A charging pile power supply system

Abstract

The application discloses a charging pile power supply system, which comprises a surge suppression circuit, a first EMI filter circuit, a rectification filter circuit, a power conversion circuit and a power control circuit which are sequentially electrically connected. The power conversion circuit is used for outputting positive and negative direct current voltages, and the power control circuit is used for adjusting and outputting the positive and negative direct current voltages. The output end of the rectification filter circuit is electrically connected with a system ground through a Y capacitor. The first EMI filter circuit comprises a first Y capacitor and a second Y capacitor which are connected in series. The connection node between the first Y capacitor and the second Y capacitor is connected to a system ground and an earth. The application effectively solves the electromagnetic interference and lightning protection of the connection between the earth and the system ground, significantly improves the stability and reliability of the charging pile power supply system, and realizes real-time adjustment and high-precision output of the power supply through the power control circuit.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic interference and lightning protection for the connection of charging pile ground, vehicle-end ground and system ground, and particularly to a charging pile power supply system applicable to electric vehicle AC charging piles, industrial power equipment and other scenarios. Background Technology

[0002] With the increasing popularity of electric vehicles, charging stations, as a crucial supporting infrastructure, are of paramount importance in terms of safety and stability. For example... Figure 1 As shown, in actual use, the PE (Protective Earth) of the charging pile and the PE of the vehicle are on the same network. Since the charging pile and the electric vehicle communicate and control each other via the CP (Control Pilot) signal line, and the PE of the charging pile is the reference ground for the PWM control pilot CP, the PE needs to be connected to the system ground of the charging pile. Therefore, the CP signal of the vehicle must be connected to the system ground of the charging pile control board, meaning the system ground of the charging pile control board is electrically connected to the ground to achieve control and communication of the CP signal. This leads to the charging pile control board and the CP signal frequently facing challenges from various natural factors. Lightning surges are one of the most destructive; a 6kV lightning surge can instantly generate ultra-high voltage and large current, easily causing irreversible damage to the CP signal line and its connected electronic components through the ground, such as chip breakdown, circuit burnout, communication interruption, abnormal charging, or even safety accidents. Therefore, the accuracy and stability of the +12V and -12V power supplies of the CP signal line are crucial.

[0003] Traditional power supply systems and grounding methods cannot fully and efficiently protect the CP signal line from such high-intensity impacts, and innovative protection technologies are urgently needed to ensure the reliable operation of charging piles. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention provides a power supply system for charging piles.

[0005] To achieve the above objectives, the specific solution of the present invention is as follows:

[0006] A charging pile power supply system includes a surge suppression circuit, a first EMI filter circuit, a rectifier filter circuit, a power conversion circuit, and a power control circuit connected in sequence. The power conversion circuit is used to output a positive DC voltage and a negative DC voltage, and the power control circuit is used to adjust and output the positive DC voltage and the negative DC voltage.

[0007] The output of the rectifier filter circuit is electrically connected to the system ground via a Y capacitor. The first EMI filter circuit includes a first Y capacitor and a second Y capacitor connected in series. The connection node between the first Y capacitor and the second Y capacitor is connected to the system ground and earth ground.

[0008] Preferably, the power control circuit includes a first power control circuit, a second power control circuit, and a second EMI filter circuit. The first power control circuit includes a first peak suppression circuit and a first precision adjustment circuit. The second power control circuit includes a second peak suppression circuit and a second precision adjustment circuit that are electrically connected. Both the first peak suppression circuit and the second precision adjustment circuit are electrically connected to the second EMI filter circuit.

[0009] Preferably, the first peak suppression circuit includes resistors R3 and R4, capacitor C2, and diode D1. After resistors R3 and R4 are connected in parallel, one end is electrically connected to capacitor C2, and the other end is electrically connected to the positive terminal of diode D1. The negative terminal of diode D1 is electrically connected to the other end of capacitor C2.

