An air conditioning apparatus

Abstract

This application discloses an air conditioning device, in which a protection circuit detects leakage current generated in the power supply circuit through a leakage current detection module and outputs a detection voltage based on the leakage current. A comparison module determines whether the detection voltage falls within a first voltage range, and outputs a first signal if the detection voltage does not fall within the first voltage range. Upon receiving the first signal, the protection module disconnects the power supply circuit. Simultaneously, a controller determines whether the detection voltage value falls within a second voltage range, and outputs a second signal if the detection voltage does not fall within the second voltage range. Upon receiving the second signal, the protection module can also disconnect the power supply circuit. Since the judgments of the comparison module and the controller are independent of each other, even if either the comparison module or the controller fails, the protection circuit can still disconnect the power supply circuit when the leakage current is too large. This protection circuit has a low failure rate and high reliability of leakage protection.

Description

Technical Field

[0001] This application relates to the field of air conditioning equipment technology, specifically to an air conditioning device. Background Technology

[0002] Air conditioning units typically do not have built-in leakage current detection, as existing air conditioning units are used in conjunction with leakage current protection devices.

[0003] Leakage current typically occurs due to insulation damage in electrical equipment or damage to the outer sheath of wires, causing current to flow through unexpected paths. Excessive leakage current can lead to equipment damage, short circuits, and other problems. Leakage current protection prevents equipment from continuing to operate and avoids serious electrical faults by promptly detecting and cutting off the power supply.

[0004] In related technologies, residual current devices (RCDs) are generally used to protect against leakage current. However, the high degree of interdependence between the various components in an RCD means that the RCD cannot provide leakage protection when a component fails. As a result, the failure rate of RCDs is high and the reliability of leakage protection is poor. Summary of the Invention

[0005] This application discloses an air conditioning device with a low failure rate of the protection circuit, which improves the reliability of leakage protection.

[0006] This application discloses an air conditioning device, including:

[0007] load;

[0008] A power supply module, which forms a power supply circuit with the load, is used to supply power to the load;

[0009] A protection circuit, connected to the power supply module, includes:

[0010] The leakage current detection module is used to detect the leakage current generated in the power supply circuit and output a detection voltage based on the leakage current.

[0011] A comparison module is connected to the leakage current detection module. The comparison module is used to determine whether the detected voltage belongs to a first voltage range. If the detected voltage does not belong to the first voltage range, a first signal is output.

[0012] A controller, connected to the leakage current detection module, is used to determine whether the voltage value of the detected voltage belongs to a second voltage range. If the voltage value of the detected voltage does not belong to the second voltage range, a second signal is output; wherein, the second voltage range belongs to the first voltage range.

[0013] A protection module is connected to both the comparison module and the controller. The protection module is used to disconnect the power supply circuit upon receiving the first signal or the second signal.

[0014] The protection module includes a first switching unit, which is connected to the comparison module and the controller respectively, and is connected in series in the power supply circuit.

[0015] The first switching unit is configured to be in an open state upon receiving the first signal or the second signal, thereby disconnecting the power supply circuit.

[0016] In this embodiment, a leakage current detection module detects the leakage current generated in the power supply circuit and outputs a detection voltage based on the leakage current. A comparison module determines whether the detection voltage falls within a first voltage range. If the detection voltage does not fall within the first voltage range, it outputs a first signal. Upon receiving the first signal, the protection module disconnects the power supply circuit. Simultaneously, a controller determines whether the detection voltage value falls within a second voltage range. If the detection voltage does not fall within the second voltage range, it outputs a second signal. Upon receiving the second signal, the protection module can also disconnect the power supply circuit. Since the judgments of the comparison module and the controller are independent of each other, and the protection module can disconnect the power supply circuit in response to the first signal output by the comparison module and the second signal output by the controller, the functions and connections of the comparison module and the controller in this protection circuit are independent. Even if either the comparison module or the controller fails, the judgment can still be achieved through another undamaged device. This ensures that the protection circuit can still disconnect the power supply circuit when the leakage current is too large. This protection circuit has a low failure rate and high reliability of leakage protection.

[0017] Meanwhile, since the controller's response speed is slower than that of the comparator module, and the leakage current in the power supply circuit gradually increases, by setting the second voltage range to fall within the range of the first voltage range, the controller outputs the second signal when the leakage current is smaller. This avoids the power supply circuit from deteriorating too much before being disconnected due to the controller's slow response speed. This ensures that even if the comparator module is damaged, the power supply circuit can be disconnected in time, further improving the reliability of the leakage protection circuit.

[0018] Furthermore, by connecting the first switching unit in series with the power supply circuit, the first switching unit is in an open state when it receives the first signal or the second signal, thereby disconnecting the power supply circuit, simplifying the circuit structure and reducing the hardware cost of the protection circuit.

[0019] In some embodiments, the power supply circuit includes a first bus and a second bus; the leakage current detection module includes a leakage current sensor and a sampling unit, the leakage current sensor being connected to the first bus and the second bus respectively, and the sampling unit being connected to the leakage current sensor, the comparison module and the controller respectively;

[0020] The leakage current sensor is used to collect the first bus current of the first bus and the second bus current of the second bus, and output a first voltage based on the first bus current and the second bus current.

[0021] The sampling unit is used to sample the first voltage output by the leakage current sensor to obtain the detection voltage.

[0022] In this embodiment, the leakage current sensor can collect the first bus current of the first bus and the second bus current of the second bus, and output a first voltage based on the first bus current and the second bus current, so that the sampling unit can directly sample the first voltage output by the leakage current sensor to obtain the detection voltage. Compared with the leakage current sensor that directly outputs current, the leakage current sensor in this embodiment outputs a first voltage without the need to set up a component to convert the current signal into a voltage signal, thus reducing the hardware cost of the protection circuit.

[0023] In some embodiments, the sampling unit includes a bias subunit and an amplification subunit, wherein the amplification subunit is connected to the leakage current sensor, the bias subunit, the comparison module, and the controller, respectively.

[0024] The bias subunit is used to provide a positive bias voltage to the amplification subunit;

[0025] The amplification subunit is used to amplify the voltage based on the bias voltage, the first voltage, and the reference voltage to obtain the detection voltage.

[0026] In this embodiment, by setting the bias subunit to provide a positive bias voltage to the amplification subunit, compared to using the amplification subunit to sample based on the first voltage to obtain the detection voltage, the voltage range to which the detection voltage belongs can be adjusted, thereby obtaining a detection voltage within the required voltage range, so that the controller or comparison module can judge the detection voltage, thus improving the judgment accuracy of the controller and comparison module.

[0027] In some embodiments, the bias subunit includes:

[0028] A voltage divider circuit is connected to the voltage input terminal. The voltage divider circuit is used to divide the second voltage provided by the voltage input terminal to obtain a voltage divider.

[0029] A voltage follower is connected to both the voltage divider circuit and the amplification subunit, and generates a positive bias voltage based on the voltage divider voltage to provide the positive bias voltage to the amplification subunit.

[0030] In this embodiment, the voltage follower can effectively output a bias voltage that follows the voltage divider voltage of the input voltage follower, which can improve the stability of the positive bias voltage provided to the amplification subunit. This ensures the stability of the detection voltage obtained by the amplification subunit based on the bias voltage, the first voltage, and the reference voltage.

[0031] In some embodiments, the amplification subunit includes a differential amplifier circuit, the first input terminal of the differential amplifier circuit is connected to the voltage output terminal of the leakage current sensor, the second input terminal of the differential amplifier circuit is connected to the reference voltage terminal of the leakage current sensor, the third input terminal of the differential amplifier circuit is connected to the bias subunit, and the output terminal of the differential amplifier circuit is connected to the comparison module and the controller, respectively.

[0032] The differential amplifier circuit is used to differentially amplify the first voltage and the reference voltage corresponding to the reference voltage terminal of the leakage current sensor based on the bias voltage to obtain the detection voltage.

[0033] Since both the first voltage and the reference voltage are provided by the leakage current sensor, the first voltage and the reference voltage are similarly affected by noise, or even the same. In this embodiment, by selecting a leakage current sensor with a reference voltage terminal, and using a differential amplifier circuit based on the bias voltage to differentially amplify the first voltage output from the voltage output terminal of the leakage current sensor and the reference voltage output from the reference voltage terminal of the leakage current sensor, the same noise can be canceled out. That is, the detection voltage output by the differential amplifier circuit contains less noise components, improving the accuracy of the obtained detection voltage, thereby ensuring the accuracy of the judgment of the comparison module and the controller.

[0034] In some embodiments, the upper limit of the first voltage range corresponds to a first reference voltage, and the lower limit of the first voltage range corresponds to a second reference voltage; the comparison module includes:

[0035] The first comparison unit is connected to the leakage current detection module and the protection module respectively. The first comparison unit is used to compare the detected voltage with the first reference voltage. If the detected voltage is greater than the first reference voltage, a first signal is output.

[0036] The second comparison unit is connected to both the leakage current detection module and the protection module. The second comparison unit is used to compare the detected voltage with the second reference voltage. If the detected voltage is less than the second reference voltage, a first signal is output.

[0037] In this embodiment, a first comparison unit is set to detect whether the detected voltage exceeds the upper limit value corresponding to the first voltage range, and a second comparison unit is set to detect whether the detected voltage is lower than the lower limit value of the first voltage range. The first and second comparison units provide a first signal to the protection module 140 when the detected voltage exceeds the upper limit value corresponding to the first voltage range and when the detected voltage is lower than the lower limit value of the first voltage range, so that the protection module disconnects the power supply circuit, thereby avoiding damage to the load due to excessive leakage current.

