A leakage protection circuit and power supply circuit for aircraft

Abstract

The present application provides a leakage protection circuit for aircraft and a power supply circuit thereof, wherein the leakage protection circuit comprises: a current detection unit, a relay, a first switch unit, a control unit, and a second switch unit. The test signal is received by the second switch unit so that at least one resistor on the output end is connected between the neutral line and the live line so that a current difference greater than a preset first current value is formed between the neutral line and the live line. Then, it is determined whether a fault occurs in the leakage protection circuit by determining whether the control unit controls the first switch unit to connect the power supply of the relay after the current detection unit transmits the detected current difference greater than the first current value to the control unit, so that the connection between the live line and the load is disconnected when the relay is powered on to stop the power supply. If the leakage protection circuit does not cut off the power supply under the test condition, it indicates that there is a fault, thereby realizing self-inspection of the leakage protection circuit and improving the safety of the line.

Description

Technical Field

[0001] The present application relates to the technical field of leakage protection, and in particular to a leakage protection circuit and a power supply circuit thereof for aircraft. Background Art

[0002] At present, the power supply circuit of aircraft generally has a leakage protection circuit, which can cut off the power supply in time when there is leakage during the power transmission process. However, when the leakage protection circuit in the power supply circuit fails, it cannot be detected, resulting in a low safety problem. Summary of the invention

[0003] The purpose of the embodiments of the present application is to provide a leakage protection circuit and a power supply circuit thereof for aircraft, so as to solve the problem that the leakage protection circuit in the existing power supply circuit cannot be detected when a fault occurs, resulting in low safety.

[0004] In a first aspect, an embodiment of the present invention provides a leakage protection circuit for an aircraft, wherein the leakage protection circuit is arranged on a neutral line and a live line between a power source and a load, and the leakage protection circuit comprises: a current detection unit, whose input ends are respectively connected to the neutral line and the live line, so as to detect the current difference between the neutral line and the live line; a relay and a first switch unit, wherein the first switch unit is connected to the relay, and the relay is arranged between the live line and the load, and the first switch unit is used to connect the power supply of the relay or cut off the power supply of the relay so that the relay connects the connection between the live line and the load when the power supply is cut off or disconnects the connection between the live line and the load when the power supply is turned on; a control unit, which respectively connected to the current detection unit and the first switch unit, so as to control the first switch unit to conduct to connect the coil power supply of the relay when the current difference transmitted by the current detection unit is greater than a preset first current value, so that the relay disconnects the connection between the live wire and the load; a second switch unit, whose output end is respectively connected to the neutral wire and the live wire through at least one first resistor, and whose input end is respectively connected to the first power supply voltage and an external testing device, so as to receive a test signal sent by the external testing device, and control the second switch unit to conduct according to the test signal, so that the at least one first resistor connects the neutral wire and the live wire so that the current difference between the neutral wire and the live wire is greater than the preset first current value.

[0005] In the leakage protection circuit for aircraft designed as above, a test signal is received by the second switch unit so that at least one resistor on the output end of the second switch unit is connected between the neutral line and the live line so that a current difference greater than a preset first current value is formed between the neutral line and the live line. Then, it is determined whether the leakage protection circuit fails by controlling the first switch unit to turn on the power supply of the relay after the current detection unit transmits the detected current difference greater than the first current value to the control unit, so that the connection between the live line and the load is disconnected when the relay is powered on to stop the power supply to the load. If the leakage protection circuit does not cut off the power supply to the load under the test condition, it means that there is a fault in the leakage protection, thereby realizing the self-check function of the leakage protection, thereby solving the problem of low safety caused by the inability to detect the leakage protection circuit in the existing power supply circuit, so that the leakage protection failure of the power supply line can be discovered in time, thereby improving the safety of the power supply line.

[0006] In an optional implementation of the first aspect, the second switch unit includes a packaged four-pin photoelectric relay, the input end of the packaged four-pin photoelectric relay includes a first terminal and a second terminal, and the output end includes a third terminal and a fourth terminal, the first terminal is connected to the first power supply voltage, the second terminal is connected to the external testing device, the third terminal is connected to the neutral line through the at least one first resistor, and the fourth terminal is connected to the live line.

[0007] In an optional implementation of the first aspect, the first wiring terminal is connected to the first supply voltage via a second resistor.

[0008] In an optional implementation of the first aspect, the current detection unit includes a zero-sequence current transformer, a primary side of the zero-sequence current transformer is respectively connected to the neutral line and the live line, and a secondary side of the zero-sequence current transformer is connected to the control unit.