[0010] The first precision adjustment circuit includes a voltage regulator U4, resistors R29, R31, R32, R30, R33, R34, and capacitor C14. Resistors R29, R31, R32, capacitor C14, and resistor R30 are connected in sequence. Resistors R33 and R34 are connected in parallel between resistor R30 and capacitor C14. The anode and reference terminal of the voltage regulator U4 are electrically connected to the two ends of resistor R33, respectively. The cathode of the voltage regulator U4 is connected between resistors R31 and R32.

[0011] Preferably, the second peak suppression circuit includes a resistor R14, a capacitor C7, and a diode D4, wherein the cathode of the diode D4, the resistor R14, the capacitor C7, and the anode of the diode D4 are connected in sequence electrically.

[0012] The second precision adjustment circuit includes a voltage regulator U1 and resistors R13, R16, R17 and capacitor EC4 connected in sequence. The cathode and reference terminal of the voltage regulator U1 are electrically connected to both ends of resistor R13, and the anode of the voltage regulator U1 is electrically connected to the other end of resistor R16.

[0013] Preferably, the second EMI filter circuit includes electrolytic capacitor EC5, capacitor C8, C9 and a DC single-stage EMI filter circuit composed of electrolytic capacitor EC3, common-mode inductor LF1, capacitor C1, C4. Electrolytic capacitor EC5 and capacitor C8 are connected in parallel and then electrically connected to common-mode inductor LF1. One end of capacitor C9 is electrically connected to capacitor C8 and the other end is electrically connected to common-mode inductor LF1.

[0014] Preferably, a fuse is connected to the positive and / or negative output terminals of the power control circuit.

[0015] Preferably, the power conversion circuit includes a first set of transformers and a second set of transformers, wherein the secondary coil of the first set of transformers is electrically connected to the input terminal of the first power control circuit, and the secondary coil of the second set of transformers is electrically connected to the input terminal of the second power control circuit.

[0016] Preferably, the power conversion circuit is electrically connected to the first power control circuit via an optocoupler.

[0017] Preferably, the first EMI filter circuit includes resistors R1 and R2, capacitor CX1, common-mode inductor L1, and Y capacitors CY1 and CY2. The capacitors CX1, common-mode inductor L1, and Y capacitors CY1 and CY2 form a single-stage EMI filter circuit. The resistors R1 and R2 are connected in series and electrically connected to both ends of the capacitor CX1. One end of the CY1 is connected to the live wire, and one end of the CY2 is connected to the neutral wire. The other ends of the CY1 and CY2 are connected to the ground. The connection point between the other ends of the CY1 and CY2 and the ground is connected to one end of the ferrite bead L3. The other end of the ferrite bead L3 is grounded to the system ground at a single point.

[0018] Preferably, the surge suppression circuit includes a fuse F1, varistors RV1, RV2, RV3, discharge tubes G1, G2, and a thermistor RT1; one end of the varistor RV2 is connected to the live wire, and the other end is connected to one end of the discharge tube G2, the other end of which is connected to the neutral wire; one end of the varistor RV1 is connected to the live wire, one end of the varistor RV3 is connected to the neutral wire, the other ends of the varistors RV1 and RV3 are connected to one end of the discharge tube G1, the other end of which is connected to the ground; one end of the thermistor RT1 is connected to the neutral wire, and the other end is connected to the first EMI filter circuit.

[0019] The technical solution of this invention has the following beneficial effects:

[0020] In this invention, the high-voltage DC output from the rectifier and filter circuit is connected to the system ground via a Y capacitor. The electrical contacts of the two Y capacitors in the first EMI filter circuit are connected to the system ground and the earth ground via ferrite beads. This effectively solves the electromagnetic interference and lightning protection issues associated with the connection between the earth ground and the system ground, significantly improves the stability and reliability of the charging pile power supply system, and achieves real-time power adjustment and high-precision output through the power control circuit. Attached Figure Description

[0021] Figure 1 This is a schematic diagram illustrating an application scenario of the present invention;

[0022] Figure 2This is a functional block diagram of the present invention;

[0023] Figure 3 This is the circuit diagram of the present invention.

