge current of the power battery pack assembly (2) is less than or equal to 30A.

8. The electric vehicle power-taking control method according to claim 7, characterized in that:

step two, in S3 in the power taking program and the high-voltage control under the system, the step that the bidirectional vehicle-mounted charger OBC (3) stops sending a VCU awakening signal to the vehicle control unit VCU (1) and enters the dormant state comprises the following steps:

after the OBC (3) sends an electricity-taking stopping instruction to the power battery pack assembly (2), the OBC (3) detects whether the power battery pack assembly (2) stops discharging:

when the power battery pack assembly (2) stops discharging, the bidirectional vehicle-mounted charger OBC (3) controls the electronic lock (7) to unlock after the power battery pack assembly (2) stops discharging, the bidirectional vehicle-mounted charger OBC (3) stops sending VCU awakening signals to the vehicle control unit VCU (1) after the electronic lock (7) is unlocked, and the bidirectional vehicle-mounted charger OBC (3) enters a dormant state after stopping sending the VCU awakening signals 2s to the vehicle control unit VCU (1);

when the power battery pack assembly (2) does not stop discharging, the two-way vehicle-mounted charger OBC (3) controls the electronic lock (7) to unlock after being overtime for 3s, the two-way vehicle-mounted charger OBC (3) stops sending VCU awakening signals to the vehicle control unit VCU (1) after the electronic lock (7) is unlocked, and the two-way vehicle-mounted charger OBC (3) enters a dormant state after stopping sending the VCU awakening signals for 2s to the vehicle control unit VCU (1);

and step two, S3 in the power taking program and during high-voltage control under the system, when the power battery pack assembly (2) receives a power taking termination instruction and controls the slow charging contactor to be disconnected, if the slow charging contactor is not successfully disconnected, the power battery pack assembly (2) reports the disconnection fault of the slow charging contactor to the vehicle control unit VCU (1) after time out is 3S.

9. The electric vehicle power-taking control method according to any one of claims 1 to 8, characterized in that:

a first resistor (R1) and a power-taking confirmation resistor (R2) are arranged inside the alternating current power-taking gun (6), a connection confirmation switch (S3) is arranged on a shell of the alternating current power-taking gun (6), one end of the first resistor (R1) is connected with a grounding terminal (61) on the alternating current power-taking gun (6), the other end of the first resistor (R1) is connected with one end of a power-taking confirmation resistor (R2), the other end of the power-taking confirmation resistor (R2) is connected with a power-taking confirmation interface terminal (62) on the alternating current power-taking gun (6), and the connection confirmation switch (S3) is connected with the first resistor (R1) in parallel;

when the alternating current power taking gun (6) is inserted into the alternating current charging and discharging interface (5), a power taking confirmation interface end (62) on the alternating current power taking gun (6) is connected with a charging and discharging connection confirmation interface end (CC) on the alternating current charging and discharging interface (5), and a grounding end (61) on the alternating current power taking gun (6) is connected with a vehicle body ground interface end (PE) on the alternating current charging and discharging interface (5);

in the step two, in S1 and system awakening and self-checking in the power taking program, the bidirectional vehicle-mounted charger OBC (3) detects a power taking signal on a charging and discharging connection confirmation interface end (CC) through an alternating current charging and discharging interface (5);

and step two, S2 in the power taking program, and in the high-voltage control on the system, when the resistance value between the charging and discharging connection confirmation interface end (CC) on the alternating current charging and discharging interface (5) and the ground interface end (PE) of the vehicle body is equal to the resistance value of the power taking confirmation resistor (R2), the power taking signal is normal.

10. The electric vehicle power-taking control method according to claim 9, characterized in that:

the resistance value of the power taking confirmation resistor (R2) is 2K omega;

and step two, S2 in the power taking program and high-voltage control on the system, when the bidirectional vehicle-mounted charger OBC (3) detects that the charging and discharging connection on the alternating current charging and discharging interface (5) confirms that the resistance value between the interface end (CC) and the vehicle body ground interface end (PE) is 2K omega, the power taking signal is normal.