A high-voltage filter, motor control system and vehicle

Abstract

This invention discloses a high-voltage filter, a motor control system, and a vehicle, comprising: first and second capacitor filter circuits, a common-mode magnetic ring, an interference coupling coil, a voltage processing circuit, a power amplifier circuit, and a modulation coil. The common-mode magnetic ring is simultaneously mounted outside the positive and negative copper busbars and located between the first and second capacitor filter circuits. The interference coupling coil is also simultaneously mounted outside the positive and negative copper busbars and is located close to the output terminals of the positive and negative copper busbars. The second capacitor filter circuit is located between the common-mode magnetic ring and the interference coupling coil. One end of the interference coupling coil is connected to the input terminal of the voltage processing circuit, and the other end is connected to the first input terminal of the power amplifier circuit. The output terminal of the voltage processing circuit is connected to the second input terminal of the power amplifier circuit. The two output terminals of the power amplifier circuit are respectively connected to the two ends of the modulation coil, which is wound around the common-mode magnetic ring. Using this invention can enhance the filtering effect, reduce size, and lighten weight.

Description

Technical Field

[0001] This invention belongs to the field of electromagnetic interference filters, specifically relating to a high-voltage filter, a motor control system, and a vehicle. Background Technology

[0002] When a motor controller is operating, the switching of its internal power devices generates significant electromagnetic interference, affecting its own stability and that of surrounding equipment. Furthermore, it may fail to meet electromagnetic compatibility (EMC) standards. Therefore, a high-voltage filter is a critical component. Currently, all high-voltage filter solutions used in motor control systems have shortcomings, making it difficult to balance filtering effectiveness, size, cost, and practicality. A detailed analysis follows:

[0003] The first type is the most widely used passive filter solution using a magnetic ring and capacitor. A common-mode inductor / magnetic ring is inserted in series on the DC bus or filter path, along with Y and X capacitors for filtering. This solution has fixed parameters and a narrow filtering bandwidth. To cope with wide-frequency interference, different materials are needed for the magnetic ring / common-mode inductor, resulting in a large filter size, large space occupation, and large weight, which is not conducive to miniaturization and lightweight design.

[0004] The second approach adds an adjustable Y-capacitor switching mechanism to the first approach, adapting to different interference sources by switching the Y-capacitors. However, this requires adding a Y-capacitor bank and switching circuit, leading to increased size and cost. Furthermore, simply switching the Y-capacitors has limited interference attenuation, resulting in limited filtering effectiveness.

[0005] The third approach is a multi-filter switching scheme, which configures corresponding filters for different types of interference. This scheme is complex in structure, costly, and has cumbersome switching logic, making it inconvenient for practical applications and impractical.

[0006] The fourth method involves collecting interference using induction coils, calculating the frequency, and then selecting the array capacitor value for filtering based on the frequency. This method is only suitable for low-power applications; its effect is weak in high-power applications. Furthermore, similar to the second and third methods, designing high-power filters still presents problems such as large size, high cost, and complex structure.

[0007] In summary, existing high-voltage filter solutions all have shortcomings, cannot meet multiple requirements, and are difficult to adapt to the needs of motor control systems. Summary of the Invention

[0008] In view of the shortcomings of the prior art, the purpose of this invention is to provide a high-voltage filter, a motor control system and a vehicle to enhance the filtering effect, reduce the size and weight.

[0009] In a first aspect, the present invention provides a high-voltage filter, comprising a first capacitor filter circuit, a second capacitor filter circuit, and a common-mode magnetic ring. The two ends of the first capacitor filter circuit are respectively connected to the input end of the positive copper busbar and the input end of the negative copper busbar. The two ends of the second capacitor filter circuit are respectively connected to the output end of the positive copper busbar and the output end of the negative copper busbar. The common-mode magnetic ring is simultaneously fitted outside the positive and negative copper busbars (i.e., the positive and negative copper busbars pass through the central hole of the common-mode magnetic ring) and is located between the first capacitor filter circuit and the second capacitor filter circuit. The high-voltage filter also includes an interference coupling coil, a voltage processing circuit, a power amplifier circuit, and a modulation coil. The interference coupling coil is simultaneously mounted outside the positive and negative copper busbars (i.e., the positive and negative copper busbars pass through the central hole of the interference coupling coil) and is close to the output terminals of the positive and negative copper busbars. The second capacitor filter circuit is located between the common-mode magnetic ring and the interference coupling coil (i.e., the interference coupling coil is located behind the second capacitor filter circuit, closer to the output terminals of the positive and negative copper busbars). One end of the interference coupling coil is connected to the input terminal of the voltage processing circuit, and the other end is connected to the first input terminal of the power amplifier circuit. The output terminal of the voltage processing circuit is connected to the second input terminal of the power amplifier circuit. The two output terminals of the power amplifier circuit are respectively connected to the two ends of the modulation coil, which is wound around the common-mode magnetic ring.