[0024] Among them, 1-surge suppression circuit, 2-first EMI filter circuit, 3-rectifier filter circuit, 4-power conversion circuit, 5-power control circuit, 501-first spike suppression circuit, 502-first precision adjustment circuit, 503-second spike suppression circuit, 504-second precision adjustment circuit, 505-second EMI filter circuit. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0026] Reference Figures 2 to 3 This invention provides a charging pile power supply system, comprising a surge suppression circuit 1, a first EMI filter circuit 2, a rectifier filter circuit 3, a power conversion circuit 4, and a power control circuit 5 connected in sequence. The surge suppression circuit 1 is used for AC signal surge and lightning strike suppression. The first EMI filter circuit 2 is used to suppress electromagnetic interference to ensure that the electromagnetic compatibility (EMC) of the power supply meets the standards and to avoid interference with other electronic equipment. The rectifier filter circuit 3 is used to convert the AC signal into pulsating DC and filter out differential mode interference and smooth high-frequency ripple after rectification. The power conversion circuit 4 is used to convert the high voltage of the bus into low-voltage DC through the primary winding of the transformer and output positive and negative DC voltages. The power control circuit 5 is used to adjust and output the positive and negative DC voltages.

[0027] The output of the rectifier filter circuit 3 is electrically connected to the system ground via a Y capacitor. The first EMI filter circuit 2 includes a first Y capacitor and a second Y capacitor connected in series. The connection node between the first Y capacitor and the second Y capacitor is connected to the system ground and earth ground.

[0028] The power control circuit 5 includes a first power control circuit, a second power control circuit, and a second EMI filter circuit 505. The first power control circuit includes a first peak suppression circuit 501 and a first precision adjustment circuit 502. The second power control circuit includes a second peak suppression circuit 503 and a second precision adjustment circuit 504 that are electrically connected. The first peak suppression circuit 501 and the second precision adjustment circuit 505 are both electrically connected to the second EMI filter circuit 505.

[0029] The power conversion circuit 4 includes a first set of transformers and a second set of transformers. The secondary coil of the first set of transformers is electrically connected to the input terminal of the first power control circuit, and the secondary coil of the second set of transformers is electrically connected to the input terminal of the second power control circuit. The power conversion circuit is electrically connected to the first power control circuit through an optocoupler.

[0030] Example 1:

[0031] In this embodiment, the first peak suppression circuit 501 includes resistors R3 and R4, capacitor C2, and diode D1. After resistors R3 and R4 are connected in parallel, one end is electrically connected to capacitor C2, and the other end is electrically connected to the positive terminal of diode D1. The negative terminal of diode D1 is electrically connected to the other end of capacitor C2.

[0032] The first precision adjustment circuit 502 includes a voltage regulator U4, resistors R29, R31, R32, R30, R33, R34, and capacitor C14. Resistors R29, R31, R32, C14, and R30 are electrically connected in sequence. Resistors R33 and R34 are connected in parallel between resistor R30 and capacitor C14. The anode and reference terminal of the voltage regulator U4 are electrically connected to the two ends of resistor R33, respectively. The cathode of the voltage regulator U4 is connected between resistors R31 and R32.

[0033] The second peak suppression circuit 503 includes a resistor R14, a capacitor C7, and a diode D4, wherein the cathode of the diode D4, the resistor R14, the capacitor C7, and the anode of the diode D4 are connected in sequence.

[0034] The second precision adjustment circuit 504 includes a voltage regulator U1 and resistors R13, R16, R17 and capacitor EC4 connected in sequence. The cathode and reference terminal of the voltage regulator U1 are electrically connected to both ends of resistor R13, and the anode of the voltage regulator U1 is electrically connected to the other end of resistor R16.

[0035] The second EMI filter circuit 505 includes electrolytic capacitor EC5, capacitor C8, C9 and a DC single-stage EMI filter circuit composed of electrolytic capacitor EC3, common-mode inductor LF1, capacitor C1, C4. Electrolytic capacitor EC5 and capacitor C8 are connected in parallel and then electrically connected to common-mode inductor LF1. One end of capacitor C9 is electrically connected to capacitor C8 and the other end is electrically connected to common-mode inductor LF1.

