Active filter circuit, power supply circuit, motor controller and vehicle

Abstract

The application relates to an active filter circuit, a power supply circuit, a motor controller and a vehicle, the active filter circuit comprising a first isolation module, a collection amplification module, a current amplification module and a second isolation module, the current amplification module being arranged between the collection amplification module and the second isolation module, so that a third signal can be generated by amplifying the current of a second signal, and the second isolation module generates a compensation current according to the third signal, which can not only improve the compensation current, thereby improving the current compensation capability for common-mode interference in a main loop, helping to widen the applicable noise power range, but also reduces the current value required to be provided by the collection amplification module, thereby reducing power consumption and alleviating the heating phenomenon.

Description

Technical Field

[0001] This application relates to the field of electronic technology, and in particular to an active filter circuit, a power supply circuit, a motor controller, and a vehicle. Background Technology

[0002] An active filter is an electronic filter that combines active electronic components with passive components such as resistors and capacitors. Active filters reduce common-mode voltage by injecting compensation current into the main circuit to cancel out the common-mode current.

[0003] However, if the compensation current is too large, it will lead to increased power consumption and heat generation, while if it is too small, it will cause clipping distortion, thereby reducing the current compensation capability. Utility Model Content

[0004] This application provides an active filter circuit, a power supply circuit, a motor controller, and a vehicle, which improves the current compensation capability of the active filter circuit and reduces power consumption and heat generation, thereby at least partially solving the above-mentioned technical problems.

[0005] To achieve the above objectives, according to a first aspect of this application, an active filter circuit is provided. The active filter circuit includes a first isolation module, a data acquisition and amplification module, a current amplification module, and a second isolation module. The first isolation module is connected to the main circuit and configured to provide voltage isolation between the main circuit and the active filter circuit, and to generate a first signal based on the electrical signal of the main circuit. The data acquisition and amplification module is connected to the first isolation module and configured to acquire and invert the voltage of the first signal to generate a second signal. The current amplification module is connected to the data acquisition and amplification module and configured to amplify the current of the second signal to generate a third signal. The second isolation module is connected to the current amplification module and the main circuit and configured to generate a compensation current based on the third signal and inject the compensation current into the main circuit.

[0006] Optionally, the current amplification module includes at least one current amplification unit, which is connected between the acquisition amplification module and the second isolation module; wherein, when there are multiple current amplification units, the multiple current amplification units are connected in parallel.

[0007] Optionally, the current amplification unit includes a first transistor and a second transistor. The first terminal of the first transistor is connected to the power supply terminal, the control terminal of the first transistor is connected to the output terminal of the acquisition and amplification module, and the second terminal of the first transistor is connected to the input terminal of the second isolation module. The first terminal of the second transistor is connected to the second terminal of the first transistor and the input terminal of the second isolation module, the control terminal of the second transistor is connected to the control terminal of the first transistor and the output terminal of the acquisition and amplification module, and the second terminal of the second transistor is connected to the ground terminal.

[0008] Optionally, the current amplification unit includes a first amplifier, the first input terminal of which is connected to the output terminal of the acquisition amplification module, and the second input terminal of which is connected to the output terminal of the first amplifier and the input terminal of the second isolation module.

[0009] Optionally, the first isolation module includes at least one first capacitor, with a first end of the first capacitor connected to the input terminal of the acquisition and amplification module, and a second end of the first capacitor connected to at least one node of the main circuit.

[0010] Optionally, the second isolation module includes at least one second capacitor, the first end of which is connected to the output terminal of the current amplification module, and the second end of which is connected to at least one node of the main circuit.

[0011] Optionally, the acquisition and amplification module includes a common-collector amplifier, a common-emitter amplifier, and an asymmetric current mirror. The common-collector amplifier is connected to the output of the first isolation module and is configured to perform voltage following and current isolation on the first signal. The common-emitter amplifier is connected to the common-collector amplifier. The asymmetric current mirror is connected to the common-emitter amplifier and is configured to work with the common-emitter amplifier to invert and amplify the output signal of the common-collector amplifier to generate a second signal.

[0012] Optionally, the acquisition and amplification module further includes a third capacitor, a first resistor, and a fourth capacitor. The first terminal of the third capacitor is connected to the output terminal of the common collector amplifier; the first terminal of the first resistor is connected to the second terminal of the third capacitor, and the second terminal of the first resistor is connected to the input terminal of the common emitter amplifier; the first terminal of the fourth capacitor is connected to the common emitter amplifier and the asymmetric current mirror, and the second terminal of the fourth capacitor is connected to the input terminal of the current amplification module.

[0013] Optionally, the common-collector amplifier includes a third transistor, a second resistor, a third resistor, and a fourth resistor. The first terminal of the third transistor is connected to the power supply terminal, and the control terminal of the third transistor is connected to the output terminal of the first isolation module. The first terminal of the second resistor is connected to the first terminal of the third transistor and the power supply terminal, and the second terminal of the second resistor is connected to the control terminal of the third transistor and the output terminal of the first isolation module. The first terminal of the third resistor is connected to the second terminal of the second resistor and the control terminal of the third transistor, and the second terminal of the third resistor is connected to the ground terminal. The first terminal of the fourth resistor is connected to the second terminal of the third transistor and the first terminal of the third capacitor, and the second terminal of the fourth resistor is connected to the ground terminal.

