A control system and method for converting national standard to European standard charging communication protocol

Abstract

The present invention provides a control system and method for converting a national standard to a European standard charging communication protocol, including a charging stand, a BMS, a battery pack and an EVCC; the EVCC includes a PP signal interface, a CP, a PE signal interface, an A+ wake-up signal interface, a CC2 signal interface, and a CAN communication signal interface; after the first interaction between the EVCC and the BMS reaches the BCP stage, the vehicle-end battery voltage is obtained in advance, and in the second or re-interaction stage, the EVCC starts pre-charging when receiving a BRM message; if the vehicle has the ability to detect the voltage outside the contactor, the voltage difference between the outside voltage of the contactor and the battery voltage is determined after receiving the CTS and CML messages. The present invention realizes that the national standard electric vehicle BMS can directly use the standard GB / T 27930 protocol to communicate with the EVCC for CAN, so that the national standard electric vehicle BMS is modified to the minimum, and it is convenient and fast to meet the European standard charging standard, and has the advantages of strong feasibility and high compatibility.

Description

Technical Field

[0001] The present invention belongs to the field of electric vehicle charging systems, and in particular relates to a national standard to European standard charging communication protocol conversion control system and method. Background Art

[0002] Due to the differences in charging interface and communication protocol standards, domestic new energy vehicle exports need to install European standard electric vehicle charging communication controller EVCC products to enable PLC communication between electric vehicles and European and American standard charging piles to meet the charging standards of the European and American markets. At present, the communication protocol between EVCC and BMS produced by most domestic manufacturers is based on a revised version of GB / T27930, rather than the standard GB / T27930 protocol. For example, adding new CAN messages, modifying the content of CAN messages, and modifying the reception timeout of CAN messages require the BMS on the vehicle side to make more modifications and adjustments in the program, otherwise it will not be able to charge successfully, at least including the following aspects:

[0003] 1. In the pre-charging stage, the pre-charging mechanism of European standard charging is completely different from that of national standard charging. In the European standard, pre-charging is completed by the vehicle, and the timeout judgment time for pre-charging completion is 7 seconds, while in the national standard, pre-charging is completed by the charging pile. If the communication protocol adopts a revised version based on GB / T27930, this requires that in the European standard pre-charging stage, the national standard BMS modifies the timeout time of CML and CTS messages in the GB / T27930 protocol from 5 seconds to 7 to 15 seconds;

[0004] 2. The European standard insulation test requires that the pile end be completed in 38 seconds, the EVCC timeout judgment for the pile insulation test is 40 seconds, and the national standard insulation test is completed in 30 seconds. If the communication protocol adopts a revised version based on GB / T27930, this requires that during the European standard insulation test phase, the national standard BMS modify the timeout time of the CRM message in the GB / T27930 protocol from 30 seconds to 45 to 60 seconds;

[0005] 3. The detection resistance of the PP signal of the European standard charging interface after the gun is inserted is 1.5K, while the detection resistance of the CC2 signal of the national standard charging interface after the gun is inserted is 1K. If the communication protocol adopts the revised version based on GB / T27930, the BMS needs to modify the detection resistance of CC2 to 1.5K.

[0006] It can be seen that if the communication protocol between the domestic electric vehicle BMS and EVCC is based on the revised version of GB / T27930 instead of the standard GB / T27930 protocol, the vehicle-side BMS software needs to be modified and adjusted, otherwise the electric vehicle will not be able to charge normally with the European standard charging pile. Therefore, the existing EVCC products have shortcomings such as inconvenience in use and poor adaptability. The method of converting the national standard GB / T27930 protocol to the European standard PLC of domestic EVCC manufacturers needs to be improved.

[0007] In addition, the communication protocol adopts a revised version based on GB / T27930. During the European standard pre-charging stage, the EVCC will determine whether the pre-charging is appropriate based on the output voltage of the PLC message at the pile end. However, if the BMS closes the high-voltage contactor on the vehicle end based solely on the judgment of the EVCC without actually measuring the voltage on the outside of the contactor, there is a risk of compromising battery safety. Summary of the invention

[0008] In view of this, in order to solve the deficiencies of the above-mentioned prior art, the purpose of the present invention is to provide a national standard to European standard charging communication protocol conversion control system and method. By improving the control method, the BMS of the national standard electric vehicle can directly use the standard GB / T27930 protocol to communicate with the EVCC for CAN, so that the modification of the BMS of the national standard electric vehicle is minimal, and the domestically produced vehicles are converted into electric vehicles that meet the European charging standards, while ensuring the safety of the battery when the BMS closes the vehicle-end contactor during the charging process.