[0038] In some embodiments, the comparison module further includes an output unit, which is connected to the first comparison unit, the second comparison unit, and the protection module respectively;

[0039] The output unit is configured to be in an ON state when it receives a first signal output by the first comparison unit or a first signal output by the second comparison unit, so as to open the path between the comparison module and the protection module and output the first signal to the protection module.

[0040] In this embodiment, by setting an output unit, the output unit is in the conducting state when either the first comparison unit outputs a first signal or the second comparison unit outputs a first signal, so as to output the first signal received by the output unit to the protection module. This eliminates the need for the protection module to judge the received signal, thereby reducing the design difficulty of the protection module.

[0041] In some embodiments, the protection module further includes an input unit, which is connected to the comparison module, the controller, and the first switch unit respectively;

[0042] The input unit is configured to be in an ON state when it receives the first signal output by the comparison module, so as to open the path between the comparison module and the first switch unit and output the first signal to the first switch unit.

[0043] In some embodiments, the input unit is further configured to be in an ON state when receiving a second signal output by the controller, so as to open the path between the controller and the first switch unit and output the second signal to the first switch unit.

[0044] In this embodiment, the input unit can be in a conducting state when it receives a first signal output by the comparison module, thereby establishing a path between the comparison module and the first switching unit to output a first signal to the first switching unit. The input unit can also be in a conducting state when it receives a second signal output by the controller, thereby establishing a path between the controller and the first switching unit to output the second signal to the first switching unit. By configuring the input unit so that it is in a conducting state whether the comparison module outputs a first signal or the controller outputs a second signal, and outputs the received first or second signal to the first switching unit, the power supply circuit can be disconnected when the leakage current deviates from the voltage range, thus improving the safety of the power supply circuit. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in 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.

[0046] Figure 1 This is a schematic diagram of the structure of a protection circuit disclosed in an embodiment of this application;

[0047] Figure 2 This is a schematic diagram of a leakage current detection module disclosed in an embodiment of this application;

[0048] Figure 3 This is a schematic diagram of a sampling unit disclosed in an embodiment of this application;

[0049] Figure 4 This is a schematic diagram of a bias sub-unit disclosed in an embodiment of this application;

[0050] Figure 5 This is a schematic diagram of a subunit of an enlarged subunit disclosed in an embodiment of this application;

[0051] Figure 6 This is a schematic diagram of a comparison module disclosed in an embodiment of this application;

[0052] Figure 7 This is a schematic diagram of another comparison module disclosed in an embodiment of this application;

[0053] Figure 8 This is a schematic diagram of an output unit disclosed in an embodiment of this application;

[0054] Figure 9 This is a schematic diagram of a protection module disclosed in an embodiment of this application;

[0055] Figure 10 This is a schematic diagram of a first switching unit disclosed in an embodiment of this application;

[0056] Figure 11 This is a schematic diagram of another protection module disclosed in an embodiment of this application;

[0057] Figure 12 This is a schematic diagram of another protection circuit disclosed in an embodiment of this application;

[0058] Figure 13 This is a schematic diagram of another protection module disclosed in an embodiment of this application;

[0059] Figure 14 This is a flowchart illustrating a protection method disclosed in an embodiment of this application. Detailed Implementation

[0060] 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.

[0061] It should be noted that the terms "comprising" and "having," and any variations thereof, in the embodiments and accompanying drawings of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices.

[0062] In related technologies, leakage current protectors generally include a detection circuit, a comparison circuit, and an actuator. The detection circuit detects the leakage current in the circuit under test, and the comparison circuit determines whether the leakage current is too large. If the leakage current is too large, the actuator is triggered to disconnect the circuit under test. Because any circuit in the leakage current protector will fail if any circuit fails, meaning the actuator will not disconnect the circuit even if the leakage current is too large, the leakage current protector has a high failure rate and poor reliability.

[0063] This application discloses an air conditioning device with a low failure rate of the protection circuit, which improves the reliability of leakage protection.

[0064] The air conditioning unit includes a load, a power supply module, and a protection circuit. A power supply loop is formed between the load and the power supply module. The power supply module supplies power to the load, and the protection circuit is connected to the power supply module.

[0065] The load can be a device that requires power, such as a compressor motor or a fan motor.

[0066] Please refer to Figure 1 It shows a schematic diagram of the structure of a protection circuit provided in an embodiment of this application, such as... Figure 1 As shown, the protection circuit 100 may include a leakage current detection module 110, a comparison module 120, a controller 130, and a protection module 140. The comparison module 120 is connected to the leakage current detection module 110, the controller 130 is connected to the leakage current detection module 110, and the protection module 140 is connected to both the comparison module 120 and the controller 130. The leakage current detection module 110 detects the leakage current generated in the power supply circuit and outputs a detection voltage based on the leakage current. The comparison module 120 determines whether the detection voltage falls within a first voltage range; if the detection voltage does not fall within the first voltage range, it outputs a first signal. The controller 130 determines whether the detection voltage value falls within a second voltage range; if the detection voltage value does not fall within the second voltage range, it outputs a second signal. The protection module 140 disconnects the power supply circuit upon receiving either the first or second signal. The second voltage range is within the first voltage range.

[0067] It should be noted that the power supply circuit may include a power supply module and a load, that is, a power supply circuit is formed between the power supply module and the load. The power supply module is used to supply power to the load. The leakage current generated by the power supply circuit can refer to the unbalanced part of the current in the power supply circuit, that is, the part where the current flowing out of the power supply module is not equal to the current flowing into the power supply module. The detection voltage output by the leakage current detection module 110 is correlated with the leakage current generated by the power supply circuit, such as a positive correlation or a positive correlation between the detection voltage output by the leakage current detection module 110 and the leakage current generated by the power supply circuit. The second voltage range belonging to the first voltage range means that the second voltage range is a subset of the first voltage range. For example, the second voltage range is [a, b], and the first voltage range is [c, d], where a is greater than c and b is less than d. Optionally, the controller may include an MCU (Microcontroller Unit).

[0068] It should be noted that the comparison module 120 implements the comparison of the detected voltage through hardware circuitry. The controller 130 needs to perform analog-to-digital conversion on the analog detected voltage to obtain a digital signal, that is, to obtain the voltage value corresponding to the detected voltage, and then perform numerical comparison. The response time of the controller 130 is longer than that of the comparison module 120. By setting the second voltage range to be within the range of the first voltage range, it is possible to avoid serious damage to the palace circuit due to the long time required to output the second signal, which could result in the power supply circuit being disconnected in a timely manner.

[0069] It should be noted that the power supply circuit may generate both forward and reverse leakage current. Taking the positive correlation between the detection voltage output by the leakage current detection module 110 and the leakage current generated by the power supply circuit as an example, the larger the forward leakage current, the larger the detection voltage; conversely, the larger the reverse leakage current, the smaller the detection voltage. Alternatively, taking the negative correlation between the detection voltage output by the leakage current detection module 110 and the leakage current generated by the power supply circuit as an example, the larger the forward leakage current, the smaller the detection voltage; and the larger the reverse leakage current, the larger the detection voltage. By comparing the detection voltage with the first voltage range (as determined by the comparison module 120), it is possible to determine whether the forward or reverse leakage current generated by the power supply circuit is excessive. Similarly, by controlling the detection voltage with the second voltage range (as determined by the controller 130), it is possible to determine whether the forward or reverse leakage current generated by the power supply circuit is excessive.

[0070] It should be noted that, upon receiving the first signal or the second signal, the protection module 140 disconnects the power supply circuit to prevent the power supply circuit from becoming dangerous if the leakage current generated in the power supply circuit is too large. It should also be noted that the first signal and the second signal can be the same or different. For example, both the first signal and the second signal can be high-level signals, or both can be low-level signals, or one of the first signal and the other can be high-level signals and the other low-level signal. This embodiment does not limit this.

[0071] In some embodiments, the power supply circuit may include a first bus and a second bus. The leakage current detection module can be used to detect the current difference between the first bus current of the first bus and the second bus current of the second bus, and output a detection voltage based on the current difference. Optionally, the leakage current detection module 110 may include a current transformer and a sampling resistor. The current transformer includes a toroidal core and a coil wound on the toroidal core. A first end of the coil is connected to a first end of the sampling resistor, and a second end of the coil is connected to a second end of the sampling resistor. The induced current induced by the current transformer is converted into a voltage through the sampling resistor, and the voltage difference across the sampling resistor can be used as the detection voltage.

[0072] It should be noted that the first and second busbars pass through the toroidal core. The current transformer can determine whether leakage current occurs in the power supply circuit by detecting the current difference between the first and second busbars. When the leakage current in the power supply circuit is small or non-existent, the currents in the first and second busbars are equal in magnitude and opposite in direction. The magnetic flux generated by the currents in the first and second busbars in the current transformer largely cancels each other out, resulting in a very small or no induced current signal output from the current transformer coil, and a low detection voltage. When the leakage current in the power supply circuit is large, the currents in the first and second busbars differ significantly, resulting in a large induced current output from the secondary side of the current transformer, and a large detection voltage.

[0073] For example, a positive leakage current can refer to a situation where the first bus current of the first bus is greater than the second bus current of the second bus. In this case, the current difference between the first bus current and the second bus current is positive, and the detection voltage is negative. A reverse leakage current can refer to a situation where the first bus current of the first bus is less than the second bus current of the second bus. In this case, the current difference between the first bus current and the second bus current is negative, and the detection voltage is negative. Furthermore, the larger the absolute value of the current difference, the larger the absolute value of the detection voltage. Optionally, the first bus can be a positive DC bus, and the second bus can be a negative DC bus.