[0014] Optionally, the common-emitter amplifier includes a fourth transistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a fifth capacitor, a ninth resistor, and a sixth capacitor. The first terminal of the fourth transistor is connected to the first terminal of the fourth capacitor and an asymmetric current mirror. The control terminal of the fourth transistor is connected to the second terminal of the first resistor. The first terminal of the fifth resistor is connected to the first terminal of the fourth transistor. The first terminal of the sixth resistor is connected to the second terminal of the fifth resistor, and the second terminal of the sixth resistor is connected to the control terminal of the fourth transistor. The first terminal of the seventh resistor is connected to the second terminal of the sixth resistor and the control terminal of the fourth transistor, and the second terminal of the seventh resistor is connected to ground. The first terminal of the eighth resistor is connected to the second terminal of the fourth transistor, and the second terminal of the eighth resistor is connected to ground. The first terminal of the fifth capacitor is connected to the first terminal of the eighth resistor and the second terminal of the fourth transistor, and the second terminal of the fifth capacitor is connected to ground. The first terminal of the ninth resistor is connected to the second terminal of the fifth resistor. The first terminal of the sixth capacitor is connected to the second terminal of the ninth resistor, and the second terminal of the sixth capacitor is connected to ground.

[0015] Optionally, the asymmetric current mirror includes a tenth resistor, a fifth transistor, an eleventh resistor, a sixth transistor, and a twelfth resistor. The first terminal of the tenth resistor is connected to the power supply terminal; the first terminal of the fifth transistor is connected to the second terminal of the tenth resistor, and the second terminal of the fifth transistor is connected to the first terminal of the fourth transistor and the first terminal of the fourth capacitor; the first terminal of the eleventh resistor is connected to the power supply terminal; the first terminal of the sixth transistor is connected to the second terminal of the eleventh resistor, and the control terminal of the sixth transistor is connected to the second terminal of the sixth transistor and the control terminal of the fifth transistor; the first terminal of the twelfth resistor is connected to the second terminal of the sixth transistor, and the second terminal of the twelfth resistor is connected to the ground terminal.

[0016] Optionally, the active filter circuit further includes a first Zener diode and a first diode. The cathode of the first Zener diode is connected to the output terminal of the first isolation module and the input terminal of the acquisition and amplification module; the anode of the first diode is connected to the anode of the first Zener diode, and the cathode of the first diode is connected to the ground terminal.

[0017] Optionally, the active filter circuit further includes a second Zener diode and a second diode. The cathode of the second Zener diode is connected to the current amplification module and the second isolation module; the anode of the second diode is connected to the anode of the second Zener diode, and the cathode of the second diode is connected to the ground terminal.

[0018] According to a second aspect of this application, a power supply circuit is provided, which includes the active filter circuit described above.

[0019] According to a third aspect of this application, a motor controller is also provided, which includes the active filter circuit described above.

[0020] Optionally, the motor controller further includes a passive filter, which includes a first magnetic ring and a second magnetic ring surrounding the main circuit; wherein the first isolation module and the second isolation module are connected to the same node of the main circuit.

[0021] According to a fourth aspect of this application, a vehicle is also provided, the vehicle including the above-described active filter circuit, or the vehicle including the above-described power supply circuit and / or the above-described motor controller.

[0022] The active filter circuit, power supply circuit, motor controller, and vehicle of this application embodiment, by setting a current amplification module between the acquisition amplification module and the second isolation module, can amplify the current of the second signal to generate a third signal. The second isolation module generates a compensation current based on the third signal, which not only increases the compensation current, thereby improving the current compensation capability for common-mode interference in the main circuit and helping to broaden the applicable noise power range, but also reduces the current value required by the acquisition amplification module, thereby reducing power consumption and mitigating heat generation.

[0023] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0026] Figure 1 This is a first circuit schematic diagram of an active filter circuit provided in an exemplary embodiment of this disclosure;

[0027] Figure 2 This is a second circuit schematic diagram of the active filter circuit provided in the exemplary embodiments of this disclosure;

[0028] Figure 3 This is a first circuit schematic diagram of the current amplification module provided in the exemplary embodiments of this disclosure;

[0029] Figure 4 This is a second circuit schematic diagram of the current amplification module provided in the exemplary embodiments of this disclosure;

[0030] Figure 5This is a schematic diagram illustrating the connection relationship between the active filter circuit and the main circuit provided in an exemplary embodiment of this disclosure;

[0031] Figure 6 This is a schematic diagram of the power supply circuit provided in an exemplary embodiment of this disclosure;

[0032] Figure 7 This is a schematic diagram of the structure of the motor controller provided in an exemplary embodiment of this disclosure;

[0033] Figure 8 This is a schematic diagram of the vehicle structure provided in an exemplary embodiment of this disclosure.

