Control method of wireless charging contactor

Abstract

The invention belongs to the technical field of wireless charging of new energy vehicles, and particularly discloses a control method of a wireless charging contactor, which is characterized in that a vehicle node exchanges information in a CAN communication mode, and a vehicle control unit VCU is used as an information interaction hub and a control dispatching center to achieve automatic control of a wireless charging full cycle. The wireless charging contactor can be automatically controlled in the wireless charging process, manual participation is not needed, and safety risks caused by the fact that a user directly makes contact with a charging medium are avoided; the control instruction of the wireless charging contactor is reliable, flexible and safe, only two control instructions exist in one charging period, the frequent action of the wireless charging controller among multiple charging cycles in one charging period is effectively avoided, the disconnection instruction is sent only when the wireless charging current is within the safe range, and the wireless charging contactor is safe. Therefore, the service life of hardware of the wireless charging contactor is prolonged, and the maintenance cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless charging for new energy vehicles, and in particular to a control method for a wireless charging contactor. Background Art

[0002] As the only energy source for new energy electric vehicles, electricity can be supplemented in a variety of ways, from the increasingly fast charging gun to wireless charging, which shows the continuous progress of the industrialization technology of new energy electric vehicles. Gun charging is the main charging method for new energy electric vehicles because of its relatively mature charging system and low cost, but it is too dependent on human-computer interaction and requires manual insertion of the charging gun, which greatly reduces its convenience and safety. The entire charging process of wireless charging only requires parking the car at the charging point for charging, and the user does not need to touch any charging device, which greatly makes up for the shortcomings of the inconvenient operation and low safety of the gun charging method. Wireless charging uses the principle of electromagnetic induction. When the coil of the transmitter is energized, a magnetic field is generated, and the coil of the receiver generates an induced current. The induced current will be transferred to the battery through the wireless charging contactor of the battery for charging. In this way, the charging medium changes from the manual insertion of the charging gun to the fully automatically controlled wireless charging contactor engagement, which improves convenience and safety, and the reliable, flexible and safe control method of the wireless charging contactor is also highlighted. Summary of the invention

[0003] The purpose of the present invention is to solve the technical problems existing in the background technology. To this end, a control method for a wireless charging contactor is provided to make up for the shortcomings of the charging medium of the gun charging method of new energy electric vehicles, namely the charging gun, which is inconvenient to operate and has low safety. A reliable, flexible and safe control method is provided for the full-automatic control of the wireless charging contactor during the wireless charging process, thereby achieving the effect of safe, controllable and sustainable wireless charging of the vehicle.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0005] A control method for a wireless charging contactor comprises the following steps:

[0006] Step S1: When the vehicle is not powered, the wireless charging is in the Sleeping state;

[0007] Step S2: When the vehicle is powered and the VCU is awakened, it enters the WPT_Idle state. After receiving the wireless charging request from the WCU, the VCU diagnoses the vehicle status and determines whether the wireless charging conditions are met. If the vehicle still does not have a wireless charging environment after the calibration time, the VCU diagnoses that the charging current is less than or equal to the current that allows the wireless charging contactor to be disconnected, and a wireless charging contactor disconnection instruction should be issued;

[0008] Step S3: When the vehicle network is in good condition and there is no fault that affects wireless charging, and the wireless charging environment is available, the vehicle enters the WPT_Prepare state, and the VCU sends a request for the wireless charging contactor to close and a signal to allow wireless charging;

[0009] Step S4: When the BMS reports that the wireless charging contactor is closed, the WPT_On state is entered, and the VCU diagnoses the vehicle status in real time during wireless charging;

[0010] Step S5: When the vehicle wireless charging conditions are not met, the vehicle enters the WPT_Stop state, the VCU controls the wireless charging to be suspended, and sends a signal that does not allow wireless charging. At the same time, after receiving the signal that does not allow charging, the WCU should immediately reduce the wireless charging current and feed back the charging current value to the VCU;

[0011] Step S6: If the VCU determines that the reason for the loss of wireless charging conditions of the vehicle is: a serious fault occurs in the vehicle and the battery power has reached the charging upper limit, the VCU diagnoses the wireless charging current and issues a wireless charging contactor disconnection instruction only when the charging current drops to a safe range;

[0012] If the VCU determines that the reason for the loss of wireless charging conditions for the vehicle is: the charging current is low and the BMS allows the charging current to be low, the wireless charging enters the WPT_Idle state. The VCU re-determines that the vehicle has a wireless charging environment and allows it to enter the charging cycle again;

[0013] Step S7: When the VCU receives a signal from the BMS that the wireless charging contactor has been disconnected, it enters the WPT_PrepareToStop state, the wireless charging cycle ends, and the VCU issues a wireless charging sleep instruction;

[0014] Step S8: The vehicle enters the Sleeping state after losing power.

