Alternating current electronic load module, apparatus and device

Abstract

The embodiment of the application relates to the field of circuit structures, and provides an alternating current (AC) electronic load module, device and equipment, the module comprising a filter circuit, a bridgeless PFC, an overcurrent protection circuit, a resonance circuit, a redundant load and a control unit, wherein an AC input port is connected with an input end of the bridgeless PFC through the filter circuit, an output end of the bridgeless PFC is connected with an input end of the resonance circuit through the overcurrent protection circuit, a control end of the bridgeless PFC is connected with the control unit, and an output end of the resonance circuit is connected with an input end of an inverter power supply to be detected through the redundant load; the overcurrent protection circuit is used for carrying out overcurrent protection on the circuit after an output current of the bridgeless PFC is higher than a preset current threshold value, overcurrent protection can be carried out on the bridgeless PFC after the output current of the bridgeless PFC is higher than the preset current threshold value by using the overcurrent protection circuit, and the safety and reliability of the AC electronic load module during operation are improved.

Description

Technical Field

[0001] This application relates to the field of circuit structure technology, specifically to an AC electronic load module, device, and equipment. Background Technology

[0002] To verify and improve the reliability, stability, and safety of inverter power supplies (also known as inverters), aging tests are typically performed. "Aging" refers to simulating a harsh, high-temperature condition and subjecting the inverter power supply to a long-term full-load test, then evaluating the product performance based on the test results.

[0003] Traditional inverter aging test equipment mostly uses purely resistive dummy loads such as light bulbs, high-power resistors, or heating wires. These consume a significant amount of electrical energy during the aging process. Existing solutions have made some improvements by designing AC electronic load modules with feedback functions. However, since these AC electronic load modules also need to operate alongside the inverter for extended periods, their stability and reliability must be considered. Current solutions typically directly connect the feedback unit to achieve the feedback function, which reduces the safety and reliability of the AC electronic load module during aging tests. Summary of the Invention

[0004] This application provides an AC electronic load module, device, and equipment that can use an overcurrent protection circuit to protect the AC electronic load module from overcurrent when the output current of the bridgeless PFC exceeds a preset current threshold, thereby improving the safety and reliability of the AC electronic load module during operation.

[0005] A first aspect of this application provides an AC electronic load module, the module including a filter circuit, a bridgeless power filter (PFC), an overcurrent protection circuit, a resonant circuit, a redundant load, and a control unit. The AC input port is connected to the input terminal of the bridgeless PFC through the filter circuit; the output terminal of the bridgeless PFC is connected to the input terminal of the resonant circuit through the overcurrent protection circuit; the control terminal of the bridgeless PFC is connected to the control unit; and the output terminal of the resonant circuit is connected to the input terminal of an inverter power supply under test through the redundant load.

[0006] The overcurrent protection circuit is used to provide overcurrent protection for the circuit after the output current of the bridgeless PFC exceeds a preset current threshold.

[0007] The bridgeless PFC includes: a first inductor, a first diode, a second diode, a first MOSFET Q1, a second MOSFET Q2, a first capacitor, a first resistor, a second resistor, a third resistor, and a second capacitor. The first terminal of the first inductor is a first signal input terminal. The second terminal of the first inductor is connected to the first terminal of the first MOSFET and the first terminal of the first diode. The second terminal of the first diode is connected to the second terminal of the second diode and then connected in series with the first resistor to form a first rectified output line. The first terminal of the first capacitor is connected to the first rectified output line, and its second terminal is grounded. The first terminal of the second diode D2 is connected to an output terminal of the filter circuit and the drain of the second MOSFET Q2.

[0008] The control ports of the first MOSFET and the second MOSFET are connected to the control unit, and the second ports of the first MOSFET and the second MOSFET are connected to form a second rectified output line;

[0009] The second capacitor and the second resistor are connected in series between the first rectifier output line and the second rectifier output line, and the connection point between them is grounded.

[0010] The third resistor is connected to the first rectifier output line and then to the overcurrent protection circuit.