[0034] Explanation of reference numerals in the attached figures:

[0035] 10. First isolation module; C5. First capacitor;

[0036] 20. Acquisition and Amplification Module; 21. Common Collector Amplifier; Q1, Third Transistor; R1, Second Resistor; R2, Third Resistor; R3, Fourth Resistor; 22. Common Emitter Amplifier; Q2, Fourth Transistor; R12, Fifth Resistor; R5, Sixth Resistor; R6, Seventh Resistor; R7, Eighth Resistor; C2, Fifth Capacitor; R11, Ninth Resistor; C4, Sixth Capacitor; 23. Asymmetric Current Mirror; R8, Tenth Resistor; Q3, Fifth Transistor; R9, Eleventh Resistor; Q4, Sixth Transistor; R10, Twelfth Resistor; C1, Third Capacitor; R4, First Resistor; C3, Fourth Capacitor;

[0037] 30. Current amplification module; 31. Current amplification unit; Q5. First transistor; Q6. Second transistor; U1. First amplifier;

[0038] 40. Second isolation module; C6. Second capacitor; GND. Ground terminal;

[0039] D1, first Zener diode; D2, first diode; D3, second Zener diode; D4, second diode;

[0040] 100. Active filter circuit;

[0041] 200. Power supply circuit;

[0042] 300. Motor controller; 310. Passive filter; 311. First magnetic ring; 312. Second magnetic ring;

[0043] 400. Vehicles;

[0044] 500, Main circuit. Detailed Implementation

[0045] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0046] In traditional technologies, a constant current exists in the path formed by the asymmetric current mirror and the common-emitter amplifier. To ensure that the generated compensation current waveform is not distorted, this constant current must be greater than or equal to the maximum amplitude of the compensation current. Therefore, the power consumption generated by this path is inevitably high. High power consumption is accompanied by severe heat generation. Electronic devices usually have an upper limit standard for power consumption due to heat generation, which inevitably limits the improvement of current rating. In automotive electronic control systems, the peak common-mode current can reach several amperes, which is clearly beyond the current rating requirements of existing technologies. Therefore, traditional technologies suffer from high power consumption, severe heat generation, and hinder the improvement of current compensation rating.

[0047] This embodiment of the application sets up a current amplification module between the acquisition amplification module and the second isolation module, so that the compensation current is provided by the current amplification module. The current amplification module can automatically adapt the current magnitude according to the demand, without the need for a constant current. In addition, the acquisition amplification module only needs to provide a small amount of current to the current amplification module. Therefore, the constant current in the above path only needs to be maintained at a small value, thereby achieving a reduction in power consumption and an improvement in current compensation capability.

[0048] This application provides an active filter circuit 100, such as... Figure 1 As shown, the active filter circuit 100 includes a first isolation module 10, a data acquisition and amplification module 20, a current amplification module 30, and a second isolation module 40. The first isolation module 10 is connected to the main circuit 500 and is configured to provide voltage isolation between the main circuit 500 and the active filter circuit 100, and to generate a first signal based on the electrical signal of the main circuit 500. The data acquisition and amplification module 20 is connected to the first isolation module 10 and is configured to acquire and invert the voltage of the first signal to generate a second signal. The current amplification module 30 is connected to the data acquisition and amplification module 20 and is configured to amplify the current of the second signal to generate a third signal. The second isolation module 40 is connected to the current amplification module 30 and the main circuit 500 and is configured to generate a compensation current based on the third signal and inject the compensation current into the main circuit 500.

[0049] It is understood that the active filter circuit 100 in this embodiment of the application, by setting a current amplification module 30 between the acquisition amplification module 20 and the second isolation module 40, can amplify the current of the second signal and generate a third signal. The second isolation module 40 generates a compensation current based on the third signal, which can not only increase the compensation current, thereby improving the current compensation capability for common-mode interference in the main circuit 500 and helping to broaden the applicable noise power range, but also reduce the current value required by the acquisition amplification module 20, thereby reducing power consumption and mitigating heat generation.

[0050] In some embodiments, the current amplification module 30 includes at least one current amplification unit 31, which is connected between the acquisition amplification module 20 and the second isolation module 40. When there are multiple current amplification units 31, they are connected in parallel.

[0051] It should be noted that the number of current amplification units 31 connected in parallel can be determined according to the required current compensation capability. For example, if a larger current compensation capability is required, the number of current amplification units 31 connected in parallel can be set to more; conversely, if a smaller current compensation capability is required, the number of current amplification units 31 connected in parallel can be set to fewer.

[0052] In some embodiments, such as Figure 3 As shown, the current amplification unit 31 includes a first transistor Q5 and a second transistor Q6. The first terminal of the first transistor Q5 is connected to the power supply terminal, the control terminal of the first transistor Q5 is connected to the output terminal of the acquisition and amplification module 20, and the second terminal of the first transistor Q5 is connected to the input terminal of the second isolation module 40. The first terminal of the second transistor Q6 is connected to the second terminal of the first transistor Q5 and the input terminal of the second isolation module 40, the control terminal of the second transistor Q6 is connected to the control terminal of the first transistor Q5 and the output terminal of the acquisition and amplification module 20, and the second terminal of the second transistor Q6 is connected to the ground terminal GND.

