Charging protection circuit

Abstract

This application belongs to the field of electrical control and power batteries, specifically proposing a charging protection circuit. Based on the national standard charging protocol, it controls the access of the corresponding charging method through manual and automatic operation modes while simultaneously shielding the other charging method, thereby eliminating safety hazards and avoiding mutual interference. The charging protection circuit includes a charging control circuit, a main circuit, and a mode control circuit for circuit connection. During manual or automatic charging, this application can control the charging port of another non-charging circuit to be de-energized by switching the relay and the charging contactor, and prevents the charging port temperature sensor from being integrated into the charging control circuit, thus specifically eliminating the safety problem of the other non-charging circuit being energized.

Description

Technical Field

[0001] This application proposes a protection circuit for dynamic management of battery charging based on the national standard charging protocol, belonging to the field of electrical control and power batteries. Background Technology

[0002] Currently, power batteries are widely used in various fields such as autonomous driving and logistics transportation. For example, heavy-duty AGVs typically use high-voltage batteries, and the charging operation of these batteries usually follows national standard protocols. Since battery charging is divided into manual charging and automatic charging, when the AGV is charging, both charging circuits are simultaneously connected to the vehicle body, except that one set of charging circuits is not activated.

[0003] Due to the technical requirements of the existing national standard charging protocol, when a charging mode is adopted, the temperature sensors of the two charging ports are simultaneously connected to the battery, which affects the battery's judgment of the charging port temperature. Moreover, when one charging method is adopted, the charging port of the other charging circuit will also be energized, resulting in safety hazards. If the operator accidentally touches it, it will cause a serious safety accident.

[0004] In view of the above, this patent application is hereby filed. Utility Model Content

[0005] The charging protection circuit described in this application aims to solve the problems existing in the prior art by controlling the access of the corresponding charging method through manual and automatic operation modes based on the national standard charging protocol, while shielding another charging method, so as to eliminate safety hazards and avoid mutual interference.

[0006] Therefore, the charging protection circuit includes a charging control circuit, a main circuit, and a mode control circuit for connecting the circuits. The charging control circuit includes: The manual charging port communication interface is used to communicate and exchange charging information with the AGV battery BMS. Automatic charging port communication interface, which communicates and interacts with the AGV battery BMS to exchange charging information; The manual charging switching relay KA1 includes three sets of normally open contacts; the coil of the manual charging switching relay KA1 is connected in parallel with the coil of the manual charging contactor KM1 and then connected to the auxiliary power supply A1- and A1+ of the manual charging port. The automatic charging switching relay KA2 includes three sets of normally open contacts; the coil of the automatic charging switching relay KA2 is connected in parallel with the coil of the automatic charging contactor KM2 and then connected to the auxiliary power supply A2- and A2+ of the automatic charging port. The manual charging contactor KM1 includes two sets of normally open contacts; the coil of the manual charging contactor KM1 is connected in parallel with the coil of the manual charging switching relay KA1 and then connected to the auxiliary power supply A1- and A1+ of the manual charging port. The automatic charging contactor KM2 includes two sets of normally open contacts; the coil of the automatic charging contactor KM2 is connected in parallel with the coil of the automatic charging switching relay KA2 and then connected to the auxiliary power supply A2- and A2+ of the manual charging port. The battery charging interface connects to the manual charging port and the automatic charging port respectively; The main circuit includes: The manual charging contactor KM1 includes two sets of normally open contacts; the coil of the manual charging contactor KM1 is connected in parallel with the coil of the manual charging switching relay KA1 and then connected to the auxiliary power supply A1- and A1+ of the manual charging port. The automatic charging contactor KM2 includes two sets of normally open contacts; the coil of the automatic charging contactor KM2 is connected in parallel with the coil of the automatic charging switching relay KA2 and then connected to the auxiliary power supply A2- and A2+ of the manual charging port.