[0015] The following is a technical solution further defined by the present invention. When the WCU sends a wireless charging request to the whole vehicle, the VCU first diagnoses the status of the whole vehicle, and only sends a wireless charging contactor closing instruction to the BMS when it is determined that the whole vehicle has all the conditions for wireless charging.

[0016] The following is a technical solution further defined by the present invention. During wireless charging of the vehicle, charging is stopped when the following two situations occur:

[0017] The first is that the vehicle has a non-recoverable fault that requires power off. At this time, the VCU will send a request to the BMS to disconnect the wireless charging contactor, and the wireless charging will be completely terminated during this charging cycle.

[0018] The second type is that the vehicle charging environment is not ideal and the charging cycle is stopped. At this time, the VCU will not issue a request to disconnect the wireless charging contactor, and the WCU will continue to request charging. After the VCU determines that the charging conditions are met, it will enter a new charging cycle.

[0019] The following is a technical solution further defined in the present invention. When the VCU determines that the conditions for stopping wireless charging are met, it sends a wireless charging stop instruction to all systems involved in wireless charging, and at the same time receives the wireless charging current signal from the WCU. Only when the wireless charging current drops to a safe range, the VCU sends a wireless charging contactor disconnection instruction to the BMS.

[0020] The following is a technical solution further defined by the present invention. When the whole vehicle enters the WPT_Prepare state, the VCU issues a command requesting the wireless charging contactor to close. If the BMS still feedbacks that the wireless charging contactor is in the disconnected state after the calibration time, the VCU controls the wireless charging to enter the WPT_Stop state, determines that the wireless charging contactor closing fault flag is established, and feedbacks the fault flag to the WCU and BMS.

[0021] The following is a technical solution further defined by the present invention. When the vehicle loses the WCU node signal due to a WCU communication failure, causing the wireless charging to be suspended and enter the WPT_Stop state, the VCU cannot ensure the safe disconnection of the wireless charging contactor due to the loss of the wireless charging current information. At this time, the VCU will delay issuing a wireless charging contactor disconnection command.

[0022] The following is a technical solution further defined by the present invention: Sleeping state: the whole vehicle is in a dormant state, with no power supply and no communication conditions; WPT_Idle state: the whole vehicle is awakened, with power supply and communication conditions, waiting for the WCU wireless charging request, and allowing the issuance of a wireless charging contactor disconnection instruction; WPT_Prepare state: the whole vehicle communication state is good, there is no fault affecting wireless charging, the wireless charging conditions are met, and the issuance of a wireless charging contactor closing instruction is allowed; WPT_On state: the whole vehicle is wirelessly charging, and the wireless charging contactor is closed; WPT_Stop state: the whole vehicle wireless charging is paused, the VCU requests the wireless charging to stop, and the issuance of a wireless charging contactor disconnection instruction is allowed; WPT_PrepareToStop state: the whole vehicle wireless charging is stopped, and the wireless charging contactor is disconnected.

[0023] The following is a technical solution further defined in the present invention: the end of wireless charging in the Sleeping state is a charging cycle, and a charging cycle allows multiple entry into the WPT_On state. The end of a charging cycle for wireless charging from the WPT_Stop state to the WPT_Idle state is a charging cycle, and a charging cycle allows multiple charging cycles.

[0024] The following is a technical solution further defined by the present invention: WCU sends a wireless charging request and wireless charging information to VCU, VCU sends a wireless charging enable instruction and wireless charging status information to WCU; VCU sends wireless charging contactor control and wireless charging status information to BMS, BMS sends wireless charging contactor status and battery information to VCU; VCU sends wireless charging information to CCU, and CCU sends system information to VCU.

[0025] Compared with the prior art, the present invention has the following technical effects:

[0026] 1. The present invention enables the wireless charging process to meet the automatic control of the wireless charging contactor without manual intervention, and eliminates the safety risks caused by the user directly contacting the charging medium;

[0027] 2. The control instructions of the wireless charging contactor of the present invention are reliable, flexible and safe. There are only two control instructions in one charging cycle, which effectively avoids the frequent action of the wireless charging controller between multiple charging cycles in one charging cycle. The disconnection instruction is only issued when the wireless charging current is within a safe range, and the action of disconnection with power is eliminated, which increases the hardware service life of the wireless charging contactor and reduces the maintenance cost;

[0028] 3. The present invention realizes full-cycle fault diagnosis of wireless charging, provides instant information for each system to respond to faults, and improves the safety charging factor of wireless charging of the entire vehicle system.