[0010] The interference coupling coil is simultaneously mounted outside the positive and negative copper busbars and positioned close to the output end. It can couple and acquire residual common-mode / differential-mode interference signals on high-voltage lines in real time, ensuring the real-time performance and accuracy of interference signal acquisition without damaging the original electrical connections and insulation structure of the high-voltage lines. A second capacitor filter circuit is placed between the common-mode magnetic ring and the interference coupling coil. This allows the pre-stage filtering unit (i.e., the first and second capacitor filter circuits and the common-mode magnetic ring) to filter out most of the strong interference signals, reducing the signal acquisition load on the interference coupling coil and preventing saturation distortion in subsequent processing circuits due to strong interference. Simultaneously, it brings the interference coupling coil closer to the line output end, improving the accuracy of residual interference acquisition. The interference coupling coil transmits the acquired interference signals to the voltage processing circuit and the power amplifier circuit respectively. After the voltage processing circuit performs phase inversion adaptation on the interference signal, it is input to the power amplifier circuit. The power amplifier circuit then boosts the power of the interference signal, enabling precise amplitude and phase control of the interference signal. The power amplifier circuit outputs the processed signal to a modulation coil wound on a common-mode magnetic ring. This generates a compensation magnetic field on the common-mode magnetic ring that has the same frequency, opposite phase, and matched amplitude as the residual interference in the line. The compensation magnetic field increases the magnetic flux of the common-mode magnetic ring, thereby increasing its inductive reactance. Through magnetic coupling, it actively cancels the residual electromagnetic interference in the high-voltage line (i.e., the positive and negative copper busbars), achieving a composite filtering effect that combines passive filtering and active compensation. This significantly improves the interference suppression depth and dynamic filtering performance of the high-voltage filter, enhancing the filtering effect. The overall design adopts a copper busbar through-type structure, coaxially packaged with the common-mode magnetic ring and interference coupling coil. The structure is compact and the electrical connections are simple, making it suitable for high-voltage, high-power circuits while reducing size and weight.

[0011] Optionally, the interference coupling coil is a helical coil, which is made by winding a single wire with multiple winding radii, equivalent to the interference coupling coil being composed of multiple coils with different winding radii connected in series.

[0012] By setting the interference coupling coil as a helical coil, and making it by winding a single wire with multiple winding radii, the interference coupling coil is structurally equivalent to multiple coils with different winding radii connected in series. Thus, without increasing the number of additional coils or connection nodes, it achieves multi-resonance point suppression of interference signals in different frequency bands, expands the effective coupling bandwidth of the interference coupling coil, and improves the coupling and acquisition capability of wide-frequency interference signals.

[0013] Optionally, the interference coupling coil is a helical coil, which is made by winding a single wire with three winding radii, which is equivalent to the interference coupling coil being composed of three coils with different winding radii connected in series.

[0014] By defining the interference coupling coil as a helical coil and using a single wire wound with three winding radii, the coil is equivalent to three coils with different winding radii connected in series. Without adding independent coils or wiring nodes, three resonant frequency points are formed, which can specifically cover the typical interference frequency band of high-voltage lines. This enables efficient coupling and acquisition of residual interference signals in different frequency bands of medium, high and low frequencies within a wide frequency range, improving the frequency band adaptability and signal strength of interference pickup.

[0015] Optionally, the voltage processing circuit is an inverting voltage follower, which includes resistors R11, R12, R13 and operational amplifier U2. One end of resistor R12 (as the input terminal of the voltage processing circuit) is connected to one end of the interference coupling coil, and the other end of resistor R12 is connected to one end of resistor R11 and the inverting input terminal of operational amplifier U2. One end of resistor R13 is connected to power supply VCC2, and the other end is connected to the non-inverting input terminal of operational amplifier U2. The other end of resistor R11 is connected to the output terminal of operational amplifier U2, and the output terminal of operational amplifier U2 (as the output terminal of the voltage processing circuit) is connected to the second input terminal of the power amplifier circuit.

[0016] The voltage processing circuit consists of resistors R11, R12, and R13 and operational amplifier U2. Resistors R12 and R11 are voltage follower resistors for operational amplifier U2, forming a proportional feedback branch (amplification factor of 1). Resistor R13 is a current-limiting resistor. This voltage processing circuit can perform high input impedance acquisition and low output impedance buffering of the interference signal picked up by the interference coupling coil. It effectively isolates the front-stage coupling coil from the subsequent power amplifier circuit, avoiding the impact of the load effect of the subsequent circuit on the accuracy of interference signal acquisition, and ensuring the true transmission of the interference signal amplitude and the transmission of the opposite phase to the interference signal.