[0007] The mode control loop includes: The mode selection switch SB1 has its common terminal connected to the positive terminal of DC24V. Its first position is manual mode, which is connected in parallel with the coils of the manual charging switching relay KA1 and the manual charging contactor KM1, and then in series. The first position outputs a high-level signal to the manual mode signal interface of the vehicle controller. Its second position is automatic mode, which is divided into two branches. One branch provides DC24V power to the remote IO module, and the other branch is connected to the automatic mode signal interface of the vehicle controller. The positive terminal of the remote I / O module is connected to position 2 of the mode selection switch SB1, and the negative terminal is connected to the DC24V negative terminal of the vehicle. An industrial router has a power interface connected to DC24V, and the industrial router communicates and exchanges information with remote control devices via WIFI. The vehicle controller has its manual mode interface and automatic mode interface connected to positions 1 and 2 of the mode selection switch SB1, respectively. The vehicle controller is connected to an industrial router via a network cable for communication.

[0008] Furthermore, in the charging control circuit, the three normally open contacts of the manual charging switching relay KA1 are connected in series with the temperature feedback positive terminals T11+ and T12 of the manual charging port control circuit and the charging confirmation signal CC2-1, respectively; one set of normally closed contacts is connected between the battery BMS and the parallel connection of the coils KA2 and KM2.

[0009] Furthermore, in the charging control circuit, the three normally open contacts of the automatic charging switching relay KA2 are connected in series with the temperature feedback positive terminals T21 and T22+ of the automatic charging port control circuit and the charging confirmation signal CC2-2, respectively; one set of normally closed contacts is connected between the battery BMS and the coils of KA1 and KM1 in parallel.

[0010] Furthermore, in the charging control circuit, the two normally open contacts of the manual charging contactor KM1 are connected in series with the positive and negative terminals of the main circuit of the manual charging port, respectively.

[0011] Furthermore, in the charging control circuit, the two normally open contacts of the automatic charging contactor KM2 are connected in series with the positive and negative terminals of the main circuit of the automatic charging port, respectively.

[0012] Furthermore, in the main circuit, the two normally open contacts of the manual charging contactor KM1 are connected in series with the positive and negative terminals of the manual charging port main circuit, respectively.

[0013] Furthermore, in the main circuit, the two normally open contacts of the automatic charging contactor KM2 are connected in series with the positive and negative terminals of the main circuit of the automatic charging port, respectively.

[0014] Furthermore, in the aforementioned mode control loop, the remote IO module is connected to the industrial router via a network cable, and its output interface DO1 is connected to one end of the parallel connection between the coils of the automatic charging contactor KM2 and the automatic charging switching relay KA2.

[0015] Furthermore, in the aforementioned mode control loop, one network port of the industrial router is connected to the vehicle controller, and the other network port is connected to the remote I / O to achieve communication information exchange.

[0016] In summary, this application has the following advantages and beneficial effects: 1. This application features a simple structure and strong practicality, and completely solves the problem of one side of the circuit being unresolved when two charging ports are simultaneously connected to the control circuit under two charging modes, effectively eliminating safety hazards.

[0017] 2. During manual or automatic charging, this application can control the charging port of another non-charging circuit to be de-energized by switching the relay and the charging contactor, and prevent the charging port temperature sensor from being integrated into the charging control circuit, thereby specifically eliminating the safety problem of the other non-charging circuit being energized. Attached Figure Description

[0018] The present application will now be further illustrated with reference to the following figures.

[0019] Figure 1 This is a schematic diagram of the main circuit of the charging protection circuit described in this application; Figure 2This is a schematic diagram of the charging control circuit; Figure 3 This is a schematic diagram of the mode control loop; Detailed Implementation

[0020] Example 1, such as Figures 1 to 3 As shown, this application proposes a novel charging protection circuit applicable to heavy-duty AGVs. This circuit utilizes the auxiliary power supply of the charging pile to control relays and contactors, thereby achieving safety protection between manual and automatic charging circuits according to the charging mode.