[0009] In order to achieve the above-mentioned invention object, the present invention adopts the following technical scheme:

[0010] A national standard to European standard charging communication protocol conversion control system, including a charging seat, a BMS, a battery pack and an electric vehicle communication controller EVCC, the EVCC including:

[0011] PP signal interface, used for proximity detection, to detect whether a gun is inserted;

[0012] CP and PE signal interfaces are used for control guidance and PLC communication;

[0013] A+ wake-up signal interface, used to connect to BMS to output a high-level wake-up signal to wake up the BMS;

[0014] CC2 signal interface, used to connect to BMS to simulate national standard gun insertion and removal signals;

[0015] CAN communication signal interface, used to connect to BMS for CAN communication with BMS.

[0016] Preferably, the CAN communication protocol is GB / T27930-2015.

[0017] A control method for converting a charging communication protocol from a national standard to a European standard, the method comprising the following steps:

[0018] S1. When the charging gun is plugged into the vehicle charging dock, the CP signal of SECC in the charging gun wakes up the EVCC. After the EVCC and SECC data link layers are linked up, the interaction in the SLAC (signal level attenuation characteristic test) phase begins.

[0019] At the same time, EVCC outputs A+ wake-up signal, simulates CC2 gun plug signal, EVCC sends CHM message to BMS, and starts communication interaction with BMS;

[0020] S2. After EVCC and SECC complete the SLAC and SDP stages, they proceed to the V2G message interaction stage. When the V2G message interaction reaches the authorization stage and the charging pile authorization is completed, EVCC starts the electronic lock locking process;

[0021] S3. When the electronic lock is successfully locked, the charging pile and the vehicle begin insulation testing;

[0022] S4: When the insulation test is completed, the EVCC communicates with the BMS and prepares to enter the pre-charge phase when the EVCC receives the BRM message.

[0023] S5. After EVCC receives the ready BRO message, it stops sending CTS and CML messages, and the pre-charge phase is completed;

[0024] S6, EVCC and SECC are ready to enter the charging stage, EVCC sends a CRO (0x00) not ready message to BMS, and when EVCC is ready, it sends a CRO (0xAA) ready message to BMS;

[0025] S7, EVCC and SECC enter the charging cycle stage, EVCC sends CCS to BMS, and BMS sends BCL, BCS, BSM and other messages to EVCC;

[0026] S8. When the battery is fully charged normally, the BMS sends BST to the EVCC, and the EVCC replies with a CST message. After the BMS receives the CST message, it starts sending BSD and then disconnects the high-voltage contactor.

[0027] S9. When EVCC receives BSD, it sends CSD and starts to unlock the electronic lock, and the charging process ends.

[0028] Preferably, the communication interaction between the EVCC and the BMS in step S1 includes the following steps:

[0029] S11. When EVCC receives the BHM message from BMS, EVCC starts to send CRM (0x00) message. When EVCC receives the BRM message, EVCC sends CRM (0xAA) message.

[0030] S12. After EVCC receives the BCP message sent by BMS, EVCC starts to send CST message and terminates the interaction process with BMS.

[0031] S13. If EVCC times out and does not receive the BST message sent by BMS, the interaction process is terminated directly;

[0032] S14. If EVCC receives a BST message, EVCC starts sending a CSD message and waits for BMS to reply with a BSD message. If BSD is not received within a timeout period, communication is terminated directly.

[0033] Preferably, after the step S1 terminates the communication between EVCC and BMS, the session between EVCC and BMS ends, EVCC turns off the A+ wake-up signal, and simulates the CC2 gun-pulling signal.

[0034] Preferably, in step S4, the communication interaction between EVCC and BMS includes the following steps:

[0035] S41, EVCC outputs A+ wake-up signal, simulates CC2 gun plug signal, and sends the first frame message CHM to start the second interaction with BMS;

[0036] S42. After EVCC receives BHM from BMS, EVCC starts to send CRM (0x00) to BMS.

[0037] S43. After receiving the BRM sent by the BMS, the EVCC uses the battery voltage obtained during the first BCP phase with the BMS as the pre-charging voltage and sends it to the SECC. The vehicle end and the charging pile begin the pre-charging phase.

[0038] Preferably, after the step S1 terminates the communication between EVCC and BMS, the session between EVCC and BMS is temporarily suspended, EVCC does not turn off the A+ wake-up signal, and the CC2 signal still indicates that the gun is plugged in.

[0039] Preferably, in step S4, the communication interaction between EVCC and BMS includes the following steps:

[0040] S41, EVCC starts to send the first frame message CRM (0x00) to BMS and interacts with BMS again;

[0041] S42. After receiving the BRM sent by the BMS, the EVCC uses the battery voltage obtained during the BCP phase with the BMS as the pre-charging voltage and sends it to the SECC. The vehicle side and the European standard charging pile begin pre-charging.

