High-voltage EMC filter circuit

Abstract

Provided in the present invention is a high-voltage EMC filter circuit. The high-voltage EMC filter circuit comprises a common-mode filter circuit, a Y-capacitor circuit and a control circuit, wherein during a period where high-voltage charging is performed on an electric vehicle via an EVSE, the control circuit disconnects the Y-capacitor circuit from a grounding terminal; and during a period where high-voltage charging is not performed on the electric vehicle via the EVSE, the control circuit connects the Y-capacitor circuit to the grounding terminal, so as to perform EMC filtering via the common-mode filter circuit and the Y-capacitor circuit together. Therefore, both EMC and high-voltage safety can be taken into consideration.

Description

High voltage EMC filter circuit Technical Field

[0001] The present invention relates to the technical field of electric vehicles, and in particular to a high-voltage EMC filter circuit. Background Art

[0002] High-voltage components in electric vehicles (EVs) often contain Y capacitors, especially in power electronic units (PEUs).

[0003] Electromagnetic compatibility (EMC) requirements for PEUs continue to increase, particularly in terms of conductivity and emissions testing. Consequently, a more effective EMC filter is needed. To improve EMC filter design, increasing the Y capacitor value is often employed. In other words, to meet EMC requirements, the Y capacitor value often needs to be increased.

[0004] At the same time, the presence of the Y capacitor affects the high-voltage safety on the load side when the high voltage is cut off. Since a high-voltage safety hazard may exist if the Y capacitor value is too large, the Y capacitor needs to be as small as possible when the high voltage is cut off to avoid personal injury to the user. Therefore, electric vehicles limit the Y capacitor value. For example, the GB / T 18384.1 standard has clear requirements for this indicator (i.e., the Y capacitor value). The energy storage requirement of the Y capacitor at the maximum voltage is less than 0.2 joules (J); if the Y capacitor exceeds 0.2J, there will be a high-voltage safety hazard. Therefore, in order to meet the high-voltage safety requirements, it is usually necessary to reduce the Y capacitor value.

[0005] However, related technologies involving Y capacitors may find it difficult to simultaneously take into account EMC and high-voltage safety.

[0006] Summary of the Invention

[0007] In view of this, the present invention provides a high-voltage EMC filter circuit, thereby being able to take both EMC and high-voltage safety into consideration.

[0008] According to a first aspect of the present invention, a high-voltage EMC filter circuit is provided, comprising: a common-mode filter circuit (110), comprising a first terminal, a second terminal, a third terminal, and a fourth terminal, wherein the first terminal and the second terminal are respectively connected to a first high-voltage charging terminal (1) and a second high-voltage charging terminal (2) of an electric vehicle power supply (EVSE), and the fourth terminal is connected to a ground terminal (GND); a Y capacitor circuit (120), comprising a fifth terminal and a sixth terminal, wherein the fifth terminal is connected to the third terminal; and a control circuit (130), comprising a seventh terminal and an eighth terminal, wherein the seventh terminal is connected to the sixth terminal, and the eighth terminal is connected to the ground terminal, wherein during a period when the electric vehicle is charged at high voltage via the EVSE, the control circuit disconnects the connection between the Y capacitor circuit and the ground terminal; during a period when the electric vehicle is not charged at high voltage via the EVSE, the control circuit connects the connection between the Y capacitor circuit and the ground terminal, so as to perform EMC filtering via the common-mode filter circuit and the Y capacitor circuit.

[0009] According to a second aspect of the present invention, a power electronic unit (PEU) is provided, comprising the above-mentioned high-voltage EMC filter circuit.

[0010] According to a third aspect of the present invention, an electric vehicle is provided, comprising the above-mentioned PEU.

[0011] According to the high-voltage EMC filter circuit, PEU, and electric vehicle of the present invention, when the electric vehicle is in a high-voltage charging state (i.e., while the EVSE is performing high-voltage charging on the EV), the control circuit disconnects the Y capacitor circuit from the ground terminal GND, thereby reducing the Y capacitance value in the circuit and thus meeting high-voltage safety requirements. Conversely, when the electric vehicle is in a non-charging state (i.e., while the EVSE is not performing high-voltage charging on the EV), the control circuit connects the Y capacitor circuit to the ground terminal GND, thereby increasing the Y capacitance value in the circuit and thus meeting EMC requirements. This allows for both EMC and high-voltage safety to be taken into account simultaneously.

[0012] Further features and aspects of the present invention will become apparent from the following detailed description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the invention and, together with the description, serve to explain the principles of the invention.

[0014] FIG1 is a schematic diagram of a high-voltage EMC filter circuit applied to a PEU in the related art.

[0015] FIG. 2 is a schematic diagram of a high-voltage EMC filter circuit according to the present exemplary embodiment.

[0016] FIG3 is a schematic diagram of a high-voltage EMC filter circuit according to this exemplary embodiment.

[0017] FIG4 is a schematic diagram of a high-voltage EMC filter circuit according to the present exemplary embodiment.

[0018] FIG5 is a schematic diagram of a high-voltage EMC filter circuit according to this exemplary embodiment.

[0019] FIG6 is a schematic diagram of a high-voltage EMC filter circuit according to this exemplary embodiment.

[0020] FIG. 7 is a schematic diagram of a high-voltage EMC filter circuit according to the present exemplary embodiment.

[0021] FIG8 is a schematic diagram of a high-voltage EMC filter circuit according to this exemplary embodiment.

[0022] FIG. 9 is a schematic diagram of a high-voltage EMC filter circuit according to the present exemplary embodiment. DETAILED DESCRIPTION

[0023] Various exemplary embodiments, features, and aspects of the present invention will be described in detail below with reference to the accompanying drawings. The same reference numerals in the accompanying drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless otherwise indicated.

[0024] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0025] In addition, numerous specific details are provided in the following detailed description to better illustrate the present invention. Those skilled in the art will appreciate that the present invention may be practiced without certain specific details. In other instances, methods, means, components, and circuits well known to those skilled in the art are not described in detail in order to highlight the main points of the present invention.

[0026] Referring to Figure 1, a high-voltage EMC filter circuit in related art includes inductors L1-L3 and capacitors C1-C3. Inductor L1 is connected between terminal 1 of the electric vehicle supply equipment (EVSE) and node n1, while inductor L3 is connected between terminal 2 of the EVSE and node n3.