[0036] A fuse is connected to the positive and / or negative output terminals of the power control circuit 5.

[0037] In this embodiment, the secondary coil of the first transformer in the power conversion circuit 4 outputs a +14V DC voltage, and the secondary coil of the second transformer outputs a -14V DC voltage. These two DC voltages are adjusted to a high-precision, interference-free ±12V DC power supply by the first power control circuit and the second power control circuit, respectively. After the electromagnetic interference of the +12V and -12V power supplies is filtered out and the energy storage is smoothed by the second EMI filter circuit, the power is supplied to the CP signal circuit for communication between the charging pile and the vehicle.

[0038] Example 2:

[0039] In this embodiment, the first EMI filter circuit includes resistors R1 and R2, capacitor CX1, common-mode inductor L1, and Y capacitors CY1 and CY2. Capacitor CX1, common-mode inductor L1, and Y capacitors CY1 and CY2 form a single-stage EMI filter circuit. Resistors R1 and R2 are connected in series and electrically connected to both ends of capacitor CX1. One end of CY1 is connected to the live wire, and one end of CY2 is connected to the neutral wire. The other ends of CY1 and CY2 are connected to ground. The connection point between the other ends of CY1 and CY2 and ground is connected to one end of ferrite bead L3. The other end of ferrite bead L3 is grounded at a single point on the system ground. This single-point grounding point is directly connected to the system ground plane, and this grounding point is reinforced with insulation from the live and neutral wires, thus addressing electromagnetic interference from the power grid to the system ground, lightning protection, and providing a reliable reference for CP communication signals.

[0040] Example 3:

[0041] In this embodiment, the surge suppression circuit includes a fuse F1, varistors RV1, RV2, and RV3, discharge tubes G1 and G2, and a thermistor RT1. One end of the varistor RV2 is connected to the live wire, and the other end is connected to one end of the discharge tube G2, the other end of which is connected to the neutral wire. One end of the varistor RV1 is connected to the live wire, and one end of the varistor RV3 is connected to the neutral wire. The other ends of the varistors RV1 and RV3 are connected to one end of the discharge tube G1, the other end of which is connected to the ground. One end of the thermistor RT1 is connected to the neutral wire, and the other end is connected to the first EMI filter circuit.

[0042] In this embodiment, since the failure mode of the varistor is short circuit, when the varistor RV2 fails due to surge impact such as lightning strike, the discharge tube G2 will automatically disconnect to prevent short circuit between the live wire and the neutral wire; when the varistor RV1 and RV3 fail due to surge impact such as lightning strike, the discharge tube G1 will automatically disconnect to prevent short circuit between the live wire and the neutral wire and the ground, as well as short circuit between the live wire and the neutral wire.

[0043] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made under the inventive concept of the present invention using the contents of the present invention specification and drawings, or direct / indirect applications in other related technical fields, are included within the protection scope of the present invention.

Claims

1. A power supply system for a charging pile, characterized in that, The device includes a surge suppression circuit, a first EMI filter circuit, a rectifier filter circuit, a power conversion circuit, and a power control circuit that are connected in sequence. The power conversion circuit is used to output a positive DC voltage and a negative DC voltage, and the power control circuit is used to adjust and output the positive DC voltage and the negative DC voltage. The output of the rectifier filter circuit is electrically connected to the system ground via a Y capacitor. The first EMI filter circuit includes a first Y capacitor and a second Y capacitor connected in series. The connection node between the first Y capacitor and the second Y capacitor is connected to the system ground and earth ground. The first EMI filter circuit includes resistors R1 and R2, capacitor CX1, common-mode inductor L1, and Y capacitors CY1 and CY2. The capacitors CX1, common-mode inductor L1, and Y capacitors CY1 and CY2 form a single-stage EMI filter circuit. Resistors R1 and R2 are connected in series and electrically connected to both ends of capacitor CX1. One end of CY1 is connected to the live wire, and one end of CY2 is connected to the neutral wire. The other ends of CY1 and CY2 are connected to the ground. The connection point between the other ends of CY1 and CY2 and the ground is connected to one end of ferrite bead L3. The other end of ferrite bead L3 is grounded to the system ground at a single point.