[0074] In some embodiments, the protection circuit 100 may be disposed on the control board of the electronic device. The control board may include a circuit board, on which the leakage current detection module 110, the comparison module 120, the controller 130, and the protection module 140 are all disposed. Compared with using a leakage current protector to achieve leakage current protection, by setting the protection circuit 100 on the control board of the electronic device, the electronic device can have its own leakage current protection function, thereby improving the safety of the electronic device.

[0075] In some embodiments, the comparison module 120 can be used to compare a first reference voltage with a detected voltage, and to compare a second reference voltage with a detected voltage. If the detected voltage is greater than the first reference voltage, or less than the second reference voltage, a first signal is output. The first reference voltage corresponds to the upper limit of a first voltage range, and the second reference voltage corresponds to the lower limit of the first voltage range. That is, the voltage value corresponding to the first reference voltage is the upper limit of the first voltage range, and the voltage value corresponding to the second reference voltage is the lower limit of the first voltage range. In this embodiment, by comparing the first reference voltage with the detected voltage and comparing the second reference voltage with the detected voltage using module 120, it is possible to quickly and accurately determine whether the detected voltage belongs to the first voltage range.

[0076] In some embodiments, the comparison module 120 is further configured to output a third signal if the voltage value of the detected voltage falls within a first voltage range, wherein the third signal is different from the first signal.

[0077] In some embodiments, the controller 130 can also be used to perform analog-to-digital conversion on the detected voltage to obtain the voltage value of the detected voltage, and determine whether the voltage value of the detected voltage belongs to the second voltage range. If the voltage value of the detected voltage does not belong to the second voltage range, a second signal is output.

[0078] In some embodiments, the controller 130 can also be used to determine whether the voltage value of the detected voltage is greater than a first target voltage value and whether the voltage value of the detected voltage is less than a second target voltage value. If the voltage value of the detected voltage is greater than the first target voltage value or less than the second target voltage value, then it is determined that the voltage value of the detected voltage does not belong to the second voltage range. If the voltage value of the detected voltage is less than or equal to the first target voltage value and greater than or equal to the second target voltage value, then it is determined that the voltage value of the detected voltage belongs to the second voltage range. It should be noted that the first target voltage value is the upper limit of the second voltage range, and the second target voltage value is the lower limit of the second voltage range.

[0079] In some embodiments, the controller 130 is further configured to output a fourth signal if the voltage value of the detected voltage falls within a second voltage range, wherein the fourth signal is different from the second signal.

[0080] In some embodiments, the protection module 140 is further configured to maintain the power supply circuit on when it receives a third signal output by the comparison module 120 and a fourth signal output by the controller 130. It should be noted that when the comparison module 120 outputs the third signal and the controller 130 outputs the fourth signal, the detected voltage is considered to be within a first voltage range and a second voltage range, meaning that the power supply circuit does not generate leakage current or the generated leakage current is very small. In this case, the power supply circuit can be maintained on to allow the power supply module to supply power to the load, improving the accuracy of leakage protection and ensuring the normal operation of the power supply circuit.

[0081] In some embodiments, the input terminal of the comparison module 120 is connected to the output terminal of the leakage current detection module 110, and the comparison module 120 can receive the detection voltage output by the leakage current detection module 110. The input terminal of the controller 130 is connected to the output terminal of the leakage current detection module 110, and the controller 130 can receive the detection voltage output by the leakage current detection module 110. The protection module 140 is connected to the comparison module 120 and the controller 130 respectively, and the protection module 140 can receive the first signal or the third signal output by the comparison module 120, and the second signal or the fourth signal output by the controller 130 respectively.

[0082] It should be noted that, even if the comparator module fails, the controller can still receive the detection voltage output by the leakage current detection module 110 and determine whether the voltage value corresponding to the detection voltage falls within the second voltage range. If the voltage value does not fall within the second voltage range, a second signal is output, causing the power supply circuit to disconnect. Even if the controller fails, the comparator module can still receive the detection voltage output by the leakage current detection module 110 and determine whether the detection voltage falls within the first voltage range. If the detection voltage does not fall within the first voltage range, a first signal is output, causing the power supply circuit to disconnect. Therefore, even if either the comparator module or the controller fails, the power supply circuit can be disconnected when the leakage current generated in the power supply circuit is too large. This results in a low failure rate of the protection circuit and improves the reliability of the leakage current protection.

[0083] Optionally, the first signal and the second signal are both high-level signals, and the third signal and the fourth signal are both low-level signals; or, the first signal and the second signal are both low-level signals, and the third signal and the fourth signal are both high-level signals.

[0084] In some embodiments, the protection module 140 may be connected in series with the power supply circuit. The on / off states of the protection module 140 include an on state and an off state. The protection module 140 is configured to be in the off state to disconnect the power supply circuit when it receives a first signal or a second signal. The protection module 140 is also configured to be in the on state to connect the power supply circuit when it receives a third signal or a fourth signal.

[0085] In some embodiments, the protection circuit 100 may further include a filtering module connected to the leakage current detection module 110, the comparison module 120, and the controller 130. The filtering module filters the detection voltage output by the leakage current detection module 110. The comparison module 120 is further configured to determine whether the filtered detection voltage falls within a first voltage range; if the detection voltage does not fall within the first voltage range, it outputs a first signal. The controller 130 is further configured to determine whether the voltage value corresponding to the filtered detection voltage falls within a second voltage range; if the voltage value falls within the second voltage range, it outputs a second signal.

[0086] For example, the filtering module may include a filter resistor and a filter capacitor. The first end of the filter resistor is connected to the leakage current detection module, and the second end of the filter resistor is connected to the first end of the filter capacitor, the comparison module, and the controller. The second end of the filter capacitor is connected to the ground terminal. The voltage at the connection point of the filter resistor and the filter capacitor is the filtered detection voltage.

[0087] In this embodiment, the detection voltage output by the leakage current detection module 110 is filtered by a filtering module to obtain a stable filtered detection voltage, thereby ensuring the accuracy of the judgment of the controller 130 and the comparison module 120.

[0088] In some embodiments, the controller 130 is further configured to perform a protection operation when the detected voltage value does not fall within the second voltage range, and output a second signal when the execution duration reaches the target duration. It should be noted that since the second voltage range is set relatively small, the controller 130 can perform the protection operation first and then output the second signal when it determines that the detected voltage value does not fall within the second voltage range, so that the protection module 140 disconnects the power supply circuit. At this time, the leakage current is still within the tolerance range of the power supply circuit, meaning it will not cause significant damage to the power supply circuit. The target duration is the duration required to perform the protection operation, ensuring that the power supply circuit is disconnected only after the protection operation is completed, avoiding forced shutdown of the power supply circuit and improving the operational reliability of the power supply circuit.

[0089] For example, the controller 130 may perform protection operations such as recording leakage current and outputting prompt messages. The leakage current information may include, but is not limited to, leakage current data, a timestamp corresponding to the detection of excessive leakage current, environmental conditions (ambient temperature, ambient humidity, etc.), and equipment operating status, providing data support for subsequent leakage current analysis and circuit maintenance. The prompt messages can be used to indicate that the leakage current generated in the power supply circuit is excessive.

[0090] In this embodiment, by setting the second voltage range to be relatively small, the controller 130 can perform a protection operation first when it determines that the voltage value of the detected voltage does not belong to the second voltage range, and then output a second signal to make the protection module 140 disconnect the power supply. This reduces damage to the power supply circuit and improves stability by taking a protection operation before disconnecting the power supply circuit.

[0091] In this embodiment, the leakage current detection module 110 detects the leakage current generated in the power supply circuit and outputs a detection voltage based on the leakage current. The comparison module 120 is used to determine whether the detection voltage belongs to the first voltage range. If the detection voltage does not belong to the first voltage range, a first signal is output. When the protection module 140 receives the first signal, it disconnects the power supply circuit. Meanwhile, the controller 130 is used to determine whether the voltage value of the detected voltage belongs to the second voltage range, and outputs a second signal when the detected voltage does not belong to the second voltage range. The protection module 140 can also disconnect the power supply circuit when it receives the second signal. Since the judgments of the comparison module 120 and the controller 130 are independent of each other, and the protection module 140 can disconnect the power supply circuit in response to the first signal output by the comparison module 120 and the second signal output by the controller 130, the functions and connection relationship of the comparison module 120 and the controller 130 of the protection circuit 100 are independent of each other. If either the comparison module 120 or the controller 130 is damaged, the judgment can still be achieved through other undamaged devices, so that the protection circuit 100 can still disconnect the power supply circuit when the leakage current is too large. The failure rate of the protection circuit 100 is low and the reliability of leakage protection is high.

[0092] Meanwhile, since the response speed of the controller 130 is slower than that of the comparator module 120, and the leakage current of the power supply circuit gradually increases, by setting the second voltage range to be within the range of the first voltage range, the controller 130 outputs the second signal when the leakage current is smaller. This avoids the power supply circuit from deteriorating too much before being disconnected due to the slower response speed of the controller 130. This ensures that even if the comparator module 120 is damaged, the power supply circuit can be disconnected in time, further improving the reliability of the leakage protection of the protection circuit 100.

[0093] Furthermore, by connecting the first switching unit in series with the power supply circuit, the first switching unit is in an open state when it receives the first signal or the second signal, thereby disconnecting the power supply circuit, simplifying the circuit structure and reducing the hardware cost of the protection circuit.

[0094] Please refer to Figure 2 This illustrates a schematic diagram of a leakage current detection module provided in an embodiment of this application. Figure 2As shown, the power supply circuit may include a first bus 210 and a second bus 220. The leakage current detection module includes a leakage current sensor 230 and a sampling unit 240. The leakage current sensor 230 is connected to both the first bus 210 and the second bus 220, and the sampling unit 240 is connected to the leakage current sensor 230, the comparison module 120, and the controller 130. The leakage current sensor 230 is used to collect the first bus current of the first bus 210 and the second bus current of the second bus 220, and outputs a first voltage based on these currents. The sampling unit 240 samples the first voltage output by the leakage current sensor 230 to obtain a detection voltage.

