A cc resistance switching circuit

Abstract

The application belongs to the technical field of new energy vehicles, and particularly relates to a CC resistance switching circuit, which comprises a PMOS tube Q1, an NMOS tube Q2, a triode Q3, a resistance R1, a resistance R2, a resistance R4, a resistance R5, a resistance R6, a resistance R4_1, a resistance R4_2, a resistance RC1, a resistance RC2 and a switch S3; compared with the prior art, the circuit is built by MOS tubes, triodes and resistances and the like, has high cost performance and high reliability, and solves the problem of inconsistent CC resistances when the charging and discharging integrated gun works in different modes.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of new energy vehicles, more particularly, it relates to a CC resistance switching circuit. BACKGROUND

[0002] GB / T18487.4 and GB / T18487.1 are national standards related to the conductive charging and discharging system of electric vehicles. GB / T18487.4 focuses on the requirements for external discharging of vehicles, while GB / T18487.1 specifies general requirements for the conductive charging system. For portable charging guns, the CC signal is a connection confirmation signal in the on-board charger. By detecting the voltage condition of the CC signal, it can determine whether the AC charger has been properly plugged in and the connection status.

[0003] In charging mode, the CC resistance is used to confirm the connection status between the charging gun and the electric vehicle, and as part of the communication signal, it participates in the negotiation of charging parameters. Different charging modes (such as mode 2, mode 3, mode 4, etc.) may have different CC resistance value requirements, which are specified in standards such as GB / T18487.1.

[0004] In discharging mode, the CC resistance is also used to confirm the connection status between the discharging gun and the electric vehicle, and may participate in the setting of discharging parameters. According to GB / T18487.4, the CC resistance value in discharging mode may be different from that in charging mode to meet the safety and compatibility requirements of discharging function.

[0005] Therefore, the CC resistance combination of the charging and discharging gun in charging mode and discharging mode is inconsistent. If this problem cannot be effectively solved, the charging and discharging gun will only be limited to a single charging state or discharging mode. The traditional solution is to use a relay to switch the resistance, which is expensive and the relay is a mechanical device with low reliability. When designing a charging and discharging integrated gun, it needs to be considered that it can work correctly in both charging and discharging modes and comply with the corresponding national standards. SUMMARY

[0006] In view of the deficiencies in the prior art, the purpose of the present application is to provide a CC resistance switching circuit that solves the inconsistency of CC resistance when a charging and discharging integrated gun works in different modes.

[0007] To achieve the above purpose, the present application provides the following technical solutions:

[0008] A CC resistance switching circuit, comprising a PMOS tube Q1, an NMOS tube Q2, a transistor Q3, a resistor R1, a resistor R2, a resistor R4, a resistor R5, a resistor R6, a resistor R4_1, a resistor R4_2, a resistor RC1, a resistor RC2, and a switch S3,

[0009] One end of resistor R3 is connected to the microcontroller unit MCU_1 of the charging gun, and the other end of resistor R3 is connected to the base of transistor Q3. The emitter of transistor Q3 is grounded. The collector of transistor Q3 is connected to one end of resistor R2. The other end of resistor R2 is connected to one end of resistor R1 and the gate of PMOS transistor Q1. The drain of PMOS transistor Q1 is connected to one end of resistor RC2. The other end of resistor RC2 is connected to one end of resistor RC1, one end of resistor R4_1, and one end of switch S3. The source of PMOS transistor Q1 is connected to the other end of resistor R1, one end of resistor R6, and the other end of resistor RC1, and outputs a CC signal to the vehicle-side CC detection circuit.

[0010] One end of resistor R4 is connected to the microcontroller unit MCU_2 of the charging gun. The other end of resistor R4 is connected to one end of resistor R5, the gate of NMOS transistor Q2, and the other end of resistor R6. The drain of NMOS transistor Q2 is connected to the other end of resistor R4_1 and one end of resistor R4_2. The other end of resistor R5, the source of NMOS transistor Q2, the other end of resistor R4_2, and the other end of switch S3 are all grounded.

[0011] MCU_1 is a pin function of the microcontroller unit, which controls the on / off state of Q1 to determine whether RC2 is connected in parallel with RC1; MCU_2 is also a pin function of the microcontroller unit, which controls the on / off state of Q2 to determine whether R4_2 is short-circuited.

[0012] Furthermore, PMOS transistor Q1 is an enhancement-mode PMOS transistor.

[0013] Furthermore, NMOS transistor Q2 is an enhancement-mode NMOS transistor.

[0014] Furthermore, NMOS transistor Q2 is a depletion-type NMOS transistor.

[0015] Furthermore, transistor Q3 can be replaced with an NMOS transistor.

[0016] By adopting the above technical solution, the beneficial effects of the present invention are as follows: The circuit of the present invention is built with devices such as MOSFETs, transistors and resistors, which has high cost performance and high reliability, and solves the problem of inconsistent CC resistance when the charging and discharging gun is working in different modes; by adopting the switching circuit of the present invention, the CC resistance combination can be automatically switched according to the working conditions (charging or discharging), and the circuit structure is simpler, more intelligent and lower in cost. Attached Figure Description

[0017] Figure 1 This is a circuit diagram of a national standard charging system.

[0018] Figure 2 This is a circuit schematic diagram of Embodiment 1 of the present invention.