[0017] Optionally, the power amplifier circuit includes a first voltage amplification module, a second voltage amplification module, a first current amplification module, and a second current amplification module. The input terminal of the first voltage amplification module serves as the first input terminal of the power amplifier circuit. The output terminal of the first voltage amplification module is connected to the input terminal of the first current amplification module. The output terminal of the first current amplification module serves as the first output terminal of the power amplifier circuit and is connected to the feedback terminal of the first voltage amplification module. The input terminal of the second voltage amplification module serves as the second input terminal of the power amplifier circuit. The output terminal of the second voltage amplification module is connected to the input terminal of the second current amplification module. The output terminal of the second current amplification module serves as the second output terminal of the power amplifier circuit and is connected to the feedback terminal of the second voltage amplification module.

[0018] The power amplifier circuit, by incorporating a first voltage amplification module, a second voltage amplification module, a first current amplification module, and a second current amplification module, and by forming closed-loop feedback loops for the two amplification modules, enables graded voltage amplification and current drive of the input signal, significantly improving the output drive capability and meeting the power requirements for the modulation coil excitation. The first voltage amplification module directly receives the interference signal coupled by the interference coupling coil, while the second voltage amplification module receives an interference signal with opposite phase and same amplitude, processed by an inverting voltage follower. This allows the power amplifier circuit to output a pair of differential drive signals applied to the modulation coil, forming a stronger and directionally controllable compensating magnetic field on the common-mode magnetic ring, enhancing the active cancellation effect against residual common-mode interference from high-voltage lines.

[0019] Optionally, the first voltage amplification module includes resistors R1, R2, R3 and operational amplifier U1. One end of resistor R1 serves as the input terminal of the first voltage amplification module (connected to the other end of the interference coupling coil), and the other end of resistor R1 is connected to one end of resistor R3 and the inverting input terminal of operational amplifier U1. One end of resistor R2 is connected to power supply VCC2, and the other end is connected to the non-inverting input terminal of operational amplifier U1. The other end of resistor R3 serves as the feedback terminal of the first voltage amplification module, and the output terminal of operational amplifier U1 serves as the output terminal of the first voltage amplification module.

[0020] Optionally, the first current amplification module includes: resistors R4, R5, R6, R7, R8, and R9; diodes D1 and D2; and transistors Q1 and Q2. The cathode of diode D1 and the anode of diode D2 are connected and serve as the input terminal of the first current amplification module (connected to the output terminal of operational amplifier U1). The anode of diode D1 is connected to one end of resistor R4. The other end of resistor R4 is connected to the base of transistor Q1 and one end of resistor R5. The other end of resistor R5 and the collector of transistor Q1 are connected to power supply VCC1. The emitter of transistor Q1 is connected to one end of resistor R6. The other end of resistor R6 is connected to one end of resistor R7 and serves as the output terminal of the first current amplification module (connected to one end of the modulation coil). The other end of resistor R7 is connected to the collector of transistor Q2. The emitter of transistor Q2 is grounded. One end of resistor R9 is grounded, and the other end is connected to the base of transistor Q2 and one end of resistor R8. The other end of resistor R8 is connected to the cathode of diode D2.

[0021] The first voltage amplification module employs an inverting proportional amplifier structure composed of resistors R1, R2, and R3 and operational amplifier U1. This structure provides stable and linear voltage amplification of the interference signal acquired by the interference coupling coil. A DC bias is provided via resistor R2 connected to power supply VCC2. Simultaneously, the proportional amplification branch formed by resistors R1 and R3 ensures precise gain adjustment, guaranteeing stable output signal amplitude and controllable phase, and providing a standard drive signal for the first current amplification module. The first current amplification module uses a push-pull current amplification topology composed of transistors Q1 and Q2, diodes D1 and D2, and a resistor network. This efficiently converts the preceding voltage signal into a high-current drive signal, significantly improving the load-carrying capacity and excitation drive capability of the modulation coil, meeting the power requirements for the modulation coil to establish a compensation magnetic field in real time. The bias structure formed by diodes D1 and D2 effectively eliminates crossover distortion generated by transistors Q1 and Q2 in the crossover region, resulting in a continuous and smooth current amplification output. This ensures the waveform integrity and phase accuracy of the drive signal, thereby improving the stability of the compensation magnetic field on the common-mode magnetic ring. Resistors R4, R5, R8, and R9 respectively constitute base bias and current limiting protection, while resistors R6 and R7 are output current limiting resistors to prevent excessive output current.

[0022] Optionally, the second voltage amplification module includes resistors R10, R14, R15 and operational amplifier U3. One end of resistor R14 serves as the input terminal of the second voltage amplification module (connected to the output terminal of the voltage processing circuit), and the other end of resistor R14 is connected to one end of resistor R10 and the inverting input terminal of operational amplifier U3. One end of resistor R15 is connected to the other end of resistor R13, and the other end of resistor R15 is connected to the non-inverting input terminal of operational amplifier U3. The other end of resistor R10 serves as the feedback terminal of the second voltage amplification module, and the output terminal of operational amplifier U3 serves as the output terminal of the second voltage amplification module.