[0011] In one possible implementation, the overcurrent protection circuit includes a third MOSFET P3, a fourth MOSFET P4, a fifth MOSFET P5, a sixth MOSFET P6, a seventh MOSFET N7, a fourth resistor, a fifth resistor, a sixth resistor, and a seventh resistor. The first interface of the overcurrent protection circuit is connected to the source of the third MOSFET P3, the source of the fourth MOSFET P4, the source of the fifth MOSFET P5, and the source of the sixth MOSFET P6. The gate of the third MOSFET P3 is connected to the gate of the fourth MOSFET P4, the drain of the third MOSFET P3, and the seventh MOSFET N7. The drain of the fourth MOSFET P4 is connected to the gate of the fifth MOSFET P5 and the gate of the sixth MOSFET P6. The drain of the fifth MOSFET P5 is connected to the first end of the fifth resistor. The first end of the sixth resistor R6 forms a first detection interface. The second end of the fifth resistor is connected to the second end of the fourth resistor and the gate of the seventh MOSFET N7. The drain of the sixth MOSFET P6 is connected to the first end of the fourth resistor and the second end of the seventh resistor R7. The first end of the seventh resistor R7 forms a second detection interface. The source of the seventh MOSFET N7 is grounded.

[0012] In one possible implementation, the overcurrent protection circuit further includes a second inductor and a third inductor, with the first end of the sixth resistor R6 connected in series with the second inductor to form a first detection interface; and the first end of the seventh resistor R7 connected in series with the third inductor to form a second detection interface.

[0013] In one possible implementation, the overcurrent protection circuit further includes a third capacitor, a fourth capacitor, a third diode, and a fourth diode, wherein the anode of the fourth diode is connected to the first terminal of the fifth resistor, and the cathode of the fourth diode is grounded through the fourth capacitor; the anode of the third diode is connected to the first terminal of the fourth resistor, and the cathode of the third diode is grounded through the third capacitor.

[0014] In one possible implementation, the bridgeless PFC further includes an eighth resistor and a ninth resistor, the eighth resistor being connected in series between the first diode and the first resistor, and the ninth resistor being connected in series between the second diode and the first resistor; the first detection interface is connected between the second diode and the ninth resistor, and the second detection interface is connected between the first diode and the eighth resistor.

[0015] In one possible implementation, the preset current threshold is determined by the resistance value of the seventh resistor and the resistance value of the fourth resistor;

[0016] Alternatively, the preset current threshold can be determined by the resistance values ​​of the fifth resistor and the sixth resistor.

[0017] In one possible implementation, the redundant load includes: an eighth MOSFET P8, an eleventh resistor, and a fifth capacitor. The control terminal of the eighth MOSFET P8 is connected to the control unit, the source of the eighth MOSFET P8 is connected to the first output terminal of the resonant circuit, the drain of the eighth MOSFET P8 is connected in series with the eleventh resistor to form the first output terminal of the redundant load, the first output terminal of the resonant circuit is connected to the second output terminal of the redundant load, and one end of the fifth capacitor is connected to the first output terminal of the redundant load while the other end is grounded.

[0018] The control unit is used to control the on-resistance of the eighth MOSFET P8 according to the current output power of the inverter power supply under test, so as to adjust the power of the redundant load.

[0019] In one possible implementation, the AC electronic load module further includes a tenth resistor, which is connected in series in the filter circuit between the output terminal connected to the first inductor and one input terminal of the bridgeless PFC; the tenth resistor is a current sampling resistor.

[0020] A second aspect of this application provides an AC electronic load device, including a circuit board and an AC electronic load module as described in any one of the first aspects, wherein the AC electronic load module is disposed on the circuit board.

[0021] A third aspect of this application provides an AC electronic load device, characterized in that it includes a housing and an AC electronic load device as described in the second aspect, the AC electronic load device being disposed inside the housing.

[0022] Implementing the embodiments of this application has at least the following beneficial effects:

[0023] The AC electronic load module includes a filter circuit, a bridgeless power factor (PFC), an overcurrent protection circuit, a resonant circuit, a redundant load, and a control unit. The AC input port is connected to the input of the bridgeless PFC via the filter circuit. The output of the bridgeless PFC is connected to the input of the resonant circuit via the overcurrent protection circuit. The control terminal of the bridgeless PFC is connected to the control unit. The output of the resonant circuit is connected to the input of the inverter power supply under test via the redundant load. The overcurrent protection circuit provides overcurrent protection to the circuit when the output current of the bridgeless PFC exceeds a preset current threshold. Therefore, by using the overcurrent protection circuit to protect the bridgeless PFC from overcurrent when its output current exceeds the preset current threshold, the safety and reliability of the AC electronic load module during operation are improved. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art 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] Figure 1 This application provides a schematic diagram of the circuit structure of an AC electronic load module.