[0019] Figure 3 Circuit schematic diagram of embodiment two of the present application. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0021] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0022] As shown in Figure 1 , it is a circuit schematic diagram of a national standard charging system, wherein C1 and C2 are internal AC contactors / relays of a power supply device; S1 is an internal PWM signal switching switch of the power supply device; R1 is an internal control guide circuit resistance of the power supply device; R3 is an internal normally closed switch of a vehicle plug; R4 and RC are internal control guide circuit resistances (CC resistances) of the vehicle plug; S2 is an internal control guide circuit switch of the vehicle; S3 is a gun head key switch; R2 and R3 are internal control guide circuit resistances of the vehicle; and D1 is an internal control guide circuit diode of the vehicle.

[0023] As shown in Figure 2 , it is embodiment one of the present application, and the switching circuit includes an enhanced PMOS tube Q1, an enhanced NMOS tube Q2, a triode Q3, a resistance R1, a resistance R2, a resistance R4, a resistance R5, a resistance R6, a resistance R4_1, a resistance R4_2, a resistance RC1, a resistance RC2 and a switch S3.

[0024] When the charging and discharging integrated gun works in the charging mode, MCU_1 is low, Q1 is turned on, RC1 and RC2 are connected in parallel (the resistance value is about 680Ω), MCU_2 is low, Q2 is cut off, and R4_1 and R4_2 are connected in series (the resistance value is about 2.7KΩ).

[0025] The measurement of the resistance value is completed by the vehicle end, and the vehicle end measurement formula is as follows:

[0026]

[0027] According to GB / T18487.1-2023, the CC resistance in charging mode indicates the connection status of the vehicle interface and the capacity of the charging cable, as detailed in Table A.5.

[0028] When the charging and discharging gun is in discharge mode, MCU_1 is at a high level (or high impedance state), Q1 is off, and the total resistance of RC1 and RC2 is RC1; MCU_2 is at a high level (or high impedance state), Q2 is on, and the total resistance of R4_1 and R4_2 is R4_1.

[0029] In this embodiment: the CC resistor setting value in discharge mode is defined as 2K / 3.5K; the function of the CC resistor value in discharge mode is: the connection status of the vehicle interface and the capacity of the discharge cable.

[0030] like Figure 3 As shown in Embodiment 2 of the present invention, the switching circuit includes an enhancement-type PMOS transistor Q1, a depletion-type NMOS transistor Q2, a transistor Q3, resistors R1, R2, R4, R5, R6, R4_1, R4_2, RC1, RC2, and a switch S3.

[0031] When the charger is in charging mode, MCU_1 is low, Q1 is on, and RC1 and RC2 are connected in parallel (approximately 680Ω); MCU_2 is high, Q2 is off, and R4_1 and R4_2 are connected in series (approximately 2.7KΩ). When the charger is in discharging mode, MCU_1 is high (or in a high-resistance state), Q1 is off, and the total resistance of R4_1 and R4_2 is RC1; MCU_2 is low (or in a high-resistance state), Q2 is on, and the total resistance of R4_1 and R4_2 is R4_1.

[0032] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any ordinary changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention should be included within the protection scope of the present invention.

Claims

1. A CC resistor switching circuit, characterized in that, This includes PMOS transistor Q1, NMOS transistor Q2, transistor Q3, resistors R1, R2, R3, R4, R5, R6, R4_1, R4_2, RC1, RC2, and switch S3. One end of resistor R3 is connected to the microcontroller pin MCU_1 of the charging gun, and the other end of resistor R3 is connected to the base of transistor Q3. The emitter of transistor Q3 is grounded, and the collector of transistor Q3 is connected to one end of resistor R2. The other end of resistor R2 is connected to one end of resistor R1 and the gate of PMOS transistor Q1. The drain of PMOS transistor Q1 is connected to one end of resistor RC2. The other end of resistor RC2 is connected to one end of resistor RC1, one end of resistor R4_1, and one end of switch S3. The source of PMOS transistor Q1 is connected to the other end of resistor R1, one end of resistor R6, and the other end of resistor RC1, and outputs a CC signal to the vehicle-side CC detection circuit. One end of resistor R4 is connected to the microcontroller pin MCU_2 of the charging gun. The other end of resistor R4 is connected to one end of resistor R5, the gate of NMOS transistor Q2, and the other end of resistor R6. The drain of NMOS transistor Q2 is connected to the other end of resistor R4_1 and one end of resistor R4_2. The other end of resistor R5, the source of NMOS transistor Q2, the other end of resistor R4_2, and the other end of switch S3 are all grounded; MCU_1 controls the on / off state of Q1 to determine whether RC2 is connected in parallel with RC1; MCU_2 controls the on / off state of Q2 to determine whether R4_2 is short-circuited.

2. The CC resistor switching circuit according to claim 1, characterized in that, The PMOS transistor Q1 is an enhancement-mode PMOS transistor.

3. The CC resistor switching circuit according to claim 2, characterized in that, The NMOS transistor Q2 is an enhancement-mode NMOS transistor.

4. The CC resistor switching circuit according to claim 2, characterized in that, The NMOS transistor Q2 is a depletion-type NMOS transistor.

5. A CC resistor switching circuit according to claim 3 or 4, characterized in that, The transistor Q3 can be replaced with an NMOS transistor.

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