Intelligent alternating current charging and discharging circuit of electric automobile and control method

Abstract

The invention discloses an intelligent alternating current charging and discharging circuit of an electric automobile and a control method, the intelligent alternating current charging and discharging circuit of the electric automobile comprises an alternating current charging and discharging pile circuit, a power supply side control guide circuit and an automobile side control guide circuit, and the alternating current charging and discharging pile circuit is provided with an intelligent change-over switch capable of switching among phases of a three-phase power supply of a power grid. The power supply side control guide circuit comprises a first feedback circuit and a second feedback circuit, and the automobile side control guide circuit comprises a third feedback circuit and a fourth feedback circuit. By means of the intelligent alternating current charging and discharging circuit of the electric vehicle and the corresponding control method, the quality of a power grid is adjusted, and energy waste and the influence on the power grid in the charging and discharging process of the electric vehicle are reduced; and meanwhile, the problem that an existing alternating current charging / charging and discharging system cannot interact charging information is effectively solved by utilizing a mode that advanced communication is superposed on a control guide circuit.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicle charging, and particularly to an intelligent AC charging and discharging circuit and control method for electric vehicles. Background Art

[0002] With the development and popularization of electric vehicle technology, the demand for electric charging is increasing day by day. At the same time, electric vehicles are also an excellent energy storage carrier. The AC charging and discharging method can be better compatible with the existing grid infrastructure, so as to use the existing AC power grid for charging and discharging, reducing the infrastructure transformation cost. In addition, AC charging and discharging equipment is usually simpler and lower in cost, suitable for large-scale promotion, and helps to improve the grid stability and energy utilization efficiency, promoting the development of smart grids and renewable energy. However, the single-phase AC charging method cannot select the appropriate phase according to the current state of the grid, and cannot fully realize the reasonable allocation of electric energy. While the three-phase AC charging method has a higher cost and there are grid capacity limitations and compatibility issues. Summary of the Invention

[0003] Object of the Invention: The object of the present invention is to provide an intelligent AC charging and discharging circuit and control method for electric vehicles that are efficient, intelligent, and capable of data interaction.

[0004] Technical Solution: In a first aspect, the present invention provides an intelligent AC charging and discharging circuit for electric vehicles, including a power supply side PE terminal and a vehicle side PE terminal that cooperate with each other, a power supply side CP terminal and a vehicle side CP terminal that cooperate with each other, a power supply side CC terminal and a vehicle side CC terminal that cooperate with each other, and further including an AC charging and discharging pile circuit, a power supply side control and guidance circuit, and a vehicle side control and guidance circuit;

[0005] The AC charging and discharging pile circuit is arranged between the power supply side L terminal and the power supply side N terminal. The input terminals L1, L2, and L3 of the AC charging and discharging pile circuit are respectively connected to the three-phase power supply phase lines. An intelligent switching switch C1 is arranged on the AC charging and discharging pile circuit. The input end of the intelligent switching switch C1 has a first working position, a second working position, and a third working position. The intelligent switching switch C1 is connected to the input terminal L1 in the first working position, connected to the input terminal L2 in the second working position, and connected to the input terminal L3 in the third working position. The output end of the intelligent switching switch C1 is the power supply side L terminal. One end of the input terminal N of the AC charging and discharging pile circuit is connected to the three-phase power supply neutral line, and the other end is connected to the power supply side N terminal;

[0006] The power supply side control and guidance circuit includes a first feedback circuit and a second feedback circuit, and the vehicle side control and guidance circuit includes a third feedback circuit and a fourth feedback circuit;

[0007] The first feedback circuit is arranged between the power supply side CP terminal and the power supply side PE terminal. An equipment charging controller and a detection point 1 are provided on the first feedback circuit. The second feedback circuit is arranged between the power supply side CC terminal and the power supply side PE terminal;

[0008] The third feedback circuit is arranged between the vehicle side CP terminal and the vehicle side PE terminal. A detection point 2 and a switch S2 are provided on the third feedback circuit. The fourth feedback circuit is arranged between the vehicle side CC terminal and the vehicle side PE terminal. An vehicle charging controller and a detection point 3 are provided on the fourth feedback circuit;

[0009] The detection point 1 is used to detect the voltage between the power supply side CP terminal and the power supply side PE terminal, and feedback the detected voltage to the equipment charging controller. The detection point 2 is used to detect the PWM signal of the third feedback circuit, and feedback the detected PWM signal to the vehicle charging controller. The detection point 3 is used to detect the resistance value between the vehicle side CC terminal and the vehicle side PE terminal, and feedback the detected resistance value to the vehicle charging controller.

