A charging and discharging control system and control method of an electric vehicle charging and discharging device

Abstract

The application provides a charging and discharging control system and method of an electric vehicle charging and discharging device, relates to the electric vehicle charging and discharging technical field, and the control system comprises a vehicle plug module, a basic charging plug module connected with the vehicle plug module through a wire harness, and a discharging power strip module; the discharging power strip module can be connected with or disconnected from the basic charging plug module; and the control method changes the resistance value between CC and PE, and different resistance values between CC and PE represent different charging or discharging states. The application has the advantages of simple structure, convenient use, safety and reliability, and low cost.

Description

Technical Field

[0001] This invention relates to the field of electric vehicle charging and discharging technology, specifically to a charging and discharging control system and control method for electric vehicle charging and discharging equipment. Background Technology

[0002] Electric vehicles have generally been equipped with charging and discharging functions. Currently, they are usually equipped with separate charging guns and discharging power strips. In order to improve the user experience and reduce wiring harness configuration and cost, integrated charging and discharging cables can be used for charging and discharging.

[0003] There are currently two ways to achieve charging and discharging functions: The first type involves separate charging and discharging devices. When charging an electric vehicle, a charging gun containing both a household plug and a vehicle plug is used. When discharging, a discharging gun consisting of a vehicle plug and a power strip is used. The vehicle needs to be equipped with both charging and discharging devices. This solution requires two wiring harnesses, which is costly and inconvenient to store.

[0004] The second method integrates charging and discharging functions by sharing certain components. A connector is added to the middle of the wiring harness. When a household plug is connected to the charging head wiring harness via the connector, it is used as a charging gun. When a discharging power strip is connected to the charging head wiring harness via the connector, it is used as a discharging gun. Usually, vehicle plugs have a default discharging resistor inside. When a vehicle plug is connected to a vehicle, it directly enters the discharging state. At this time, the contactable parts of the connector or household plug will be electrified, which is dangerous to people. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the present invention provides a charging and discharging control system and control method for electric vehicle charging and discharging equipment, which is simple in structure, easy to use, safe and reliable, and low in cost.

[0006] To achieve the above technical objectives, the adopted technical solution is as follows: a charging and discharging control system for an electric vehicle charging and discharging device, including a vehicle plug module, a basic charging plug module connected to the vehicle plug module via a wiring harness, and a discharging power strip module. When the discharging power strip module is connected to the basic charging plug module, the system discharges; when the discharging power strip module is not connected to the basic charging plug module, the system charges. Inside the vehicle plug module, there is an equivalent resistance R6 between CC and PE. Normally open relays are installed on the L and N lines inside the module. The vehicle plug module also includes a charging and discharging state switching module that controls whether a charging and discharging state switching module (resistance R5) is connected in parallel with the equivalent resistance R6, a control module for controlling the charging and discharging state switching module, and a plug and power strip identification module connected to the control module. Inside the discharging power strip module, there is a resistance R3 between CC and PE, and a resistance R4 between PE and the MT signal line. The plug and power strip identification module identifies the plug module type at the other end of the wiring harness connected to the vehicle plug module based on the MT signal line. The control module controls the charging and discharging state switching module to connect the resistance R5 between CC and PE, thus entering different charging and discharging states.

[0007] It also includes other charging plug modules. When other charging plug modules are connected to the basic charging plug module, the system realizes other charging. There is a resistor R1 between CC and PE inside the other charging plug module, and a resistor R2 between PE and MT signal line.

[0008] The basic charging plug module has a normally open temperature switch S3 between the MT signal line and PE.

[0009] The discharge connector module has a normally open temperature switch S2 between the MT signal line and the PE.

[0010] The other charging plug module has a normally open temperature switch S1 between the MT signal line and PE.

[0011] The plug and socket identification module consists of an input port protection circuit, a pull-up resistor R7, and an MCU port protection circuit. One end of the input port protection circuit and the MCU port protection circuit are connected in series to the MT signal line, and the other end is connected to the control module. A pull-up resistor R7 is connected between the input port protection circuit and the MCU port protection circuit.