[0009] In an optional implementation of the first aspect, the control unit includes a ground fault circuit breaker controller, a VFB pin and a VREF pin of the ground fault circuit breaker controller are respectively connected to two ends of the secondary side of the zero-sequence current transformer, an AmpOut pin of the ground fault circuit breaker controller is connected in parallel with the VFB pin, an SCR pin of the ground fault circuit breaker controller is connected to the first switch unit, the first switch unit is connected to the Neutral pin of the ground fault circuit breaker controller and then grounded, and a Line pin of the ground fault circuit breaker controller is connected to a second supply voltage.

[0010] In an optional implementation of the first aspect, the first switch unit includes a thyristor, a control stage of the thyristor is connected to the SCR pin of the ground fault circuit breaker controller, a cathode of the thyristor is connected to the Neutral pin of the ground fault circuit breaker controller and then grounded, and an anode of the thyristor is connected to the relay.

[0011] In an optional implementation of the first aspect, the relay includes a coil and a contact group, the contact group includes a static contact, a normally closed moving contact and a normally open moving contact, one end of the coil is connected to the anode of the thyristor, the other end of the coil is connected to a third power supply voltage, the static contact is connected to the live wire, the normally closed moving contact is connected to the load, and the normally open moving contact is connected to the ground wire.

[0012] In a second aspect, an embodiment of the present invention provides a power supply circuit, which includes a leakage protection circuit, a filter and rectifier circuit, a power factor correction circuit and an inverter circuit as described in any one of the aforementioned embodiments; the live wire input terminal and the neutral wire input terminal of the filter and rectifier circuit are respectively connected to the power supply, the live wire output terminal of the filter and rectifier circuit is connected to the live wire input terminal of the power factor correction circuit, the neutral wire output terminal of the filter and rectifier circuit is connected to the neutral wire input terminal of the power factor correction circuit, the live wire output terminal of the power factor correction circuit is connected to the live wire input terminal of the inverter circuit, the neutral wire output terminal of the power factor correction circuit is connected to the neutral wire input terminal of the inverter circuit, and the neutral wire and live wire output terminals of the inverter circuit are connected to the load through the current detection unit in the leakage protection circuit and the relay.

[0013] In an optional implementation of the second aspect, the filtering and rectifying circuit includes a filtering circuit and a bridge rectifier circuit, the live wire input terminal and the neutral wire input terminal of the filtering circuit are connected to the power supply, the filtering circuit is connected to the bridge rectifier circuit, the live wire output terminal of the bridge rectifier circuit is connected to the live wire input terminal of the power factor correction circuit, and the neutral wire output terminal of the bridge rectifier circuit is connected to the neutral wire input terminal of the power factor correction circuit.

[0014] In an optional implementation of the second aspect, the power supply circuit further includes an output filter circuit, and the neutral line and live line output ends of the inverter circuit are connected to the load through the output filter circuit, the current detection unit and the relay. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 A schematic diagram of the structure of a leakage protection circuit provided in an embodiment of the present application;

[0017] Figure 2 A specific circuit diagram of a leakage protection circuit provided in an embodiment of the present application;

[0018] Figure 3 A schematic diagram of the structure of a power supply circuit provided in an embodiment of the present application;

[0019] Figure 4 A specific circuit diagram of the filter and rectifier circuit provided in an embodiment of the present application.

[0020] Icon: 1-first terminal; 2-second terminal; 3-third terminal; 4-fourth terminal; L-live wire; N-neutral wire; 10-current detection unit; 101-zero sequence current transformer; 20-relay; 201-coil; 2021-static contact; 2022-normally closed moving contact; 2023-normally open moving contact; 30-first switch unit; Q1-thyristor; 40-control unit; 401-ground fault circuit breaker controller; 50-second switch unit; 501-encapsulated four-pin photoelectric relay; 200-filter rectifier circuit; 300-power factor correction circuit; 400-inverter circuit; 500-output filter Wave circuit; R1-first resistor; R2-second resistor; R3-third resistor; R4-fourth resistor; R5-fifth resistor; C1-first capacitor; C2-second capacitor; C3-third capacitor; C4-fourth capacitor; C5-fifth capacitor; C6-sixth capacitor; C7-seventh capacitor; C8-eighth capacitor; C9-ninth capacitor; C10-tenth capacitor; C11-eleventh capacitor; C12-twelfth capacitor; C13-thirteenth capacitor; C14-fourteenth capacitor; L1-common mode inductor; L2-first iron core inductor; L3-second iron core inductor; D1-bridge rectifier; Q2-three-terminal bidirectional thyristor; M1-DC sensor. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0022] First embodiment

[0023] like Figure 1As shown, an embodiment of the present application provides a leakage protection circuit for an aircraft, and the leakage protection circuit has a self-test function. The leakage protection circuit is arranged on a part and a live wire L between a power source and a load. For example, it can be specifically arranged on a neutral wire N and a live wire of a power supply line on an aircraft to detect whether the aircraft's power transmission line has leakage. The leakage protection circuit with self-test power supply designed in the present application can enable the staff to automatically initiate a test of the leakage protection circuit in the transmission line, and then determine whether the leakage protection circuit in the transmission line is in normal operation.