[0010] Preferably, a switch C2 is provided on the input end N of the AC charging and discharging pile circuit.

[0011] Specifically, the power supply side PE terminal is a PE pin, the vehicle side PE terminal is a socket matching the PE pin, the power supply side CC terminal is a CC pin, the vehicle side CC terminal is a socket matching the CC pin, the power supply side CP terminal is a CP pin, and the vehicle side CP terminal is a socket matching the CP pin.

[0012] In a second aspect, the present invention also provides a control method for the above-mentioned intelligent AC charging and discharging circuit of an electric vehicle, including the following steps:

[0013] (1) Connect the power supply side and the vehicle side, and keep the intelligent switching switch C1 in the off state;

[0014] (2) After the equipment charging controller detects that the voltage of the detection point 1 on the first feedback circuit is the standard value, it is considered that the CP terminal and the PE terminal are normally connected, and a PWM signal is output;

[0015] (3) After the vehicle charging controller receives the PWM signal at the detection point 2, it closes the S2 switch on the third feedback circuit and enters the charging and discharging state;

[0016] (4) Perform charging or discharging of the vehicle. According to the currently detected voltage of the three-phase power supply of the power grid, during charging, the input end of the intelligent switching switch C1 is automatically connected to the input end of the AC charging and discharging pile circuit corresponding to the phase with the highest voltage of the three-phase power supply of the power grid; during discharging, the input end of the intelligent switching switch C1 is automatically connected to the input end of the AC charging and discharging pile circuit corresponding to the phase with the lowest voltage of the three-phase power supply of the power grid.

[0017] Specifically, in step (4), during discharging, according to the instruction sent from the vehicle side, the input end of the intelligent changeover switch C1 can also be connected to one of the input ends L1, L2, and L3 of the AC charging and discharging pile circuit.

[0018] Specifically, the vehicle charging controller receives the resistance value at detection point 3 of the fourth feedback circuit, compares it with the standard value, and determines whether the plug on the power supply side is fully connected to the socket on the vehicle side.

[0019] In a third aspect, the present invention further provides an intelligent AC charging and discharging circuit for an electric vehicle, including the above-mentioned intelligent AC charging and discharging circuit for an electric vehicle, and further including a LIN communication line, where the LIN communication line connects the CP end on the power supply side with the device charging controller and the vehicle charging controller.

[0020] In a fourth aspect, the present invention further provides a control method for the above-mentioned intelligent AC charging and discharging circuit of an electric vehicle, including the following steps:

[0021] (1) Connect the power supply side and the vehicle side, and keep the intelligent changeover switch C1 in the off state;

[0022] (2) After the device charging controller detects that the voltage at detection point 1 on the first feedback circuit is the standard value, it considers that the CP end and the PE end are normally connected, outputs a PWM signal, and simultaneously sends a LIN signal, waiting for a response from the vehicle; if the vehicle supports LIN communication, the vehicle responds within the set time, and the device charging controller receives the response signal, and the version negotiation and initialization between the vehicle and the AC charging and discharging pile are completed; if the vehicle does not support LIN communication and the device charging controller does not receive a response signal within the set time, the duty cycle of the PWM signal is changed to a value corresponding to the power supply capacity of the AC charging and discharging pile.

[0023] (3) After the vehicle charging controller receives the PWM signal at detection point 2, it closes the S2 switch on the third feedback circuit and enters the charging and discharging state.

[0024] (4) During the charging or discharging of the vehicle, according to the currently detected voltage of the three-phase power supply of the power grid, during charging, the input end of the intelligent changeover switch C1 is connected to the input end of the AC charging and discharging pile circuit corresponding to the phase with the highest voltage of the three-phase power supply of the power grid; during discharging, the input end of the intelligent changeover switch C1 is connected to the input end of the AC charging and discharging pile circuit corresponding to the phase with the lowest voltage of the three-phase power supply of the power grid; according to the instruction sent from the vehicle side, the input end of the intelligent changeover switch C1 can also be connected to one of the input ends L1, L2, and L3 of the AC charging and discharging pile circuit.

[0025] (5) According to the power grid state or vehicle instruction, perform the conversion from the charging process to the discharging process or the conversion from the discharging process to the charging process.