[0021] The charging protection circuit includes a charging control circuit, a main circuit, and a mode control circuit that enable circuit connections. The charging control circuit includes: The manual charging port communication interface is used to communicate and exchange charging information with the AGV battery BMS. Automatic charging port communication interface, which communicates and interacts with the AGV battery BMS to exchange charging information; The manual charging switching relay KA1 includes three sets of normally open contacts. These three sets of normally open contacts are connected in series with the temperature feedback positive terminals T11+ and T12 of the manual charging port control circuit, as well as the charging confirmation signal CC2-1, to control the on / off state of the temperature feedback and charging confirmation feedback signals between the manual charging port and the battery BMS. One set of normally closed contacts is connected in parallel between the battery BMS and the coils of KA2 and KM2 to isolate the auxiliary power positive terminal A2+ of the automatic charging port from the auxiliary power positive terminal A1+ of the manual charging port. The coil of the manual charging switching relay KA1 is connected in parallel with the coil of the manual charging contactor KM1 and then connected to the auxiliary power supply A1- and A1+ of the manual charging port. The automatic charging switching relay KA2 includes three sets of normally open contacts. These three sets of normally open contacts are connected in series with the temperature feedback positive terminals T21 and T22+ of the automatic charging port control circuit and the charging confirmation signal CC2-2, respectively, to control the on / off state of the temperature feedback and charging confirmation feedback signals between the automatic charging port and the battery BMS. One set of normally closed contacts is connected between the battery BMS and the coils of KA1 and KM1 in parallel, to isolate the auxiliary power positive terminal A2+ of the manual charging port from the auxiliary power positive terminal A1+ of the automatic charging port. The coil of the automatic charging switching relay KA2 is connected in parallel with the coil of the automatic charging contactor KM2 and then connected to the auxiliary power supply A2- and A2+ of the automatic charging port. The manual charging contactor KM1 includes two sets of normally open contacts, which are connected in series with the positive and negative terminals of the main circuit of the manual charging port to control the opening and closing of the main circuit of the manual charging port. The coil of the manual charging contactor KM1 is connected in parallel with the coil of the manual charging switching relay KA1 and then connected to the auxiliary power supply A1- and A1+ of the manual charging port. The automatic charging contactor KM2 includes two sets of normally open contacts, which are connected in series with the positive and negative terminals of the main circuit of the automatic charging port to control the opening and closing of the main circuit of the automatic charging port. The coil of the automatic charging contactor KM2 is connected in parallel with the coil of the automatic charging switching relay KA2 and then connected to the auxiliary power supply A2- and A2+ of the manual charging port. The battery charging interface connects to the manual charging port and the automatic charging port respectively; In the above control loop, the manual charging port control interface is defined as follows: S+: Communication interface, connected to the battery BMS CANH interface for communication and interaction; S-: Communication interface, connected to the battery BMS CANL interface for communication and interaction; A1+: Auxiliary power positive terminal, which provides DC24V power to the battery after the charging pile is connected to the vehicle body; A1-: Auxiliary power supply negative terminal, which provides DC24V power to the battery after the charging pile is connected to the vehicle body; T11+: Positive terminal of the charging port positive electrode temperature detection sensor, which feeds back the charging port positive electrode temperature to the BMS; T12+: Positive terminal of the charging port negative electrode temperature detection sensor, which feeds back the charging port negative electrode temperature to the BMS; T11-: Negative terminal of the charging port positive electrode temperature detection sensor, which feeds back the charging port positive electrode temperature to the BMS; T12-: Negative terminal of the charging port negative terminal temperature detection sensor, which feeds back the charging port negative terminal temperature to the BMS; CC2-1: Charging confirmation signal, which sends a confirmation signal to the battery BMS that charging can proceed.

[0022] In the above control loop, the automatic charging port control interface is defined as follows: CANH: Communication interface, connected to the CANH interface of the battery BMS for communication and interaction; CANL: Communication interface, connected to the battery BMS CANL interface for communication and interaction; A2+: Auxiliary power positive terminal, which provides DC24V power to the battery after the charging pile is connected to the vehicle body; A2-: Auxiliary power supply negative terminal, which provides DC24V power to the battery after the charging pile is connected to the vehicle body; T21+: Positive terminal of the charging port positive electrode temperature detection sensor, which feeds back the charging port positive electrode temperature to the BMS; T22+: Positive terminal of the charging port negative electrode temperature detection sensor, which feeds back the charging port negative electrode temperature to the BMS; T21-: Negative terminal of the charging port positive electrode temperature detection sensor, which feeds back the charging port positive electrode temperature to the BMS; T22-: Negative terminal of the charging port negative terminal temperature detection sensor, which feeds back the charging port negative terminal temperature to the BMS; CC2-2: Charging confirmation signal, which sends a confirmation signal to the battery BMS that charging can proceed.