[0012] The charge / discharge state switching module consists of a transistor Q1 and its peripheral resistors R5, R9 and R10. The collector of transistor Q1 is connected in series with resistor R5 (CC), and its base is connected in series with R10 and then connected to the charge / discharge switching pin of the control module. R9 is connected between the base and the emitter, and the emitter is connected to PE.

[0013] A control method for a charging and discharging control system of an electric vehicle charging and discharging device includes: Actively control the resistance value between the CC line and PE line within the vehicle plug module; The basic charging plug module has been plugged into the power socket. The plug and socket identification module identifies the basic charging plug module through the MT signal line. The control module controls the charging and discharging state switching module to connect resistors R5 and R6 in parallel. The resistance value between the CC line and PE line in the vehicle plug module is the value after R5 is connected in parallel with R6. The relays on the L line and N line are closed to enter the basic charging state. After the discharge power strip module is plugged into the basic charging plug module and the vehicle plug module is plugged into the vehicle socket, the plug and power strip identification module identifies the discharge power strip module through the MT signal line. The control module controls the charging and discharging state switching module to not connect R5 into the CC and PE circuits. The resistance value between the CC line and PE line in the vehicle plug module is R6, which is connected in parallel with the resistance value R3 between the CC line and PE line in the discharge power strip module, and the module enters the discharge state.

[0014] Other charging plug modules are plugged into the basic charging plug module and then into the power socket. The plug and socket identification module identifies other charging plug modules via the MT signal line. The control module ensures that the charging / discharging state switching module does not connect R5 to the CC and PE circuits. The resistance value between the CC and PE lines in the vehicle plug module is R6, which is connected in parallel with the resistance value R1 between the CC and PE lines in other charging plug modules, thus entering other charging states. The plug and socket identification module identifies different modules via the MT signal line by detecting the resistance value between the PE and MT signal lines in different modules to determine the plug module type at the other end of the wiring harness connected to the vehicle plug module.

[0015] When the basic charging plug module overheats, the impedance between the MT signal line and the PE short circuit in the basic charging plug module changes. The plug and socket identification module detects the change in the MT signal, and the control module controls the charging and discharging state switching module to disconnect resistor R5 from CC. When the resistance between CC and PE is detected to be R6, charging is stopped, thus achieving overheat protection.

[0016] When other charging plug modules overheat, the impedance between the MT signal line and PE in the other charging plug module changes. The plug and socket identification module detects the change in the MT signal, and the control module controls the charging and discharging state switching module to connect resistor R5 in parallel between CC and PE. The resistance between CC and PE is detected to be the parallel value of R6, R5 and the resistance R1 between the CC line and PE line in other charging plug modules, and charging is stopped to achieve overheat protection.

[0017] When the discharge power strip module overheats, the impedance between the MT signal line and PE inside the discharge power strip module changes. The plug and power strip identification module detects the change in the MT signal, and the control module controls the charge and discharge state switching module to connect resistor R5 in parallel between CC and PE. The resistance between CC and PE is detected to be the parallel value of R6, R5 and the resistance R3 between the CC line and PE line inside the discharge power strip module, and charging is stopped to achieve over-temperature protection.

[0018] The beneficial effects of this invention are: 1. Connect other charging plug modules and discharge power strip modules as separate modules to the basic charging plug module. Based on relevant charging and discharging standards, allocate resistance values ​​appropriately. Different parallel combinations of resistors allow for different charging / discharging or discharging modes. The circuit is simple, reliable, and low-cost. Furthermore, the initial state is neither charging nor discharging. After power-on, the product autonomously controls whether to enter charging or discharging mode based on the combined state, preventing user-accessible parts from becoming electrified, ensuring safety and reliability.

[0019] 2. The basic charging plug module, other charging plug modules, and discharge power strip module each have an over-temperature protection switch to reduce the risk of product use.