[0027] An EVSE, also known as an electric vehicle (EV) charging station, electric charging point, charging point, charging point, charging pile, or electric charging station (ECS), is an infrastructure component that supplies electrical energy for charging electric vehicles (EVs), including electric vehicles, urban electric vehicles, and plug-in hybrid vehicles, via charging cables and charging connectors. In this embodiment, the EVSE is used to charge the EV where the PEU is located.

[0028] Capacitor C1 is connected between node n2 and node n3, one end of inductor L2 is connected to node n2 and the other end is connected to the load, one end of inductor L4 is connected to node n4 and the other end is connected to the load, capacitor C2 is connected between node n1 and ground GND, and capacitor C3 is connected between node n4 and ground GND. It should be understood that capacitors C2 and C3 are Y capacitors.

[0029] As described in the background technology section, to meet EMC requirements and thus achieve better filtering, it is necessary to increase the size of the Y capacitors C2 and C3. In other words, to meet EMC requirements, the larger the Y capacitors C2 and C3, the better.

[0030] However, since the Y capacitors C2 and C3 are connected to the ground terminal GND, during the high-voltage charging process, the end of the Y capacitor C2 connected to the node n1 is at high voltage and the end of the Y capacitor C3 connected to the node n4 is also at high voltage. If the Y capacitors C2 and C3 are too large, and the EVSE's own Y capacitor is added, the Y capacitance of the entire circuit may be too large, resulting in excessive leakage current. If the user touches the GND terminal, he will be electrocuted, which may cause a high-voltage safety problem.

[0031] Therefore, in actual design, it is difficult to take into account both EMC and high-voltage safety. Among them, EMC requires the Y capacitor to be as large as possible, while high-voltage safety requires the Y capacitor to be as small as possible.

[0032] In other words, EMC and high-voltage safety must be taken into account in actual design, but it is difficult to take both EMC and high-voltage safety into account in actual application.

[0033] To this end, the present invention recognizes that when an electric vehicle is being charged at high voltage, the electric vehicle is stopped, the motor is not running, and the PEU is not functioning. Therefore, the impact of the PEU on EMC is negligible. Therefore, when charging an electric vehicle at high voltage, only high-voltage safety requirements can be considered, regardless of EMC requirements. Conversely, when the electric vehicle is being driven, the motor is running and the PEU is functioning, so the impact of the PEU on EMC needs to be considered. However, high-voltage charging is not occurring at this time, so only EMC requirements can be considered, regardless of high-voltage safety requirements.

[0034] Therefore, the Y capacitor in the circuit can be controlled based on whether the electric vehicle is in a high-voltage charging state. Specifically, according to the high-voltage EMC filter circuit of the present invention, it includes a common-mode filter circuit, a Y capacitor circuit, and a control circuit. During the period when the electric vehicle is being charged at high voltage via the EVSE, the control circuit disconnects the Y capacitor circuit from the ground terminal GND; during the period when the electric vehicle is not being charged at high voltage via the EVSE, the control circuit connects the Y capacitor circuit to the ground terminal GND to perform EMC filtering via the common-mode filter circuit and the Y capacitor circuit.

[0035] Therefore, when the electric vehicle is in a high-voltage charging state, the connection between the Y capacitor circuit and the ground terminal GND is disconnected via the control circuit, thereby reducing the Y capacitance value in the circuit, thereby meeting the high-voltage safety requirements; when the electric vehicle is in a non-high-voltage charging state, the connection between the Y capacitor circuit and the ground terminal GND is connected via the control circuit, thereby increasing the Y capacitance value in the circuit, thereby meeting the EMC requirements. Therefore, both EMC and high-voltage safety can be taken into account at the same time, thereby solving the technical problems described above.

[0036] Based on the above concept, a high-voltage EMC filter circuit as shown in Figures 2 to 9 is proposed. The high-voltage EMC filter circuit can be applied to the PEU of an EV.

[0037] Example 1:

[0038] 2 , the high-voltage EMC filter circuit 100 of this exemplary embodiment may include a common-mode filter circuit 110 , a Y capacitor circuit 120 , and a control circuit 130 .

[0039] The common-mode filter circuit 110 may include a first terminal 3, a second terminal 4, a third terminal 6, and a fourth terminal 5. The first terminal 3 and the second terminal 4 are connected to the first high-voltage charging terminal 1 and the second high-voltage charging terminal 2 of the EVSE, respectively. The fourth terminal 5 is connected to the ground terminal GND. The Y-capacitor circuit 120 may include a fifth terminal 7 and a sixth terminal 8. The fifth terminal 7 is connected to the third terminal 6. GND is the PEU grounding point for ground protection.

[0040] The control circuit 130 may include a seventh terminal 9 and an eighth terminal 10. The seventh terminal 9 is connected to the sixth terminal 8, and the eighth terminal 10 is connected to the ground terminal GND. During high-voltage charging of the EV via the EVSE, the control circuit 130 disconnects the Y capacitor circuit 120 from the ground terminal GND. During high-voltage charging of the EV without the EVSE, the control circuit 130 connects the Y capacitor circuit 120 to the ground terminal GND, thereby performing EMC filtering via the common-mode filter circuit 110 and the Y capacitor circuit 120.

[0041] In this embodiment, when an EV is connected to an EVSE for high-voltage charging, the EVSE sends a charging signal to the Vehicle Control Unit (VCU) indicating that the EVSE is currently charging the EV at high voltage. Based on the charging signal received from the EVSE, the VCU can determine that high-voltage charging is currently in progress and can send this charging signal to the Power Electronics Unit (PEU). Based on the charging signal received from the VCU, the PEU can determine that the EVSE is currently charging the EV at high voltage. Accordingly, the PEU can control the control circuit 130 to disconnect the Y capacitor circuit 120 from the ground terminal GND.

[0042] Accordingly, when the EV is disconnected from the EVSE to prevent high-voltage charging, the EVSE stops sending charging signals to the VCU indicating that the EVSE is performing high-voltage charging. Based on the failure to receive the charging signals, the VCU can determine that the EVSE is not performing high-voltage charging on the EV. The VCU can then send a non-charging signal to the PEU indicating that the EVSE is not performing high-voltage charging on the EV. Based on the non-charging signal received from the VCU, the PEU can determine that the EVSE is not performing high-voltage charging on the EV. Accordingly, the PEU can control the control circuit 130 to connect the Y-capacitor circuit 120 to the ground terminal GND, thereby performing common-mode filtering on the EMC in the circuit via the common-mode filter circuit 110 and the Y-capacitor circuit 120.