[0042] Preferably, the pre-charging stage in step S4 includes the following steps:

[0043] A. When EVCC determines that the voltage difference between the current output voltage of the charging pile and the battery voltage is less than 10V, EVCC believes that the pre-charge voltage is appropriate, or the pre-charge has been carried out for 3-5 seconds. If either of these two conditions is met, EVCC sends CRM (0xAA) to BMS;

[0044] B. EVCC receives the BCP message sent by BMS, and EVCC updates the pre-charge request voltage according to the current battery voltage in BCP;

[0045] C. EVCC again determines the voltage difference between the current output voltage of the charging pile and the battery voltage. If it is less than 10V, EVCC believes that the pre-charge voltage is appropriate.

[0046] D. EVCC sends CTS and CML messages to BMS. After receiving the messages, BMS stops sending BCP messages and starts sending BRO messages. However, the content of the BRO message is not ready at this time.

[0047] E. BMS determines whether the charging pile parameters are appropriate. If the charging pile parameters are appropriate, it controls the high-voltage contactor to close, and BMS prohibits the vehicle-side insulation from opening. Then the BRO message content changes to ready.

[0048] Preferably, in step E, if the vehicle has the ability to detect the voltage outside the contactor, after receiving the CTS and CML messages, it is determined whether the voltage difference between the voltage outside the contactor and the battery voltage is less than 10V, and if it is less than 10V, the vehicle contactor is closed.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] The present invention provides a communication protocol conversion control system and method for converting the national standard GB / T27930 to the European standard PLC. The national standard electric vehicle can directly use the standard GB / T27930 charging protocol and EVCC to perform CAN communication, and there is no need for the BMS to modify the CRM timeout in the European standard pile insulation detection stage, and there is no need for the BMS to modify the CML and CTS message timeouts in the European standard pile pre-charging stage, and there is no need for the BMS to modify the CC2 detection resistor. The BMS does not need to start insulation detection during charging, so that the national standard electric vehicle BMS modification is minimal, and it can be conveniently and quickly converted into an electric vehicle that meets the European standard charging standard;

[0051] According to the control method provided, in the pre-charging stage of the European standard charging pile, the EVCC first determines whether the pre-charging voltage is appropriate based on the pile end output voltage in the European standard charging pile PLC message. If it is appropriate, the EVCC starts to send CTS and CML messages to the BMS. After receiving the messages, the BMS determines whether the charger parameters are appropriate and then closes the vehicle contactor. If the vehicle has the ability to detect the voltage outside the contactor, it can determine whether the voltage difference between the contactor outside voltage and the battery voltage is less than 10V after receiving the CTS and CML messages. If it is less than 10V, the vehicle contactor is closed, thereby ensuring the safety of the battery when the BMS closes the vehicle-end contactor during the charging process. It has the advantages of strong feasibility, high compatibility and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] 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 description of 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.

[0053] Figure 1 It is a normal charging timing flow chart of the national standard to European standard control method of the present invention;

[0054] Figure 2 It is a timing flow chart of the national standard to European standard conversion in the pre-charging stage of the control method of the present invention;

[0055] Figure 3 is a schematic diagram of a flow chart of Embodiment 1 of the present invention;

[0056] Figure 4 It is a schematic diagram of the flow chart of Example 2 of the present invention. DETAILED DESCRIPTION

[0057] The following specific examples are given to further clearly, completely and in detail illustrate the technical solution of the present invention. This example is the best example based on the technical solution of the present invention, but the protection scope of the present invention is not limited to the following examples. Specific implementation method:

[0059] A national standard to European standard charging communication protocol conversion control system, such as Figure 1 As shown, it includes a charging station, a BMS, a battery pack and an electric vehicle communication controller EVCC, and the EVCC includes:

[0060] PP signal interface, used for proximity detection, to detect whether a gun is inserted;

[0061] CP and PE signal interfaces are used for control guidance and PLC communication;

[0062] A+ wake-up signal interface, used to connect to BMS to output a high-level wake-up signal to wake up the BMS;

[0063] CC2 signal interface, used to connect to BMS to simulate national standard gun insertion and removal signals;

[0064] CAN communication signal interface, used to connect to BMS for CAN communication with BMS.

[0065] A control method for converting a charging communication protocol from a national standard to a European standard, the method comprising the following steps:

[0066] S1. When the charging gun is plugged into the vehicle charging dock, the CP signal of SECC in the charging gun wakes up the EVCC. After the EVCC and SECC data link layers are linked up, the interaction in the SLAC (signal level attenuation characteristic test) phase begins.

[0067] At the same time, EVCC outputs A+ wake-up signal, simulates CC2 gun plug signal, EVCC sends CHM message to BMS, and starts the first communication interaction with BMS:

[0068] S11. When EVCC receives the BHM message from BMS, EVCC starts to send CRM (0x00) message. When EVCC receives the BRM message, EVCC sends CRM (0xAA) message.