[0053] It should be noted that the first terminal, control terminal, and second terminal of the first transistor Q5 are, respectively, the collector, base, and emitter. The first terminal, control terminal, and second terminal of the second transistor Q6 are, respectively, the emitter, base, and collector. This current amplification unit 31, through the complementary symmetrical design of the NPN-type first transistor Q5 and the PNP-type second transistor Q6, combined with push-pull amplification and emitter follower characteristics, achieves efficient amplification of the full-cycle signal, low-distortion output, and high-current drive capability. F1 is the connection node between the output terminal of the acquisition amplification module 20 and the input terminal of the current amplification module 30. F2 is the connection node between the output terminal of the current amplification module 30 and the input terminal of the second isolation module 40.

[0054] In some embodiments, such as Figure 4 As shown, the current amplification unit 31 includes a first amplifier U1, the first input terminal of the first amplifier U1 is connected to the output terminal of the acquisition amplification module 20, and the second input terminal of the first amplifier U1 is connected to the output terminal of the first amplifier U1 and the input terminal of the second isolation module 40.

[0055] It should be noted that the first input terminal and the second input terminal of the first amplifier U1 are, respectively, the non-inverting input and the inverting input. The output signal of the acquisition and amplification module 20 is input to the first amplifier U1 through the non-inverting input, and output after internal amplification. Since the inverting input is directly fed back to the output terminal, a voltage follower structure is formed, and the output voltage is equal to or approximately equal to the input voltage, thus significantly enhancing the current driving capability. In other embodiments, the current amplification unit 31 can also add at least one of a capacitor and a resistor to the first amplifier U1.

[0056] In some embodiments, the first isolation module 10 includes at least one first capacitor C5, the first end of the first capacitor C5 is connected to the input terminal of the acquisition amplification module 20, and the second end of the first capacitor C5 is connected to at least one node of the main circuit 500.

[0057] It should be noted that, Figure 1 The first isolation module 10 shown exemplarily includes a first capacitor C5. Figure 2 The first isolation module 10 shown exemplarily includes two first capacitors C5. At least one first capacitor C5 is used to isolate the high voltage of the main circuit 500 and the static low voltage of the acquisition and amplification module 20, while its high-pass characteristic helps to suppress low-frequency signals below 150kHz from entering the acquisition and amplification module 20. At least one node of the main circuit 500 can be at least one of compensation access points A1, A2, B1, and B2.

[0058] In some embodiments, the second isolation module 40 includes at least one second capacitor C6, the first end of the second capacitor C6 is connected to the output terminal of the current amplification module 30, and the second end of the second capacitor C6 is connected to at least one node of the main circuit 500.

[0059] It should be noted that, Figure 1 The first isolation module 10 shown exemplarily includes a second capacitor C6. Figure 2 The first isolation module 10 shown exemplarily includes two second capacitors C6. At least one second capacitor C6 is used to isolate the high voltage of the main circuit 500 and the low voltage of the current amplification module 30. At the same time, the voltage difference generated on both sides of it will cause current to flow, forming an anti-phase common-mode compensation current, which is injected into the main circuit 500 through the compensation access point B1, to a certain extent offsetting the original common-mode current in the main circuit 500, thereby reducing the common-mode voltage.

[0060] In some embodiments, such as Figure 2 As shown, the acquisition and amplification module 20 includes a common-collector amplifier 21, a common-emitter amplifier 22, and an asymmetric current mirror 23. The common-collector amplifier 21 is connected to the output terminal of the first isolation module 10 and is configured to perform voltage following and current isolation on the first signal. The common-emitter amplifier 22 is connected to the common-collector amplifier 21. The asymmetric current mirror 23 is connected to the common-emitter amplifier 22 and is configured to work with the common-emitter amplifier 22 to invert and amplify the output signal of the common-collector amplifier 21 to generate the second signal.

[0061] It should be noted that the common-collector amplifier 21 is used to follow the noise voltage of the output source in the self-circuit 500, while simultaneously achieving current isolation on both sides. The common-emitter amplifier 22 and the asymmetric current mirror 23 together achieve inverted amplification of the noise voltage. This inverted amplified noise voltage is transmitted and applied to one end of the second capacitor C6, forming a voltage difference to generate an injection compensation current. At the same time, the common-emitter amplifier 22 and the asymmetric current mirror 23 will form a small-amplitude constant current in the above path. This constant current is used to provide the maximum current required to drive the current amplification module 30. Therefore, this constant current must be greater than or equal to the maximum current required to drive the current amplification module 30.

[0062] The current amplification module 30 provides and follows the injected compensation current generated on the second capacitor C6 in real time, and is nearly equal to the compensation current required by the main circuit 500. Its power loss is proportional to the required compensation current. The output voltage of the current amplification module 30 is theoretically equal to its input voltage, meaning that the current amplification module 30 does not affect the conduction of the voltage signal to the second capacitor C6, but helps to provide a larger compensation current. Because the current generated by the current amplification module 30 is nearly equal to the required compensation current and varies with the required compensation current, its power loss is proportional to the required compensation current, resulting in a low power consumption level.