[0043] Therefore, the PEU can determine whether it is currently in a period of high-voltage charging via the EVSE or a period of high-voltage charging without the EVSE based on the signal received from the VCU, and then control the control circuit 130 to disconnect the connection between the Y capacitor circuit 120 and the ground terminal GND, or to connect the connection between the Y capacitor circuit 120 and the ground terminal GND.

[0044] According to the high-voltage EMC filter circuit of this embodiment, when the electric vehicle is in a high-voltage charging state (i.e., while the EVSE is performing high-voltage charging on the EV), the control circuit 130 disconnects the Y capacitor circuit 120 from the ground terminal GND, thereby reducing the Y capacitance value in the circuit and thus meeting high-voltage safety requirements. Conversely, when the electric vehicle is not charging (i.e., while the EVSE is not performing high-voltage charging on the EV), the control circuit 130 connects the Y capacitor circuit 120 to the ground terminal GND, thereby increasing the Y capacitance value in the circuit and thus meeting EMC requirements. This achieves a balanced approach to both EMC and high-voltage safety.

[0045] On the basis of the technical solution described in the first embodiment, the second embodiment can be obtained by further expanding the control circuit 130 .

[0046] Example 2:

[0047] Referring to Figure 3 , the high-voltage EMC filter circuit 200 of this exemplary embodiment may include a common-mode filter circuit 110, a Y-capacitor circuit 120, and a first switch 210. It should be understood that the control circuit 130 may include the first switch 210. For a detailed description of the common-mode filter circuit 110 and the Y-capacitor circuit 120, please refer to the detailed description of the first embodiment. Due to space limitations, they will not be repeated here.

[0048] The first switch 210 may include a terminal 9 and a terminal 10, wherein the terminal 9 is connected to the sixth terminal 8, and the terminal 10 is connected to the ground terminal GND. The first switch 210 is turned off during high-voltage charging of the EV via the EVSE, and turned on during high-voltage charging of the EV without the EVSE.

[0049] In this embodiment, the PEU can determine that the EVSE is performing high-voltage charging on the EV based on a charging signal received from the VCU indicating that the EVSE is performing high-voltage charging on the EV. Accordingly, the PEU can control the first switch 210 to open, thereby disconnecting the Y-capacitor circuit 120 from the ground terminal GND.

[0050] Conversely, the PEU can determine that the EVSE is not performing high-voltage charging of the EV based on a non-charging signal received from the VCU indicating that the EVSE is not performing high-voltage charging of the EV. Accordingly, the PEU can control first switch 210 to turn on first switch 210, thereby connecting Y-capacitor circuit 120 to ground terminal GND. This allows common-mode filtering of EMC signals in the circuit via common-mode filter circuit 110 and Y-capacitor circuit 120.

[0051] Therefore, the PEU can determine whether it is currently in a period of high-voltage charging via the EVSE or a period of high-voltage charging without the EVSE based on the signal received from the VCU, and then control the first switch 210 to disconnect the first switch 210, thereby disconnecting the connection between the Y capacitor circuit 120 and the ground terminal GND, or to turn on the first switch 210, thereby connecting the connection between the Y capacitor circuit 120 and the ground terminal GND.

[0052] According to the high-voltage EMC filter circuit of this embodiment, only one switch (first switch 210) is required to control the Y capacitor circuit 120, thereby controlling the Y capacitance value in the circuit. When the electric vehicle is in a high-voltage charging state (i.e., during high-voltage charging of the EV by the EVSE), the first switch 210 is disconnected to disconnect the Y capacitor circuit 120 from the ground terminal GND, thereby reducing the Y capacitance value in the circuit and meeting high-voltage safety requirements. This can fundamentally improve the high-voltage safety of the system.

[0053] In one possible implementation, the on and off of the first switch 210 is controlled by the PEU according to whether the PEU operates in the charging mode, wherein the PEU disconnects the first switch 210 when the PEU operates in the charging mode, and turns on the first switch 210 when the PEU operates in a mode other than the charging mode.

[0054] In a possible implementation, the other modes include a driving mode, wherein the motor operates in the driving mode.

[0055] In this embodiment, the PEU can operate in various modes, including but not limited to a driving mode indicating that the electric vehicle is in a driving state, a charging mode indicating that the electric vehicle is in a high-voltage charging state, and the like.

[0056] When the electric vehicle is driving, the motor needs to work, and the VCU sends a drive request to the PEU. The PEU determines that it is operating in the drive mode based on the drive request sent by the VCU. Accordingly, the PEU controls the first switch 210 to turn on, thereby connecting the Y capacitor circuit 120 to the ground terminal GND, thereby increasing the Y capacitor value in the circuit to meet EMC requirements.

[0057] According to the high-voltage EMC filter circuit of this embodiment, the PEU flexibly controls the on and off of the first switch 210 according to the mode in which the PEU is located.

[0058] On the basis of the technical solution described in the second embodiment, the common-mode filter circuit 110 and the Y capacitor circuit 120 can be further expanded to obtain the third embodiment.

[0059] Example 3:

[0060] 4 , the high-voltage EMC filter circuit 300 of this exemplary embodiment may include a first inductor L1, a second inductor L3, a first Y-capacitor C2, a second Y-capacitor C3, a third Y-capacitor C4, a fourth Y-capacitor C5, and a first switch 210. The first inductor L1 is connected between the first high-voltage charging terminal 1 and the node p1, the second inductor L3 is connected between the second high-voltage charging terminal 2 and the node p3, the first Y-capacitor C2 is connected between the node p1 and the node p7, the second Y-capacitor C3 is connected between the node p6 and the node p7, the third Y-capacitor C4 is connected between the node p2 and the node p4, the fourth Y-capacitor C5 is connected between the node p3 and the node p4, and the first switch 210 is connected between the node p4 and the ground terminal GND. Node p7 is connected to the ground terminal GND.

[0061] It should be understood that the common-mode filter circuit 110 may include a first inductor L1, a second inductor L3, a first Y capacitor C2, and a second Y capacitor C3; the Y capacitor circuit 120 may include a third Y capacitor C4 and a fourth Y capacitor C5; and the control circuit 130 may include a first switch 210. For a description of the first switch 210, please refer to the detailed description of the second embodiment and will not be repeated here due to space limitations.