[0069] S12. After EVCC receives the BCP message sent by BMS, EVCC starts to send CST message and terminates the interaction process with BMS.

[0070] S13. If EVCC times out and does not receive the BST message sent by BMS, the interaction process is terminated directly;

[0071] S14. If EVCC receives a BST message, EVCC starts sending a CSD message and waits for BMS to reply with a BSD message. If BSD is not received within a timeout period, communication is terminated directly.

[0072] S2. After EVCC and SEC complete the SLAC and SDP stages, they proceed to the V2G message interaction stage. When the V2G message interaction reaches the authorization stage and the charging pile authorization is completed, EVCC starts the electronic lock locking process;

[0073] S3. When the electronic lock is successfully locked, the charging pile and the vehicle begin insulation testing;

[0074] S4. After the insulation detection is completed, the EVCC communicates with the BMS again. When the EVCC receives the BRM message, it is ready to enter the pre-charging stage; the pre-charging stage includes the following steps:

[0075] A. When EVCC determines that the voltage difference between the current output voltage of the charging pile and the battery voltage is less than 10V, EVCC believes that the pre-charge voltage is appropriate, or the pre-charge has been carried out for 3-5 seconds. If either of these two conditions is met, EVCC sends CRM (0xAA) to BMS;

[0076] B. EVCC receives the BCP message sent by BMS, and EVCC updates the pre-charge request voltage according to the current battery voltage in BCP;

[0077] C. EVCC again determines the voltage difference between the current output voltage of the charging pile and the battery voltage. If it is less than 10V, EVCC believes that the pre-charge voltage is appropriate.

[0078] D. EVCC sends CTS and CML messages to BMS. After receiving the messages, BMS stops sending BCP messages and starts sending BRO messages. However, the content of the BRO message is not ready at this time.

[0079] E. BMS determines whether the charging pile parameters are appropriate. If the charging pile parameters are appropriate, it controls the high-voltage contactor to close, and BMS prohibits the vehicle-side insulation from opening. Then the BRO message content changes to ready;

[0080] S5. After EVCC receives the ready BRO message, it stops sending CTS and CML messages, and the pre-charge phase is completed;

[0081] S6, EVCC and SECC are ready to enter the charging stage, EVCC sends a CRO (0x00) not ready message to BMS, and when EVCC is ready, it sends a CRO (0xAA) ready message to BMS;

[0082] S7, EVCC and SECC enter the charging cycle stage, EVCC sends CCS to BMS, and BMS sends BCL, BCS, BSM and other messages to EVCC;

[0083] S8. When the battery is fully charged normally, the BMS sends BST to the EVCC, and the EVCC replies with a CST message. After the BMS receives the CST message, it starts sending BSD and then disconnects the high-voltage contactor.

[0084] S9. When EVCC receives BSD, it sends CSD and starts to unlock the electronic lock, and the charging process ends.

[0085] Through this method, national standard electric vehicles can directly use the standard GB / T27930 charging protocol and EVCC for CAN communication. There is no need for BMS to modify the CRM timeout during the insulation detection stage of the European standard charging pile, and there is no need for BMS to modify the CML and CTS message timeouts during the pre-charging stage of the European standard charging pile. There is no need for BMS to modify the detection resistor of CC2, which effectively reduces the workload of internal program design of the charging system.

[0086] Preferably, in the first communication interaction between EVCC and BMS, EVCC receives the BCP message sent by BMS, obtains and saves parameters such as battery voltage, and then EVCC sends CST to terminate.

[0087] Preferably, after the communication between EVCC and BMS is terminated in step S1, the session between EVCC and BMS is ended, EVCC turns off the A+ wake-up signal, and simulates the CC2 gun-pulling signal; in step S4, EVCC and BMS communicate for the second interaction, including the following steps:

[0088] S41, EVCC outputs A+ wake-up signal, simulates CC2 gun plug signal, and sends the first frame message CHM to start the second interaction with BMS;

[0089] S42. After EVCC receives BHM from BMS, EVCC starts to send CRM (0x00) to BMS.

[0090] S43. After receiving the BRM sent by the BMS, the EVCC uses the battery voltage obtained during the first BCP phase with the BMS as the pre-charging voltage and sends it to the SECC. The vehicle end and the charging pile begin the pre-charging phase.

[0091] Preferably, after the communication between EVCC and BMS is terminated in step S1, the session between EVCC and BMS is temporarily suspended, EVCC does not turn off the A+ wake-up signal, and the CC2 signal still indicates that the gun is plugged in; in step S4, EVCC and BMS communicate and interact again, including the following steps:

[0092] S41, EVCC starts to send the first frame message CRM (0x00) to BMS and interacts with BMS again;

[0093] S42. After receiving the BRM sent by the BMS, the EVCC uses the battery voltage obtained during the BCP phase with the BMS as the pre-charging voltage and sends it to the SECC. The vehicle side and the European standard charging pile begin pre-charging.