[0095] It should be noted that the first bus current is the current of the first bus 210, or the current output from the output terminal of the power supply module, and the second bus current is the current on the second bus 220, or the current flowing into the input terminal of the power supply module. For example, the first bus 210 and the second bus 220 are DC buses. In this embodiment, a leakage current sensor 230, capable of outputting a corresponding voltage value based on the first bus current and the second bus current, is selected to detect the leakage current of the power supply circuit. Thus, the detection voltage corresponding to the leakage current of the power supply circuit can be directly obtained through the leakage current sensor 230. Compared to using a leakage current sensor 230 that outputs current based on the first bus current and the second bus current, the detection voltage can be obtained simply by setting up the leakage current sensor 230, without needing to set up components to convert current values ​​to voltage values. This reduces the need for components that convert current to voltage, lowering the hardware cost of the protection circuit.

[0096] In some embodiments, the leakage current sensor 230 may include a first current input terminal, a second current input terminal, and a voltage output terminal. The first current input terminal of the leakage current sensor 230 is connected to the first bus 210, and the second current input terminal is connected to the second bus 220. The leakage current sensor 230 can output a first voltage from its voltage output terminal based on the current difference between the first bus current and the second bus current. This first voltage is positively correlated with the current difference between the first bus current and the second bus current. For example, if the first bus current is greater than the second bus current, the first voltage is positive; if the first bus current is less than the second bus current, the first voltage is negative.

[0097] In some embodiments, the sampling unit 240 may include a first operational amplifier, the inverting input of which is connected to the output of the first operational amplifier, the non-inverting input of a second operational amplifier which is connected to the leakage current sensor 230, and the output of the first operational amplifier which is connected to the comparison module 120 and the controller 130, respectively.

[0098] It should be noted that the voltage at the output terminal of the first operational amplifier is the same as the voltage at the inverting input terminal of the first operational amplifier. Since the voltage at the inverting input terminal of the first operational amplifier is the same as the voltage at the non-inverting input terminal of the first operational amplifier, the voltage at the output terminal of the first operational amplifier is the same as the first voltage output by the leakage current sensor 230, meaning the detected voltage is the same as the first voltage. In this embodiment, by connecting the first operational amplifier to the leakage current sensor 230, the comparator module 120, and the controller 130, the leakage current sensor 230 can be isolated from the comparator module 120 and the controller 130, avoiding mutual interference and influence between the leakage current sensor 230 and the comparator module 120, and between the leakage current sensor 230 and the controller 130.

[0099] In some embodiments, the sampling unit 240 may include a first resistor and a second resistor connected in series. A first end of the first resistor is connected to a first end of the second resistor, a second end of the first resistor is connected to a leakage current sensor 230, and a second end of the second resistor is connected to a ground terminal. The connection point of the first and second resistors is connected to a comparison module 120 and a control module, respectively. It should be noted that the voltage at the connection point of the first and second resistors is the detection voltage. By adjusting the values ​​of the first and second resistors, the relationship between the detection voltage and the first voltage can be adjusted.

[0100] In this embodiment, the leakage current sensor 230 can collect the first bus current of the first bus 210 and the second bus current of the second bus 220, and output a first voltage based on the first bus current and the second bus current, so that the sampling unit 240 can directly sample the first voltage output by the leakage current sensor 230 to obtain the detection voltage. Compared with the leakage current sensor that directly outputs current, the leakage current sensor in this embodiment outputs a first voltage without the need to set up a component to convert the current signal into a voltage signal, thus reducing the hardware cost of the protection circuit.

[0101] Please refer to Figure 3 This illustrates a schematic diagram of a sampling unit provided in an embodiment of this application. Figure 3 As shown, the sampling unit 300 may include a bias subunit 310 and an amplification subunit 320. The amplification subunit 320 is connected to the leakage current sensor 230, the bias subunit 310, the comparison module 120, and the controller 130, respectively. The bias subunit 310 provides a positive bias voltage to the amplification subunit 320, and the amplification subunit 320 amplifies the voltage based on the bias voltage, a first voltage, and a reference voltage to obtain the detection voltage.

[0102] It should be noted that the positive bias voltage refers to a voltage higher than the zero potential of the protection circuit, and the reference voltage can refer to the voltage used to amplify the first voltage. Since the detection circuit may generate both positive and reverse leakage current, in this embodiment, a bias subunit 310 is provided to offer a positive bias voltage to the amplification subunit 320. This allows the amplification subunit 320 to amplify the first voltage and the reference voltage based on the bias voltage g, obtaining a detection voltage that is greater than the detection voltage obtained after sampling the first voltage. This ensures the detection voltage falls within the positive voltage range, facilitating judgment by the controller 130 and the comparison module 120. For example, some controllers 130 can only perform analog-to-digital conversion on positive voltages. In this embodiment, by setting a bias voltage to ensure the obtained detection voltage falls within the positive voltage range, even a controller 130 that can only perform analog-to-digital conversion on positive voltages can determine whether the voltage value corresponding to the detection voltage belongs to the second voltage range, reducing the requirements of the protection circuit on the controller 130.

[0103] Taking the example where the first bus current collected by the leakage current sensor 230 is less than the second bus current, the power supply circuit generates a reverse leakage current, and the first voltage output by the leakage current sensor 230 is a reverse voltage, in some embodiments, the amplification subunit 320 can be used to add the bias voltage and the first voltage, and amplify the first voltage after addition and the reference voltage to obtain the detection voltage. The positive bias voltage provided by the bias subunit is greater than the detection voltage corresponding to the reverse leakage current generated by the power supply circuit. In this embodiment, since the positive bias voltage is greater than the voltage output by the leakage current sensor 230 based on the reverse leakage current generated by the power supply circuit, the amplification subunit 320 adds the bias voltage and the first voltage, resulting in a positive first voltage. This allows the detection voltage to be obtained. Even for the controller 130, which can only process positive voltages, the corresponding voltage value can be obtained and judged, enabling the controller 130 to determine whether the reverse leakage current and the in-phase leakage current are too large, thus improving the comprehensiveness of the judgment on whether the leakage current is too large.

[0104] Please refer to Figure 4 This illustrates a schematic diagram of a bias sub-unit provided in an embodiment of this application. For example... Figure 4As shown, the bias subunit 400 may include a voltage divider circuit 410 and a voltage follower 420. The voltage divider circuit 410 is connected to the voltage input terminal V1, and the voltage follower 420 is connected to both the voltage divider circuit 410 and the amplification subunit 320. The voltage divider circuit 410 is used to divide the second voltage provided at the voltage input terminal to obtain a divided voltage. The voltage follower 420 is used to generate a positive bias voltage based on the divided voltage to provide a positive bias voltage to the amplification subunit 320.

[0105] It should be noted that the positive bias voltage range may include 0 to U2, where U2 is the second voltage provided by the voltage input terminal V1. For example, the voltage divider circuit 410 may include a third resistor R1 and a fourth resistor R2. By selecting appropriate values ​​for the third resistor R1 and the fourth resistor R2, the magnitude of the divided voltage can be adjusted to provide a suitable positive bias voltage for the amplification subunit 320. For example, the third resistor R1 and the fourth resistor R2 are connected, with the first end of the third resistor R1 connected to the voltage input terminal V1, the connection point of the third resistor R1 and the fourth resistor R2 connected to the voltage follower 420, and the first end of the fourth resistor R2 connected to the ground terminal GND.

[0106] For example, the voltage follower 420 may include a first operational amplifier Q1, the inverting input of which is connected to its output, and a second operational amplifier whose non-inverting input is connected to the output of a voltage divider circuit 410. The non-inverting input of the first operational amplifier Q1 receives the divided voltage provided by the voltage divider circuit 410 and outputs the divided voltage. It should be noted that by connecting the output of the first operational amplifier Q1 to the amplification sub-unit 320, the first operational amplifier Q1 can provide a bias voltage to the amplification sub-unit 320 while simultaneously increasing the input impedance of the amplification sub-unit 320. This ensures the stability of the bias voltage output by the first operational amplifier Q1, thereby guaranteeing the stability of the detection voltage obtained by the amplification sub-unit 320 based on the bias voltage, the first voltage, and the reference voltage.

[0107] In this embodiment, the bias voltage output by the voltage follower 420 can effectively follow the voltage divider voltage of the input voltage follower 420, which can improve the stability of the positive bias voltage provided to the amplification subunit 320, thereby ensuring the stability of the detection voltage obtained by the amplification subunit 320 based on the bias voltage, according to the first voltage and the reference voltage.

[0108] Please refer to Figure 5 It shows a schematic diagram of a subunit of an enlarged subunit provided in an embodiment of this application, such as... Figure 5As shown, the amplification subunit may include a differential amplifier circuit 510. The first input terminal of the differential amplifier circuit 510 is connected to the voltage output terminal Vout of the leakage current sensor 520. The second input terminal of the differential amplifier circuit 510 is connected to the reference voltage terminal Vref of the leakage current sensor 520. The third input terminal of the differential amplifier circuit 510 is connected to the bias subunit 310. The output terminals of the differential amplifier circuit 510 are connected to the comparison module 120 and the controller 130, respectively. The differential amplifier circuit 510 is used to differentially amplify the first voltage and the reference voltage corresponding to the reference voltage terminal of the leakage current sensor based on the bias voltage to obtain the detection voltage.