[0029] The present invention is further described below in conjunction with the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 It is a schematic diagram of the module connection relationship of the present invention;

[0032] Figure 2 It is a schematic flow chart of the method of the present invention. DETAILED DESCRIPTION

[0033] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0034] like Figure 1 and 2 As shown, this embodiment provides a control method for a wireless charging contactor.

[0035] like Figure 1 As shown, there are wireless charging controller WCU, vehicle controller VCU, battery management system BMS and other system controllers CCU. WCU sends wireless charging request and wireless charging information to VCU, VCU sends wireless charging enable instruction and wireless charging status information to WCU; VCU sends wireless charging contactor control and wireless charging status information to BMS, BMS sends wireless charging contactor status and battery information to VCU; VCU sends wireless charging information to CCU, CCU sends system information to VCU. The vehicle nodes exchange information through CAN communication, with the vehicle controller VCU as the information exchange hub and control and dispatch center, so as to achieve automatic control of the entire wireless charging cycle.

[0036] like Figure 2 As shown, the wireless charging states are named:

[0037] Sleeping state: The vehicle is in a dormant state, with no power supply and no communication conditions;

[0038] WPT_Idle state: The vehicle is awakened, powered, and has communication conditions, waiting for the WCU wireless charging request, and allowing the wireless charging contactor disconnection command to be issued;

[0039] WPT_Prepare status: The vehicle communication status is good, there is no fault that affects wireless charging, the conditions for wireless charging are met, and the wireless charging contactor closing command can be issued;

[0040] WPT_On state: The vehicle is wirelessly charging and the wireless charging contactor is closed;

[0041] WPT_Stop state: The wireless charging of the vehicle is suspended, the VCU requests the wireless charging to stop, and the wireless charging contactor disconnection command is allowed to be issued;

[0042] WPT_PrepareToStop status: The wireless charging of the vehicle is stopped and the wireless charging contactor is disconnected.

[0043] The end of wireless charging in the Sleeping state is a charging cycle. A charging cycle can enter the WPT_On (wireless charging) state multiple times. The end of a charging cycle is when wireless charging changes from the WPT_Stop (wireless charging pause) state to the WPT_Idle (wireless charging waiting) state. A charging cycle can have multiple charging cycles.

[0044] The following will explain the control method of wireless charging contactor from three aspects: control strategy, control characteristics, and fault monitoring:

[0045] 1. Control strategy

[0046] 1. When the vehicle is not powered, the wireless charging is in Sleeping state;

[0047] 2. When the vehicle is powered and the VCU is awakened, it enters the WPT_Idle state. After receiving the wireless charging request from the WCU, the VCU diagnoses the vehicle status and determines whether the wireless charging conditions are met. If the vehicle still does not have a wireless charging environment after the calibration time, the VCU diagnoses that the charging current is less than or equal to the current that allows the wireless charging contactor to be disconnected, and a wireless charging contactor disconnection instruction should be issued;

[0048] 3. When the vehicle network is in good condition and there is no fault that affects wireless charging, and the wireless charging environment is available, it enters the WPT_Prepare state, and the VCU sends a request for the wireless charging contactor to close and a signal to allow wireless charging;

[0049] 4. When the BMS reports that the wireless charging contactor is closed, it enters the WPT_On state, and the VCU diagnoses the vehicle status in real time during wireless charging;

[0050] 5. When the vehicle wireless charging conditions are not met, it enters the WPT_Stop state, the VCU controls the wireless charging to be suspended, and sends a signal that does not allow wireless charging. At the same time, after receiving the signal that does not allow charging, the WCU should immediately reduce the wireless charging current and feedback the charging current value to the VCU;

[0051] If the VCU determines that the reason for the loss of wireless charging conditions for the vehicle is: a serious fault occurs in the vehicle, the battery power has reached the charging limit, and other conditions that require the termination of wireless charging occur, the VCU diagnoses the wireless charging current, and only when the charging current drops to a safe range will it issue a wireless charging contactor disconnection command;

[0052] If the VCU determines that the reason for the loss of wireless charging conditions for the vehicle is: low charging current, low charging current allowed by the BMS, and other unsatisfactory charging conditions that require charging to be suspended, the wireless charging enters the WPT_Idle state, and the VCU re-determines that the vehicle has a wireless charging environment before entering the charging cycle again;

[0053] 6. When the VCU receives a signal from the BMS that the wireless charging contactor has been disconnected, it enters the WPT_PrepareToStop state, the wireless charging cycle ends, and the VCU issues a wireless charging sleep command;

[0054] 7. The vehicle enters Sleeping state after losing power.