[0023] Optionally, the second current amplification module includes: resistors R16, R17, R18, R19, R20, and R21; diodes D3 and D4; and transistors Q3 and Q4. The cathode of diode D3 and the anode of diode D4 are connected and serve as the input terminal of the second current amplification module (connected to the output terminal of operational amplifier U3). The anode of diode D3 is connected to one end of resistor R16, and the other end of resistor R16 is connected to the base of transistor Q3 and one end of resistor R17. The other end of resistor R17 is connected to... The collector of transistor Q3 is connected to power supply VCC1. The emitter of transistor Q3 is connected to one end of resistor R18. The other end of resistor R18 is connected to one end of resistor R19 and serves as the output terminal of the second current amplification module (connected to the other end of the modulation coil). The other end of resistor R19 is connected to the collector of transistor Q4. The emitter of transistor Q4 is grounded. One end of resistor R21 is grounded, and the other end is connected to the base of transistor Q4 and one end of resistor R20. The other end of resistor R20 is connected to the cathode of diode D4.

[0024] The second voltage amplification module uses resistors R10, R14, and R15 to form an inverting proportional amplifier circuit with operational amplifier U3. Its non-inverting input terminal shares the same bias potential with resistor R13 in the voltage processing circuit through resistor R15, enabling both voltage amplification modules to maintain a consistent DC operating point. The proportional amplification branch formed by resistors R14 and R10 allows for linear and stable amplitude adjustment of the interference reference signal output from the voltage processing circuit, ensuring a regular output signal waveform and accurate phase, providing a low-distortion, highly stable voltage drive signal for the second current amplification module. The second current amplification module employs a push-pull current amplification topology composed of transistors Q3 and Q4, diodes D3 and D4, and a resistor network. This efficiently converts the preceding voltage signal into a high-current drive signal, significantly improving the load-carrying capacity and excitation drive capability of the modulation coil, meeting the power requirements for the modulation coil to establish a compensation magnetic field in real time. The bias structure formed by diodes D3 and D4 effectively eliminates the crossover distortion generated by transistors Q3 and Q4 in the crossover region, making the current amplification output continuous and smooth, ensuring the waveform integrity and phase accuracy of the drive signal, and thus improving the stability of the compensation magnetic field on the common-mode magnetic ring. Resistors R16, R17, R20, and R21 respectively constitute base bias and current limiting protection, while resistors R18 and R19 are output current limiting resistors to prevent excessive output current.

[0025] Optionally, the first capacitor filter circuit includes capacitors Y1, Y2, and X1. One end of capacitor Y1 is connected to the input terminal of the positive copper busbar, and the other end is grounded. One end of capacitor Y2 is connected to the input terminal of the negative copper busbar, and the other end is grounded. One end of capacitor X1 is connected to the input terminal of the positive copper busbar, and the other end is connected to the input terminal of the negative copper busbar. The second capacitor filter circuit includes capacitors Y3, Y4, and X2. One end of capacitor Y3 is connected to the output terminal of the positive copper busbar, and the other end is grounded. One end of capacitor Y4 is connected to the output terminal of the negative copper busbar, and the other end is grounded. One end of capacitor X2 is connected to the output terminal of the positive copper busbar, and the other end is connected to the output terminal of the negative copper busbar.

[0026] The first capacitor filter circuit uses capacitors Y1 and Y2 to form a Y-capacitor network with a path to ground, and works in conjunction with capacitor X1 connected between the positive and negative copper busbar input terminals. This provides primary bypass discharge for both common-mode and differential-mode interference at the high-voltage circuit input, blocking external conducted interference from entering subsequent circuits and improving the electromagnetic compatibility performance at the input. The second capacitor filter circuit uses capacitors Y3 and Y4 with the same topology to form common-mode and differential-mode filter branches with X2, respectively. This provides secondary bypass absorption for interference signals remaining after the previous stage filtering and magnetic ring suppression, further reducing the amplitude of residual interference at the output. This achieves two-stage synergistic filtering, broadening the interference suppression bandwidth and increasing the overall filtering depth. The symmetrical capacitor filter layout of the two stages ensures balanced suppression of interference signals on the positive and negative copper busbars, reducing additional common-mode interference caused by line asymmetry.

[0027] Secondly, the present invention provides a motor control system, which includes the aforementioned high-voltage filter.

[0028] Thirdly, the present invention provides a vehicle that includes the aforementioned motor control system. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the circuit principle of the high-voltage filter in an embodiment of the present invention.

[0030] Figure 2 This is a schematic diagram of the modulation coil wound on a common-mode magnetic ring in an embodiment of the present invention.