[0109] In some embodiments, the differential amplifier circuit 510 includes a second operational amplifier Q2, a fifth resistor R3, a sixth resistor R4, a seventh resistor R5, and an eighth resistor R6. The fifth resistor R3 is connected to the sixth resistor R4, and the seventh resistor R5 is connected to the eighth resistor R6. The inverting input terminal of the second operational amplifier Q2 is connected to the connection terminals of the fifth resistor R3 and the sixth resistor R4, respectively. The non-inverting input terminal of the second operational amplifier Q2 is connected to the connection terminals of the seventh resistor R5 and the eighth resistor R6, respectively. The first terminal of the fifth resistor R3 is connected to the reference voltage terminal Vref of the leakage current sensor 520. The first terminal of the sixth resistor R4 is connected to the output terminal of the second operational amplifier Q2, the comparator module 120, and the controller 130, respectively. The first terminal of the seventh resistor R5 is connected to the non-inverting input terminal of the second operational amplifier Q2. The connection terminal of the seventh resistor R5 and the eighth resistor R6 is connected to the voltage output terminal Vout of the leakage current sensor 520. The first terminal of the eighth resistor R6 is connected to the bias subunit 310.

[0110] It should be noted that in this differential amplifier circuit 510, the amplification factor of the differential amplifier circuit 510 can be adjusted by selecting appropriate values ​​for the fifth resistor R3, the sixth resistor R4, the seventh resistor R5, and the eighth resistor R6. Increasing the amplification factor can increase the leakage current detection range, but will reduce the accuracy. Decreasing the amplification factor can improve the accuracy, but will reduce the leakage current detection range. Appropriate fifth resistor R3, sixth resistor R4, seventh resistor R5, and eighth resistor R6 can be selected according to actual needs. This embodiment does not limit this selection.

[0111] Since both the first voltage and the reference voltage are provided by the leakage current sensor 520, the first voltage and the reference voltage are similarly affected by noise, or even the same. In this embodiment, by selecting the leakage current sensor 520 with the reference voltage terminal Vref, and by using the differential amplifier circuit 510 based on the bias voltage to differentially amplify the first voltage output by the voltage output terminal Vout of the leakage current sensor 520 and the reference voltage output by the reference voltage terminal Vref of the leakage current sensor 520, the same noise can be canceled out. That is, the detection voltage output by the differential amplifier circuit 510 contains less noise components, thereby improving the accuracy of the obtained detection voltage and ensuring the accuracy of the judgment of the comparison module and the controller.

[0112] In this embodiment, by setting the bias subunit 310 to provide a positive bias voltage to the amplification subunit, compared to using the amplification subunit to sample based on the first voltage to obtain the detection voltage, the voltage range to which the detection voltage belongs can be adjusted, thereby obtaining a detection voltage within the required voltage range, so that the controller or comparison module can judge the detection voltage, thus improving the judgment accuracy of the controller 130 and the comparison module 120.

[0113] Please refer to Figure 6 It shows a schematic diagram of a comparison module provided in an embodiment of this application, such as... Figure 6 As shown, the comparison module 600 may include a first comparison unit 610 and a second comparison unit 620. The first comparison unit 610 is connected to both the leakage current detection module 110 and the protection module 140, and the second comparison unit 620 is also connected to both the leakage current detection module 110 and the protection module 140. The first comparison unit 610 compares the detected voltage with a first reference voltage; if the detected voltage is greater than the first reference voltage, it outputs a first signal. The second comparison unit 620 compares the detected voltage with a second reference voltage; if the detected voltage is less than the second reference voltage, it outputs a first signal.

[0114] It should be noted that the protection module 140 is connected to the output terminals of the first comparison unit 610 and the second comparison unit 620. When the first comparison unit 610 outputs the first signal or the second comparison unit 620 outputs the second signal, the protection module 140 disconnects the power supply circuit.

[0115] In some embodiments, the first comparison unit 610 is used to compare the detected voltage with a first reference voltage, and if the detected voltage is less than the first reference voltage, then outputs a third signal. The second comparison unit 620 is used to compare the detected voltage with a second reference voltage, and if the detected voltage is greater than the second reference voltage, then outputs a third signal. Exemplarily, the first signal is a low-level signal and the third signal is a high-level signal. Exemplarily, the first signal is a high-level signal and the third signal is a low-level signal.

[0116] In some embodiments, the protection module 140 may include a second switching unit and a third switching unit. The second switching unit is connected to the first comparison unit 610, and the third switching unit is connected to the second comparison unit 620. The second switching unit is connected in series with the power supply circuit, and the third switching unit is also connected in series with the power supply circuit. The second switching unit is configured to be in an open state when receiving a first signal, thereby disconnecting the power supply circuit. The third switching unit is configured to be in an open state when receiving a second signal, thereby disconnecting the power supply circuit. In this embodiment, by setting the second and third switching units, the two switching units are respectively in an open or open state according to the signals output by the two comparison units, so that the protection module 140 can disconnect the power supply circuit when either comparison unit outputs the first signal.

[0117] In some embodiments, the first comparison unit 610 may include a third operational amplifier Q3, the inverting input of which is connected to the leakage current detection module 110, and the non-inverting input of which is used to connect to a first reference voltage. When the detected voltage is greater than the first reference voltage, the first comparison unit 610 outputs a low-level signal; when the detected voltage is less than the first reference voltage, the first comparison unit 610 outputs a high-level signal.

[0118] In some embodiments, the first comparison unit 610 further includes a ninth resistor R7 and a tenth resistor R8 connected in series. The non-inverting input of the third operational amplifier Q3 is connected to the junction of the ninth resistor R7 and the tenth resistor R8. The first terminal of the ninth resistor R7 is connected to the voltage input terminal V1, and the first terminal of the tenth resistor R8 is connected to the ground terminal GND. By adjusting the resistance values ​​of the ninth resistor R7 and the tenth resistor R8, the desired first reference voltage can be obtained.

[0119] In some embodiments, the second comparison unit 620 may include a fourth operational amplifier Q4, the inverting input of which is connected to the leakage current detection module 110, and the non-inverting input of which is used to connect to a second reference voltage. When the detected voltage is greater than the second reference voltage, the second comparison unit 620 outputs a high-level signal; when the detected voltage is less than the second reference voltage, the second comparison unit 620 outputs a low-level signal.

[0120] In some embodiments, the first comparison unit 610 further includes an eleventh resistor R9 and a twelfth resistor R10 connected in series. The inverting input of the fourth operational amplifier Q4 is connected to the connection point of the eleventh resistor R9 and the twelfth resistor R10. The first end of the eleventh resistor R9 is connected to the voltage input terminal V1, and the first end of the twelfth resistor R10 is connected to the ground terminal GND. By adjusting the resistance values ​​of the eleventh resistor R9 and the twelfth resistor R10, the desired second reference voltage can be obtained.

[0121] In some embodiments, the power supply terminal of the operational amplifier may also be connected to a voltage input terminal V1, and the connection between the power supply terminal and the voltage input terminal of the operational amplifier is connected to a capacitor to improve the stability of the voltage obtained at the power supply terminal of the operational amplifier.

[0122] In this embodiment, a first comparison unit 610 is set to detect whether the detected voltage exceeds the upper limit value corresponding to the first voltage range, and a second comparison unit 620 is set to detect whether the detected voltage is lower than the lower limit value of the first voltage range. The first comparison unit 610 and the second comparison unit 620 provide a first signal to the protection module 140 when the detected voltage exceeds the upper limit value corresponding to the first voltage range and when the detected voltage is lower than the lower limit value of the first voltage range, so that the protection module 140 disconnects the power supply circuit, thereby avoiding damage to the load due to excessive leakage current.

[0123] Please refer to Figure 7 It shows a schematic diagram of another comparison module provided in an embodiment of this application, such as Figure 7 As shown, the comparison module 700 may include a first comparison unit 710, a second comparison unit 720, and an output unit 730. The output unit 730 is connected to the first comparison unit 710, the second comparison unit 720, and the protection module, respectively. The output unit 730 is configured to be in an ON state when it receives a first signal output by the first comparison unit 710 or the second comparison unit 720, thereby establishing a connection between the comparison module and the protection module and outputting a first signal to the protection module.

[0124] In some embodiments, the output unit 730 is further configured to be in an open state upon receiving a third signal output by the first comparison unit 710 and a third signal output by the second comparison unit 720, thereby disconnecting the path between the comparison module and the protection module. It should be noted that when both the first comparison unit 710 and the second comparison unit 720 output a third signal, i.e., the detection voltage corresponding to the leakage current generated in the power supply circuit is within the first voltage range, the output unit 730 is in an open state, ensuring the reliability of the leakage protection. Simultaneously, it isolates the first comparison unit 710 from the protection module, and isolates the second comparison unit 720 from the protection module, improving the safety of the protection circuit.

[0125] In some embodiments, the first input terminal of the output unit 730 is connected to the output terminal of the first comparison unit 710, the second input terminal of the output unit 730 is connected to the output terminal of the second comparison unit 720, and the output terminal of the output unit 730 is connected to the protection module 140. When the first signal is received at either the first input terminal or the second input terminal of the output unit 730, the output unit 730 outputs the first signal from its output terminal to the protection module 140.

[0126] In some embodiments, the output unit 730 has a first conduction state and a second conduction state. The output unit 730 is configured to be in the first conduction state when it receives a first signal output by the first comparison unit 710, thus establishing a first path between the first comparison unit 710 and the protection module 140, and outputting the first signal output by the first comparison unit 710 to the protection module 140. The output unit 730 is also configured to be in the second conduction state when it receives a second signal output by the second comparison unit 720, thus establishing a second path between the second comparison unit 720 and the protection module 140, and outputting the first signal output by the second comparison unit 720 to the protection module 140.