[0023] The wiring definition for the battery BMS control interface in the above control loop is as follows: CANH: Communication interface, which connects to the CANH or S+ interface of the charging port for communication. CANL: Communication interface, connected to the charging port CANL or S-interface for communication. A+: Auxiliary power positive terminal, after the vehicle body is connected to the charging pile, it receives DC24V power from the charging pile; A-: Auxiliary power supply negative terminal, after the vehicle body is connected to the charging pile, it receives DC24V power from the charging pile; T1+: Positive terminal of the charging port positive temperature detection sensor, which receives the temperature of the charging port positive terminal; T2+: Positive terminal of the charging port negative terminal temperature detection sensor, which receives the temperature of the charging port negative terminal; T1-: Negative terminal of the charging port positive temperature detection sensor, which receives the temperature of the charging port positive terminal; T2-: Negative terminal of the charging port negative terminal temperature detection sensor, which receives feedback on the charging port negative terminal temperature; CC2: Charging confirmation signal. This signal confirms that charging can proceed.

[0024] The main circuit includes: The manual charging contactor KM1 includes two sets of normally open contacts, which are connected in series with the positive and negative terminals of the main circuit of the manual charging port to control the opening and closing of the main circuit of the manual charging port. The coil of the manual charging contactor KM1 is connected in parallel with the coil of the manual charging switching relay KA1 and then connected to the auxiliary power supply A1- and A1+ of the manual charging port. The automatic charging contactor KM2 includes two sets of normally open contacts, which are connected in series with the positive and negative terminals of the main circuit of the automatic charging port to control the on / off state of the main circuit of the automatic charging port. The coil of the automatic charging contactor KM2 is connected in parallel with the coil of the automatic charging switching relay KA2 and then connected to the auxiliary power supply A2- and A2+ of the manual charging port.

[0025] In the above main circuit, the battery charging interface main circuit is defined as follows: B1+: The positive terminal of the manual charging port, which receives power from the positive charging terminal; B1-: The negative terminal of the manual charging port, which receives power from the negative charging terminal; B2+: The positive terminal of the automatic charging interface, which receives power from the positive charging terminal; B2-: The negative terminal of the automatic charging interface, which receives power from the negative charging terminal.

[0026] The aforementioned mode control loop includes, The mode selection switch SB1 has its common terminal connected to the positive DC24V of the vehicle. Its first position is manual mode, which is connected in parallel with the coils of the manual charging switching relay KA1 and the manual charging contactor KM1, and then in series. In addition, its first position outputs a high-level signal to the manual mode signal interface of the vehicle controller. Its second position is automatic mode, which is divided into two branches. One branch provides DC24V power to the remote IO module, and the other branch is connected to the automatic mode signal interface of the vehicle controller. The positive terminal of the remote I / O module is connected to position 2 of the mode selection switch SB1, and the negative terminal is connected to the DC24V negative terminal of the vehicle. The remote I / O module is connected to the industrial router via a network cable, and its output interface DO1 is connected to one end of the parallel connection between the coils of the automatic charging contactor KM2 and the automatic charging switching relay KA2. The industrial router's power interface is connected to the vehicle's DC24V, and it communicates and exchanges information with remote control devices via WIFI; one network port of the industrial router is connected to the vehicle controller, and the other network port is connected to the remote I / O to realize communication information exchange. The vehicle controller has its manual mode interface and automatic mode interface connected to positions 1 and 2 of the mode selection switch SB1, respectively. The vehicle controller is connected to an industrial router via a network cable for communication.