[0031] Figure 3 This is a schematic diagram showing the interference coupling coils wrapped around the positive and negative copper busbars in an embodiment of the present invention.

[0032] Figure 4 This is an equivalent schematic diagram of the common-mode magnetic ring and the modulation coil in an embodiment of the present invention.

[0033] Figure 5 This is a schematic diagram of the equivalent multi-winding radius of the interference coupling coil in an embodiment of the present invention.

[0034] Figure 6 This is a circuit diagram of the interference coupling coil, voltage processing circuit, power amplification circuit, and modulation coil in an embodiment of the present invention. Detailed Implementation

[0035] To gain a more detailed understanding of the features and technical content of the embodiments of the present invention, the implementation of the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for reference and illustration only and are not intended to limit the embodiments of the present invention.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing embodiments of the invention only and is not intended to limit the invention.

[0037] In the following description, references are made to “some embodiments,” which describe a subset of all possible embodiments. However, it is understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0038] like Figures 1 to 6As shown, the high-voltage filter in this embodiment of the invention includes a first capacitor filter circuit 1, a second capacitor filter circuit 2, a common-mode magnetic ring 3, an interference coupling coil 6, a voltage processing circuit 7, a power amplifier circuit 8, and a modulation coil 9. The two ends of the first capacitor filter circuit 1 are connected to the input terminals (IN+) of the positive copper busbar 4 and (IN-) of the negative copper busbar 5, respectively. The two ends of the second capacitor filter circuit 2 are connected to the output terminals (OUT+) of the positive copper busbar 4 and (OUT-) of the negative copper busbar 5, respectively. The common-mode magnetic ring 3 is simultaneously fitted around the positive copper busbar 4 and the negative copper busbar 5 (i.e., the positive copper busbar 4 and the negative copper busbar 5 both pass through the central hole of the common-mode magnetic ring 3). The common-mode magnetic ring 3 is located between the first capacitor filter circuit 1 and the second capacitor filter circuit 2. Interference coupling coil 6 is simultaneously mounted outside positive copper busbar 4 and negative copper busbar 5 (i.e., positive copper busbar 4 and negative copper busbar 5 both pass through the center hole of interference coupling coil 6). Interference coupling coil 6 is close to the output terminals of positive copper busbar 4 and negative copper busbar 5. The second capacitor filter circuit 2 is located between common mode magnetic ring 3 and interference coupling coil 6. One end of interference coupling coil 6 is connected to the input terminal of voltage processing circuit 7, and the other end is connected to the first input terminal of power amplifier circuit 8. The output terminal of voltage processing circuit 7 is connected to the second input terminal of power amplifier circuit 8. The two output terminals of power amplifier circuit 8 are respectively connected to the two ends of modulation coil 9. Modulation coil 9 is wound on common mode magnetic ring 3.

[0039] In some embodiments, such as Figure 5 As shown, the interference coupling coil 6 is a helical coil, made by winding a single wire with three different radii. This is equivalent to the interference coupling coil 6 being composed of three coils with different radii connected in series. Figure 5 The interference coupling coil 6 is constructed by connecting a first coil 61 with a winding radius of R1, a second coil 62 with a winding radius of R2, and a third coil 63 with a winding radius of R3 in series. For example, the first coil 61 is wound 10 turns continuously with a winding radius of R1, the second coil 62 is wound 10 turns continuously with a winding radius of R2, and the third coil 63 is wound 10 turns continuously with a winding radius of R3, forming an approximate circle with two connecting ends, thus forming the interference coupling coil 6. The winding radius can be determined through electromagnetic simulation and theoretical calculation. To improve the interference coupling capability at a certain frequency, a larger number of turns can be wound according to the winding radius corresponding to that frequency.

[0040] In some embodiments, such as Figure 1As shown, the first capacitor filter circuit 1 includes capacitors Y1, Y2, and X1. One end of capacitor Y1 is connected to the input terminal of the positive copper busbar 4, and the other end of capacitor Y1 is grounded. One end of capacitor Y2 is connected to the input terminal of the negative copper busbar 5, and the other end of capacitor Y2 is grounded. One end of capacitor X1 is connected to the input terminal of the positive copper busbar 4, and the other end of capacitor X1 is connected to the input terminal of the negative copper busbar 5. The second capacitor filter circuit 2 includes capacitors Y3, Y4, and X2. One end of capacitor Y3 is connected to the output terminal of the positive copper busbar 4, and the other end of capacitor Y3 is grounded. One end of capacitor Y4 is connected to the output terminal of the negative copper busbar 5, and the other end of capacitor Y4 is grounded. One end of capacitor X2 is connected to the output terminal of the positive copper busbar 4, and the other end of capacitor X2 is connected to the output terminal of the negative copper busbar 5.