[0063] In some embodiments, such as Figure 2 As shown, the acquisition and amplification module 20 also includes a third capacitor C1, a first resistor R4, and a fourth capacitor C3. The first terminal of the third capacitor C1 is connected to the output terminal of the common-collector amplifier 21. The first terminal of the first resistor R4 is connected to the second terminal of the third capacitor C1, and the second terminal of the first resistor R4 is connected to the input terminal of the common-emitter amplifier 22. The first terminal of the fourth capacitor C3 is connected to the common-emitter amplifier 22 and the asymmetric current mirror 23, and the second terminal of the fourth capacitor C3 is connected to the input terminal of the current amplification module 30.

[0064] It should be noted that the signal output by the common-collector amplifier 21 may contain a DC bias component. The third capacitor C1 blocks the DC component through its capacitive reactance, allowing only AC noise signals (such as high-frequency interference) to pass through, thus preventing DC offset from affecting the input bias point of the common-emitter amplifier 22. The third capacitor C1 and the first resistor R4 form an RC high-pass filter network, which can filter out low-frequency noise (such as power frequency interference), allowing only high-frequency noise signals to enter the common-emitter amplifier 22 for inverting amplification.

[0065] The common-collector amplifier 21 has a low output impedance (approximately tens of Ω), while the common-emitter amplifier 22 has a high input impedance (in the kiloΩ range). The first resistor R4 achieves impedance matching between the preceding and following stages through resistance adjustment, reducing signal reflection and power loss, and ensuring efficient transmission of noise voltage. Simultaneously, it limits the current flowing into the common-emitter amplifier 22, preventing transistor overload or breakdown due to excessively strong input signals.

[0066] The inverted amplified signal output by the common-emitter amplifier 22 and the asymmetric current mirror 23 contains high-frequency noise and dynamic compensation current. The fourth capacitor C3 transmits the AC component to the current amplification module 30 through capacitive coupling, while blocking the influence of the DC bias voltage on the subsequent circuit.

[0067] The fourth capacitor C3 can also form a low-pass filter network with the input impedance of the current amplification module 30 to suppress high-frequency ripple interference and ensure the stability of the compensation current. By adjusting the capacitance value of the fourth capacitor C3, the phase of the signal can be finely adjusted to cancel the delay caused by the inverting characteristic of the common-emitter amplifier 22, ensuring that the compensation current is in phase with the noise in the main circuit 500, thus achieving precise cancellation.

[0068] In some embodiments, such as Figure 2 As shown, the common-collector amplifier 21 includes a third transistor Q1, a second resistor R1, a third resistor R2, and a fourth resistor R3. The first terminal of the third transistor Q1 is connected to the power supply terminal, and the control terminal of the third transistor Q1 is connected to the output terminal of the first isolation module 10. The first terminal of the second resistor R1 is connected to the first terminal of the third transistor Q1 and the power supply terminal, and the second terminal of the second resistor R1 is connected to the control terminal of the third transistor Q1 and the output terminal of the first isolation module 10. The first terminal of the third resistor R2 is connected to the second terminal of the second resistor R1 and the control terminal of the third transistor Q1, and the second terminal of the third resistor R2 is connected to the ground terminal GND. The first terminal of the fourth resistor R3 is connected to the second terminal of the third transistor Q1 and the first terminal of the third capacitor C1, and the second terminal of the fourth resistor R3 is connected to the ground terminal GND.

[0069] It should be noted that the second resistor R1 and the third resistor R2 set the base voltage of the third transistor Q1 through a voltage divider, and the fourth resistor R3 stabilizes the quiescent operating point and suppresses temperature drift. The third transistor Q1 achieves zero-voltage attenuation transmission of noise voltage (voltage gain ≈ 1), and simultaneously isolates the DC component interference between the preceding and following stages of the circuit through high input impedance (megaohms) and low output impedance (tens of ohms). In some embodiments, such as Figure 2 As shown, the common-emitter amplifier 22 includes a fourth transistor Q2, a fifth resistor R12, a sixth resistor R5, a seventh resistor R6, an eighth resistor R7, a fifth capacitor C2, a ninth resistor R11, and a sixth capacitor C4. The first terminal of the fourth transistor Q2 is connected to the first terminal of the fourth capacitor C3 and an asymmetric current mirror 23. The control terminal of the fourth transistor Q2 is connected to the second terminal of the first resistor R4. The first terminal of the fifth resistor R12 is connected to the first terminal of the fourth transistor Q2. The first terminal of the sixth resistor R5 is connected to the second terminal of the fifth resistor R12, and the second terminal of the sixth resistor R5 is connected to the control terminal of the fourth transistor Q2. The first terminal of the seventh resistor R6 is connected to the second terminal of the sixth resistor R5 and the control terminal of the fourth transistor Q2, and the second terminal of the seventh resistor R6 is connected to ground GND. The first terminal of the eighth resistor R7 is connected to the second terminal of the fourth transistor Q2, and the second terminal of the eighth resistor R7 is connected to ground GND. The first terminal of the fifth capacitor C2 is connected to the first terminal of the eighth resistor R7 and the second terminal of the fourth transistor Q2. The second terminal of the fifth capacitor C2 is connected to the ground terminal GND. The first terminal of the ninth resistor R11 is connected to the second terminal of the fifth resistor R12. The first terminal of the sixth capacitor C4 is connected to the second terminal of the ninth resistor R11. The second terminal of the sixth capacitor C4 is connected to the ground terminal GND.