[0055] 2. Control characteristics

[0056] 1. Reliability: When the wireless charging controller sends a wireless charging request to the vehicle, the vehicle controller first diagnoses the vehicle status. Only when it determines that the vehicle is fully equipped with wireless charging conditions will it send a wireless charging contactor closing command to the BMS. This can prevent the wireless charging contactor from being closed and then disconnected in a short time due to the wireless charging contactor command being sent first but the vehicle's wireless charging environment is not ready.

[0057] 2. Flexibility: The wireless charging of the whole vehicle will stop charging due to the following two situations: the first is that the whole vehicle has a fault that cannot be recovered without power off. At this time, the whole vehicle controller will send a request to disconnect the wireless charging contactor to the BMS, and the wireless charging will be completely ended in this charging cycle; the second is that the charging environment of the whole vehicle is not ideal and the current charging cycle should be stopped. At this time, the whole vehicle controller will not send a request to disconnect the wireless charging contactor. The wireless charging controller can continue to request charging. The whole vehicle controller can enter a new charging cycle only when it determines that the charging conditions are met. In this way, different wireless charging control instructions can be issued according to different reasons for stopping charging. There are only two wireless charging contactor control instructions in one charging cycle, which effectively avoids the frequent action of the wireless charging contactor between multiple charging cycles in one charging cycle, and improves the control flexibility of the wireless charging contactor.

[0058] 3. Safety: When the vehicle controller determines that the conditions for stopping wireless charging are met, it sends a wireless charging stop command to all systems involved in wireless charging, and receives the wireless charging current signal from the wireless charging controller. Only when the wireless charging current drops to a safe range will the vehicle controller send a wireless charging contactor disconnect command to the BMS. Disconnecting the wireless charging contactor with current will increase the probability of adhesion failure of the wireless charging contactor, which will not only reduce the accuracy of the vehicle controller's diagnosis of the charging environment during wireless charging, but also reduce the service life of the wireless charging contactor, thereby increasing the cost of using the wireless charging function of the vehicle.

[0059] 3. Fault Monitoring

[0060] VCU meets the requirements of real-time fault diagnosis during the entire wireless charging cycle

[0061] 1. When the vehicle enters the WPT_Prepare state, the VCU sends a request for the wireless charging contactor to close. If the BMS still reports that the wireless charging contactor is in the disconnected state after the calibration time, the VCU controls the wireless charging to enter the WPT_Stop state, determines that the wireless charging contactor closure fault flag is established, and feeds back the fault flag to the WCU, BMS and other display systems to know the fault status for immediate response.

[0062] 2. When the vehicle loses the WCU node signal due to a WCU communication failure, causing the wireless charging to suspend and enter the WPT_Stop state, the VCU cannot ensure the safe disconnection of the wireless charging contactor due to the loss of wireless charging current information. At this time, the VCU will delay the issuance of the wireless charging contactor disconnection command to minimize the risk of disconnecting the wireless charging contactor with current.

[0063] The above is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Any technician familiar with the art can make many possible changes and modifications to the technical solution of the present invention by using the above disclosed methods and technical contents without departing from the scope of the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, all equivalent changes made according to the shape, structure and principle of the present invention without departing from the content of the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. A control method for a wireless charging contactor, characterized in that: The following steps are involved: Step S1: When the vehicle is not powered, the wireless charging is in the Sleeping state; Step S2: When the vehicle is powered and the VCU is awakened, it enters the WPT_Idle state. After receiving the wireless charging request from the WCU, the VCU diagnoses the vehicle status and determines whether the wireless charging conditions are met. If the vehicle still does not have a wireless charging environment after the calibration time, the VCU diagnoses that the charging current is less than or equal to the current that allows the wireless charging contactor to be disconnected, and a wireless charging contactor disconnection instruction should be issued; Step S3: When the vehicle network is in good condition and there is no fault that affects wireless charging, and the wireless charging environment is available, the vehicle enters the WPT_Prepare state, and the VCU sends a request for the wireless charging contactor to close and a signal to allow wireless charging; Step S4: When the BMS reports that the wireless charging contactor is closed, the WPT_On state is entered, and the VCU diagnoses the vehicle status in real time during wireless charging; Step S5: When the vehicle wireless charging conditions are not met, the vehicle enters the WPT_Stop state, the VCU controls the wireless charging to be suspended, and sends a signal that does not allow wireless charging. At the same time, after receiving the signal that does not allow charging, the WCU should immediately reduce the wireless charging current and feed back the charging current value to the VCU; Step S6: If the VCU determines that the reason for the loss of wireless charging conditions of the vehicle is: a serious fault occurs in the vehicle and the battery power has reached the charging upper limit, the VCU diagnoses the wireless charging current and issues a wireless charging contactor disconnection instruction only when the charging current drops to a safe range; If the VCU determines that the reason for the loss of wireless charging conditions for the vehicle is: the charging current is low and the BMS allows the charging current to be low, the wireless charging enters the WPT_Idle state. The VCU re-determines that the vehicle has a wireless charging environment and allows it to enter the charging cycle again; Step S7: When the VCU receives a signal from the BMS that the wireless charging contactor has been disconnected, it enters the WPT_PrepareToStop state, the wireless charging cycle ends, and the VCU issues a wireless charging sleep instruction; Step S8: The vehicle enters the Sleeping state after losing power.