[0094] When EVCC and BMS interact for the second time or again, EVCC and SECC can pre-charge earlier than the prior art method, maximizing the time of the pre-charging stage. In this way, BMS does not need to extend the 5-second timeout period for BMS to wait for EVCC to send CTS and CML messages, thus achieving the purpose of not requiring BMS to be modified.

[0095] Preferably, in step E, if the vehicle has the ability to detect the voltage outside the contactor, after receiving the CTS and CML messages, it is determined whether the voltage difference between the voltage outside the contactor and the battery voltage is less than 10V, and if it is less than 10V, the vehicle contactor is closed.

[0096] During the pre-charging stage of the European standard charging pile, the EVCC first determines whether the pre-charging voltage is appropriate based on the pile end output voltage in the European standard charging pile PLC message. If it is appropriate, the EVCC starts to send CTS and CML messages to the BMS. After receiving them, the BMS determines whether the charger parameters are appropriate, and then closes the vehicle contactor to ensure the safety of the battery during the charging process.

[0097] Preferably, the vehicle-side insulation detection is not enabled during the charging process. The vehicle-side insulation detection can be performed when:

[0098] After the charging gun is plugged in and before the contactor on the vehicle side is closed, the vehicle side can perform insulation testing;

[0099] When the contactor on the vehicle side is closed, the EV cannot perform insulation testing;

[0100] When charging is completed and the vehicle-side contactor is disconnected, the EV can perform insulation testing.

[0101] Preferably, the CAN communication protocol is GB / T27930-2015.

[0102] Preferably, EVCC and SECC proceed to the authorization stage of the V2G message, and the pile end authorization is completed, and EVCC starts to close the electronic lock. When the electronic lock is successfully closed, the vehicle end and the European standard pile end start insulation detection.

[0103] Preferably, the timing for EVCC to communicate with BMS again is when the insulation test on the vehicle side and the European standard charging pile side has been completed.

[0104] Preferably, the timing of pre-charging at the vehicle end and the European standard charging pile end is: EVCC receives the BRM message sent by BMS. The pre-charging voltage is: EVCC uses the battery voltage previously obtained in the BCP stage as the pre-charging voltage.

[0105] Preferably, the timing for BMS to close the vehicle-end contactor: EVCC first determines whether the pre-charging voltage is appropriate based on the pile-end output voltage in the European standard pile PLC message. If appropriate, EVCC starts to send CTS and CML messages to BMS. After receiving them, BMS determines whether the charger parameters are appropriate and then closes the vehicle contactor. If the vehicle has the ability to detect the voltage outside the contactor, it can determine whether the voltage difference between the contactor outside voltage and the battery voltage is less than 10V after receiving the CTS and CML messages. If it is less than 10V, the vehicle contactor is closed. The voltage detection device can accurately determine whether the charging pile parameters are appropriate; thereby improving the safety of the charging system during the charging process of electric vehicles.

[0106] The control system of the present invention enables the national standard electric vehicle to directly use the standard GB / T27930 charging protocol and EVCC for CAN communication. There is no need for the BMS to modify the CRM timeout during the insulation detection stage of the European standard pile, there is no need for the BMS to modify the CML and CTS message timeouts during the pre-charging stage of the European standard pile, there is no need for the BMS to modify the detection resistance of CC2 after the gun is plugged in, and the BMS does not need to start insulation detection during charging, so that the BMS modification of the national standard vehicle is minimal, and it can be easily and quickly converted into an electric vehicle that meets the European standard charging standard.

[0107] Embodiment 1:

[0108] An EVCC that converts the national standard GB / T27930 protocol to the European standard PLC communication and a control method thereof. The BMS of the national standard electric vehicle can directly use the standard GB / T27930 protocol to perform CAN communication with the EVCC, thereby converting the domestic vehicle into an electric vehicle that meets the European standard charging standard.

[0109] Control method 1 for EVCC national standard to European standard charging, the steps are as follows:

[0110] 1. When the charging gun is plugged into the vehicle charging dock, the charging dock wakes up the EVCC. The wake-up process is completed through the CP signal end of the charging dock. After the data link layer of EVCC and SECC is linked up, EVCC and SECC begin to interact in the SLAC (signal level attenuation characteristic test) phase. At the same time, EVCC outputs A+ wake-up signal to simulate CC2 gun plug signal. EVCC sends CHM message to BMS and starts the first communication interaction with BMS.

[0111] 2. When EVCC receives the BHM message from BMS, EVCC starts to send CRM (0x00) message. When EVCC receives the BRM message, EVCC sends CRM (0xAA) message. When EVCC receives the BCP message from BMS, EVCC starts to send CST message to terminate the first interaction process with BMS.