[0026] Figure 2 A schematic diagram of another AC electronic load module is provided for an embodiment of this application;

[0027] Figure 3 This application provides a schematic diagram of another AC electronic load module circuit structure. Detailed Implementation

[0028] 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 some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0029] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0030] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0031] To better understand the AC electronic load module provided in this application embodiment, a brief introduction to existing AC electronic load modules is given below. In existing solutions, the AC electronic load module includes a filter circuit, a bridgeless PFC, a resonant circuit, and a control unit. During operation, its output is connected to the input of an inverter power supply. Since the input of the inverter power supply is necessarily connected to a DC power supply, the load module can be used for energy feedback. Only the inverter power supply itself and the AC electronic load module consume power, thereby reducing the DC power supply and achieving energy saving. However, in its design, it is usually controlled or handled by a control module, such as shutting off relevant energy inputs after an anomaly occurs to improve safety. However, during operation, it requires parameter detection and analysis, and there is a certain delay in handling anomalies, leading to certain risks during overall aging tests.

[0032] For example, when an abnormally high current occurs at the output of the inverter power supply, the control unit performs high current detection. After detecting the signal, it processes the signal and determines that a high current exists before performing corresponding shutdown or abnormal warning. There is a certain delay, which means that if a short-term high current occurs, it cannot respond in time, resulting in lower safety.

[0033] To address the aforementioned technical problems, this application provides an AC electronic load module that integrates an overcurrent protection circuit into the AC electronic load module. This eliminates the need for high current detection through a control unit, enabling corresponding overcurrent protection and greatly improving the timeliness of overcurrent protection, thereby enhancing safety.

[0034] Please see Figure 1 , Figure 1 This application provides a schematic diagram of the circuit structure of an AC electronic load module. For example... Figure 1 As shown, the AC electronic load module includes a filter circuit 1, a bridgeless PFC 2, an overcurrent protection circuit 3, a resonant circuit 4, a redundant load 5, and a control unit 6. The AC input port is connected to the input terminal of the bridgeless PFC 2 through the filter circuit 1. The output terminal of the bridgeless PFC 2 is connected to the input terminal of the resonant circuit 4 through the overcurrent protection circuit 3. The control terminal of the bridgeless PFC 2 is connected to the control unit. The output terminal of the resonant circuit 4 is connected to the input terminal of the inverter power supply under test through the redundant load.

[0035] The overcurrent protection circuit 3 is used to provide overcurrent protection for the circuit after the output current of the bridgeless PFC2 exceeds a preset current threshold.

[0036] The bridgeless PFC2 includes: a first inductor L1, a first diode D1, a second diode D2, a first MOSFET Q1, a second MOSFET Q2, a first capacitor C1, a first resistor R1, a second resistor R2, a third resistor R3, and a second capacitor C2. The first terminal of the first inductor L1 is a first signal input terminal. The second terminal of the first inductor L1 is connected to the first terminal (drain) of the first MOSFET Q1 and the first terminal of the first diode D1. The second terminal of the first diode D1 is connected to the second terminal of the second diode D2 and then connected in series with the first resistor R1 to form a first rectified output line. The first terminal of the first capacitor C1 is connected to the first rectified output line, and its second terminal is grounded. The first terminal of the second diode D2 is connected to an output terminal of the filter circuit and the drain of the second MOSFET Q2.

[0037] The control ports (gates) of the first MOSFET Q1 and the second MOSFET Q2 are connected to the control unit 6. The second port (source) of the first MOSFET Q1 and the second port (source) of the second MOSFET Q2 are connected to form a second rectified output line.

[0038] The second capacitor C2 and the second resistor R2 are connected in series between the first rectifier output line and the second rectifier output line, and the connection point with the second rectifier output line is grounded;

[0039] The third resistor R3 is connected to the first rectifier output line and then to the overcurrent protection circuit 3.

[0040] Specifically, the detection interface of the overcurrent protection circuit 3 can be connected to the cathodes of the first diode D1 and the second diode D2 in the bridgeless PFC2, thereby detecting the current value output by the cathode. When the current value exceeds the preset current threshold, the overcurrent protection circuit 3 will be triggered to work and quickly discharge the current. The overcurrent response time is usually on the order of microseconds to avoid damage to subsequent modules by large current, thereby improving the safety and reliability of the AC electronic load module.

[0041] Control unit 6 can acquire the voltage, current and phase of the AC input in the module, as well as the voltage and current of the output, and control Q1 and Q2 to convert the AC input into DC output. The specific control and acquisition processing can refer to the general control and acquisition methods in the existing scheme, which will not be elaborated here.