[0024] The leakage protection circuit for aircraft designed in the present application includes a current detection unit 10, a relay 20, a first switch unit 30, a control unit 40 and a second switch unit 50. The input end of the current detection unit 10 is respectively connected to the neutral line N and the live line L, the output end of the current detection unit 10 is connected to the control unit 40, the control unit 40 is also connected to the relay 20 through the first switch unit 30, the output end of the second switch unit 50 is respectively connected to the neutral line N and the live line L through at least one first resistor R1, and the Figure 1 It can be seen that the connection point between the output end of the second switch unit 50 connected to the first resistor R1 and the neutral line N is before the connection point between the current detection unit 10 and the neutral line N, and the connection point between the other output end of the second switch unit 50 and the live line L is after the connection point between the current detection unit 10 and the live line L. The input end of the second switch unit 50 is respectively connected to the first power supply voltage and the external testing device.

[0025] When the leakage protection circuit designed above is used for aircraft, an external test device can send a preset test signal to the second switch unit 50. After receiving the preset test signal, the output end of the second switch unit 50 is closed, so that at least one first resistor R1 on the output end of the second switch unit 50 connects the neutral line N and the live line L, and generates a current difference greater than the preset first current value. Specifically, the resistance value of the resistor can be adaptively selected according to the voltage between the neutral line N and the live line L and the first current value to be preset, so that after the at least one first resistor R1 is connected, the current difference between the neutral line N and the live line L is greater than the first current value to be preset.

[0026] Under the above premise, if the leakage protection circuit is working normally, the current detection unit 10 will detect the current difference between the neutral line N and the live line L connected thereto, and then transmit the current difference to the control unit 40 through the line. After the control unit 40 receives the current difference transmitted by the current detection unit 10, it compares the current difference with the first current value preset in the control unit 40. At this time, it is compared that the current difference is definitely greater than the first current value, and then the control unit 40 controls the first switch unit 30 to turn on so that the power supply of the relay 20 is turned on. After the power supply of the relay 20 is turned on, the relay 20 disconnects the connection between the live line L and the load, so that the power supply is cut off, thereby achieving the protection action when the current difference between the leakage neutral line N and the live line L is too large (leakage); if the leakage protection circuit fails, the connection between the load and the live line L will not be disconnected, and the leakage protection circuit will not cut off the power supply.

[0027] The leakage protection circuit designed for aircraft receives the test signal through the second switch unit 50 so that at least one resistor on the output end of the second switch unit 50 is connected between the neutral line N and the live line L so that a current difference greater than a preset first current value is formed between the neutral line N and the live line L. Then, by determining whether the current detection unit 10 transmits the detected current difference greater than the first current value to the control unit, whether the control unit 40 controls the first switch unit 30 to connect the power supply of the relay 20 so that the connection between the live line L and the load is disconnected when the relay 20 is powered on to stop the power supply to the load, it is determined whether the leakage protection circuit fails. If the leakage protection circuit does not cut off the power supply to the load under the test condition, it means that there is a fault in the leakage protection, thereby realizing the self-check function of the leakage protection, thereby solving the problem that the leakage protection circuit in the existing power supply circuit cannot be detected when it fails, resulting in low safety, so that the leakage protection failure of the power supply line can be discovered in time, thereby improving the safety of the power supply line.

[0028] In an optional implementation of this embodiment, if Figure 2As shown, the second switch unit 50 includes a packaged four-pin photoelectric relay 501, the input end of the packaged four-pin photoelectric relay 501 includes a first wiring terminal 1, a second wiring terminal 2, a third wiring terminal 3 and a fourth wiring terminal 4, wherein the first wiring terminal 1 and the second wiring terminal 2 are the input ends of the packaged four-pin photoelectric relay 501, the third wiring terminal 3 and the fourth wiring terminal 4 are the output ends of the packaged four-pin photoelectric relay 501, the first wiring terminal 1 is connected to the first power supply voltage, the second wiring terminal 2 is connected to the external test device, the third wiring terminal 3 is connected to the neutral line N through the at least one resistor R1, and the fourth wiring terminal 4 is connected to the live line L. In addition, the second switch unit 50 may also include a second resistor R2, which is arranged between the first wiring terminal 1 and the first power supply voltage to reduce the input voltage to the packaged four-pin photoelectric relay 501. Specifically, the model of the packaged four-pin photoelectric relay 501 can be AQY214S photoelectric relay; the voltage value of the first power supply voltage can be 5V, the number of the at least one resistor R1 can be three, the resistance values ​​of the three resistors R1 can be 6.2KΩ respectively, and the resistance value of the second resistor R2 can be 1KΩ.