[0127] In some embodiments, the output unit 730 is further configured to disconnect the path between the first comparison unit 710 and the protection module 140 when receiving a third signal output by the first comparison unit 710; and to disconnect the path between the second comparison unit 720 and the protection module 140 when receiving a third signal output by the second comparison unit 720.

[0128] In some embodiments, the first signal is a level signal, and the output unit 730 may include a first unidirectional conducting element, a second unidirectional conducting element, and a first clamping resistor. The first end of the first unidirectional conducting element is connected to the first comparison unit 710, and the second end of the first unidirectional conducting element is connected to the clamping end of the first clamping resistor and the protection module, respectively. The first end of the second unidirectional conducting element is connected to the second comparison unit 720, and the second end of the second unidirectional conducting element is connected to the clamping end of the first clamping resistor and the protection module, respectively.

[0129] It should be noted that the first clamping voltage corresponding to the clamping terminal of the first clamping resistor is fixed. The first unidirectional conducting element is in a conducting state when the first voltage difference between its first and second terminals falls within its conduction voltage range; otherwise, it is in a de-conducting state. When the first comparison unit 710 outputs a first signal, the voltage at the first terminal of the first unidirectional conducting element matches the voltage corresponding to the first signal. The first voltage difference between the voltage corresponding to the first signal and the first clamping voltage falls within the conduction voltage range of the first unidirectional conducting element. Therefore, when the first unidirectional conducting element receives the first signal, it conducts, and the output unit 730 is in a first conducting state.

[0130] Similarly, when the first voltage difference between the first and second terminals of the second unidirectional conducting element falls within the conduction voltage range of the second unidirectional conducting element, the second unidirectional conducting element is in a conducting state; if the first voltage difference does not fall within the conduction voltage range, the second unidirectional conducting element is in a de-conducting state. When the second comparison unit 720 outputs the first signal, the voltage at the first terminal of the second unidirectional conducting element is consistent with the voltage corresponding to the first signal. The second voltage difference between the voltage corresponding to the first signal and the first clamping voltage falls within the conduction voltage range of the second unidirectional conducting element. Therefore, when the second unidirectional conducting element receives the first signal, the second unidirectional conducting element is turned on, and the output unit 730 is in a second conducting state.

[0131] Taking a low-level signal as an example, please refer to... Figure 8The first unidirectional conducting element may include a first diode D1, and the second unidirectional conducting element may include a second diode D2. The first clamping resistor is a first pull-up resistor R11, with its first terminal connected to the voltage input terminal V1. The cathode of the first diode D1 is connected to the first comparator unit 710, and the anode of the first diode D1 is connected to both the second terminal of the first pull-up resistor R11 and the protection module 140. The cathode of the second diode D2 is connected to the second comparator unit 720, and the anode of the second diode D2 is connected to both the second terminal of the first pull-up resistor R11 and the protection module 140. Optionally, the voltage provided by the voltage input terminal V1 is +5V.

[0132] In this embodiment, the output unit 730 can connect the first path between the first comparison unit 710 and the protection module when it receives the first signal output by the first comparison unit 710. The output unit 730 can also connect the second path between the second comparison unit 720 and the protection module 140 when it receives the second signal output by the second comparison unit 720. This ensures that the output unit 730 is in a conducting state when the first comparison unit 710 outputs the third signal and the second comparison unit 720 outputs the first signal, or when the first comparison unit 710 outputs the first signal and the second comparison unit 720 outputs the third signal, so as to transmit the first signal to the protection module 140.

[0133] In this embodiment, by setting the output unit 730, the output unit 730 is in the conducting state when the first comparison unit 710 outputs the first signal or the second comparison unit 720 outputs the first signal, so as to output the first signal received by the output unit 730 to the protection module. The protection module 140 does not need to judge the received signal, which can reduce the design difficulty of the protection module 140.

[0134] Please refer to Figure 9 It shows a schematic diagram of a protection module provided in an embodiment of this application, such as... Figure 9 As shown, the protection module may include a first switch unit 910, which is connected to the comparison module 120 and the controller 130 respectively, and is connected in series in the power supply circuit. The first switch unit 910 is used to be in an open state when receiving a first signal or a second signal, so as to disconnect the power supply circuit.

[0135] It should be noted that the on / off state of the first switching unit 910 may include a conducting state and an off state. When the first switching unit 910 is in the conducting state, the first end of the first switching unit 910 is electrically connected to the second end of the first switching unit 910. When the first switching unit 910 is in the off state, the first end of the first switching unit 910 is disconnected from the second end of the first switching unit 910.

[0136] For example, the first end of the first switching unit 910 is connected to the output end of the power supply module in the power supply circuit, and the second end of the first switching unit 910 is connected to the input end of the load in the power supply circuit, so that the first switching unit 910 is connected in series in the power supply circuit.

[0137] In another example, the first end of the first switching unit 910 is connected to the input end of the power supply module in the power supply circuit, and the second end of the first switching unit 910 is connected to the output end of the load in the power supply circuit, so that the first switching unit 910 is connected in series in the power supply circuit.

[0138] In some embodiments, please refer to Figure 10 The first switching unit may include a first switching transistor Q5 and a second switching transistor Q6. The first switching transistor Q5 is connected in series in the power supply circuit. The second switching transistor Q6 is connected to the comparator module 120 and the controller 130 respectively. The second switching transistor Q6 is connected in series in the first path between the ground terminal GND and the power supply module. The control terminal of the first switching transistor Q5 is connected to the first path.

[0139] It should be noted that when the second switch Q6 receives the first signal or the second signal, it is in the first on / off state, and the voltage at the control terminal of the first switch Q5 is the third voltage. At this time, the first switch Q5 is turned on to conduct the power supply circuit. When the second switch Q6 receives the third signal and the fourth signal, it is in the second on / off state, and the voltage at the control terminal of the first switch Q5 is the fourth voltage. At this time, the first switch Q5 is turned off to disconnect the power supply circuit.

[0140] In some embodiments, the first switching transistor Q5 is a PNP transistor, and the second switching transistor Q6 is an NPN transistor. Specifically, the base of the NPN transistor is used to receive a first signal or a second signal, the collector of the NPN transistor is connected to the first terminal of the thirteenth resistor R12 and the base of the PNP transistor, the emitter of the NPN transistor is connected to the ground terminal GND, the emitter of the PNP transistor is connected to the power supply module 1010 and the second terminal of the thirteenth resistor R12, and the collector of the PNP transistor is connected to the load 1020.

[0141] In some embodiments, the protection module may further include a fourteenth resistor R13 and a fifteenth resistor R14. The fourteenth resistor R13 is connected to the base of the PNP transistor and the collector of the NPN transistor, respectively, to prevent excessive base current of the PNP transistor. The fifteenth resistor R14 is connected to the comparator module 120, the controller 130, and the base of the NPN transistor, respectively, to prevent excessive base current of the NPN transistor.

[0142] In some embodiments, the protection module may further include a sixteenth resistor R15, which is connected to the base and emitter of the NPN transistor respectively, thereby improving the stability of the NPN transistor.

[0143] In this embodiment, by connecting the first switching unit in series with the power supply circuit, the first switching unit is in an open state when it receives a first signal or a second signal, thereby disconnecting the power supply circuit, simplifying the circuit structure and reducing the hardware cost of the protection circuit.

[0144] In another embodiment, the protection module may further include a relay and a second switching unit. The relay may include a relay switch and a coil. The second switching unit is connected in series with the coil of the relay and a second path between the relay and the power supply input terminal corresponding to the coil. The relay switch is connected in series in the power supply circuit.

[0145] The relay can be either a normally open relay or a normally closed relay. Taking a normally open relay as an example, the second switching unit is used to be in an open state when receiving the first or second signal, thereby disconnecting the second path between the relay coil and the corresponding power supply input terminal, so that the relay switch remains in an open state, thus disconnecting the power supply circuit. The second switching unit is also used to be in a closed state when receiving the third and fourth signals, thereby connecting the relay coil and the corresponding power supply input terminal, so that the relay switch is in a closed state, thus closing the power supply circuit.

[0146] Taking a normally closed relay as an example, the second switching unit is used to be in a conducting state when receiving a first signal or a second signal, so as to conduct the second path between the relay coil and the power supply input terminal corresponding to the coil, thereby keeping the relay switch in an open state and disconnecting the power supply circuit. The second switching unit is used to be in an open state when receiving a third signal and a fourth signal, so as to disconnect the second path between the relay coil and the power supply input terminal corresponding to the coil, thereby keeping the relay switch in a conducting state and connecting the power supply circuit.

[0147] The structure of the second switching unit can be referenced from that of the first switching unit, and will not be described again in this embodiment. In this embodiment, a relay can be used to control the on / off state of the second switching unit, thereby controlling the on / off state of the coil and the second path between the coil and the corresponding power supply input terminal, and thus controlling the on / off state of the relay switch, improving the safety of the protection circuit, especially when the voltage of the power supply circuit is very high.

[0148] Please refer to Figure 11 It shows a schematic diagram of another protection module provided in an embodiment of this application, such as Figure 11 As shown, the protection module 1100 may include a first switch unit 1110 and an input unit 1120. The input unit 1120 is connected to the comparison module 1130, the controller 1140, and the first switch unit 1110, respectively. The input unit 1120 is configured to be in a conducting state when it receives a first signal output by the comparison module 1130, thereby establishing a path between the comparison module 1130 and the first switch unit 1110 to output a first signal to the first switch unit 1110. Alternatively, the input unit 1120 is also configured to be in a conducting state when it receives a second signal output by the controller 1140, thereby establishing a path between the controller 1140 and the first switch unit 1110 to output a second signal to the first switch unit 1110.