[0026] Specifically, the conversion from charging to discharging process includes:

[0027] During the charging process, when the device charging controller receives a discharging instruction from the power grid, it sends a discharging instruction to the vehicle. When the vehicle is in a state allowing discharging, it sends a response discharging instruction, reduces the current below the set value, disconnects switch S2, adjusts the working mode of the OBC, sends an instruction to the device charging controller, and controls the input end of the intelligent switching switch C1 to be connected to one of the input ends L1, L2, and L3 of the AC charging and discharging pile circuit to start discharging output. If the vehicle does not allow discharging, it sends a response discharging instruction, and the charging and discharging pile determines whether to continue or stop charging.

[0028] During the charging process, when the device charging controller receives a discharging instruction sent by the vehicle, and when the current power grid state allows discharging, the device charging controller sends a response discharging instruction to the vehicle. The vehicle reduces the current below the set value, disconnects switch S2, adjusts the working mode of the OBC, sends an instruction to the device charging controller, and controls the input end of the intelligent switching switch C1 to be connected to one of the input ends L1, L2, and L3 of the AC charging and discharging pile circuit to start discharging output. If the current power grid state does not allow discharging, the device charging controller sends a charging interruption instruction to the vehicle to stop outputting the PWM signal. The vehicle reduces the current below the set value and disconnects switch S2.

[0029] Specifically, the conversion from discharging to charging process includes:

[0030] During the discharging process, when the device charging controller receives a charging instruction from the power grid, it sends a charging instruction to the vehicle. When the vehicle is in a state allowing charging, it sends a response charging instruction, reduces the current below the set value, disconnects switch S2, adjusts the working mode of the OBC, sends an instruction to the device charging controller to indicate readiness, and starts charging. If the vehicle does not allow charging, it sends a response charging instruction, and the AC charging and discharging pile determines whether to continue or stop discharging.

[0031] During the discharging process, when the device charging controller receives a charging instruction sent by the vehicle, and when the current power grid state allows charging, the device charging controller sends a response charging instruction to the vehicle. The vehicle reduces the current below the set value, disconnects switch S2, adjusts the working mode of the OBC, sends an instruction to the device charging controller to indicate readiness, and starts charging. If the current power grid state does not allow charging, the device charging controller sends a discharging interruption instruction to the vehicle to stop outputting the PWM signal. The vehicle reduces the current below the set value and disconnects switch S2.

[0032] Beneficial effects: Compared with the prior art, the remarkable effects of the present invention are as follows: By providing a multi-way switching circuit in the AC charging and discharging pile with three-phase power supply for AC charging of electric vehicles with single-phase charging, when the electric vehicle needs to charge or discharge, the intelligent switching switch automatically switches among the three phases according to the real-time state of the power grid, realizes the regulation of the power grid quality, effectively manages the input and output of electric energy, such as selecting the phase with the highest three-phase power supply voltage of the power grid during charging, or selecting the phase with the lowest three-phase power supply voltage of the power grid during discharging; Through the three-phase switching switch and the preset automatic phase switching strategy, the waste of energy and the impact on the power grid are reduced. At the same time, by using the advanced communication superimposed on the control and guidance circuit, the problem that the existing AC charging / charging and discharging system cannot interact charging information is effectively solved. Brief Description of the Drawings

[0033] Figure 1 It is the circuit structure diagram of Embodiment 1 of the present invention.

[0034] Figure 2 It is the working flow chart of the conversion process from charging to discharging in Embodiment 2 of the present invention. Detailed Embodiments

[0035] The following further illustrates the solution of the present invention with reference to the drawings.

[0036] Embodiment 1

[0037] Please refer to Figure 1 As shown, this embodiment provides an intelligent AC charging and discharging circuit for electric vehicles, including a mutually cooperating power supply side PE terminal and vehicle side PE terminal, a mutually cooperating power supply side CP terminal and vehicle side CP terminal, a mutually cooperating power supply side CC terminal and vehicle side CC terminal, and further including an AC charging and discharging pile circuit, a power supply side control and guidance circuit, and a vehicle side control and guidance circuit. The power supply side control and guidance circuit and the vehicle side control and guidance circuit are control and guidance circuits that conform to connection mode C of Mode 3 in Appendix A.1.1 of Standard GB / T 18487.1—2023. Both the AC charging and discharging pile and the electric vehicle conform to the vehicle interface of Standard GB / T 20234.2.