[0020] 3. The identification of the basic charging plug module, other charging plug modules, and discharge power strip module shares one signal line with the over-temperature protection function; this saves multiple signal lines, reduces product cost and weight, and the temperature protection and pattern recognition circuits are interlocked in parallel. When an over-temperature fault occurs, the resistance of the identification circuit can be directly changed to quickly stop the charging and discharging state, reducing the risk of serious failures and making the product safer and more reliable. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the control system of the present invention; Figure 2 This is a schematic diagram of the basic charging state of the present invention; Figure 3 This is a schematic diagram of other charging states of the present invention; Figure 4 This is a circuit diagram showing the discharge state of the present invention; Figure 5 This is a circuit diagram of the plug and socket identification module of the present invention; Figure 6 This is a circuit diagram of the charging / discharging state switching module of the present invention. Detailed Implementation

[0022] The preferred embodiments of the invention are given below with reference to the accompanying drawings to illustrate the technical solution of the invention in detail. The corresponding drawings will be provided for detailed explanation of the invention. It should be particularly noted that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit or restrict the invention.

[0023] This invention discloses a charging and discharging control system and control method for electric vehicle charging and discharging equipment, which can realize automatic identification of charging current, automatic identification of charging and discharging functions, and over-temperature protection for household plugs and power strips.

[0024] like Figure 1 As shown, the control system includes a vehicle plug module, a basic charging plug module connected to the vehicle plug module via a wiring harness, other charging plug modules, and a discharge power strip module. The discharge power strip module or other charging plug modules can be interchangeably connected to the basic charging plug module. The charging amperage of the other charging plug modules is less than that of the basic charging plug module. The technology has three modes: (1) When the vehicle plug module is connected to the basic charging plug module via a wiring harness, charging is achieved; (2) When the discharge power strip module is plugged into the basic charging plug module, discharging is achieved; (3) When other charging plug modules are connected to the basic charging plug module, charging with other amperages is achieved.

[0025] Inside the vehicle plug module, there is an equivalent resistance R6 between CC and PE. Normally open relays are installed on the L and N lines. The vehicle plug module also includes a charge / discharge state switching module that controls whether resistor R5 is connected in parallel with the equivalent resistance R6, a control module for controlling the charge / discharge state switching module, and a plug / socket identification module connected to the control module. Other charging plug modules have a resistor R1 between CC and PE, and a resistor R2 between PE and the MT signal line. In the discharge plug module, there is a resistor R3 between CC and PE, and a resistor R4 between PE and the MT signal line. The plug / socket identification module identifies the plug module type at the other end of the wiring harness connected to the vehicle plug module based on the MT signal line. The control module then controls the charge / discharge state switching module to connect resistor R5 between CC and PE to enter different charge / discharge states. In each module, CC represents charging connection confirmation, CP represents control guidance, PE represents protective ground, L represents AC power live wire, and N represents AC power neutral wire. The resistance values ​​of resistors R1, R2, R3, R4, R5, and R6 are defined according to the relevant standards for charging and discharging electric vehicles.

[0026] The impedance change between the MT signal line and the PE line is achieved through a temperature switch connected between them. When an over-temperature condition is triggered, the temperature switch closes, short-circuiting the MT signal line and the PE line. The plug / socket identification module then detects that the MT signal resistance is zero. The temperature switch can be replaced with an NTC switch; as the temperature rises, the resistance of the NTC decreases, thus decreasing the resistance between the MT signal line and the PE line. Alternatively, the temperature switch can be replaced with a PTC switch; as the temperature rises, its resistance increases, thus increasing the resistance between the MT signal line and the PE line. The following description uses a temperature switch as an example to illustrate the specific connection and control process.

[0027] The MT signal line inside the basic charging plug module has a normally open temperature switch S3 between it and the PE. That is, the two ends of S3 are connected to the MT signal line and the PE respectively for over-temperature protection. Similarly, the MT signal line inside other charging plug modules has a normally open temperature switch S1 between it and the PE, and the MT signal line inside the discharge plug module has a normally open temperature switch S2 between it and the PE.