[0027] Based on the charging protection circuit proposed in this application, the following charging control process can be achieved: 1) Manual charging process; When the mode selection switch SB1 is set to position 1, the vehicle enters manual mode control. The vehicle controller receives the manual mode signal and transmits the current manual mode status to the remote control device through the industrial router. At the same time, the coils of the manual charging contactor KM1 and the manual charging switching relay KA1 are energized, and the three normally open contacts of KA1 close. The manual charging port feeds back the positive and negative temperatures of the charging port to the battery BMS. When the manual charging gun is inserted, the manual charging ports S+ and S- communicate with the battery BMS, CANH, and CANL. At the same time, the auxiliary power supplies A1+ and A1- provide DC24V positive power to the battery, waking it up. The manual charging port sends back a charging confirmation signal CC2-1. After receiving the signal, the battery BMS confirms that charging can begin. Simultaneously, as the coil of the manual charging contactor KM1 is energized, its two normally open contacts close, connecting the positive terminals B1+ and B1- of the manual charging port with the positive terminals B1+ and B1- of the battery charging port, thus initiating battery charging. At this time, because the mode selection switch SB1 is set to position 1, position 2 is de-energized, the remote IO module is powered off, and its output interface DO1 has no output. The automatic charging contactor KM2 and the automatic charging switching relay KA2 remain de-energized. Therefore, it is ensured that during manual charging, the temperature sensor of the automatic charging port will not be connected in parallel to the charging circuit, affecting the battery BMS's judgment of the charging circuit temperature, thus ensuring the most accurate and effective temperature data. At the same time, the connection between the automatic charging port and the battery charging port is also cut off, ensuring that the automatic charging port will not be energized during manual charging, preventing accidental contact and potential safety hazards. 2) Automatic charging process; When the mode selection switch SB1 is set to position 2, the vehicle enters automatic mode control, which powers the remote IO module. At the same time, the vehicle controller receives the automatic mode signal and transmits the current manual mode to the remote control device through the industrial router. Based on the vehicle status feedback from the vehicle controller, the remote control device controls the output interface DO1 of the remote IO through the industrial router to output, which powers the coils of the automatic charging contactor KM2 and the automatic charging switching relay KA2. As a result, the three normally open contacts of KA2 close, and the automatic charging port feeds back the positive and negative temperatures of the charging port to the battery BMS. When the automatic charging station plug is inserted, the automatic charging port CANH and CANL communicate with the battery BMS CANH and CANL. At the same time, the auxiliary power supply A2+ and A2- provides DC24V positive power to the battery, waking up the battery. The automatic charging port sends back a charging confirmation signal CC2-2. After receiving the signal, the battery BMS confirms that charging can begin. Simultaneously, with the automatic charging contactor KM2 coil energized, its two normally open contacts close, connecting the positive (B2+) and negative (B2-) terminals of the automatic charging port to the positive (B2+) and negative (B2-) terminals of the battery charging interface, and the battery begins charging. At this time, because the mode selection switch SB1 is set to position 2, position 1 is de-energized. Therefore, the manual charging contactor KM1 and the manual charging switching relay KA1 remain de-energized. This ensures that during automatic charging, the temperature sensor of the manual charging port will not be connected in parallel to the charging circuit, affecting the battery BMS's judgment of the charging circuit temperature, thus ensuring the most accurate and effective temperature data. It also disconnects the connection between the manual charging port and the battery charging port, ensuring that the manual charging port will not be energized during automatic charging, preventing accidental contact and potential safety hazards.

[0028] In summary, the embodiments shown in the accompanying drawings are merely preferred solutions. Those skilled in the art can draw inspiration from these embodiments and directly derive other alternative structures that conform to the design concept of this utility model; all such alternative structures should fall within the scope of protection described in this application.