[0062] During high-voltage charging of the EV via the EVSE, the first switch 210 is turned off, thereby disconnecting the third and fourth Y capacitors C4 and C5 from the ground terminal GND. At this time, the Y capacitors in the circuit include the first and second Y capacitors C2 and C3, and the EVSE's own Y capacitor. Compared to a circuit in which the Y capacitors include the first and second Y capacitors C2, C3, the EVSE's own Y capacitor, the third and fourth Y capacitors C4 and C5, the Y capacitor value in the circuit is reduced, thereby meeting high-voltage safety requirements.

[0063] Conversely, when the EV is not being charged at high voltage by the EVSE, the first switch 210 is turned on, thereby connecting the third and fourth Y capacitors C4 and C5 to the ground terminal GND. This allows the first inductor L1, the second inductor L3, the first Y capacitor C2, the second Y capacitor C3, the third Y capacitor C4, and the fourth Y capacitor C5 to collectively perform common-mode filtering for EMC in the circuit. In this case, the Y capacitors in the circuit include the first Y capacitor C2, the second Y capacitor C3, the third Y capacitor C4, and the fourth Y capacitor C5. Compared to a circuit in which the Y capacitors consist of the first Y capacitor C2 and the second Y capacitor C3, the Y capacitor values ​​in the circuit are increased, thereby meeting EMC requirements.

[0064] According to the high-voltage EMC filter circuit of this embodiment, only one switch (first switch 210) is required to control the two Y capacitors C4-C5, thereby controlling the Y capacitance value in the circuit. When the electric vehicle is in a high-voltage charging state (i.e., during high-voltage charging by the EVSE), the first switch 210 is disconnected, disconnecting the Y capacitors C4-C5 from the ground terminal GND. This reduces the Y capacitance value in the circuit and thus meets high-voltage safety requirements. This fundamentally improves the high-voltage safety of the system.

[0065] Since only the third Y capacitor C4, the fourth Y capacitor C5, and the first switch 210 are added to the existing EMC circuit, the newly added components occupy a relatively small area and can be integrated into the existing EMC filter circuit. In addition, the design of this embodiment is flexible and can be easily expanded to other electronic control units (ECUs).

[0066] On the basis of the technical solution described in the third embodiment, the fourth embodiment can be obtained by further expanding the common-mode filter circuit 110 .

[0067] Example 4:

[0068] Referring to FIG5 , the high-voltage EMC filter circuit 400 of this exemplary embodiment may include first to fourth inductors L1 to L4, first to fourth Y-capacitors C2 to C5, a first capacitor C1, and a first switch 210. Compared to the high-voltage EMC filter circuit 300 shown in FIG4 , the high-voltage EMC filter circuit 400 shown in FIG5 adds a third inductor L3, a fourth inductor L4, and a first capacitor C1 to facilitate better EMC filtering.

[0069] The first inductor L1 is connected between the first high-voltage charging terminal 1 and the node p1, the second inductor L3 is connected between the second high-voltage charging terminal 2 and the node p5, and the first Y-capacitor C2 is connected between the node p1 and the node p7. The first capacitor C1 is connected between the node p8 and the node p5, the third inductor L2 is connected between the node p8 and the node p2, the fourth inductor L4 is connected between the node p6 and the node p3, the second Y-capacitor C3 is connected between the node p6 and the node p7, and the node p7 is connected to the ground terminal GND. The third Y-capacitor C4 is connected between the node p2 and the node p4, the fourth Y-capacitor C5 is connected between the node p3 and the node p4, and the first switch 210 is connected between the node p4 and the ground terminal GND.

[0070] The first Y capacitor C2 and the second Y capacitor C3 are fixed Y capacitors for EMC filtering and have smaller values. The third Y capacitor C4 and the fourth Y capacitor C5 are adjustable Y capacitors for EMC filtering and have larger values ​​than the fixed Y capacitors.

[0071] It should be understood that the common-mode filter circuit 110 may include first to fourth inductors L1 to L4, a first capacitor C1, a first Y capacitor C2, and a second Y capacitor C3; the Y capacitor circuit 120 may include a third Y capacitor C4 and a fourth Y capacitor C5; and the control circuit 130 may include a first switch 210. For a description of the first switch 210, refer to the detailed description of the second embodiment; for a description of the fourth inductor L4 and the second Y capacitor C3, refer to the detailed description of the third embodiment; and due to space limitations, they are not further described here.

[0072] During high-voltage charging of the EV via the EVSE, the first switch 210 is disconnected, thereby disconnecting the third and fourth Y capacitors C4 and C5 from the ground terminal GND. At this time, the Y capacitors in the circuit include the first Y capacitor C2, the second Y capacitor C3, and the EVSE's own Y capacitor. Compared with a circuit in which the Y capacitors include the first to fourth Y capacitors C2 to C5 and the EVSE's own Y capacitor, the Y capacitor value in the circuit is reduced, thereby meeting high-voltage safety requirements.

[0073] Conversely, when the EV is not being charged at high voltage by the EVSE, first switch 210 is turned on, connecting the third and fourth Y-capacitors C4 and C5 to ground terminal GND. This allows common-mode filtering of the EMC circuit via the first to fourth inductors L1 to L4, the first to fourth Y-capacitors C2 to C5, and the first capacitor C1. In this case, the Y-capacitors in the circuit, including the first to fourth Y-capacitors C2 to C5, have a larger value than those in a circuit consisting of the first and second Y-capacitors C2 and C3, thereby meeting EMC requirements.

[0074] According to the high-voltage EMC filter circuit of this embodiment, only one switch (first switch 210) is required to control the two Y capacitors C4-C5, thereby controlling the Y capacitance value in the circuit. When the electric vehicle is in a high-voltage charging state (i.e., during high-voltage charging by the EVSE), the first switch 210 is disconnected, disconnecting the Y capacitors C4-C5 from the ground terminal GND. This reduces the Y capacitance value in the circuit and thus meets high-voltage safety requirements. This fundamentally improves the high-voltage safety of the system.

[0075] Since only the third Y capacitor C4, the fourth Y capacitor C5, and the first switch 210 are added to the existing EMC circuit, the newly added components occupy a smaller area and can be integrated into the existing EMC filter circuit. In addition, the design of this embodiment is flexible and can be easily expanded to other ECUs.