[0149] It should be noted that the input unit 1120 is also configured to be in an off state when receiving the third signal output by the comparison module 1130 and the fourth signal output by the controller 1140, so as to disconnect the path between the comparison module 1130 and the first switching unit 1110, and the path between the controller 1140 and the first switching unit 1110, so as to keep the power supply circuit in a conducting state. The circuit structure of the input unit 1120 can be referred to the circuit structure of the output unit. In some embodiments, the first signal and the second signal may be level signals. The input unit 1120 may include a third unidirectional conducting element, a fourth unidirectional conducting element, and a second clamping resistor. The first end of the third unidirectional conducting element is connected to the comparison module 1130, and the second end of the third unidirectional conducting element is connected to the clamping end of the second clamping resistor and the first switching unit 1110, respectively. The first end of the fourth unidirectional conducting element is connected to the controller 1140, and the second end of the fourth unidirectional conducting element is connected to the clamping end of the second clamping resistor and the first switching unit 1110, respectively.

[0150] It should be noted that the second clamping voltage corresponding to the clamping terminal of the second clamping resistor is fixed. The third unidirectional conducting element is in a conducting state when the third voltage difference between its first and second terminals falls within its conduction voltage range; otherwise, it is in a de-energized state. When the comparator module 1130 outputs the first signal, the voltage at the first terminal of the third unidirectional conducting element matches the voltage corresponding to the first signal. The third voltage difference between the voltage corresponding to the first signal and the second clamping voltage falls within the conduction voltage range of the third unidirectional conducting element. Therefore, when the third unidirectional conducting element receives the first signal, it conducts.

[0151] Similarly, the fourth unidirectional conducting element is in a conducting state when the first voltage difference between its first and second terminals falls within its conduction voltage range; otherwise, it is in a de-conducting state. When the controller 1140 outputs the second signal, the voltage at the first terminal of the fourth unidirectional conducting element matches the voltage corresponding to the second signal. The fourth voltage difference between the voltage corresponding to the second signal and the second clamping voltage falls within the conduction voltage range of the fourth unidirectional conducting element. Therefore, when the fourth unidirectional conducting element receives the second signal, it conducts.

[0152] Taking a scenario where the first signal is low and the second signal is low as an example, please continue to refer to [the documentation / reference]. Figure 11 The third unidirectional conducting element may include a third diode D3, and the fourth unidirectional conducting element may include a fourth diode D4. The second clamping resistor is a second pull-up resistor R17, with its first terminal connected to the voltage input terminal V1. The cathode of the third diode D3 is connected to the comparator module 1130, and its anode is connected to both the second terminal of the second pull-up resistor R17 and the first switching unit 1110. The cathode of the fourth diode D4 is connected to the controller 1140, and its anode is connected to both the second terminal of the second pull-up resistor R17 and the first switching unit 1110. Optionally, the voltage provided at the voltage input terminal V1 is +5V.

[0153] In this embodiment, the input unit 1120 can be in a conducting state when it receives a first signal output by the comparison module 1130, thereby establishing a connection between the comparison module 1130 and the first switching unit 1110 and outputting the first signal to the first switching unit 1110. The input unit 1120 can also be in a conducting state when it receives a second signal output by the controller 1140, thereby establishing a connection between the controller 1140 and the first switching unit 1110 and outputting the second signal to the first switching unit 1110. By configuring the input unit 1120 such that it is in a conducting state whether the comparison module 1130 outputs the first signal or the controller 1140 outputs the second signal, it can output the received first or second signal to the first switching unit 1110. This ensures that the power supply circuit can be disconnected when the leakage current deviates from the voltage range, improving the safety of the power supply circuit.

[0154] In some embodiments, the protection module may further include a manual switch that can be connected in series between the first switching unit and the load. The user can use this manual switch to disconnect the power supply module from the load, enabling power disconnection of the downstream load even when the leakage current is not excessive, thus meeting user needs (such as maintenance requirements) and improving circuit flexibility.

[0155] Please refer to Figure 12 It shows a schematic diagram of another protection circuit provided in an embodiment of this application, such as Figure 12 As shown. Figure 12 As shown, the protection circuit may include a leakage current sensor 1210, a differential amplifier circuit 1220, a bias subunit 1230, a controller 1240, a first comparison unit 1250, a second comparison unit 1260, an output unit 1270, a filter module 1280, and a protection module 1290.

[0156] Among them, the leakage current sensor 1210 is selected as a leakage current sensor 1210 with a reference voltage terminal Vref.

[0157] In this circuit, the reference voltage Vref of the leakage current sensor 1210 is connected to the inverting input of the second operational amplifier Q2 via the fifth resistor R3. The inverting input of the second operational amplifier Q2 is connected to its output via the sixth resistor R4. The voltage output Vout of the leakage current sensor 1210 is connected to the non-inverting input of the second operational amplifier Q2 via the seventh resistor R5. The non-inverting input of the second operational amplifier Q2 is connected to the output of the first operational amplifier Q1 via the eighth resistor R6. Adjusting the resistance values ​​of the fifth resistor R3 to the eighth resistor R6 can adjust the amplification factor, making the leakage current sampling range wider or the sampling more accurate. The first operational amplifier Q1 forms a bias voltage of x volts (x is adjustable) to apply a bias voltage to the second operational amplifier Q2. The purpose of applying the bias voltage is to raise the output voltage of the second operational amplifier Q2 by x volts on average, so as to properly collect the forward and reverse leakage currents. Resistors R20 and C1 form a filter module 1280 to filter out high-frequency interference and stabilize the output. The filtered AD value is input to the controller 1240, i.e., the MCU, for sampling, so that the leakage current can be read in real time; on the other hand, it is input to the comparison module behind it for hardware protection.

[0158] The inverting input of the third operational amplifier Q3 and the non-inverting input of the fourth operational amplifier Q4 are connected to the output of the differential amplifier circuit 1220. The first reference voltage can be adjusted by adjusting the values ​​of the ninth resistor R7 and the tenth resistor R8, and the second reference voltage can be adjusted by adjusting the values ​​of the eleventh resistor R9 and the twelfth resistor R10. When the detected voltage output by the differential amplifier circuit 1220 is less than the voltage difference across the tenth resistor R8, the third operational amplifier Q3 outputs a high-level signal; when the detected voltage output by the differential amplifier circuit 1220 is greater than the voltage difference across the tenth resistor R8, the third operational amplifier Q3 outputs a low-level signal. When the detected voltage output by the differential amplifier circuit 1220 is less than the voltage difference across the twelfth resistor R10, the fourth operational amplifier Q4 outputs a low-level signal; when the detected voltage output by the differential amplifier circuit 1220 is greater than the voltage difference across the twelfth resistor R10, the fourth operational amplifier Q4 outputs a high-level signal.

[0159] In some embodiments, the first comparison unit 1250 further includes a resistor R18, which is connected to the output terminal and the voltage input terminal of the third operational amplifier Q3, respectively, so that when the detection voltage output by the differential amplifier circuit 1220 is less than the voltage difference across the tenth resistor R8, the third operational amplifier Q3 can stably output a high-level signal.

[0160] In some embodiments, the second comparison unit 1260 further includes a resistor R19, which is connected to the output terminal and the voltage input terminal of the fourth operational amplifier Q4, respectively, so that when the detection voltage output by the differential amplifier circuit 1220 is greater than the voltage difference across the twelfth resistor R18, the fourth operational amplifier Q4 can stably output a high-level signal.

[0161] Specifically, when either the third operational amplifier Q3 or the fourth operational amplifier Q4 outputs a low level, the output unit 1270 is turned on and outputs a low-level signal to the protection module 1290.

[0162] Please refer to Figure 13 It shows a schematic diagram of the structure of another protection module provided in the embodiments of this application, such as Figure 13As shown, the protection module includes an input unit 1310, a first switch unit 1320, and a manual switch K1. The third diode D3 is connected to the terminals of the first diode D1 and the second diode D2, and the fourth diode D4 is connected to the controller 1340. When either the controller 1340 or the comparator module 1350 outputs a low-level signal, the input unit 1310 is turned on, pulling the base of the second switch Q6 low, thus turning off the second switch Q6. The turning off of the second switch Q6 then turns off the first switch Q5, thereby cutting off the 12V (power supply module) supply to the downstream load 1360, de-energizing the downstream load 1360. When both the controller 1340 and the comparator module 1350 output high-level signals, the input unit 1310 is cut off, and the base of the second switch Q6 is pulled up to 5V, which is a high level. This causes the second switch Q6 to conduct, and the conduction of the second switch Q6 in turn turns on the first switch Q5, allowing 12V to be supplied to the downstream load 1360, thus energizing it. The manual switch K1 is normally closed. When an abnormal leakage current occurs and it is desired that only the downstream load is de-energized while the protection circuit itself remains powered, the manual switch K1 can be manually opened.

[0163] The following are simplified explanations based on the different scenarios when manual switch K1 is closed: When both the controller 1340 and the comparator module 1350 output signals are low, the 12V power supply to load 1360 is disconnected; when both the controller 1340 and the comparator module 1350 output signals are low, the 12V power supply to load 1360 is disconnected; when both the controller 1340 and the comparator module 1350 output signals are high, the 12V power supply to load 1360 is disconnected; and when both the controller 1340 and the comparator module 1350 output signals are high, load 1360 receives 12V power.

[0164] In some embodiments, the protection module further includes a fifth diode D5 and a sixth diode D6, which can prevent current from flowing to the first switching unit 1320.

[0165] In some embodiments, the protection module further includes an LED (Light Emitting Diode), which is lit when the first switching unit 1320 is in the on state and turned off when the first switching unit 1320 is in the off state, to indicate whether the leakage current of the power supply circuit is too large.