[0112] If EVCC times out and does not receive the BST message sent by BMS, the first interaction process is terminated directly; if a BST message is received, EVCC starts to send a CSD message and waits for BMS to reply with a BSD message; if BSD is not received after timeout, it is terminated directly;

[0113] Then, EVCC turns off the A+ wake-up signal and simulates the CC2 gun-pulling signal.

[0114] 3. After EVCC and SECC complete the SLAC, SDP (SECC Discovery Protocol) and other stages, they proceed to the V2G message interaction stage. When the V2G message interaction between EVCC and SECC reaches the authorization stage and the charging pile authorization is completed, EVCC starts the electronic lock locking process.

[0115] 4. When the electronic lock is successfully locked, the charging pile and the vehicle begin insulation testing.

[0116] 5. When the insulation detection is completed, EVCC outputs A+ wake-up signal, simulates CC2 gun plug signal, and sends CHM to start the second interaction with BMS.

[0117] 6. When EVCC receives BHM from BMS, EVCC starts to send CRM (0x00) to BMS. After receiving BRM from BMS, EVCC uses the battery voltage obtained in the first BCP phase with BMS as the pre-charge voltage and sends it to SECC. The vehicle and the charging pile start the pre-charge phase. EVCC obtains the current output voltage value of the charging pile from the PLC interaction message between EVCC and SECC.

[0118] 7. When EVCC determines that the voltage difference between the current output voltage of the charging pile and the battery voltage is less than 10V, EVCC believes that the pre-charge voltage is appropriate, or that it has been pre-charged for 3-5 seconds. If either of these two conditions is met, EVCC sends CRM (0xAA) to BMS.

[0119] 8. After receiving the BCP message sent by BMS, EVCC updates the pre-charge request voltage according to the current battery voltage in BCP; EVCC again determines the voltage difference between the current output voltage value of the charging pile and the battery voltage. If it is less than 10V, EVCC considers the pre-charge voltage appropriate. EVCC starts to send CTS and CML messages to BMS. After receiving the message, BMS stops sending BCP messages and starts sending BRO messages, but the content of the BRO message is not ready at this time.

[0120] 9. BMS determines whether the charging pile parameters are appropriate. If the charging pile parameters are appropriate (if the vehicle has the ability to detect the voltage outside the contactor, it determines whether the voltage difference between the voltage outside the contactor and the battery voltage is less than 10V), the high-voltage contactor is controlled to close, and the BMS prohibits the vehicle-side insulation from opening. Then the BRO message content changes to ready;

[0121] 10. After EVCC receives the ready BRO message, it stops sending CTS and CML messages, and the pre-charge phase is completed; EVCC and SECC are ready to enter the charging phase, and EVCC sends a CRO (0x00) not ready message to BMS; when EVCC is ready, it sends a CRO (0xAA) ready message to BMS.

[0122] 11. EVCC and SECC enter the charging cycle stage. EVCC sends CCS to BMS, and BMS sends BCL, BCS, BSM and other messages to EVCC.

[0123] 12. When the battery is fully charged and the process ends normally, the BMS sends BST to the EVCC, and the EVCC replies with a CST message. After the BMS receives the CST message, it starts sending BSD and then disconnects the high-voltage contactor.

[0124] 13. When EVCC receives BSD, it sends CSD and starts to unlock the electronic lock, and the charging process ends.

[0125] Embodiment 2:

[0126] A national standard to European standard charging communication protocol conversion control system and control method thereof, BMS can directly use the standard GB / T 27930 protocol to communicate with EVCC for CAN communication, and convert domestic vehicles into electric vehicles that meet the European standard charging standards. The method includes the following steps:

[0127] 1. When the charging gun is plugged into the vehicle charging dock, the charging dock wakes up the EVCC. The wake-up process is completed through the CP signal end of the charging dock. After the data link layer of EVCC and SECC is linked up, EVCC and SECC begin to interact in the SLAC (signal level attenuation characteristic test) phase. At the same time, EVCC outputs an A+ wake-up signal to simulate the CC2 gun plug signal. EVCC sends a CHM message to BMS and starts communication interaction with BMS.

[0128] 2. When EVCC receives the BHM message from BMS, EVCC starts to send CRM (0x00) message. When EVCC receives the BRM message, EVCC sends CRM (0xAA) message; when EVCC receives the BCP message sent by BMS, EVCC starts to send CST message to terminate the interaction process with BMS;

[0129] If EVCC times out and does not receive the BST message sent by BMS, the inter-process will be terminated directly. If a BST message is received, EVCC starts sending CSD messages and waits for BMS to reply with a BSD message. If BSD is not received after timeout, the process will be terminated directly;

[0130] Then, EVCC does not turn off the A+ wake-up signal, and the CC2 signal still indicates that the gun is plugged in.