[0028] like Figure 5 As shown, the plug and socket identification module consists of an input port protection circuit, a pull-up resistor R7, and an MCU port protection circuit. One end of the input port protection circuit and the MCU port protection circuit are connected in series to the MT signal line, and the other end is connected to the control module. A pull-up resistor R7 is connected between the input port protection circuit and the MCU port protection circuit. The input port protection circuit typically consists of surge protection device D1 and capacitor C1, while the MCU port protection circuit consists of resistor R8 and capacitor C2. The protection circuits can be adjusted according to actual conditions.

[0029] like Figure 6 As shown, the charge / discharge state switching module consists of transistor Q1 and its peripheral resistors R5, R9, and R10. The collector of transistor Q1 is connected in series with resistor R5, and then connected to the collector (CC). Its base is connected in series with R10 and then connected to the charge / discharge state switching pin of the control module. R9 is connected between the base and emitter, and the emitter is connected to the emitter (PE). The charge / discharge state switching signal controls the switching of transistor Q1, thereby controlling whether R5 and R6 are connected in parallel, thus changing the resistance between CC and PE. Different resistance values ​​between CC and PE represent different charging or discharging states.

[0030] A control method for a charging and discharging control system of an electric vehicle charging and discharging device, taking a 16A charging plug module as the basic charging plug module and 10A charging plug modules as other examples, the specific implementation process is as follows: (1) such as Figure 2As shown, the 16A charging plug module, together with the vehicle plug module, forms a charging gun via a wiring harness. The equivalent resistance between the CC and PE wires inside the vehicle plug module is R6. The relays on the L and N lines are in the open state, meaning the resistance is neither in the charging nor discharging state. When the vehicle plug is connected to a vehicle socket, the product does not operate, preventing the 16A charging plug module from becoming energized. When the 16A charging plug module is connected to a household socket, the plug / socket identification module identifies the 16A charging plug module via the MT signal line. The control module then controls the charge / discharge state switching module to connect R5 and R6 in parallel, making the equivalent resistance between CC and PE the 16A charging state resistance, thus entering the 16A charging state. Alternatively, the actual charging current can be set to no more than 16A, such as a rated 13A charging current.

[0031] The vehicle plug module plugs into the vehicle charging socket, while the 16A charging plug module plugs into a household power outlet. When the circuit board inside the vehicle plug module powers on, the control module recognizes the 16A charging mode via the MT signal and activates the charging / discharging state switching module, connecting resistors R5 and R6 in parallel. At this point, the resistance between the CC and PE terminals is equal to the parallel resistance of R5 and R6, which is also the resistance the vehicle can recognize as 16A charging. The control module also sends a PWM wave signal to the vehicle via the CP line. Upon recognizing the CP and CC signals, the vehicle closes the switch in its internal CP signal circuit, causing a change in the high level of the PWM wave signal. After detecting this change in the high level of the CP signal, the control module closes the LN relay, initiating charging. Regardless of whether charging or discharging is in progress, the LN relay will always disconnect if either end of the plug is unplugged.

[0032] S3 is a normally open temperature switch. When the 16A charging plug module overheats, S3 closes, and the MT signal is short-circuited with PE. At this time, the plug and socket identification module detects the change in the MT signal, and the control module controls the charging and discharging state switching module to disconnect R5 from CC. The resistance between CC and PE is R6. The vehicle detects the change in the resistance between CC and PE and stops charging to achieve over-temperature protection.

[0033] (2) such as Figure 3 As shown, when 10A charging is required, the 10A charging plug module and the 16A charging plug module are plugged into each other. Then, the 10A charging plug module is plugged into a household socket. The plug and socket identification module detects the resistor R2 through the MT signal line and thus identifies the 10A charging plug module. The control module prevents the charging / discharging state switching module from connecting R5 in parallel with the CC and PE circuits. At this time, the equivalent resistance between CC and PE is R6 and R1 in parallel, and its resistance is the 10A charging state resistance. When the vehicle plug and vehicle socket are plugged in, the 10A charging state is entered. Alternatively, the actual charging current can be set to no more than 10A, such as a rated 8A charging.