2. A control method for a wireless charging contactor as claimed in claim 1, characterized in that: When the WCU sends a wireless charging request to the vehicle, the VCU first diagnoses the vehicle status. Only when it determines that the vehicle has all the conditions for wireless charging will it send a wireless charging contactor closing command to the BMS.

3. The control method of a wireless charging contactor according to claim 1, characterized in that: During vehicle wireless charging, charging stops when the following two situations occur: The first is that the vehicle has a non-recoverable fault that requires power off. At this time, the VCU will send a request to the BMS to disconnect the wireless charging contactor, and the wireless charging will be completely terminated during this charging cycle. The second type is that the vehicle charging environment is not ideal and the charging cycle is stopped. At this time, the VCU will not issue a request to disconnect the wireless charging contactor, and the WCU will continue to request charging. After the VCU determines that the charging conditions are met, it will enter a new charging cycle.

4. A control method for a wireless charging contactor as claimed in claim 1, characterized in that: When the VCU determines that the conditions for stopping wireless charging are met, it sends a wireless charging stop command to all systems involved in wireless charging, and at the same time receives the wireless charging current signal from the WCU. Only when the wireless charging current drops to a safe range, the VCU sends a wireless charging contactor disconnect command to the BMS.

5. The control method of a wireless charging contactor according to claim 1, characterized in that: When the vehicle enters the WPT_Prepare state, the VCU sends a command requesting the wireless charging contactor to close. If the BMS still reports that the wireless charging contactor is in the disconnected state after the calibration time, the VCU controls the wireless charging to enter the WPT_Stop state, determines that the wireless charging contactor closing fault flag is set, and feeds back the fault flag to the WCU and BMS.

6. The control method of a wireless charging contactor according to claim 1, characterized in that: When the vehicle loses the WCU node signal due to a WCU communication failure, causing the wireless charging to suspend and enter the WPT_Stop state, the VCU cannot ensure the safe disconnection of the wireless charging contactor due to the loss of wireless charging current information. At this time, the VCU will delay issuing the wireless charging contactor disconnection command.

7. A control method for a wireless charging contactor as claimed in claim 1, characterized in that: Sleeping state: The vehicle is in a dormant state, with no power supply and no communication conditions; WPT_Idle state: The vehicle is awakened, powered, and has communication conditions, waiting for the WCU wireless charging request, and allowing the wireless charging contactor disconnection command to be issued; WPT_Prepare status: The vehicle communication status is good, there is no fault that affects wireless charging, the conditions for wireless charging are met, and the wireless charging contactor closing command is allowed to be issued; WPT_On state: The vehicle is wirelessly charging and the wireless charging contactor is closed; WPT_Stop state: The wireless charging of the vehicle is suspended, the VCU requests the wireless charging to stop, and the wireless charging contactor disconnection command is allowed to be issued; WPT_PrepareToStop status: The wireless charging of the vehicle is stopped and the wireless charging contactor is disconnected.

8. The control method of a wireless charging contactor according to claim 1, characterized in that: The end of wireless charging in the Sleeping state is a charging cycle. One charging cycle allows multiple entry into the WPT_On state. The end of a charging cycle for wireless charging from the WPT_Stop state to the WPT_Idle state is a charging cycle. One charging cycle allows multiple charging cycles.

9. The control method of a wireless charging contactor according to claim 1, characterized in that: WCU sends wireless charging request and wireless charging information to VCU, VCU sends wireless charging enable instruction and wireless charging status information to WCU; VCU sends wireless charging contactor control and wireless charging status information to BMS, BMS sends wireless charging contactor status and battery information to VCU; VCU sends wireless charging information to CCU, and CCU sends system information to VCU.

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