[0041] In some embodiments, such as Figure 6 As shown, the voltage processing circuit 7 is an inverting voltage follower, which includes resistors R11, R12, R13 and operational amplifier U2. One end of resistor R12 is connected to one end of interference coupling coil 6 (i.e., NI2), and the other end of resistor R12 is connected to one end of resistor R11 and the inverting input terminal of operational amplifier U2. One end of resistor R13 is connected to power supply VCC2, and the other end of resistor R13 is connected to the non-inverting input terminal of operational amplifier U2. The other end of resistor R11 is connected to the output terminal of operational amplifier U2. The output terminal of operational amplifier U2 is connected to the second input terminal of power amplifier circuit 8. The ground terminal of operational amplifier U2 is grounded, and the power supply terminal of operational amplifier U2 is connected to power supply VCC1.

[0042] In some embodiments, such as Figure 6 As shown, the power amplifier circuit 8 includes a first voltage amplification module 81, a second voltage amplification module 82, a first current amplification module 83, and a second current amplification module 84. The input terminal of the first voltage amplification module 81 serves as the first input terminal of the power amplifier circuit 8. The output terminal of the first voltage amplification module 81 is connected to the input terminal of the first current amplification module 83. The output terminal of the first current amplification module 83 serves as the first output terminal of the power amplifier circuit 8 and is connected to the feedback terminal of the first voltage amplification module 81. The input terminal of the second voltage amplification module 82 serves as the second input terminal of the power amplifier circuit 8. The output terminal of the second voltage amplification module 82 is connected to the input terminal of the second current amplification module 84. The output terminal of the second current amplification module 84 serves as the second output terminal of the power amplifier circuit 8 and is connected to the feedback terminal of the second voltage amplification module 82.

[0043] In some embodiments, such as Figure 6As shown, the first voltage amplification module 81 includes resistors R1, R2, and R3 and operational amplifier U1. The first current amplification module 83 includes resistors R4, R5, R6, R7, R8, and R9, diodes D1 and D2, and transistors Q1 and Q2. One end of resistor R1 serves as the input terminal of the first voltage amplification module 81 and is connected to the other end (i.e., NI1) of the interference coupling coil 6. The other end of resistor R1 is connected to one end of resistor R3 and the inverting input terminal of operational amplifier U1. One end of resistor R2 is connected to power supply VCC2, and the other end of resistor R2 is connected to the non-inverting input terminal of operational amplifier U1. The other end of resistor R3 serves as the feedback terminal of the first voltage amplification module 81. The ground terminal of operational amplifier U1 is grounded, and the power supply terminal of operational amplifier U1 is connected to power supply VCC1. The output terminal of operational amplifier U1 serves as the output terminal of the first voltage amplification module 81, connected to the cathode of diode D1 and the anode of diode D2. The anode of diode D1 is connected to one end of resistor R4, the other end of resistor R4 is connected to the base of transistor Q1 and one end of resistor R5, the other end of resistor R5 and the collector of transistor Q1 are connected to power supply VCC1, the emitter of transistor Q1 is connected to one end of resistor R6, the other end of resistor R6 is connected to one end of resistor R7 and serves as the output terminal (i.e., OUT1) of the first current amplification module 83, connected to the other end of resistor R3 and one end of modulation coil 9, the other end of resistor R7 is connected to the collector of transistor Q2, the emitter of transistor Q2 is grounded, one end of resistor R9 is grounded, the other end is connected to the base of transistor Q2 and one end of resistor R8, and the other end of resistor R8 is connected to the cathode of diode D2.

[0044] In some embodiments, such as Figure 6As shown, the second voltage amplification module 82 includes resistors R10, R14, and R15 and operational amplifier U3. The second current amplification module 84 includes resistors R16, R17, R18, R19, R20, and R21, diodes D3 and D4, and transistors Q3 and Q4. One end of resistor R14 serves as the input terminal of the second voltage amplification module 82, connected to the output terminal of operational amplifier U2. The other end of resistor R14 is connected to one end of resistor R10 and the inverting input terminal of operational amplifier U3. One end of resistor R15 is connected to the other end of resistor R13, and the other end of resistor R15 is connected to the non-inverting input terminal of operational amplifier U3. The other end of resistor R10 serves as the feedback terminal of the second voltage amplification module 82. The ground terminal of operational amplifier U3 is grounded, and the power supply terminal of operational amplifier U3 is connected to power supply VCC1. The output terminal of operational amplifier U3 serves as the output terminal of the second voltage amplification module 82, connected to the cathode of diode D3 and the anode of diode D4. The anode of diode D3 is connected to one end of resistor R16, the other end of resistor R16 is connected to the base of transistor Q3 and one end of resistor R17, the other end of resistor R17 and the collector of transistor Q3 are connected to power supply VCC1, the emitter of transistor Q3 is connected to one end of resistor R18, the other end of resistor R18 is connected to one end of resistor R19 and serves as the output terminal (i.e., OUT2) of the second current amplification module 84, connected to the other end of resistor R10, the other end of resistor R19 is connected to the collector of transistor Q4, the emitter of transistor Q4 is grounded, one end of resistor R21 is grounded, the other end is connected to the base of transistor Q4 and one end of resistor R20, the other end of resistor R20 is connected to the cathode of diode D4.