[0070] It should be noted that the fourth transistor Q2, as the core component of the common-emitter amplifier circuit, receives the pre-amplifier signal at its base (control electrode), which is then amplified and output with a 180° phase reversal. The sixth resistor R5 and the seventh resistor R6, through voltage division, set a suitable voltage at the base of the fourth transistor Q2. The eighth resistor R7 introduces DC negative feedback to stabilize the quiescent operating point; under dynamic AC signals, the eighth resistor R7 is connected in parallel with the fifth capacitor C2, which bypasses the AC signal (low-impedance path), preventing the eighth resistor R7 from reducing the AC gain. The ninth resistor R11 and the sixth capacitor C4 are connected in series to form an RC filter or phase compensation network, suppressing high-frequency noise and optimizing the output signal bandwidth. The fifth resistor R12, as the collector load resistor, converts the collector current of the fourth transistor Q2 into a voltage output and is used to adjust the voltage gain of the fourth transistor Q2.

[0071] In some embodiments, such as Figure 2As shown, the asymmetric current mirror 23 includes a tenth resistor R8, a fifth transistor Q3, an eleventh resistor R9, a sixth transistor Q4, and a twelfth resistor R10. The first terminal of the tenth resistor R8 is connected to the power supply. The first terminal of the fifth transistor Q3 is connected to the second terminal of the tenth resistor R8, and the second terminal of the fifth transistor Q3 is connected to the first terminal of the fourth transistor Q2 and the first terminal of the fourth capacitor C3. The first terminal of the eleventh resistor R9 is connected to the power supply. The first terminal of the sixth transistor Q4 is connected to the second terminal of the eleventh resistor R9, and the control terminal of the sixth transistor Q4 is connected to the second terminal of the sixth transistor Q4 and the control terminal of the fifth transistor Q3. The first terminal of the twelfth resistor R10 is connected to the second terminal of the sixth transistor Q4, and the second terminal of the twelfth resistor R10 is connected to the ground terminal GND.

[0072] It should be noted that the asymmetric current mirror 23 includes both steady-state current and dynamic current, with the steady-state current determining the upper limit of the dynamic current. The asymmetric current mirror 23 primarily regulates the steady-state current (the aforementioned constant current) flowing through the fourth transistor Q2 and the eighth resistor R7. The magnitude of this steady-state current determines the peak dynamic current that can be supplied to the subsequent fourth capacitor C3. Simultaneously, the tenth resistor R8 and the fifth transistor Q3 assist in achieving inverted amplification of the noise voltage. When the noise voltage connected to the base of the fourth transistor Q2 increases, the dynamic current flowing through the tenth resistor R8, the fifth transistor Q3, the fourth transistor Q2, and the eighth resistor R7 increases. The voltage drop across the tenth resistor R8 increases, while the voltage drop across the fifth capacitor C2 remains approximately constant compared to the eighth resistor R7. Therefore, the noise voltage at the connection between the fifth transistor Q3 and the fourth transistor Q2 decreases, meaning the noise voltage is amplified inverted.

[0073] Eleventh resistor R9 and twelfth resistor R10 form a resistive voltage divider. By changing the resistance values ​​of eleventh resistor R9 and twelfth resistor R10, the steady-state current in the path of eleventh resistor R9 and twelfth resistor R10 can be adjusted, and the voltage drop across eleventh resistor R9 can be changed. Since tenth resistor R8 and fifth transistor Q3, and eleventh resistor R9 and sixth transistor Q4 form a symmetrical structure, the voltage drop across eleventh resistor R9 is approximately equal to the voltage drop across tenth resistor R8. Therefore, the current across the voltage drops of tenth resistor R8 and eleventh resistor R9 is inversely proportional to their resistance values. By adjusting the resistance values ​​of tenth resistor R8 and eleventh resistor R9, the magnitude of the steady-state current in the above paths can be changed.

[0074] In some embodiments, such as Figure 2 As shown, the active filter circuit 100 also includes a first Zener diode D1 and a first diode D2. The cathode of the first Zener diode D1 is connected to the output terminal of the first isolation module 10 and the input terminal of the acquisition and amplification module 20. The anode of the first diode D2 is connected to the anode of the first Zener diode D1, and the cathode of the first diode D2 is connected to the ground terminal GND.

[0075] It should be noted that the combination of the first Zener diode D1 and the first diode D2 in the active filter circuit 100 achieves bidirectional voltage clamping, high-frequency noise suppression and thermal stability compensation, thereby improving the system's anti-interference capability and reliability through synergistic effect.

[0076] In some embodiments, such as Figure 2 As shown, the active filter circuit 100 also includes a second Zener diode D3 and a second diode D4. The cathode of the second Zener diode D3 is connected to the current amplification module 30 and the second isolation module 40. The anode of the second diode D4 is connected to the anode of the second Zener diode D3, and the cathode of the second diode D4 is connected to the ground terminal GND.

[0077] It should be noted that the combination of the second Zener diode D3 and the second diode D4 in the active filter circuit 100 achieves bidirectional voltage clamping, high-frequency noise suppression and thermal stability compensation, and protects the interface safety between the current amplification module 30 and the second isolation module 40 through synergistic effect.