[0076] In one possible implementation, the first inductor L1 and the second inductor L3 constitute a common-mode inductor, and the value of the common-mode inductor is, for example, 4 microhenries (uH), the third inductor L2 and the fourth inductor L4 constitute another common-mode inductor, and the value of the common-mode inductor is, for example, 6uH to 80uH, the value of the first capacitor C1 is, for example, 1 microfarad (uF), the value of the first Y capacitor C2 is, for example, 20 nanofarads (nF), the value of the second Y capacitor C3 is, for example, 20nF, the value of the third Y capacitor C4 is, for example, 400nF, and the value of the fourth Y capacitor C5 is, for example, 400nF.

[0077] It should be understood that the values ​​of capacitors C1-C5 and inductors L1-L4 of this embodiment are not limited to the above values. Appropriate values ​​can be selected based on actual application requirements, such as EMC requirements, as long as the high-voltage EMC filter circuit can filter out EMC in the circuit. In one possible implementation, the values ​​of capacitors C1-C5 and inductors L1-L4 in the circuit can be adjusted according to the interference frequency. For example, the values ​​of C2-C5 can be arbitrarily selected as long as the sum of C2, C3, C4, and C5 is less than 500nF.

[0078] On the basis of the technical solution described in the fourth embodiment, the fifth embodiment can be obtained by further expanding the common-mode filter circuit 110 .

[0079] Embodiment 5:

[0080] Referring to FIG6 , the high-voltage EMC filter circuit 500 of this exemplary embodiment may include first to sixth inductors L1 to L6, first to fourth Y-type capacitors C2 to C5, a first capacitor C1, a second capacitor C6, and a first switch 210. Compared to the high-voltage EMC filter circuit 400 shown in FIG5 , the high-voltage EMC filter circuit 500 shown in FIG6 adds a fifth inductor L5, a sixth inductor L6, and a second capacitor C6 to facilitate better EMC filtering. The values ​​of the fifth inductor L5, the sixth inductor L6, and the second capacitor C6 can be determined in accordance with the values ​​of the capacitors and inductors in the fourth embodiment, as long as they can eliminate EMC in the circuit.

[0081] Among them, the first inductor L1 is connected between the first high-voltage charging terminal 1 and the node p1, the second inductor L3 is connected between the second high-voltage charging terminal 2 and the node p5, the first Y capacitor C2 is connected between the node p1 and the node p7, the second Y capacitor C3 is connected between the node p6 and the node p7, and the node p7 is connected to the ground terminal GND.

[0082] The first capacitor C1 is connected between node p8 and node p5, the third inductor L2 is connected between node p8 and node p2, and the fourth inductor L4 is connected between node p6 and node p3. The second capacitor C6 is connected between node p10 and node p9, the fifth inductor L5 is connected between node p9 and node p2, and the sixth inductor L6 is connected between node p10 and node p3. The third Y capacitor C4 is connected between node p2 and node p4, the fourth Y capacitor C5 is connected between node p3 and node p4, and the first switch 210 is connected between node p4 and the ground terminal GND.

[0083] It should be understood that the common-mode filter circuit 110 may include first to sixth inductors L1 to L6, a first capacitor C1, a second capacitor C6, a first Y capacitor C2, and a second Y capacitor C3; the Y capacitor circuit 120 may include a third Y capacitor C4 and a fourth Y capacitor C5; and the control circuit 130 may include a first switch 210. For a description of the first switch 210, refer to the detailed description of the second embodiment; for a description of the fourth inductor L4 and the second Y capacitor C3, refer to the detailed description of the third embodiment; and due to space limitations, they are not further described here.

[0084] During high-voltage charging of the EV via the EVSE, the first switch 210 is disconnected, thereby disconnecting the third and fourth Y capacitors C4 and C5 from the ground terminal GND. At this time, the Y capacitors in the circuit include the first Y capacitor C2, the second Y capacitor C3, and the EVSE's own Y capacitor. Compared with a circuit in which the Y capacitors include the first to fourth Y capacitors C2 to C5 and the EVSE's own Y capacitor, the Y capacitor value in the circuit is reduced, thereby meeting high-voltage safety requirements.

[0085] Conversely, when the EV is not being charged at high voltage by the EVSE, first switch 210 is turned on, connecting the third and fourth Y-capacitors C4 and C5 to ground terminal GND. This allows common-mode filtering of the EMC circuit via the first to sixth inductors L1 to L6, the first capacitor C1, the second capacitor C6, and the first to fourth Y-capacitors C2 to C5. In this case, the Y-capacitors in the circuit, including the first to fourth Y-capacitors C2 to C5, have a larger Y-capacitor value than when the Y-capacitors in the circuit consist of the first and second Y-capacitors C2 and C3, thereby meeting EMC requirements.

[0086] According to the high-voltage EMC filter circuit of this embodiment, only one switch (first switch 210) is required to control the two Y capacitors C4-C5, thereby controlling the Y capacitance value in the circuit. When the electric vehicle is in a high-voltage charging state (i.e., during high-voltage charging by the EVSE), the first switch 210 is disconnected, disconnecting the Y capacitors C4-C5 from the ground terminal GND. This reduces the Y capacitance value in the circuit and thus meets high-voltage safety requirements. This fundamentally improves the high-voltage safety of the system.

[0087] Since only the third Y capacitor C4, the fourth Y capacitor C5, and the first switch 210 are added to the existing EMC circuit, the newly added components occupy a smaller area and can be integrated into the existing EMC filter circuit. In addition, the design of this embodiment is flexible and can be easily expanded to other ECUs.

[0088] On the basis of the technical solution described in the fourth embodiment, the sixth embodiment can be obtained by further expanding the Y capacitor circuit 120 .

[0089] Example 6:

[0090] Referring to FIG. 7 , a high-voltage EMC filter circuit 700 of this exemplary embodiment may include first to fourth inductors L1 to L4, first to fourth Y-capacitors C2 to C5, fifth and sixth Y-capacitors C7 to C8, a first capacitor C1, a first switch 210, and a second switch 211. Compared to the high-voltage EMC filter circuit 400 shown in FIG. 5 , the high-voltage EMC filter circuit 700 shown in FIG. 7 includes a fifth Y-capacitor C7, a sixth Y-capacitor C8, and a second switch 211 to facilitate better EMC filtering. The values ​​of the fifth Y-capacitor C7 and the sixth Y-capacitor C8 can be determined based on the values ​​of the capacitors and inductors in Example 4, as long as they can eliminate EMC in the circuit.