2. The charging pile power supply system according to claim 1, characterized in that, The power control circuit includes a first power control circuit, a second power control circuit, and a second EMI filter circuit. The first power control circuit includes a first peak suppression circuit and a first precision adjustment circuit. The second power control circuit includes a second peak suppression circuit and a second precision adjustment circuit that are electrically connected. Both the first peak suppression circuit and the second precision adjustment circuit are electrically connected to the second EMI filter circuit.

3. The charging pile power supply system according to claim 2, characterized in that, The first peak suppression circuit includes resistors R3 and R4, capacitor C2, and diode D1. After resistors R3 and R4 are connected in parallel, one end is electrically connected to capacitor C2, and the other end is electrically connected to the positive terminal of diode D1. The negative terminal of diode D1 is electrically connected to the other end of capacitor C2. The first precision adjustment circuit includes a voltage regulator U4, resistors R29, R31, R32, R30, R33, R34, and capacitor C14. Resistors R29, R31, R32, capacitor C14, and resistor R30 are connected in sequence. Resistors R33 and R34 are connected in parallel between resistor R30 and capacitor C14. The anode and reference terminal of the voltage regulator U4 are electrically connected to the two ends of resistor R33, respectively. The cathode of the voltage regulator U4 is connected between resistors R31 and R32.

4. The charging pile power supply system according to claim 2, characterized in that, The second peak suppression circuit includes a resistor R14, a capacitor C7, and a diode D4, wherein the cathode of the diode D4, the resistor R14, the capacitor C7, and the anode of the diode D4 are connected in sequence. The second precision adjustment circuit includes a voltage regulator U1 and resistors R13, R16, R17 and capacitor EC4 connected in sequence. The cathode and reference terminal of the voltage regulator U1 are electrically connected to both ends of resistor R13, and the anode of the voltage regulator U1 is electrically connected to the other end of resistor R16.

5. The charging pile power supply system according to claim 2, characterized in that, The second EMI filter circuit includes electrolytic capacitor EC5, capacitor C8, C9 and a DC single-stage EMI filter circuit composed of electrolytic capacitor EC3, common-mode inductor LF1, capacitor C1, C4. Electrolytic capacitor EC5 and capacitor C8 are connected in parallel and then electrically connected to common-mode inductor LF1. One end of capacitor C9 is electrically connected to capacitor C8 and the other end is electrically connected to common-mode inductor LF1.

6. The charging pile power supply system according to claim 2, characterized in that, A fuse is connected to the positive and / or negative output terminals of the power control circuit.

7. The charging pile power supply system according to claim 2, characterized in that, The power conversion circuit includes a first set of transformers and a second set of transformers. The secondary coil of the first set of transformers is electrically connected to the input terminal of the first power control circuit, and the secondary coil of the second set of transformers is electrically connected to the input terminal of the second power control circuit.

8. The charging pile power supply system according to claim 7, characterized in that, The power conversion circuit is electrically connected to the first power control circuit via an optocoupler.

9. The charging pile power supply system according to claim 1, characterized in that, The surge suppression circuit includes a fuse F1, varistors RV1, RV2, and RV3, discharge tubes G1 and G2, and a thermistor RT1. One end of the varistor RV2 is connected to the live wire, and the other end is connected to one end of the discharge tube G2, the other end of which is connected to the neutral wire. One end of the varistor RV1 is connected to the live wire, and one end of the varistor RV3 is connected to the neutral wire. The other ends of the varistor RV1 and RV3 are connected to one end of the discharge tube G1, the other end of which is connected to the ground. One end of the thermistor RT1 is connected to the neutral wire, and the other end is connected to the first EMI filter circuit.

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