[0038] The AC charging and discharging pile circuit is arranged between the power supply side L terminal and the power supply side N terminal. The input terminals L1, L2, and L3 of the AC charging and discharging pile circuit are respectively connected to the phase lines of the three-phase power grid. An intelligent switching switch C1 is provided on the AC charging and discharging pile circuit. The input end of the intelligent switching switch C1 is optionally connected to the input terminals L1, L2, and L3, corresponding to the positions 1, 2, and 3 of the intelligent switching switch C1 respectively. The default position of the intelligent switching switch C1 is position 1 or position 0 (disconnected state). The output end of the intelligent switching switch C1 is the power supply side L terminal. One end of the input terminal N of the AC charging and discharging pile circuit is connected to the neutral line of the three-phase power grid, and the other end is connected to the power supply side N terminal. In some specific embodiments, a switch C2 is also provided on the input terminal N of the AC charging and discharging pile circuit. Installing the switch can improve the safety and stability of the system and facilitate subsequent maintenance and repair work.

[0039] The power supply side control and guidance circuit includes a first feedback circuit and a second feedback circuit, and the vehicle side control and guidance circuit includes a third feedback circuit and a fourth feedback circuit:

[0040] The first feedback circuit is arranged between the power supply side CP terminal and the power supply side PE terminal. An equipment charging controller, a resistor R1, and a detection point 1 are sequentially connected in series on the first feedback circuit. The second feedback circuit is arranged between the power supply side CC terminal and the power supply side PE terminal, and a resistor Rc and a resistor R4 are sequentially connected in series. A switch S3 is connected in parallel with the resistor R4;

[0041] The third feedback circuit is arranged between the vehicle side CP terminal and the vehicle side PE terminal. A diode D1, a detection point 2, a switch S2, and a resistor R2 are sequentially connected in series on the third feedback circuit. A resistor R3 is connected in parallel with the switch S2 and the resistor R2. The fourth feedback circuit is arranged between the vehicle side CC terminal and the vehicle side PE terminal. An vehicle charging controller and a detection point 3 are provided on the fourth feedback circuit;

[0042] The detection point 1 is used to detect the voltage between the power supply side CP terminal and the power supply side PE terminal and feed the detected voltage back to the equipment charging controller. The detection point 2 is used to detect the PWM signal of the third feedback circuit and feed the detected PWM signal back to the vehicle charging controller. The detection point 3 is used to detect the resistance value between the vehicle side CC terminal and the vehicle side PE terminal and feed the detected resistance value back to the vehicle charging controller.

[0043] The power supply side PE terminal is the PE pin, the vehicle side PE terminal is a socket matching the PE pin, the power supply side CC terminal is the CC pin, the vehicle side CC terminal is a socket matching the CC pin, the power supply side CP terminal is the CP pin, and the vehicle side CP terminal is a socket matching the CP pin.

[0044] In this embodiment, the equipment charging controller is arranged on the AC charging and discharging pile, and a vehicle charging controller is provided on the vehicle side. The above charging controllers are all used for signal transmission and reception.

[0045] Example 2

[0046] This embodiment provides an intelligent AC charging and discharging circuit for an electric vehicle. While including the intelligent AC charging and discharging circuit of the electric vehicle described in Embodiment 1, it also includes a LIN communication line superimposed on the CP terminal of the power supply side. The LIN communication line connects the CP terminal of the power supply side with the device charging controller and the vehicle charging controller.

[0047] LIN (Local Interconnect Network) is a low-cost serial communication network with good compatibility, mainly applied to automotive distributed electronic systems. At the same time, LIN signals can be transmitted unidirectionally or bidirectionally, so it can be applied in the present invention to achieve high-level communication between the power supply side and the vehicle side, thereby realizing the interaction of charging information.

[0048] Example 3

[0049] This embodiment provides a control method for the intelligent AC charging and discharging circuit of the electric vehicle described in Embodiment 1, including the following steps:

[0050] (1) Connect the plug on the power supply side to the socket on the vehicle side, and the intelligent switching switch C1 remains in the off state;

[0051] (2) After the device charging controller detects that the voltage at detection point 1 on the first feedback circuit is the standard value (9V), it considers that the CP terminal and the PE terminal are normally connected and outputs a PWM signal;

[0052] (3) After the vehicle charging controller receives the PWM signal at detection point 2, it closes the S2 switch on the third feedback circuit and enters the charging and discharging state;

[0053] (4) Perform charging or discharging of the vehicle. According to the currently detected voltage of the three-phase power supply of the power grid, during charging, the input end of the intelligent switching switch C1 is automatically connected to the input end of the AC charging and discharging pile circuit corresponding to the phase with the highest voltage of the three-phase power supply of the power grid, and at the same time, the switch C2 is closed; during discharging, the input end of the intelligent switching switch C1 is automatically connected to the input end of the AC charging and discharging pile circuit corresponding to the phase with the lowest voltage of the three-phase power supply of the power grid, and at the same time, the switch C2 is closed; during discharging, according to the instruction sent from the vehicle side, the input end of the intelligent switching switch C1 can also be connected to one of the input ends L1, L2, and L3 of the AC charging and discharging pile circuit, and at the same time, the switch C2 is closed.