[0034] S1 is a normally open temperature switch. When the 10A charging plug module overheats, S1 closes, and the MT signal is short-circuited with PE. At this time, the plug and socket identification module detects the change in the MT signal, and the control module controls the charging and discharging state switching module to connect R5 in parallel between CC and PE. The resistance between CC and PE is R1, R5 and R6 in parallel. The vehicle detects the change in the resistance between CC and PE and stops charging to achieve over-temperature protection.

[0035] (3) such as Figure 4 As shown, when discharging is required, the discharge power strip module and the 16A charging plug module are plugged in together, and the vehicle plug and vehicle socket are plugged in together. At this time, the equivalent resistance between CC and PE is R6 and R3 in parallel, and its resistance value is the discharge state resistance, and the vehicle enters the discharge state. Furthermore, the plug and power strip identification module detects the R4 resistor through the MT signal line and thus identifies the discharge power strip module. The control module controls the charging / discharging state switching module to prevent R5 from being connected in parallel to the CC and PE circuits, continuing to maintain the discharge state, closing the LN relay, and enabling the power strip to output power.

[0036] S2 is a normally open temperature switch. When the discharge power strip module overheats, S2 closes, and the MT signal is short-circuited with PE. At this time, the plug and power strip identification module detects the change in the MT signal and controls the charging and discharging state switching module to connect R5 in parallel between CC and PE. The resistance between CC and PE is the parallel value of R3, R5 and R6. The vehicle detects the change in the resistance between CC and PE and stops discharging, thus achieving over-temperature protection. The above are merely preferred embodiments of the present invention and are not intended to limit or restrict the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection declared by the present invention.

Claims

1. A charging and discharging control system for an electric vehicle charging and discharging device, characterized in that: The system includes a vehicle plug module, a basic charging plug module connected to the vehicle plug module via a wiring harness, and a discharge power strip module. When the discharge power strip module is connected to the basic charging plug module, the system discharges; when the discharge power strip module is not connected to the basic charging plug module, the system charges. Inside the vehicle plug module, there is an equivalent resistance R6 between CC and PE. Normally open relays are installed on the L and N lines inside the module. The vehicle plug module also includes a charge / discharge state switching module that controls whether a resistance R5 is connected in parallel with the equivalent resistance R6, a control module for controlling the charge / discharge state switching module, and a plug / power strip identification module connected to the control module. Inside the discharge power strip module, there is a resistance R3 between CC and PE, and a resistance R4 between PE and the MT signal line. The plug / power strip identification module identifies the plug module type at the other end of the wiring harness connected to the vehicle plug module based on the MT signal line. The control module then controls the charge / discharge state switching module to connect resistance R5 between CC and PE to enter different charge / discharge states.

2. The charging and discharging control system for an electric vehicle charging and discharging device as described in claim 1, characterized in that: It also includes other charging plug modules. When other charging plug modules are connected to the basic charging plug module, the system realizes other charging. There is a resistor R1 between CC and PE inside the other charging plug module, and a resistor R2 between PE and MT signal line.

3. The charging and discharging control system for an electric vehicle charging and discharging device as described in claim 1, characterized in that: The basic charging plug module has a normally open temperature switch S3 between the MT signal line and PE.

4. The charging and discharging control system for an electric vehicle charging and discharging device as described in claim 1, characterized in that: The discharge connector module has a normally open temperature switch S2 between the MT signal line and the PE.

5. The charging and discharging control system for an electric vehicle charging and discharging device as described in claim 2, characterized in that: The other charging plug module has a normally open temperature switch S1 between the MT signal line and PE.

6. The charging and discharging control system for an electric vehicle charging and discharging device as described in claim 1, characterized in that: The plug and socket identification module consists of an input port protection circuit, a pull-up resistor R7, and an MCU port protection circuit. One end of the input port protection circuit and the MCU port protection circuit are connected in series to the MT signal line, and the other end is connected to the control module. A pull-up resistor R7 is connected between the input port protection circuit and the MCU port protection circuit.