[0131] 3. After EVCC and SECC complete the SLAC, SDP (SECC Discovery Protocol) and other stages, they proceed to the V2G message interaction stage. When the V2G message interaction between EVCC and SECC reaches the authorization stage and the charging pile authorization is completed, EVCC starts the electronic lock locking process.

[0132] 4. When the electronic lock is successfully locked, the charging pile and the vehicle begin insulation testing.

[0133] 5. When the insulation test is completed, EVCC starts to send CRM (0x00) to BMS and interacts with BMS again.

[0134] 6. After receiving the BRM sent by the BMS, the vehicle and the European standard charging pile start pre-charging. The EVCC uses the battery voltage obtained in the BCP stage with the BMS as the pre-charging voltage and sends it to the SECC. The EVCC obtains the current output voltage value of the charging pile from the PLC interaction message between it and the SECC.

[0135] 7. When EVCC determines that the voltage difference between the current output voltage of the charging pile and the battery voltage is less than 10V, EVCC believes that the pre-charge voltage is appropriate, or the pre-charge has been carried out for 3-5 seconds. If either of these two situations is met, EVCC sends CRM (0xAA) to BMS.

[0136] 8. When EVCC receives the BCP message sent by BMS, EVCC updates the pre-charge request voltage according to the current battery voltage in BCP; EVCC again determines the voltage difference between the current output voltage value of the charging pile and the battery voltage. If it is less than 10V, EVCC considers the pre-charge voltage appropriate. EVCC starts to send CTS and CML messages to BMS. After receiving the message, BMS stops sending BCP messages and starts sending BRO messages, but the content of the BRO message is not ready at this time.

[0137] 9. BMS determines whether the charging pile parameters are appropriate. If the charging pile parameters are appropriate (if the vehicle has the ability to detect the voltage outside the contactor, it determines whether the voltage difference between the voltage outside the contactor and the battery voltage is less than 10V), then the high-voltage contactor is controlled to close, and the BMS prohibits the vehicle-side insulation from opening, and then the BRO message content changes to ready.

[0138] 10. After EVCC receives the ready BRO message, it stops sending CTS and CML messages, and the pre-charge phase is completed; EVCC and SECC are ready to enter the charging phase, and EVCC sends a CRO (0x00) not ready message to BMS; when EVCC is ready, it sends a CRO (0xAA) ready message to BMS.

[0139] 11.EVCC and SECC enter the charging cycle stage. EVCC sends CCS to BMS, and BMS sends BCL, BCS, BSM and other messages to EVCC.

[0140] 12. When the battery is fully charged and the process ends normally, the BMS sends BST to the EVCC, and the EVCC replies with a CST message. When the BMS receives the CST message, it starts sending BSD and then disconnects the high-voltage contactor.

[0141] 13. When EVCC receives BSD, it sends CSD and starts to unlock the electronic lock, and the charging process ends.

[0142] In summary, the present invention provides a control system and method for converting a national standard to a European standard charging communication protocol, so that national standard electric vehicles can directly use the standard GB / T27930 protocol to communicate with the EVCC for CAN communication, minimizing the modification of the national standard electric vehicle BMS, while ensuring the safety of the battery when the BMS closes the vehicle-end contactor during the charging process.

[0143] The above shows and describes the main features, basic principles and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may be modified or altered in various ways according to actual conditions. These equivalent changes and modifications also fall within the scope defined by the claims of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A control method for converting a charging communication protocol from a national standard to a European standard. The method is applied to a control system for converting a charging communication protocol from a national standard to a European standard. The system includes a charging station, a BMS, a battery pack, and an electric vehicle communication controller EVCC. The method is characterized in that: The EVCC includes: PP signal interface, used for proximity detection, to detect whether the gun is plugged in; CP, PE signal interface, used for control guidance and PLC communication; A+ wake-up signal interface, used to connect to BMS to output high-level wake-up signal to wake up BMS; CC2 signal interface, used to connect to BMS to simulate national standard gun plugging and pulling out signals; CAN communication signal interface, used to connect to BMS for CAN communication with BMS; The method comprises the following steps: S1. When the charging gun is plugged into the vehicle charging dock, the CP signal of the SECC in the charging gun wakes up the EVCC. After the EVCC and SECC data link layers are linked up, the interaction of the SLAC signal level attenuation characteristic test phase begins; At the same time, EVCC outputs A+ wake-up signal, simulates CC2 gun plug signal, EVCC sends CHM message to BMS, and starts communication interaction with BMS; In the first communication interaction between EVCC and BMS, EVCC receives the BCP message sent by BMS, obtains and saves the battery voltage parameters, and then EVCC sends CST to terminate; S2. After EVCC and SECC complete the SLAC and SDP stages, they proceed to the V2G message interaction stage. When the V2G message interaction reaches the authorization stage and the charging pile authorization is completed, EVCC starts the electronic lock locking process; S3. When the electronic lock is successfully locked, the charging pile and the vehicle begin insulation testing; S4: When the insulation test is completed, the EVCC communicates with the BMS, and when the EVCC receives the BRM message, it enters the pre-charge stage; S5. After EVCC receives the ready BRO message, it stops sending CTS and CML messages, and the pre-charge phase is completed; S6, EVCC and SECC are ready to enter the charging stage, EVCC sends CRO 0x00 Not Ready message to BMS, when EVCC is ready, it sends CRO 0xAA Ready message to BMS; S7, EVCC and SECC enter the charging cycle stage, EVCC sends CCS to BMS, and BMS sends BCL, BCS, BSM and other messages to EVCC; S8. When the battery is fully charged normally, the BMS sends BST to the EVCC, and the EVCC replies with a CST message. After the BMS receives the CST message, it starts sending BSD and then disconnects the high-voltage contactor. S9. When EVCC receives BSD, it sends CSD and starts to unlock the electronic lock, and the charging process ends.