[0054] This method further includes: The vehicle charging controller receives the resistance value at detection point 3 of the fourth feedback circuit, compares it with the standard value, and judges whether the plug on the power supply side is fully connected to the socket on the vehicle side.

[0055] The intelligent AC charging and discharging circuit of the electric vehicle provided in Embodiment 1 supports independent control of the power supply network or the vehicle for the charging / discharging mode. However, due to the lack of advanced communication functions, it does not support mode switching during the charging / discharging process.

[0056] Embodiment 4

[0057] This embodiment provides a control method for the intelligent AC charging and discharging circuit of the electric vehicle described in Embodiment 2, including the following steps:

[0058] (1) Connect the plug on the power supply side to the socket on the vehicle side, and the intelligent switching switch C1 remains in the off state;

[0059] (2) After the device charging controller detects that the voltage at detection point 1 on the first feedback circuit is the standard value (9V), it considers that the CP terminal and the PE terminal are normally connected, outputs a PWM signal (duty cycle is 100%), and simultaneously sends a LIN signal, waiting for the vehicle to respond; if the vehicle supports LIN communication, the vehicle will reply with a response signal within the set time, and the device charging controller receives the response signal, and the version negotiation and initialization between the vehicle and the AC charging and discharging pile are completed; if the vehicle does not support LIN communication and the device charging controller does not receive a response signal within the set time, it changes the duty cycle of the PWM signal (set according to the power supply capacity of the charging and discharging pile);

[0060] (3) After the vehicle charging controller receives the PWM signal at detection point 2, it closes the S2 switch on the third feedback circuit and enters the charging and discharging state;

[0061] (4) Perform charging or discharging of the vehicle. According to the currently detected voltage of the three-phase power supply of the power grid, during charging, the input end of the intelligent switching switch C1 is connected to the input end of the AC charging and discharging pile circuit corresponding to the phase with the highest voltage of the three-phase power supply of the power grid, and at the same time, the switch C2 is closed; during discharging, the input end of the intelligent switching switch C1 is connected to the input end of the AC charging and discharging pile circuit corresponding to the phase with the lowest voltage of the three-phase power supply of the power grid, and at the same time, the switch C2 is closed; during discharging, according to the instruction sent from the vehicle end, the input end of the intelligent switching switch C1 can also be connected to one of the input ends L1, input end L2, and input end L3 of the AC charging and discharging pile circuit, and at the same time, the switch C2 is closed;

[0062] (5) According to the power grid state or vehicle instruction, perform the conversion from charging to discharging or from discharging to charging.

[0063] The conversion from charging to discharging includes:

[0064] During the charging process, when the device charging controller receives a discharge instruction from the power grid, it sends a discharge instruction to the vehicle. When the vehicle is in a state allowing discharge, it sends a response discharge instruction, reduces the current to below the set value (1A, the same below), disconnects switch S2, adjusts the OBC working mode (phase-locked, inverter output), sends an instruction to the charging controller, and controls the input end of the intelligent switching switch C1 to be connected to one of the input ends L1, L2, and L3 of the AC charging and discharging pile circuit to start discharge output. If the vehicle does not allow discharge, the vehicle charging controller sends a response discharge instruction, and the AC charging and discharging pile determines whether to continue or stop charging.

[0065] During the charging process, when the device charging controller receives a discharge instruction sent by the vehicle, and when the current power grid state allows discharge, the device charging controller sends a response discharge instruction to the vehicle. The vehicle reduces the current to below the set value, disconnects switch S2, adjusts the OBC working mode, sends an instruction to the charging controller, and controls the input end of the intelligent switching switch C1 to be connected to one of the input ends L1, L2, and L3 of the AC charging and discharging pile circuit to start discharge output. If the current power grid state does not allow discharge, the device charging controller sends a charging suspension instruction to the vehicle to stop outputting the PWM signal. The vehicle reduces the current to below the set value and disconnects switch S2.