[0091] The first inductor L1 is connected between the first high-voltage charging terminal 1 and the node p1, the second inductor L3 is connected between the second high-voltage charging terminal 2 and the node p5, and the first Y-capacitor C2 is connected between the node p1 and the node p7. The first capacitor C1 is connected between the node p8 and the node p5, the third inductor L2 is connected between the node p8 and the node p2, the fourth inductor L4 is connected between the node p6 and the node p3, and the second Y-capacitor C3 is connected between the node p6 and the node p7. The node p7 is connected to the ground terminal GND.

[0092] The third Y capacitor C4 is connected between the node p2 and the node p4, the fourth Y capacitor C5 is connected between the node p3 and the node p4, the first switch 210 is connected between the node p4 and the ground terminal GND, the fifth Y capacitor C7 is connected between the node p9 and the node p11, the sixth Y capacitor C8 is connected between the node p10 and the node p11, and the second switch 211 is connected between the node p11 and the ground terminal GND.

[0093] It should be understood that the common-mode filter circuit 110 may include first to fourth inductors L1 to L4, first to second Y capacitors C2 to C3, and a first capacitor C1; the Y capacitor circuit 120 may include third to fourth Y capacitors C4 to C5 and fifth to sixth Y capacitors C7 to C8; and the control circuit 130 may include a first switch 210 and a second switch 211. For a description of the first to fourth inductors L1 to L4, the first to second Y capacitors C2 to C3, the first capacitor C1, and the first switch 210, refer to the detailed descriptions of Embodiments 2 to 5 and are not repeated here due to space limitations.

[0094] During high-voltage charging of the EV via the EVSE, both the first switch 210 and the second switch 211 are opened, thereby disconnecting the third and fourth Y capacitors C4 and C5 from the ground terminal GND, and disconnecting the fifth and sixth Y capacitors C7 and C8 from the ground terminal GND. At this time, the Y capacitors in the circuit include the first Y capacitor C2, the second Y capacitor C3, and the EVSE's own Y capacitor. Compared with a circuit in which the Y capacitors include the first to fourth Y capacitors C2 to C5, the EVSE's own Y capacitor, the fifth Y capacitor C7, and the sixth Y capacitor C8, the Y capacitor value in the circuit is reduced, thereby meeting high-voltage safety requirements.

[0095] Conversely, when the EV is not being charged at high voltage by the EVSE, both the first switch 210 and the second switch 211 are turned on, thereby connecting the third and fourth Y capacitors C4 and C5 to the ground terminal GND, and connecting the fifth and sixth Y capacitors C7 and C8 to the ground terminal GND. This allows common-mode filtering of the EMC circuit via the first to fourth inductors L1 to L4, the first to fourth Y capacitors C2 to C5, the first capacitor C1, the fifth Y capacitor C7, and the sixth Y capacitor C8. In this case, the Y capacitors in the circuit include the first to fourth Y capacitors C2 to C5 and the fifth to sixth Y capacitors C7 and C8. Compared to a circuit in which the Y capacitors include the first and second Y capacitors C2 and C3, the Y capacitor values ​​in the circuit are increased, thereby meeting EMC requirements.

[0096] According to the high-voltage EMC filter circuit of this embodiment, only two switches (first switch 210 and second switch 211) are required to control the four Y capacitors C4-C5 and C7-C8, thereby controlling the Y capacitance value in the circuit. When the electric vehicle is in a high-voltage charging state (i.e., during high-voltage charging of the EV by the EVSE), the first switch 210 is disconnected to disconnect the Y capacitors C4-C5 from the ground terminal GND, and the second switch 211 is disconnected to disconnect the Y capacitors C7-C8 from the ground terminal GND, thereby reducing the Y capacitance value in the circuit and meeting high-voltage safety requirements. This can fundamentally improve the high-voltage safety of the system.

[0097] Since only the third Y capacitor C4, the fourth Y capacitor C5, the fifth Y capacitor C7, the sixth Y capacitor C8, the first switch 210, and the second switch 211 are added to the existing EMC circuit, the newly added components occupy a relatively small area and can be integrated into the existing EMC filter circuit. In addition, the design of this embodiment is flexible and can be easily expanded to other ECUs.

[0098] On the basis of the technical solution described in the third embodiment, the seventh embodiment can be obtained by further expanding the Y capacitor circuit 120 .

[0099] Embodiment seven:

[0100] Referring to FIG8 , a high-voltage EMC filter circuit 800 of this exemplary embodiment may include a first inductor L1, a second inductor L3, first to fourth Y-capacitors C2 to C5, fifth to sixth Y-capacitors C7 to C8, a first switch 210, and a second switch 211. Compared to the high-voltage EMC filter circuit 300 shown in FIG4 , the high-voltage EMC filter circuit 800 shown in FIG8 adds a fifth Y-capacitor C7, a sixth Y-capacitor C8, and a second switch 211 to facilitate better EMC filtering. The values ​​of the fifth Y-capacitor C7 and the sixth Y-capacitor C8 can be determined in accordance with the values ​​of the capacitors and inductors in Example 4, as long as they can eliminate EMC in the circuit.

[0101] The first inductor L1 is connected between the first high-voltage charging terminal 1 and the node p1, the second inductor L3 is connected between the second high-voltage charging terminal 2 and the node p5, the first Y capacitor C2 is connected between the node p1 and the node p7, the second Y capacitor C3 is connected between the node p6 and the node p7, and the node p7 is connected to the ground terminal GND. The third Y capacitor C4 is connected between the node p2 and the node p4, the fourth Y capacitor C5 is connected between the node p3 and the node p4, the first switch 210 is connected between the node p4 and the ground terminal GND, the fifth Y capacitor C7 is connected between the node p9 and the node p11, the sixth Y capacitor C8 is connected between the node p10 and the node p11, and the second switch 211 is connected between the node p11 and the ground terminal GND.

[0102] It should be understood that the common-mode filter circuit 110 may include a first inductor L1, a second inductor L3, a first Y capacitor C2, and a second Y capacitor C3; the Y capacitor circuit 120 may include third to fourth Y capacitors C4 to C5 and fifth to sixth Y capacitors C7 to C8; and the control circuit 130 may include a first switch 210 and a second switch 211. For a description of the first inductor L1, the second inductor L3, the first to fourth Y capacitors C2 to C5, the fifth to sixth Y capacitors C7 to C8, the first switch 210, and the second switch 211, please refer to the detailed descriptions of Embodiments 2 to 6. Due to space limitations, they are not repeated here.