2. The control method according to claim 1, characterized in that: The CAN communication protocol is GB / T 27930-2015.

3. The control method according to claim 1, characterized in that: The communication interaction between the EVCC and the BMS in step S1 includes the following steps: S11. When EVCC receives the BHM message from BMS, EVCC starts to send CRM 0x00 message. When EVCC receives the BRM message, EVCC sends CRM 0xAA message. S12. After EVCC receives the BCP message sent by BMS, EVCC starts to send CST message and terminates the interaction process with BMS. S13. If EVCC times out and does not receive the BST message sent by BMS, the interaction process is terminated directly; S14. If EVCC receives a BST message, EVCC starts sending a CSD message and waits for BMS to reply with a BSD message. If BSD is not received within a timeout period, communication is terminated directly.

4. The control method according to claim 3, characterized in that: After the step S1 terminates the communication between EVCC and BMS, the session between EVCC and BMS ends, EVCC turns off the A+ wake-up signal, and simulates the CC2 gun-pulling signal.

5. The control method according to claim 4, characterized in that: In step S4, the communication interaction between EVCC and BMS includes the following steps: S41, EVCC outputs A+ wake-up signal, simulates CC2 gun plug signal, and sends the first frame message CHM to start the second interaction with BMS; S42. After EVCC receives BHM from BMS, EVCC starts to send CRM 0x00 to BMS. S43. After receiving the BRM sent by the BMS, the EVCC uses the battery voltage obtained during the first BCP phase with the BMS as the pre-charging voltage and sends it to the SECC. The vehicle end and the charging pile begin the pre-charging phase.

6. The control method according to claim 3, characterized in that: After the step S1 terminates the communication between EVCC and BMS, the session between EVCC and BMS is temporarily suspended, EVCC does not turn off the A+ wake-up signal, and the CC2 signal still indicates that the gun is plugged in.

7. The control method according to claim 6, characterized in that: In step S4, the communication interaction between EVCC and BMS includes the following steps: S41, EVCC starts to send the first frame message CRM 0x00 to BMS and interacts with BMS again; S42. After receiving the BRM sent by the BMS, the EVCC uses the battery voltage obtained in the BCP phase with the BMS as the pre-charging voltage and sends it to the SECC, and the vehicle end and the charging pile begin the pre-charging phase.

8. The control method according to any one of claims 4 to 7, characterized in that: The pre-charging stage in step S4 includes the following steps: A. When EVCC determines that the voltage difference between the current output voltage of the charging pile and the battery voltage is less than 10V, EVCC believes that the pre-charge voltage is appropriate, or the pre-charge has been carried out for 3-5 seconds. If either of these two conditions is met, EVCC sends CRM 0xAA to BMS; B. EVCC receives the BCP message sent by BMS, and EVCC updates the pre-charge request voltage according to the current battery voltage in BCP; C. EVCC again determines the voltage difference between the current output voltage of the charging pile and the battery voltage. If it is less than 10V, EVCC believes that the pre-charge voltage is appropriate. D. EVCC sends CTS and CML messages to BMS. After receiving the messages, BMS stops sending BCP messages and starts sending BRO messages. However, the content of the BRO message is not ready at this time. E. BMS determines whether the charging pile parameters are appropriate. If the charging pile parameters are appropriate, it controls the high-voltage contactor to close, and BMS prohibits the vehicle-side insulation from opening. Then the BRO message content changes to ready.

9. The control method according to claim 8, characterized in that: In step E, if the vehicle has the ability to detect the voltage outside the contactor, after receiving the CTS and CML messages, it is determined whether the voltage difference between the voltage outside the contactor and the battery voltage is less than 10V. If it is less than 10V, the vehicle contactor is closed.

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