[0078] Figure 5 This is a schematic diagram illustrating the connection relationship between the active filter circuit 100 and the main circuit 500 provided in an exemplary embodiment of this disclosure. The main circuit 500 may include a first DC bus (+) and a second DC bus (-). Figure 2 A2 can be connected to the first DC bus, and A1 and B1 can be connected to the second DC bus, forming a closed loop.

[0079] In some embodiments, such as Figure 6 As shown, a power supply circuit 200 is also provided, which includes the active filter circuit 100 described above.

[0080] It is understood that since the power supply circuit 200 of this application embodiment includes the active filter circuit 100 described above, it is also possible to amplify the current of the second signal and generate a third signal by setting a current amplification module 30 between the acquisition amplification module 20 and the second isolation module 40. The second isolation module 40 generates a compensation current based on the third signal, which not only increases the compensation current, thereby improving the current compensation capability for common-mode interference in the main circuit 500 and helping to broaden the applicable noise power range, but also reduces the current value required by the acquisition amplification module 20, thereby reducing power consumption and mitigating heat generation.

[0081] In some embodiments, such as Figure 7 As shown, a motor controller 300 is also provided, which includes the active filter circuit 100 described above.

[0082] It is understood that since the motor controller 300 of this application embodiment includes the above-mentioned active filter circuit 100, it can also amplify the current of the second signal and generate a third signal by setting a current amplification module 30 between the acquisition amplification module 20 and the second isolation module 40. The second isolation module 40 generates a compensation current based on the third signal, which can not only increase the compensation current, thereby improving the current compensation capability for common mode interference in the main circuit 500 and helping to broaden the applicable noise power range, but also reduce the current value required by the acquisition amplification module 20, thereby reducing power consumption and mitigating heat generation.

[0083] In some embodiments, such as Figure 7 As shown, the motor controller 300 also includes a passive filter 310, which includes a first magnetic ring 311 and a second magnetic ring 312 surrounding the main circuit 500. The first isolation module 10 and the second isolation module 40 are connected to the same node in the main circuit 500.

[0084] It should be noted that the bus voltage of the aforementioned motor controller 300 can be exemplarily 200V, and the switching frequency can be exemplarily 10kHz. Without changing the original passive filter circuit, the active filter circuit 100 is connected in parallel to the passive filter 310. The connection points A1 / B1 shown are at the same location (the diagram shows connection between the two magnetic rings, but it can also be connected at other locations on the DC bus of the passive filter 310). The upper limit of current compensation is designed to be 0.3A.

[0085] Simulation and experimental tests were conducted before and after the addition of the active filter circuit 100. The simulation and experimental measurement results at the receiving end show that after adding the improved active filter circuit 100, the common-mode voltage drops by a maximum of 12dB in the 150kHz-5MHz frequency band. In contrast, the original active filter scheme, due to excessive electronic control noise, has very limited compensation capability, showing little difference from the results before adding the original active filter scheme, resulting in minimal improvement. All the above experimental results demonstrate that the improved active filter circuit 100 of this application has better filtering performance.

[0086] In some embodiments, such as Figure 8 As shown, a vehicle 400 is also provided, which includes the active filter circuit 100 described above, or the vehicle 400 includes the power supply circuit 200 described above and / or the motor controller 300 described above.

[0087] It is understood that, since the vehicle 400 in this embodiment includes the active filter circuit 100 described above, or the vehicle 400 includes the power supply circuit 200 and / or the motor controller 300 described above, it is also possible to amplify the current of the second signal and generate a third signal by setting a current amplification module 30 between the acquisition amplification module 20 and the second isolation module 40. The second isolation module 40 generates a compensation current based on the third signal, which not only increases the compensation current, thereby improving the current compensation capability for common-mode interference in the main circuit 500 and helping to broaden the applicable noise power range, but also reduces the current value required by the acquisition amplification module 20, thereby reducing power consumption and mitigating heat generation.

[0088] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0089] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0090] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0091] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. An active filter circuit, characterized in that, The active filter circuit includes: The first isolation module, connected to the main circuit, is configured to provide voltage isolation between the main circuit and the active filter circuit, and to generate a first signal based on the electrical signal of the main circuit. The acquisition and amplification module, connected to the first isolation module, is configured to acquire and invert the voltage of the first signal to generate a second signal; A current amplification module, connected to the acquisition amplification module, is configured to amplify the current of the second signal to generate a third signal; The second isolation module, connected to the current amplification module and the main circuit, is configured to generate a compensation current based on the third signal and inject the compensation current into the main circuit.

2. The active filter circuit according to claim 1, wherein The current amplification module includes at least one current amplification unit, which is connected between the acquisition amplification module and the second isolation module. When there are multiple current amplification units, the multiple current amplification units are connected in parallel.

3. The active filter circuit according to claim 2, wherein The current amplification unit includes: The first transistor has its first terminal connected to the power supply terminal, its control terminal connected to the output terminal of the acquisition and amplification module, and its second terminal connected to the input terminal of the second isolation module. The second transistor has its first terminal connected to the second terminal of the first transistor and the input terminal of the second isolation module, its control terminal connected to the control terminal of the first transistor and the output terminal of the acquisition and amplification module, and its second terminal connected to the ground terminal.