[0103] During high-voltage charging of the EV via the EVSE, both the first switch 210 and the second switch 211 are opened, thereby disconnecting the third and fourth Y capacitors C4 and C5 from the ground terminal GND, and disconnecting the fifth and sixth Y capacitors C7 and C8 from the ground terminal GND. At this time, the Y capacitors in the circuit include the first Y capacitor C2, the second Y capacitor C3, and the EVSE's own Y capacitor. Compared with a circuit in which the Y capacitors include the first to fourth Y capacitors C2 to C5, the fifth to sixth Y capacitors C7 to C8, and the EVSE's own Y capacitor, the Y capacitor value in the circuit is reduced, thereby meeting high-voltage safety requirements.

[0104] Conversely, when the EV is not being charged at high voltage by the EVSE, both the first switch 210 and the second switch 211 are turned on, thereby connecting the third and fourth Y capacitors C4 and C5 to the ground terminal GND, and connecting the fifth and sixth Y capacitors C7 and C8 to the ground terminal GND. This allows common-mode filtering of the EMC circuit via the first inductor L1, the second inductor L3, the first to fourth Y capacitors C2 to C5, and the fifth to sixth Y capacitors C7 to C8. In this case, the Y capacitors in the circuit include the first to fourth Y capacitors C2 to C5 and the fifth to sixth Y capacitors C7 to C8. Compared to a circuit in which the Y capacitors include the first and second Y capacitors C2 and C3, the Y capacitor value in the circuit is increased, thereby meeting EMC requirements.

[0105] According to the high-voltage EMC filter circuit of this embodiment, only two switches (first switch 210 and second switch 211) are required to control the four Y capacitors C4-C5 and C7-C8, thereby controlling the Y capacitance value in the circuit. When the electric vehicle is in a high-voltage charging state (i.e., during high-voltage charging of the EV by the EVSE), the first switch 210 is disconnected to disconnect the Y capacitors C4-C5 from the ground terminal GND, and the second switch 211 is disconnected to disconnect the Y capacitors C7-C8 from the ground terminal GND, thereby reducing the Y capacitance value in the circuit and meeting high-voltage safety requirements. This can fundamentally improve the high-voltage safety of the system.

[0106] Since only the third Y capacitor C4, the fourth Y capacitor C5, the fifth Y capacitor C7, the sixth Y capacitor C8, the first switch 210, and the second switch 211 are added to the existing EMC circuit, the newly added components occupy a relatively small area and can be integrated into the existing EMC filter circuit. In addition, the design of this embodiment is flexible and can be easily expanded to other ECUs.

[0107] On the basis of the technical solution described in the fourth embodiment, the eighth embodiment can be obtained by further expanding the Y capacitor circuit 120 .

[0108] Embodiment 8:

[0109] Referring to FIG. 9 , a high-voltage EMC filter circuit 900 of this exemplary embodiment may include first to fourth inductors L1 to L4, first to fourth Y-capacitors C2 to C5, ninth to tenth Y-capacitors C9 to C10, a first capacitor C1, and a first switch 210. Compared to the high-voltage EMC filter circuit 400 shown in FIG. 5 , the high-voltage EMC filter circuit 900 shown in FIG. 9 adds a ninth Y-capacitor C9 connected in parallel with the third Y-capacitor C4 and a tenth Y-capacitor C10 connected in parallel with the fourth Y-capacitor C5 to facilitate better EMC filtering. The values ​​of the ninth Y-capacitor C9 and the tenth Y-capacitor C10 can be determined in accordance with the values ​​of the capacitors and inductors in the fourth embodiment, as long as they can eliminate EMC in the circuit.

[0110] The first inductor L1 is connected between the first high-voltage charging terminal 1 and the node p1, the second inductor L3 is connected between the second high-voltage charging terminal 2 and the node p5, and the first Y-capacitor C2 is connected between the node p1 and the node p7. The first capacitor C1 is connected between the node p8 and the node p5, the third inductor L2 is connected between the node p8 and the node p2, the fourth inductor L4 is connected between the node p6 and the node p3, and the second Y-capacitor C3 is connected between the node p6 and the node p7. The node p7 is connected to the ground terminal GND.

[0111] The third Y capacitor C4 is connected between the node p13 and the node p14, the fourth Y capacitor C5 is connected between the node p15 and the node p16, the ninth Y capacitor C9 is connected between the node p13 and the node p14, the tenth Y capacitor C10 is connected between the node p15 and the node p16, and the first switch 210 is connected between the node p17 and the ground terminal GND.

[0112] It should be understood that the common-mode filter circuit 110 may include first to fourth inductors L1 to L4, a first capacitor C1, a first Y capacitor C2, and a second Y capacitor C3; the Y capacitor circuit 120 may include a third Y capacitor C4, a fourth Y capacitor C5, a ninth Y capacitor C9, and a tenth Y capacitor C10; and the control circuit 130 may include a first switch 210. For a description of the first to fourth inductors L1 to L4, the first capacitor C1, the first Y capacitor C2, the second Y capacitor C3, and the first switch 210, refer to the detailed descriptions of Embodiments 2 to 8 and are not further elaborated here due to space limitations.

[0113] During high-voltage charging of the EV via the EVSE, the first switch 210 is turned off, thereby disconnecting the third Y capacitor C4, the fourth Y capacitor C5, the ninth Y capacitor C9, and the tenth Y capacitor C10 from the ground terminal GND. At this time, the Y capacitors in the circuit include the first Y capacitor C2, the second Y capacitor C3, and the EVSE's own Y capacitor. Compared with a circuit in which the Y capacitors include the first to fourth Y capacitors C2 to C5, the ninth Y capacitor C9, the tenth Y capacitor C10, and the EVSE's own Y capacitor, the Y capacitor value in the circuit is reduced, thereby meeting high-voltage safety requirements.

[0114] Conversely, when the EV is not being charged at high voltage by the EVSE, the first switch 210 is turned on, thereby connecting the third, fourth, ninth, and tenth Y capacitors C4, C5, C9, and C10 to the ground terminal GND. This allows common-mode filtering of the EMC circuit via the first to fourth inductors L1 to L4, the first to fourth Y capacitors C2 to C5, the first capacitor C1, the ninth Y capacitor C9, and the tenth Y capacitor C10. In this case, the Y capacitors in the circuit include the first to fourth Y capacitors C2 to C5, the ninth Y capacitor C9, and the tenth Y capacitor C10. Compared to a circuit in which the Y capacitors include the first and second Y capacitors C2 and C3, the Y capacitors in the circuit have a larger value, thereby meeting EMC requirements.