[0042] In one possible implementation, the overcurrent protection circuit 3 includes a third MOSFET P3, a fourth MOSFET P4, a fifth MOSFET P5, a sixth MOSFET P6, a seventh MOSFET P7, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, and a seventh resistor R7. The first interface of the overcurrent protection circuit 3 is connected to the source of the third MOSFET P3, the source of the fourth MOSFET P4, the source of the fifth MOSFET P5, and the source of the sixth MOSFET P6. The gate of the third MOSFET P3 is connected to the gate of the fourth MOSFET P4, the drain of the third MOSFET P3, and the... The drain of the seventh MOSFET N7 is connected to the gate of the fifth MOSFET P5 and the gate of the sixth MOSFET P6. The drain of the fifth MOSFET P5 is connected to the first end of the fifth resistor. The first end of the sixth resistor R6 forms a first detection interface. The second end of the fifth resistor R5 is connected to the second end of the fourth resistor and the gate of the seventh MOSFET N7. The drain of the sixth MOSFET P6 is connected to the first end of the fourth resistor R4 and the second end of the seventh resistor R7. The first end of the seventh resistor R7 forms a second detection interface. The source of the seventh MOSFET N7 is grounded.

[0043] When the overcurrent protection circuit 3 is working, its first interface is connected to one end of the third resistor R3. After a high current is detected at the first or second detection interface, the voltage at point A1 or A2 will increase, thereby increasing the voltage at V1. This causes the seventh MOSFET N7 to conduct, pulling down the gate voltage of the third MOSFET P3. After the third MOSFET P3 is turned on, the current at the first interface of the protection circuit will be discharged directly through the third MOSFET P3 and the seventh MOSFET N7. This ensures that the output current of the bridgeless PFC2 is immediately discharged after an abnormally high current is detected, preventing high current from being input into the resonant circuit 4 and causing damage to the resonant circuit 4. It can achieve microsecond-level rapid discharge, greatly improving the safety and reliability of the AC electronic load module.

[0044] In one possible implementation, such as Figure 2 As shown, the overcurrent protection circuit 3 further includes a second inductor L2 and a third inductor L3. The first end of the sixth resistor R6 is connected in series with the second inductor L2 to form a first detection interface; the first end of the seventh resistor R7 is connected in series with the third inductor L3 to form a second detection interface.

[0045] Therefore, by setting the second inductor L2 and the third inductor L3, the AC component in the bridgeless PFC2 can be filtered out, further reducing signal fluctuations and improving the reliability of the AC electronic load module.

[0046] In one possible implementation, the overcurrent protection circuit 3 further includes a third capacitor C3, a fourth capacitor C4, a third diode D3, and a fourth diode D4. The anode of the fourth diode D4 is connected to the first terminal of the fifth resistor R5, and the cathode of the fourth diode D4 is grounded through the fourth capacitor C4. The anode of the third diode D3 is connected to the first terminal of the fourth resistor R4, and the cathode of the third diode D3 is grounded through the third capacitor C3.

[0047] By connecting a third capacitor C3 in series between the fourth resistor R4 and the fifth resistor R5, capacitor C3 is first charged during the operation of the protection circuit. When encountering an abnormally large current, it can absorb this current, ensuring a smooth transition of the current flowing through the fourth resistor R4. For example, in the case of a non-transient strong current, such as a strong current lasting for a certain period, the discharge time required will be longer, and the voltage at V1 will remain high. Therefore, C3 can absorb some energy, thereby reducing the damage to the seventh MOSFET N7 caused by the continuous high voltage. Similarly, the fourth capacitor C4 has the same function as the third capacitor C3. This further improves the reliability of the AC electronic load module.

[0048] In one possible implementation, the bridgeless PFC2 further includes an eighth resistor R8 and a ninth resistor R9, wherein the eighth resistor R8 is connected in series between the first diode D1 and the first resistor R1, and the ninth resistor R9 is connected in series between the second diode D2 and the first resistor R1; the first detection interface is connected between the second diode D2 and the ninth resistor R9, and the second detection interface is connected between the first diode D1 and the eighth resistor R8.

[0049] By setting the eighth resistor R8 and the ninth resistor R9, the voltage at the detection interface can be distinguished from the current at the first interface of the overcurrent protection circuit 3 and the second capacitor C2, thereby maintaining the operation of the overcurrent protection circuit 3.