4. The active filter circuit according to claim 2, characterized in that, The current amplification unit includes a first amplifier, the first input terminal of which is connected to the output terminal of the acquisition amplification module, and the second input terminal of which is connected to both the output terminal of the first amplifier and the input terminal of the second isolation module.

5. The active filter circuit according to claim 1, characterized in that, The first isolation module includes at least one first capacitor, the first end of the first capacitor is connected to the input terminal of the acquisition and amplification module, and the second end of the first capacitor is connected to at least one node of the main circuit.

6. The active filter circuit according to claim 1, characterized in that, The second isolation module includes at least one second capacitor, the first end of which is connected to the output terminal of the current amplification module, and the second end of which is connected to at least one node of the main circuit.

7. The active filter circuit according to any one of claims 1-6, characterized in that, The acquisition and amplification module includes: A common-collector amplifier, connected to the output of the first isolation module, is configured to voltage follow and current isolate the first signal; A common-emitter amplifier, connected to the common-collector amplifier; An asymmetric current mirror, connected to the common-emitter amplifier, is configured to work with the common-emitter amplifier to invert and amplify the output signal of the common-collector amplifier to generate the second signal.

8. The active filter circuit according to claim 7, characterized in that, The acquisition and amplification module also includes: The third capacitor, the first terminal of which is connected to the output terminal of the common collector amplifier; A first resistor, the first end of which is connected to the second end of the third capacitor, and the second end of which is connected to the input terminal of the common-emitter amplifier; The fourth capacitor has its first terminal connected to the common-emitter amplifier and the asymmetric current mirror, and its second terminal connected to the input terminal of the current amplification module.

9. The active filter circuit according to claim 8, characterized in that, The common-collector amplifier includes: The third transistor has its first terminal connected to the power supply terminal and its control terminal connected to the output terminal of the first isolation module. The second resistor has its first end connected to the first terminal of the third transistor and the power supply terminal, and its second end connected to the control terminal of the third transistor and the output terminal of the first isolation module. The third resistor has its first end connected to the second end of the second resistor and the control electrode of the third transistor, and its second end connected to the ground terminal. The fourth resistor has its first end connected to the second terminal of the third transistor and the first end of the third capacitor, and its second end connected to the ground terminal.

10. The active filter circuit according to claim 8, characterized in that, The common-emitter amplifier includes: The fourth transistor has its first terminal connected to the first terminal of the fourth capacitor and the asymmetric current mirror, and its control terminal connected to the second terminal of the first resistor. The fifth resistor, the first end of which is connected to the first terminal of the fourth transistor; The sixth resistor has its first end connected to the second end of the fifth resistor, and its second end connected to the control electrode of the fourth transistor. The seventh resistor has its first end connected to the second end of the sixth resistor and the control electrode of the fourth transistor, and its second end connected to the ground terminal. The eighth resistor has its first end connected to the second terminal of the fourth transistor, and its second end connected to the ground terminal. The fifth capacitor has its first terminal connected to the first terminal of the eighth resistor and the second terminal of the fourth transistor, and its second terminal connected to the ground terminal. The ninth resistor, the first end of which is connected to the second end of the fifth resistor; The sixth capacitor has its first terminal connected to the second terminal of the ninth resistor, and its second terminal connected to the ground terminal.

11. The active filter circuit according to claim 8, characterized in that, The asymmetric current mirror includes: The tenth resistor, the first end of which is connected to the power supply terminal; The fifth transistor has its first terminal connected to the second terminal of the tenth resistor, and its second terminal connected to the first terminal of the fourth transistor and the first terminal of the fourth capacitor. The eleventh resistor, the first end of which is connected to the power supply terminal; The sixth transistor has its first terminal connected to the second terminal of the eleventh resistor, and its control terminal is connected to both the second terminal of the sixth transistor and the control terminal of the fifth transistor. The twelfth resistor has its first end connected to the second terminal of the sixth transistor, and its second end connected to the ground terminal.

12. The active filter circuit according to any one of claims 1-6, characterized in that, The active filter circuit further includes: The first Zener diode, the cathode of which is connected to the output terminal of the first isolation module and the input terminal of the acquisition and amplification module; The first diode has its anode connected to the anode of the first Zener diode, and its cathode connected to the ground terminal.

13. The active filter circuit according to any one of claims 1-6, characterized in that, The active filter circuit further includes: The cathode of the second Zener diode is connected to the current amplification module and the second isolation module; The second diode has its anode connected to the anode of the second Zener diode, and its cathode connected to the ground terminal.

14. A power supply circuit, characterized in that, The power supply circuit includes an active filter circuit as described in any one of claims 1-13.

15. A motor controller, characterized in that, The motor controller includes an active filter circuit as described in any one of claims 1-13.

16. The motor controller according to claim 15, characterized in that, The motor controller also includes a passive filter, which includes a first magnetic ring and a second magnetic ring surrounding the main circuit; The first isolation module and the second isolation module are connected to the same node of the main circuit.

17. A vehicle, characterized in that, The vehicle includes an active filter circuit as described in any one of claims 1-13, or the vehicle includes a power supply circuit as described in claim 14 and / or a motor controller as described in any one of claims 15-16.

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