[0045] The working principle of the above high-voltage filter is as follows: The high-voltage signal is input from the input terminal (IN+) of the positive copper busbar 4 and the input terminal (IN-) of the negative copper busbar 5. After being filtered by the first capacitor filter circuit 1, the second capacitor filter circuit 2, and the common-mode magnetic ring 3, the high-voltage signal with common-mode interference generates a ring magnetic field around the positive copper busbar 4 and the negative copper busbar 5 when it passes through the interference coupling coil 6. The magnetic lines of force passing through the interference coupling coil 6 will generate an induced voltage. One path of the induced voltage is input to the voltage processing circuit 7, which is inverted before being input to the power amplifier circuit 8. The other path of the induced voltage is directly input to the power amplifier circuit 8 for power amplification. The two differential signals after power amplification are input to the modulation coil 9, where a modulation current is generated (the frequency of the modulation current is the same as the frequency of the interference signal). The equivalent inductance at the common-mode magnetic ring increases (from the inductance of the common-mode magnetic ring alone to the inductance of the common-mode magnetic ring plus the inductance of the modulation coil, see [reference]). Figure 4 Therefore, increasing the inductive reactance at the common-mode magnetic ring can reduce the amplitude of the output interference, thereby achieving a filtering effect. Since the bandwidth of existing automotive-grade operational amplifiers can reach 250MHz and the characteristic frequency of transistors can reach 400MHz, it is sufficient to solve the common-mode interference problem on the motor control input copper busbars (i.e., positive and negative copper busbars), and the solution has high benefits.

[0046] In addition, embodiments of the present invention also provide a motor control system, which includes the aforementioned high-voltage filter.

[0047] In addition, embodiments of the present invention also provide a vehicle that includes the above-described motor control system.

[0048] 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 variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A high-voltage filter comprising a first capacitive filter circuit (1), a second capacitive filter circuit (2) and a common-mode magnetic ring (3), two ends of the first capacitive filter circuit (1) being connected with an input end of a positive copper bar (4) and an input end of a negative copper bar (5) respectively, two ends of the second capacitive filter circuit (2) being connected with an output end of the positive copper bar (4) and an output end of the negative copper bar (5) respectively, the common-mode magnetic ring (3) being sleeved on the outside of the positive copper bar (4) and the negative copper bar (5) and located between the first capacitive filter circuit (1) and the second capacitive filter circuit (2); characterized in that: It also includes an interference coupling coil (6), a voltage processing circuit (7), a power amplifier circuit (8), and a modulation coil (9). The interference coupling coil (6) is simultaneously mounted outside the positive copper busbar (4) and the negative copper busbar (5), and is close to the output terminals of the positive copper busbar (4) and the negative copper busbar (5). The second capacitor filter circuit (2) is located between the common mode magnetic ring (3) and the interference coupling coil (6). One end of the interference coupling coil (6) is connected to the input terminal of the voltage processing circuit (7), and the other end is connected to the first input terminal of the power amplifier circuit (8). The output terminal of the voltage processing circuit (7) is connected to the second input terminal of the power amplifier circuit (8). The two output terminals of the power amplifier circuit (8) are respectively connected to the two ends of the modulation coil (9). The modulation coil (9) is wound on the common mode magnetic ring (3).

2. The high-voltage filter according to claim 1, characterized in that: The interference coupling coil (6) is a spiral coil, which is made by winding a single wire with multiple winding radii.

3. The high-voltage filter according to claim 1, characterized in that: The interference coupling coil (6) is a spiral coil, which is made by winding a wire with three winding radii.

4. The high-voltage filter according to claim 1, characterized in that: The voltage processing circuit (7) is an inverting voltage follower, which includes resistors R11, R12, R13 and operational amplifier U2. One end of resistor R12 is connected to one end of the interference coupling coil (6), and the other end of resistor R12 is connected to one end of resistor R11 and the inverting input terminal of operational amplifier U2. One end of resistor R13 is connected to power supply VCC2, and the other end is connected to the non-inverting input terminal of operational amplifier U2. The other end of resistor R11 is connected to the output terminal of operational amplifier U2, and the output terminal of operational amplifier U2 is connected to the second input terminal of power amplifier circuit (8).