[0050] In one possible implementation, the preset current threshold is determined by the resistance value of the seventh resistor R7 and the resistance value of the fourth resistor R4;

[0051] Alternatively, the preset current threshold can be determined by the resistance values ​​of the fifth resistor R5 and the sixth resistor R6.

[0052] Specifically, when the preset current threshold is determined, in the inactive state, the voltage at A1 is the same as the voltage at R7 and R8; therefore, the voltage value at A1 is fixed. After an abnormal increase in current, the voltage at R8 will increase, and therefore the voltage value at A1 will increase. When this voltage increase drives the voltage at V1 to reach the threshold for N7 to turn on, the overcurrent protection circuit 3 will be activated. Therefore, the preset current threshold can be determined through the above voltage correlation. Since the resistance values ​​of R7 and R6 are the same, and the resistance values ​​of R4 and R5 are the same, the preset current threshold can be calculated by using any two of these resistance values.

[0053] Specifically, the threshold voltage Vth of N7 is the same as the voltage on R4. The current flowing through R7 and R4 is Vth / R4. The overall voltage at R8 is Vth / R4*(R4+R7). The current flowing through R8 is Vth / R4*(R4+R7) / R8. Therefore, this can be determined as the preset current threshold.

[0054] In one possible implementation, such as Figure 3As shown, the redundant load 5 includes: an eighth MOSFET P8, an eleventh resistor R11, and a fifth capacitor C5. The control terminal of the eighth MOSFET P8 is connected to the control unit 6, the source of the eighth MOSFET P8 is connected to the first output terminal of the resonant circuit 4, and the drain of the eighth MOSFET P8 is connected in series with the eleventh resistor to form the first output terminal of the redundant load 5. The first output terminal of the resonant circuit 4 is connected to the second output terminal of the redundant load 5, and one end of the fifth capacitor C5 is connected to the first output terminal of the redundant load 5 while the other end is grounded.

[0055] The control unit 6 is used to control the on-resistance of the eighth MOS transistor P8 according to the current output power of the inverter power supply to be tested, so as to adjust the power of the redundant load 5.

[0056] Specifically, since the sum of the power received by the inverter under test through the DC power supply and the output power of the AC electronic load module is the same as the input power of the inverter under test, a stable DC power supply needs to be provided to the inverter under test during aging tests. Because the performance of the inverter under test will degrade during aging tests, there may be situations where the load needs to be adjusted. Therefore, the control unit 6 can be used to control the on-resistance of the eighth MOSFET P8 to adjust the power of the redundant load 5. Specifically, controlling the on-resistance of the eighth MOSFET P8 is done by controlling the gate voltage of the eighth MOSFET P8, thereby controlling the on-voltage of the eighth MOSFET P8, making the eighth MOSFET P8 in an adjustable resistance state, and thus adjusting the overall resistance value of the redundant load.

[0057] When the control unit detects the current output power of the inverter under test, it can use a common output power detection method to obtain the current output power of the inverter under test.

[0058] In one possible implementation, the AC electronic load module further includes a tenth resistor R10, which is connected in series in the filter circuit 1 between the output terminal of the first inductor L1 and one input terminal of the bridgeless PFC2; the tenth resistor R10 is a current sampling resistor.

[0059] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0060] 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.