[0166] In some embodiments, the protection module further includes a transient suppression diode D7 and a resistor R21, wherein the transient suppression diode D7 and the resistor R21 are connected in parallel to achieve overvoltage protection to protect the load 1360.

[0167] Please refer to Figure 14 It shows a flowchart of a protection method provided in an embodiment of this application, which can be applied to protection circuits, such as... Figure 14 As shown, the protection method may include steps 1402 to 1416.

[0168] Step 1402: Detect the leakage current generated in the power supply circuit through the leakage current detection module, and output the detection voltage based on the leakage current.

[0169] Step 1404: Determine whether the detected voltage belongs to the first voltage range through the comparison module; if yes, proceed to step 1406; if no, proceed to step 1408.

[0170] Step 1406: Output the third signal through the comparison module.

[0171] Step 1408: Output the first signal through the comparison module.

[0172] Step 1410: The controller determines whether the voltage value of the detected voltage belongs to the second voltage range; if yes, then proceed to step 1412; if no, then proceed to step 1414.

[0173] Step 1412: Output the fourth signal through the controller.

[0174] Step 1414: Output the second signal through the controller.

[0175] Step 1416: The protection module disconnects the power supply circuit upon receiving the first or second signal, and connects the power supply circuit upon receiving the third and fourth signals.

[0176] In some embodiments, the leakage current generated in the power supply circuit is detected by a leakage current detection module, and a detection voltage is output based on the leakage current. This includes: acquiring the first bus current of the first bus and the second bus current of the second bus using a leakage current sensor, and outputting a first voltage based on the first bus current and the second bus current. The first voltage output by the leakage current sensor is sampled by a sampling unit to obtain the detection voltage.

[0177] In some embodiments, sampling the first voltage output by the leakage current sensor through the sampling unit to obtain a detection voltage includes: providing a positive bias voltage to the amplification subunit through the bias unit; and amplifying the detection voltage based on the bias voltage, the first voltage, and a reference voltage through the amplification subunit.

[0178] In some embodiments, providing a positive bias voltage to the amplification subunit via a bias unit includes: dividing the second voltage provided at the voltage input terminal by a voltage divider circuit to obtain a divided voltage, and generating a positive bias voltage based on the divided voltage using a voltage follower to provide a positive bias voltage to the amplification subunit.

[0179] In some embodiments, a differential amplifier circuit is used to differentially amplify the first voltage and the reference voltage corresponding to the reference voltage terminal of the leakage current sensor based on the bias voltage to obtain the detection voltage.

[0180] In some embodiments, the detected voltage is compared with a first reference voltage by a first comparison unit. If the detected voltage is greater than the first reference voltage, a first signal is output. A second comparison unit is used to compare the detected voltage with a second reference voltage. If the detected voltage is less than the second reference voltage, a first signal is output.

[0181] In some embodiments, when the output unit receives a first signal output by the first comparison unit or a first signal output by the second comparison unit, it is in an on state to open the path between the comparison module and the protection module, so as to output the first signal to the protection module.

[0182] In some embodiments, the first switching unit is in an open state upon receiving a first signal or a second signal, thereby disconnecting the power supply circuit.

[0183] In some embodiments, the input unit is in an ON state when it receives a first signal output by the comparison module, so as to open the path between the comparison module and the protection module and output the first signal to the protection module; and / or is in an ON state when it receives a second signal output by the controller, so as to open the path between the controller and the protection module and output the second signal to the protection module.

[0184] In this embodiment, a leakage current detection module detects the leakage current generated in the power supply circuit and outputs a detection voltage based on the leakage current. A comparison module determines whether the detection voltage falls within a first voltage range. If the detection voltage does not fall within the first voltage range, a first signal is output. Upon receiving the first signal, the protection module disconnects the power supply circuit. Simultaneously, a controller determines whether the detection voltage value falls within a second voltage range. If the detection voltage does not fall within the second voltage range, a second signal is output. Upon receiving the second signal, the protection module can also disconnect the power supply circuit. Since the judgments of the comparison module and the controller are independent of each other, and the protection module can disconnect the power supply circuit in response to the first signal output by the comparison module and the second signal output by the controller, the functions and connections of the comparison module and the controller in this protection circuit are independent. Even if either the comparison module or the controller fails, the judgment can still be achieved through another undamaged device. This ensures that the protection circuit can still disconnect the power supply circuit when the leakage current is too large. This protection circuit has a low failure rate and high reliability of leakage protection.

[0185] Meanwhile, since the controller's response speed is slower than that of the comparator module, and the leakage current in the power supply circuit gradually increases, by setting the second voltage range to fall within the range of the first voltage range, the controller outputs the second signal when the leakage current is smaller. This avoids the power supply circuit from deteriorating too much before being disconnected due to the controller's slow response speed. This ensures that even if the comparator module is damaged, the power supply circuit can be disconnected in time, further improving the reliability of the leakage protection circuit.

[0186] This application also provides a power grid system, which may include a first bus, a second bus, and any of the protection circuits provided in the above embodiments.

[0187] This application also provides a protection chip, which includes any of the protection circuits provided in the above embodiments.

[0188] The foregoing has provided a detailed description of a protection circuit and electronic device disclosed in the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. An air conditioning device, characterized in that, include: load; A power supply module, which forms a power supply circuit with the load, is used to supply power to the load; A protection circuit, connected to the power supply module, includes: The leakage current detection module is used to detect the leakage current generated in the power supply circuit and output a detection voltage based on the leakage current. A comparison module is connected to the leakage current detection module. The comparison module is used to determine whether the detected voltage belongs to a first voltage range. If the detected voltage does not belong to the first voltage range, a first signal is output. A controller, connected to the leakage current detection module, is used to determine whether the voltage value of the detected voltage belongs to a second voltage range. If the voltage value of the detected voltage does not belong to the second voltage range, a second signal is output; wherein, the second voltage range belongs to the first voltage range. A protection module is connected to both the comparison module and the controller. The protection module is used to disconnect the power supply circuit upon receiving the first signal or the second signal. The protection module includes a first switching unit, which is connected to the comparison module and the controller respectively, and is connected in series in the power supply circuit. The first switching unit is configured to be in an open state upon receiving the first signal or the second signal, thereby disconnecting the power supply circuit.

2. The air conditioning device according to claim 1, characterized in that, The power supply circuit includes a first bus and a second bus; the leakage current detection module includes a leakage current sensor and a sampling unit, the leakage current sensor is connected to the first bus and the second bus respectively, and the sampling unit is connected to the leakage current sensor, the comparison module and the controller respectively; The leakage current sensor is used to collect the first bus current of the first bus and the second bus current of the second bus, and output a first voltage based on the first bus current and the second bus current. The sampling unit is used to sample the first voltage output by the leakage current sensor to obtain the detection voltage.

3. The air conditioning device according to claim 2, characterized in that, The sampling unit includes a bias subunit and an amplification subunit, and the amplification subunit is connected to the leakage current sensor, the bias subunit, the comparison module and the controller respectively; The bias subunit is used to provide a positive bias voltage to the amplification subunit; The amplification subunit is used to amplify the voltage based on the bias voltage, the first voltage, and the reference voltage to obtain the detection voltage.

4. The air conditioning device according to claim 3, characterized in that, The bias subunit includes: A voltage divider circuit is connected to the voltage input terminal. The voltage divider circuit is used to divide the second voltage provided by the voltage input terminal to obtain a voltage divider. A voltage follower is connected to both the voltage divider circuit and the amplification subunit, and generates a positive bias voltage based on the voltage divider voltage to provide the positive bias voltage to the amplification subunit.

5. The air conditioning device according to claim 3, characterized in that, The amplification subunit includes a differential amplifier circuit. The first input terminal of the differential amplifier circuit is connected to the voltage output terminal of the leakage current sensor. The second input terminal of the differential amplifier circuit is connected to the reference voltage terminal of the leakage current sensor. The third input terminal of the differential amplifier circuit is connected to the bias subunit. The output terminal of the differential amplifier circuit is connected to the comparison module and the controller, respectively. The differential amplifier circuit is used to differentially amplify the first voltage and the reference voltage corresponding to the reference voltage terminal of the leakage current sensor based on the bias voltage to obtain the detection voltage.

6. The air conditioning device according to claim 1, characterized in that, The upper limit of the first voltage range corresponds to a first reference voltage, and the lower limit of the first voltage range corresponds to a second reference voltage; the comparison module includes: The first comparison unit is connected to the leakage current detection module and the protection module respectively. The first comparison unit is used to compare the detected voltage with the first reference voltage. If the detected voltage is greater than the first reference voltage, a first signal is output. The second comparison unit is connected to both the leakage current detection module and the protection module. The second comparison unit is used to compare the detected voltage with the second reference voltage. If the detected voltage is less than the second reference voltage, a first signal is output.

7. The air conditioning device according to claim 6, characterized in that, The comparison module further includes an output unit, which is connected to the first comparison unit, the second comparison unit, and the protection module respectively. The output unit is configured to be in an ON state when it receives a first signal output by the first comparison unit or a first signal output by the second comparison unit, so as to open the path between the comparison module and the protection module and output the first signal to the protection module.

8. The air conditioning device according to claim 1, characterized in that, The protection module further includes an input unit, which is connected to the comparison module, the controller, and the first switch unit.

9. The air conditioning device according to claim 8, characterized in that, The input unit is configured to be in an ON state when it receives the first signal output by the comparison module, so as to open the path between the comparison module and the first switch unit and output the first signal to the first switch unit.

10. The air conditioning device according to claim 8, characterized in that, The input unit is further configured to be in an ON state when receiving the second signal output by the controller, so as to open the path between the controller and the first switch unit and output the second signal to the first switch unit.

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