Claims

1. A charging protection circuit, characterized in that: This includes a charging control circuit, a main circuit, and a mode control circuit for realizing circuit connections; the charging control circuit includes, The manual charging port communication interface is used to communicate and exchange charging information with the AGV battery BMS. Automatic charging port communication interface, which communicates and interacts with the AGV battery BMS to exchange charging information; The manual charging switching relay KA1 includes three sets of normally open contacts; the coil of the manual charging switching relay KA1 is connected in parallel with the coil of the manual charging contactor KM1 and then connected to the auxiliary power supply A1- and A1+ of the manual charging port. The automatic charging switching relay KA2 includes three sets of normally open contacts; the coil of the automatic charging switching relay KA2 is connected in parallel with the coil of the automatic charging contactor KM2 and then connected to the auxiliary power supply A2- and A2+ of the automatic charging port. The manual charging contactor KM1 includes two sets of normally open contacts; the coil of the manual charging contactor KM1 is connected in parallel with the coil of the manual charging switching relay KA1 and then connected to the auxiliary power supply A1- and A1+ of the manual charging port. The automatic charging contactor KM2 includes two sets of normally open contacts; the coil of the automatic charging contactor KM2 is connected in parallel with the coil of the automatic charging switching relay KA2 and then connected to the auxiliary power supply A2- and A2+ of the manual charging port. The battery charging interface connects to the manual charging port and the automatic charging port respectively; The main circuit includes, The manual charging contactor KM1 includes two sets of normally open contacts; the coil of the manual charging contactor KM1 is connected in parallel with the coil of the manual charging switching relay KA1 and then connected to the auxiliary power supply A1- and A1+ of the manual charging port. The automatic charging contactor KM2 includes two sets of normally open contacts; the coil of the automatic charging contactor KM2 is connected in parallel with the coil of the automatic charging switching relay KA2 and then connected to the auxiliary power supply A2- and A2+ of the manual charging port. The mode control loop includes, The mode selection switch SB1 has its common terminal connected to the positive terminal of DC24V. Its first position is manual mode, which is connected in parallel with the coils of the manual charging switching relay KA1 and the manual charging contactor KM1, and then in series. The first position outputs a high-level signal to the manual mode signal interface of the vehicle controller. Its second position is automatic mode, which is divided into two branches. One branch provides DC24V power to the remote IO module, and the other branch is connected to the automatic mode signal interface of the vehicle controller. The positive terminal of the remote I / O module is connected to position 2 of the mode selection switch SB1, and the negative terminal is connected to the DC24V negative terminal of the vehicle. An industrial router has a power interface connected to DC24V, and the industrial router communicates and exchanges information with remote control devices via WIFI. The vehicle controller has its manual mode interface and automatic mode interface connected to positions 1 and 2 of the mode selection switch SB1, respectively. The vehicle controller is connected to an industrial router via a network cable for communication.

2. The charging protection circuit according to claim 1, characterized in that: The charging control circuit has three normally open contacts of the manual charging switching relay KA1 connected in series with the temperature feedback positive terminals T11+ and T12 of the manual charging port control circuit and the charging confirmation signal CC2-1, respectively; one set of normally closed contacts is connected between the battery BMS and the KA2 and KM2 coils in parallel.

3. The charging protection circuit according to claim 1, characterized in that: The charging control circuit has three sets of normally open contacts of the automatic charging switching relay KA2 connected in series with the temperature feedback positive terminals T21 and T22+ of the automatic charging port control circuit and the charging confirmation signal CC2-2, respectively; one set of normally closed contacts is connected between the battery BMS and the coils of KA1 and KM1 in parallel.

4. The charging protection circuit according to claim 1, characterized in that: The charging control circuit has two sets of normally open contacts of the manual charging contactor KM1 connected in series with the positive and negative terminals of the main circuit of the manual charging port.

5. The charging protection circuit according to claim 1, characterized in that: The charging control circuit has two sets of normally open contacts of the automatic charging contactor KM2 connected in series with the positive and negative terminals of the main circuit of the automatic charging port.

6. The charging protection circuit according to claim 1, characterized in that: In the main circuit, the two normally open contacts of the manual charging contactor KM1 are connected in series with the positive and negative terminals of the manual charging port main circuit, respectively.

7. The charging protection circuit according to claim 1, characterized in that: In the main circuit, the two normally open contacts of the automatic charging contactor KM2 are connected in series with the positive and negative terminals of the main circuit of the automatic charging port, respectively.

8. The charging protection circuit according to claim 1, characterized in that: The aforementioned mode control loop has its remote IO module connected to an industrial router via a network cable, and its output interface DO1 is connected to one end of the parallel connection between the coils of the automatic charging contactor KM2 and the automatic charging switching relay KA2.

9. The charging protection circuit according to claim 1, characterized in that: The aforementioned mode control loop has one network port of the industrial router connected to the vehicle controller, and another network port connected to the remote I / O to achieve communication information exchange.

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