[0066] The conversion from discharge to charging includes:

[0067] During the discharge process, when the device charging controller receives a charging instruction from the power grid, it sends a charging instruction to the vehicle. When the vehicle is in a state allowing charging, it sends a response charging instruction, reduces the current to below the set value, disconnects switch S2, adjusts the OBC working mode, sends an instruction to the device charging controller to indicate readiness, and starts charging. If the vehicle does not allow charging, the vehicle sends a discharge suspension instruction to the charging controller, reduces the current to below the set value, and disconnects switch S2.

[0068] During the discharge process, when the device charging controller receives a charging instruction sent by the vehicle, and when the current power grid state allows charging, the device charging controller sends a response charging instruction to the vehicle. The vehicle reduces the current to below the set value, disconnects switch S2, adjusts the OBC working mode, sends an instruction to the device charging controller to indicate readiness, and starts charging. If the current power grid state does not allow charging, the device charging controller sends a discharge suspension instruction to the vehicle to stop outputting the PWM signal. The vehicle reduces the current to below the set value and disconnects switch S2.

[0069] Please refer to Figure 2 As shown in the figure, the specific process of the charging-to-discharge conversion actively initiated by the device charging controller includes the following steps:

[0070] (1) Connect the plug on the power supply side (AC charging and discharging pile) to the socket on the vehicle side (electric vehicle). The intelligent switching switch C1 remains in the off state at this time;

[0071] (2) After the device charging controller detects that the voltage at detection point 1 on the first feedback circuit is the standard value of 9V, it considers that the CP terminal and the PE terminal are normally connected, outputs a PWM signal (duty cycle is 100%), and simultaneously sends a LIN signal, waiting for the vehicle to respond. If the vehicle supports LIN communication, the vehicle will reply with a response signal within the set time. The device charging controller receives the response signal, and the version negotiation and initialization between the vehicle and the AC charging and discharging pile are completed. If the vehicle does not support LIN communication and the device charging controller does not receive a response signal within the set time, it changes the duty cycle of the PWM signal (set according to the power supply capacity of the charging and discharging pile, ranging from 8% - 97% in this embodiment). The following describes the case where the vehicle supports LIN communication;

[0072] (3) After the vehicle charging controller receives the PWM signal at detection point 2, it closes the S2 switch on the third feedback circuit. After the device charging controller detects that the voltage at detection point 1 on the first feedback circuit is the standard value of 6V, it enters the charging and discharging preparation state;

[0073] (4) The device charging controller sends a charging instruction. After the vehicle responds to the charging instruction, charging starts. According to the currently detected voltage of the three-phase power supply of the power grid, the input end of the intelligent switching switch C1 is connected to the input end of the AC charging and discharging pile circuit corresponding to the phase with the highest three-phase power supply voltage of the power grid. At the same time, the switch C2 is closed, and charging starts;

[0074] (5) During the charging process, when the device charging controller receives a discharge instruction from the power supply network, it sends a discharge instruction to the vehicle. When the vehicle is in the allowed discharge state, it sends a response discharge instruction, reduces the current to below 1A, and disconnects the switch S2, adjusts the OBC working mode (phase-locked, inverter output). The vehicle and the charging and discharging pile continuously monitor and exchange information such as the charging and discharging demand parameters and measurement values of both sides, including voltage, current, frequency, etc. The vehicle charging controller can send control instructions to control the input end of the intelligent switching switch C1 of the AC charging and discharging pile to be connected to one of its input ends L1, input end L2, and input end L3, and start discharging output;

[0075] If the vehicle does not allow discharge, it sends a response charging instruction, and the charging and discharging pile determines whether to continue or stop discharging. For example, the device charging controller sends an abort charging message to the vehicle, and the vehicle responds to the abort charging message, reduces the current to below the set value, and disconnects the switch S2, or the device charging controller sends a continue charging instruction to continue charging.

[0076] On the basis of the circuit described in Embodiment 1, the circuit described in Embodiment 2 superimposes an advanced communication line on the control and guidance circuit, realizing the charging information interaction in the AC charging and discharging system. It supports the switching control of the charging / discharging mode by the power grid or the vehicle under the condition of maintaining full connection. At the same time, it is also compatible with vehicles without advanced communication functions for charging and discharging.