[0061] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. An AC electronic load module, characterized in that, The AC electronic load module includes a filter circuit, a bridgeless power accelerator (PFC), an overcurrent protection circuit, a resonant circuit, a redundant load, and a control unit. The AC input port is connected to the input terminal of the bridgeless PFC through the filter circuit. The output terminal of the bridgeless PFC is connected to the input terminal of the resonant circuit through the overcurrent protection circuit. The control terminal of the bridgeless PFC is connected to the control unit. The output terminal of the resonant circuit is connected to the input terminal of the inverter power supply under test through the redundant load. The overcurrent protection circuit is used to provide overcurrent protection for the AC electronic load module after the output current of the bridgeless PFC exceeds a preset current threshold. The bridgeless PFC includes: a first inductor, a first diode, a second diode, a first MOSFET, a second MOSFET, a first capacitor, a first resistor, a second resistor, a third resistor, and a second capacitor. The first terminal of the first inductor is a first signal input terminal and is connected to the first output terminal of the filter circuit. The second terminal of the first inductor is connected to the drain of the first MOSFET and the first terminal of the first diode. The second terminal of the first diode is connected to the second terminal of the second diode and then connected in series with the first resistor to form a first rectified output line. The first terminal of the first capacitor is connected to the first rectified output line, and the second terminal of the first capacitor is grounded. The first terminal of the second diode is connected to the second output terminal of the filter circuit and the drain of the second MOSFET. The gates of the first MOSFET and the second MOSFET are respectively connected to the control unit, and the sources of the first MOSFET and the second MOSFET are connected to form a second rectified output line. The second capacitor and the second resistor are connected in series between the first rectifier output line and the second rectifier output line, and the second rectifier output line is grounded; The third resistor is connected to the first rectifier output line and then connected to the overcurrent protection circuit. The overcurrent protection circuit includes a third MOSFET P3, a fourth MOSFET P4, a fifth MOSFET P5, a sixth MOSFET P6, a seventh MOSFET N7, a fourth resistor, a fifth resistor, a sixth resistor, and a seventh resistor. The first interface of the overcurrent protection circuit is connected to the source of the third MOSFET P3, the source of the fourth MOSFET P4, the source of the fifth MOSFET P5, the source of the sixth MOSFET P6, and the third resistor. The gate of the third MOSFET P3 is connected to the gate of the fourth MOSFET P4, the drain of the third MOSFET P3, and the seventh MOSFET N7. The drains of the fourth MOS transistor P4 are connected to the gates of the fifth MOS transistor P5 and the sixth MOS transistor P6. The drain of the fifth MOS transistor P5 is connected to the first end of the fifth resistor and the second end of the sixth resistor. The first end of the sixth resistor forms a first detection interface. The second end of the fifth resistor is connected to the second end of the fourth resistor and the gate of the seventh MOS transistor N7. The drain of the sixth MOS transistor P6 is connected to the first end of the fourth resistor and the second end of the seventh resistor. The first end of the seventh resistor forms a second detection interface. The source of the seventh MOS transistor N7 is grounded.

2. The AC electronic load module according to claim 1, characterized in that, The overcurrent protection circuit further includes a second inductor and a third inductor. The first end of the sixth resistor is connected in series with the second inductor to form a first detection interface. The first end of the seventh resistor is connected in series with the third inductor to form a second detection interface.

3. The AC electronic load module according to claim 2, characterized in that, The overcurrent protection circuit further includes a third capacitor, a fourth capacitor, a third diode, and a fourth diode. The anode of the fourth diode is connected to the first terminal of the fifth resistor, and the cathode of the fourth diode is grounded through the fourth capacitor. The anode of the third diode is connected to the first terminal of the fourth resistor, and the cathode of the third diode is grounded through the third capacitor.

4. The AC electronic load module according to claim 2 or 3, characterized in that, The bridgeless PFC also includes an eighth resistor and a ninth resistor. The eighth resistor is connected in series between the first diode and the first resistor, and the ninth resistor is connected in series between the second diode and the first resistor. The first detection interface is connected between the second diode and the ninth resistor, and the second detection interface is connected between the first diode and the eighth resistor.

5. The AC electronic load module according to claim 4, characterized in that, The preset current threshold is determined by the resistance value of the seventh resistor and the resistance value of the fourth resistor; Alternatively, the preset current threshold can be determined by the resistance values ​​of the fifth resistor and the sixth resistor.

6. The AC electronic load module according to claim 5, characterized in that, The redundant load includes an eighth MOSFET P8, an eleventh resistor, and a fifth capacitor. The gate of the eighth MOSFET P8 is connected to the control unit, the source of the eighth MOSFET P8 is connected to the first output terminal of the resonant circuit, the drain of the eighth MOSFET P8 is connected in series with the eleventh resistor to form the first output terminal of the redundant load, the second output terminal of the resonant circuit is connected to the second output terminal of the redundant load, one end of the fifth capacitor is connected to the first output terminal of the redundant load, and the other end of the fifth capacitor is grounded. The control unit is used to control the on-resistance of the eighth MOSFET P8 according to the current output power of the inverter power supply under test, so as to adjust the power of the redundant load.

7. The AC electronic load module according to claim 6, characterized in that, The AC electronic load module also includes a tenth resistor, which is connected in series between the second output terminal of the filter circuit and the first terminal of the second diode; the tenth resistor is a current sampling resistor.

8. An AC electronic load device, characterized in that, It includes a circuit board and an AC electronic load module as described in any one of claims 1-7, wherein the AC electronic load module is disposed on the circuit board.

9. An AC electronic load device, characterized in that, It includes a housing and an AC electronic load device as described in claim 8, wherein the AC electronic load device is disposed inside the housing.

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