7. The charging and discharging control system for an electric vehicle charging and discharging device as described in claim 1, characterized in that: The charge / discharge state switching module consists of a transistor Q1 and its peripheral resistors R5, R9 and R10. The collector of transistor Q1 is connected in series with resistor R5 and then connected to CC. Its base is connected in series with R10 and then connected to the charge / discharge state switching pin of the control module. R9 is connected between the base and the emitter, and the emitter is connected to PE.

8. The control method for a charging and discharging control system of an electric vehicle charging and discharging device as described in any one of claims 1-7, characterized in that, include: Actively control the resistance value between the CC line and PE line within the vehicle plug module; The basic charging plug module has been plugged into the power socket. The plug and socket identification module identifies the basic charging plug module through the MT signal line. The control module controls the charging and discharging state switching module to connect resistors R5 and R6 in parallel. The resistance value between the CC line and PE line in the vehicle plug module is the value after R5 is connected in parallel with R6. The relays on the L line and N line are closed to enter the basic charging state. After the discharge power strip module is plugged into the basic charging plug module and the vehicle plug module is plugged into the vehicle socket, the plug and power strip identification module identifies the discharge power strip module through the MT signal line. The control module controls the charging and discharging state switching module to not connect R5 into the CC and PE circuits. The resistance value between the CC line and PE line in the vehicle plug module is R6, which is connected in parallel with the resistance value R3 between the CC line and PE line in the discharge power strip module, and the module enters the discharge state.

9. The control method for a charging and discharging control system of an electric vehicle charging and discharging device as described in claim 8, characterized in that: Other charging plug modules are plugged into the basic charging plug module and then into the power socket. The plug and socket identification module identifies other charging plug modules through the MT signal line. The control module controls the charging and discharging state switching module to prevent R5 from being connected to the CC and PE circuits. The resistance value between the CC line and PE line in the vehicle plug module is R6, which is connected in parallel with the resistance value R1 between the CC line and PE line in other charging plug modules, and enters other charging states.

10. The control method for a charging and discharging control system of an electric vehicle charging and discharging device as described in claim 8, characterized in that: The plug and socket identification module identifies different modules through the MT signal line by detecting the resistance value between the PE and MT signal lines in different modules to determine the type of plug module at the other end of the wiring harness connected to the vehicle plug module.

11. The control method for a charging and discharging control system of an electric vehicle charging and discharging device as described in claim 8, characterized in that: When the basic charging plug module overheats, the impedance between the MT signal line and PE in the basic charging plug module changes. The plug and socket identification module detects the change in the MT signal, and the control module controls the charging and discharging state switching module to disconnect resistor R5 from CC. When the resistance between CC and PE is detected to be R6, charging is stopped, thus achieving overheat protection.

12. The control method for a charging and discharging control system of an electric vehicle charging and discharging device as described in claim 9, characterized in that: When other charging plug modules overheat, the impedance between the MT signal line and PE in the other charging plug module changes. The plug and socket identification module detects the change in the MT signal, and the control module controls the charging and discharging state switching module to connect resistor R5 in parallel between CC and PE. The resistance between CC and PE is detected to be the parallel value of R6, R5 and the resistance R1 between the CC line and PE line in other charging plug modules, and charging is stopped to achieve overheat protection.

13. The control method for a charging and discharging control system of an electric vehicle charging and discharging device as described in claim 8, characterized in that: When the discharge power strip module overheats, the impedance between the MT signal line and PE inside the discharge power strip module changes. The plug and power strip identification module detects the change in the MT signal, and the control module controls the charge and discharge state switching module to connect resistor R5 in parallel between CC and PE. The resistance between CC and PE is detected to be the parallel value of R6, R5 and the resistance R3 between the CC line and PE line inside the discharge power strip module, and charging is stopped to achieve over-temperature protection.

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