Claims

1. An intelligent AC charging and discharging circuit for an electric vehicle, comprising a power supply side PE terminal and a vehicle side PE terminal that cooperate with each other, a power supply side CP terminal and a vehicle side CP terminal that cooperate with each other, and a power supply side CC terminal and a vehicle side CC terminal that cooperate with each other, characterized in that: It also includes an AC charging and discharging pile circuit, a power supply side control and guidance circuit, and a vehicle side control and guidance circuit; The AC charging and discharging pile circuit is arranged between the power supply side L end and the power supply side N end, and the input end L1, input end L2, and input end L3 of the AC charging and discharging pile circuit are respectively connected to the three-phase power supply phase line, and the AC charging and discharging pile circuit is provided with an intelligent switching switch C1, and the intelligent switching switch C1 has a first working position, a second working position, and a third working position. The input end of the intelligent switching switch C1 is connected to the input end L1 in the first working position, connected to the input end L2 in the second working position, and connected to the input end L3 in the third working position. The output end of the intelligent switching switch C1 is the power supply side L end, and one end of the input end N of the AC charging and discharging pile circuit is connected to the three-phase power supply neutral line, and the other end is connected to the power supply side N end; The power supply side control guide circuit includes a first feedback circuit and a second feedback circuit, and the vehicle side control guide circuit includes a third feedback circuit and a fourth feedback circuit; The first feedback circuit is arranged between the CP terminal of the power supply side and the PE terminal of the power supply side, and the first feedback circuit is provided with a device charging controller and a detection point 1, and the second feedback circuit is arranged between the CC terminal of the power supply side and the PE terminal of the power supply side; The third feedback circuit is arranged between the CP terminal of the vehicle side and the PE terminal of the vehicle side, and the third feedback circuit is provided with a detection point 2 and a switch S2; the fourth feedback circuit is arranged between the CC terminal of the vehicle side and the PE terminal of the vehicle side, and the fourth feedback circuit is provided with a vehicle charging controller and a detection point 3; Detection point 1 is used to detect the voltage between the CP terminal on the power supply side and the PE terminal on the power supply side, and feed back the detected voltage to the device charging controller. Detection point 2 is used to detect the PWM signal of the third feedback circuit, and feed back the detected PWM signal to the vehicle charging controller. Detection point 3 is used to detect the resistance value between the CC terminal on the vehicle side and the PE terminal on the vehicle side, and feed back the detected resistance value to the vehicle charging controller.

2. The intelligent AC charging and discharging circuit of an electric vehicle according to claim 1, characterized in that: A switch C2 is provided at the input terminal N of the AC charging and discharging pile circuit.

3. The intelligent AC charging and discharging circuit of electric vehicle according to claim 1, characterized in that: The PE end on the power supply side is a PE pin, and the PE end on the car side is a socket matching the PE pin, the CC end on the power supply side is a CC pin, and the CC end on the car side is a socket matching the CC pin, and the CP end on the power supply side is a CP pin, and the CP end on the car side is a socket matching the CP pin.

4. An intelligent AC charging and discharging circuit for electric vehicles, characterized in that: It includes the intelligent AC charging and discharging circuit of an electric vehicle as described in claim 1, and also includes a LIN communication line, and the LIN communication line connects the CP end on the power supply side with the device charging controller and the vehicle charging controller.

5. A control method for the intelligent AC charging and discharging circuit of an electric vehicle according to any one of claims 1 to 3, characterized in that: The following steps are involved: (1) Connect the power supply side to the vehicle side, and keep the intelligent switch C1 in the disconnected state; (2) After the device charging controller detects that the voltage at the detection point 1 on the first feedback circuit is the standard value, it considers that the connection between the CP terminal and the PE terminal is normal and outputs a PWM signal; (3) After receiving the PWM signal at detection point 2, the vehicle charging controller closes the S2 switch on the third feedback circuit and enters the charging and discharging state; (4) When charging or discharging the car, according to the currently detected voltage of the three-phase power supply of the power grid, when charging, the input end of the intelligent switching switch C1 is automatically connected to the input end of the AC charging and discharging pile circuit corresponding to the phase with the highest voltage of the three-phase power supply of the power grid; when discharging, the input end of the intelligent switching switch C1 is automatically connected to the input end of the AC charging and discharging pile circuit corresponding to the phase with the lowest voltage of the three-phase power supply of the power grid.

6. The control method of the electric vehicle intelligent AC charging and discharging circuit according to claim 5 is characterized in that: In the step (4), during discharge, the input end of the intelligent switching switch C1 is connected to one of the input end L1, input end L2, and input end L3 of the AC charging and discharging pile circuit according to the instruction issued by the vehicle.

7. The control method of the intelligent AC charging and discharging circuit of an electric vehicle according to claim 5, characterized in that: The vehicle charging controller receives the resistance value at the detection point 3 of the fourth feedback circuit, compares it with the standard value, and determines whether the plug on the power supply side is fully connected to the socket on the vehicle side.