5. The high-voltage filter according to claim 4, characterized in that: The power amplifier circuit (8) includes a first voltage amplification module (81), a second voltage amplification module (82), a first current amplification module (83), and a second current amplification module (84). The input terminal of the first voltage amplification module (81) serves as the first input terminal of the power amplifier circuit (8). The output terminal of the first voltage amplification module (81) is connected to the input terminal of the first current amplification module (83). The output terminal of the first current amplification module (83) serves as the first output terminal of the power amplifier circuit (8) and is connected to the feedback terminal of the first voltage amplification module (81). The input terminal of the second voltage amplification module (82) serves as the second input terminal of the power amplifier circuit (8). The output terminal of the second voltage amplification module (82) is connected to the input terminal of the second current amplification module (84). The output terminal of the second current amplification module (84) serves as the second output terminal of the power amplifier circuit (8) and is connected to the feedback terminal of the second voltage amplification module (82).

6. The high-voltage filter according to claim 5, characterized in that: The first voltage amplification module (81) includes resistors R1, R2, R3 and operational amplifier U1. One end of resistor R1 serves as the input terminal of the first voltage amplification module (81), and the other end of resistor R1 is connected to one end of resistor R3 and the inverting input terminal of operational amplifier U1. One end of resistor R2 is connected to power supply VCC2 and the other end is connected to the non-inverting input terminal of operational amplifier U1. The other end of resistor R3 serves as the feedback terminal of the first voltage amplification module (81), and the output terminal of operational amplifier U1 serves as the output terminal of the first voltage amplification module (81). The first current amplification module (83) includes: resistors R4, R5, R6, R7, R8, R9, diodes D1 and D2, and transistors Q1 and Q2; the cathode of diode D1 and the anode of diode D2 are connected and serve as the input terminal of the first current amplification module (83); the anode of diode D1 is connected to one end of resistor R4; the other end of resistor R4 is connected to the base of transistor Q1 and one end of resistor R5; the other end of resistor R5 and the collector of transistor Q1 are connected to power supply VCC1; the emitter of transistor Q1 is connected to one end of resistor R6; the other end of resistor R6 is connected to one end of resistor R7 and serves as the output terminal of the first current amplification module (83); the other end of resistor R7 is connected to the collector of transistor Q2; the emitter of transistor Q2 is grounded; one end of resistor R9 is grounded and the other end is connected to the base of transistor Q2 and one end of resistor R8; the other end of resistor R8 is connected to the cathode of diode D2.

7. The high-voltage filter according to claim 5, characterized in that: The second voltage amplification module (82) includes resistors R10, R14, R15 and operational amplifier U3. One end of resistor R14 serves as the input terminal of the second voltage amplification module (82), and the other end of resistor R14 is connected to one end of resistor R10 and the inverting input terminal of operational amplifier U3. One end of resistor R15 is connected to the other end of resistor R13, and the other end of resistor R15 is connected to the non-inverting input terminal of operational amplifier U3. The other end of resistor R10 serves as the feedback terminal of the second voltage amplification module (82), and the output terminal of operational amplifier U3 serves as the output terminal of the second voltage amplification module (82). The second current amplification module (84) includes: resistors R16, R17, R18, R19, R20, R21, diodes D3 and D4, and transistors Q3 and Q4; the cathode of diode D3 and the anode of diode D4 are connected and serve as the input terminal of the second current amplification module (84); the anode of diode D3 is connected to one end of resistor R16; the other end of resistor R16 is connected to the base of transistor Q3 and one end of resistor R17; the other end of resistor R17 and the collector of transistor Q3 are connected to power supply VCC1; the emitter of transistor Q3 is connected to one end of resistor R18; the other end of resistor R18 is connected to one end of resistor R19 and serves as the output terminal of the second current amplification module (84); the other end of resistor R19 is connected to the collector of transistor Q4; the emitter of transistor Q4 is grounded; one end of resistor R21 is grounded and the other end is connected to the base of transistor Q4 and one end of resistor R20; the other end of resistor R20 is connected to the cathode of diode D4.

8. The high-voltage filter according to claim 4, characterized in that: The first capacitor filter circuit (1) includes capacitors Y1, Y2, and X1. One end of capacitor Y1 is connected to the input terminal of the positive copper busbar (4) and the other end is grounded. One end of capacitor Y2 is connected to the input terminal of the negative copper busbar (5) and the other end is grounded. One end of capacitor X1 is connected to the input terminal of the positive copper busbar (4) and the other end is connected to the input terminal of the negative copper busbar (5). The second capacitor filter circuit (2) includes capacitors Y3, Y4 and X2. One end of capacitor Y3 is connected to the output terminal of the positive copper busbar (4) and the other end is grounded. One end of capacitor Y4 is connected to the output terminal of the negative copper busbar (5) and the other end is grounded. One end of capacitor X2 is connected to the output terminal of the positive copper busbar (4) and the other end is connected to the output terminal of the negative copper busbar (5).

9. A motor control system, characterized in that: Including the high-voltage filter as described in any one of claims 1 to 8.

10. A vehicle, characterized in that: Includes the motor control system as described in claim 9.

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