[0115] According to this embodiment of the high-voltage EMC filter circuit, only one switch (first switch 210) is required to control the four Y capacitors C4-C5 and C9-C10, thereby controlling the Y capacitance value in the circuit. When the electric vehicle is in a high-voltage charging state (i.e., during high-voltage charging by the EVSE), the first switch 210 is disconnected, disconnecting the Y capacitors C4-C5 and C9-C10 from the ground terminal GND. This reduces the Y capacitance value in the circuit and thus meets high-voltage safety requirements. This fundamentally improves the high-voltage safety of the system.

[0116] Since only the third Y capacitor C4, the ninth Y capacitor C9, the tenth Y capacitor C10, and the first switch 210 are added to the existing EMC circuit, the newly added components occupy a relatively small area and can be integrated into the existing EMC filter circuit. In addition, the design of this embodiment is flexible and can be easily expanded to other ECUs.

[0117] It should be noted that, in the first to eighth embodiments, the technical solution of the present invention is described by taking the high-voltage EMC filter circuit applied to the EPU as an example. However, the present invention is not limited thereto. It should be understood that the high-voltage EMC filter circuit of the present invention can also be applied to other circuits in the vehicle that require EMC filtering and high-voltage charging, such as DC / DC circuits.

[0118] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A high voltage electromagnetic compatibility (EMC) filter circuit, characterized in that: include: A common mode filter circuit (110) comprising a first terminal, a second terminal, a third terminal and a fourth terminal, wherein the first terminal and the second terminal are respectively connected to a first high voltage charging terminal (1) and a second high voltage charging terminal (2) of an electric vehicle power supply equipment (EVSE), and the fourth terminal is connected to a ground terminal (GND); A Y capacitor circuit (120), comprising a fifth terminal and a sixth terminal, wherein the fifth terminal is connected to the third terminal; as well as a control circuit (130) comprising a seventh terminal and an eighth terminal, the seventh terminal being connected to the sixth terminal, and the eighth terminal being connected to the ground terminal, Wherein, during the period of high-voltage charging of the electric vehicle via the EVSE, the control circuit disconnects the connection between the Y capacitor circuit and the ground terminal; During a period when the electric vehicle is not charged with high voltage by the EVSE, the control circuit connects the Y capacitor circuit to the ground terminal to perform EMC filtering via the common mode filter circuit and the Y capacitor circuit.

2. The high voltage EMC filter circuit according to claim 1, characterized in that: The control circuit comprises: a first switch (210), two ends of which are connected to the sixth terminal and the ground terminal respectively, Wherein, during the period of high-voltage charging of the electric vehicle via the EVSE, the first switch is disconnected; During a period when the electric vehicle is not charged with high voltage by the EVSE, the first switch is turned on.

3. The high voltage EMC filter circuit according to claim 2, characterized in that: The on and off of the first switch is controlled by the power electronic unit PEU according to whether it is operating in charging mode. The PEU turns off the first switch when the PEU operates in the charging mode, and turns on the first switch when the PEU operates in a mode other than the charging mode.

4. The high voltage EMC filter circuit according to claim 2, characterized in that: The Y capacitor circuit comprises: a third Y capacitor (C4), two ends of which are connected to the first high-voltage charging terminal and the first switch respectively; and A fourth Y capacitor (C5), two ends of which are connected to the second high-voltage charging terminal and the first switch respectively.

5. The high voltage EMC filter circuit according to claim 4, characterized in that: The common mode filter circuit includes a first inductor (L1), a second inductor (L3), a first Y capacitor (C2) and a second Y capacitor (C3). The first inductor and the first Y capacitor are connected in series between the first high-voltage charging terminal and the ground terminal, and the second inductor and the second Y capacitor are connected in series between the second high-voltage charging terminal and the ground terminal.

6. The high voltage EMC filter circuit according to claim 5, characterized in that: The common mode filter circuit further includes a first capacitor (C1), a third inductor (L2) and a fourth inductor (L4). The first inductor, the third inductor, the third Y capacitor, and the first switch are connected in series between the first high-voltage charging terminal and the ground terminal. The second inductor, the fourth inductor, the fourth Y capacitor, and the first switch are connected in series between the second high-voltage charging terminal and the ground terminal. Two ends of the first capacitor are connected to a first node and a second node respectively. The first node is an intersection point between the first inductor and the third inductor, and the second node is an intersection point between the second inductor and the fourth inductor.

7. The high voltage EMC filter circuit according to claim 6, characterized in that: The common mode filtering circuit further includes a second capacitor (C6), a fifth inductor (L5) and a sixth inductor (L6). The first inductor, the third inductor, the fifth inductor, the third Y capacitor, and the first switch are connected in series between the first high-voltage charging terminal and the ground terminal. The second inductor, the fourth inductor, the sixth inductor, the fourth Y capacitor, and the first switch are connected in series between the second high-voltage charging terminal and the ground terminal. Two ends of the second capacitor are connected to a third node and a fourth node respectively. The third node is an intersection point between the third inductor and the fifth inductor, and the fourth node is an intersection point between the fourth inductor and the sixth inductor.

8. The high voltage EMC filter circuit according to claim 6, characterized in that: The Y capacitor circuit further includes a fifth Y capacitor (C7) and a sixth Y capacitor (C8), and the control circuit further includes a second switch (211), The first inductor, the third inductor, the fifth Y capacitor, and the second switch are connected in series between the first high-voltage charging terminal and the ground terminal. The second inductor, the fourth inductor, the sixth Y capacitor, and the second switch are connected in series between the second high-voltage charging terminal and the ground terminal.

9. The high voltage EMC filter circuit according to claim 5, characterized in that: The Y capacitor circuit further includes a fifth Y capacitor (C7) and a sixth Y capacitor (C8), and the control circuit further includes a second switch (211), The first inductor, the fifth Y capacitor, and the second switch are connected in series between the first high-voltage charging terminal and the ground terminal. The second inductor, the sixth Y capacitor, and the second switch are connected in series between the second high-voltage charging terminal and the ground terminal.

10. The high voltage EMC filter circuit according to claim 6, characterized in that: The Y capacitor circuit further includes a ninth Y capacitor (C9) and a tenth Y capacitor (C10), The ninth Y capacitor is connected in parallel with the third Y capacitor between the third inductor and the first switch. The tenth Y capacitor is connected in parallel with the fourth Y capacitor between the fourth inductor and the first switch.

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