8. A control method for the intelligent AC charging and discharging circuit of an electric vehicle according to claim 4, characterized in that: The following steps are involved: (1) Connect the power supply side to the vehicle side, and keep the intelligent switch C1 in the disconnected state; (2) After the device charging controller detects that the voltage at the detection point 1 on the first feedback circuit is the standard value, it considers that the connection between the CP terminal and the PE terminal is normal, outputs a PWM signal, and sends a LIN signal at the same time, waiting for the vehicle to respond; if the vehicle supports LIN communication, the vehicle replies with a response signal within a set time, the vehicle charging controller receives the response signal, and the version negotiation and initialization between the vehicle and the AC charging and discharging pile are completed; if the vehicle does not support LIN communication, the device charging controller does not receive a response signal within a set time, and switches the PWM signal duty cycle to a value corresponding to the power supply capacity of the AC charging and discharging pile; (3) After receiving the PWM signal at detection point 2, the vehicle charging controller closes the S2 switch on the third feedback circuit and enters the charging and discharging state; (4) Charging or discharging the car. According to the currently detected voltage of the three-phase power supply of the power grid, when charging, the input end of the intelligent switching switch C1 is connected to the input end of the AC charging and discharging pile circuit corresponding to the phase with the highest voltage of the three-phase power supply of the power grid; when discharging, the input end of the intelligent switching switch C1 is connected to the input end of the AC charging and discharging pile circuit corresponding to the phase with the lowest voltage of the three-phase power supply of the power grid; or according to the instruction issued by the car end, the input end of the intelligent switching switch C1 is connected to one of the input end L1, input end L2, and input end L3 of the AC charging and discharging pile circuit; (5) According to the grid status or vehicle instructions, the charging process is converted to the discharging process, or the discharging process is converted to the charging process.

9. The control method of the intelligent AC charging and discharging circuit of an electric vehicle according to claim 8, characterized in that: The conversion from charging to discharging process includes: During the charging process, the device charging controller receives a discharge instruction from the power supply network and sends a discharge instruction to the car. The car sends a response discharge instruction when the discharge is allowed, reduces the current to below the set value, disconnects switch S2, adjusts the OBC working mode, and sends an instruction to the device charging controller when it is ready to control the input end of the intelligent switching switch C1 to be connected to one of the input ends L1, L2, and L3 of the AC charging and discharging pile circuit to start discharging output; if the car is not allowed to discharge, the car charging controller sends a response discharge instruction, and the AC charging and discharging pile determines whether to continue or stop charging.

10. The control method of the intelligent AC charging and discharging circuit of an electric vehicle according to claim 8, characterized in that: The conversion from charging to discharging process includes: During the charging process, the device charging controller receives a discharge instruction sent by the car. When the current power supply network status allows discharge, the device charging controller sends a response discharge instruction to the car. The car reduces the current to below the set value and disconnects switch S2, adjusts the OBC working mode, and sends instructions to the device charging controller to control the input end of the intelligent switching switch C1 to be connected to one of the input ends L1, L2, and L3 of the AC charging and discharging pile circuit to start discharging output; if the current power supply network status does not allow discharge, the device charging controller sends a charging termination instruction to the car and stops outputting the PWM signal; the car reduces the current to below the set value and disconnects switch S2.

11. The control method of the intelligent AC charging and discharging circuit of an electric vehicle according to claim 8, characterized in that: The conversion from discharge to charging process includes: During the discharge process, the device charging controller receives the charging instruction from the power supply network and sends the charging instruction to the car. The car sends a response charging instruction when charging is allowed, reduces the current to below the set value, disconnects switch S2, adjusts the OBC working mode, and sends an instruction to the device charging controller to inform it to start charging. If the car does not allow charging, the car charging controller sends a response discharge instruction, and the AC charging and discharging pile determines whether to continue or stop discharging.

12. The control method of the electric vehicle intelligent AC charging and discharging circuit according to claim 8, characterized in that: The conversion from discharge to charging process includes: During the discharge process, the device charging controller receives a charging instruction sent by the car. When the current power supply network status allows charging, the device charging controller sends a response charging instruction to the car. The car reduces the current to below the set value, disconnects switch S2, adjusts the OBC working mode, and sends an instruction to the device charging controller to inform it to start charging. If the current power supply network status does not allow charging, the device charging controller sends a discharge termination instruction to the car and stops outputting the PWM signal. The car reduces the current to below the set value and disconnects switch S2.

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