[0029] The third terminal 3 and the fourth terminal 4 at the output end of the packaged four-pin photoelectric relay 501 of the above-mentioned design are normally open. When the second terminal 2 of the packaged four-pin photoelectric relay 501 receives a test signal from an external testing device, the light-emitting diode in the packaged four-pin photoelectric relay 501 generates light energy and then shines on the output end, so that the third terminal 3 and the fourth terminal 4 at the output end are connected, thereby connecting at least one resistor R1 between the live wire L and the neutral wire N.

[0030] In an optional implementation of this embodiment, if Figure 2 As shown, the current detection unit 10 can be specifically a zero-sequence current transformer 101 , the primary side of the zero-sequence current transformer 101 is connected to the neutral line N and the live line L respectively, and the secondary side of the zero-sequence current transformer 101 is connected to the control unit 40 .

[0031] like Figure 2As shown, the control unit 40 may include a ground fault interrupter (GIF) controller 401, which includes a VFB pin, a VREF pin, an AmpOut pin, an SCR pin, a Neutral pin and a Line pin. The VFB pin and the VREF pin are respectively connected to two ends of the secondary side of the zero-sequence current transformer 101. Specifically, the VFB pin can be connected to one end of the secondary side of the zero-sequence current transformer 101 through a third resistor R3; the AmpOut pin of the GIF controller is connected in parallel with the VFB pin, the SCR pin of the GIF controller is connected to the first switch unit 30, the first switch unit 30 is connected to the Neutral pin of the GIF controller and then grounded, and the Line pin of the GIF controller is connected to the second power supply voltage; in addition, Figure 2 As shown, a first capacitor C1 can be connected between the SCR pin and the Neutral pin, a second capacitor C2 can be connected between the Neutral pin and the Line pin, a third capacitor C3 can also be connected to both ends of the secondary side of the zero-sequence current transformer 101, and the second power supply voltage connected to the Line pin of the GIF controller can specifically be 12V.

[0032] The control unit 40 designed as above can preset the first current value in the AO pin of the GIF controller in advance, and then receive the current difference transmitted by the zero-sequence current transformer 101 through the VFB pin and the VREF pin, and then control the level output of the SCR pin through the first current value preset in the AO pin and the current difference received by the VFB pin and the VREF pin. For example, when the current difference is greater than the preset first current value, the SCR pin drives the first switch unit 30 to turn on, thereby disconnecting the connection between the live wire L and the load when the relay 20 is powered on to stop the power supply output of the power supply.

[0033] In an optional implementation of this embodiment, if Figure 2As shown, the first switch unit 30 may include a thyristor Q1, the relay 20 includes a coil 201 and a contact group, the contact group includes a static contact 2021, a normally closed moving contact 2022 and a normally open moving contact 2023, the control stage of the thyristor Q1 is connected to the SCR pin of the ground fault circuit breaker controller 401, the cathode of the thyristor Q1 is connected to the Neutral pin of the ground fault circuit breaker controller 401 and then grounded, the anode of the thyristor Q1 is connected to one end of the coil 201 of the relay 20, the other end of the coil 201 is connected to the third power supply level, the static contact 2021 is connected to the live wire L, the normally closed moving contact 2022 is connected to the load, and the normally open moving contact 2023 is connected to the ground wire. Specifically, under normal circumstances, the static contact 2021 is connected to the normally closed moving contact 2022. When the current difference is greater than the preset first current value, the SCR pin of the ground fault circuit breaker controller 401 sends a control signal to the control stage of the thyristor Q1, thereby controlling the thyristor Q1 to be turned on. After the thyristor Q1 is turned on, the third power supply level is the power supply turn-on of the coil 201 of the relay 20, and the coil 201 of the relay 20 works, so that the static contact 2021 and the normally closed moving contact 2022 connected to each other in the relay 20 are disconnected, so that the static contact 2021 is connected to the normally open moving contact 2023, and then the live wire L is connected to the bottom line, so that the live wire L and the neutral wire N are not connected to the load at the same time, so as to cut off the power supply output of the power supply. Of course, the normally closed moving contact 2022 of the relay 20 can also be connected to the neutral wire N, as long as the neutral wire N and the live wire L are not connected to the load at the same time.

[0034] Second embodiment

[0035] The present application provides a power supply circuit, which can be a power supply circuit of an aircraft, such as Figure 3 As shown, the power supply circuit may specifically include the leakage protection circuit for aircraft in the first embodiment, the filter rectifier circuit 200, the power factor correction circuit 300 and the inverter circuit 400, the live wire input terminal and the neutral wire input terminal of the filter rectifier circuit 200 are respectively connected to the power supply, the live wire output terminal of the filter rectifier circuit 200 is connected to the live wire input terminal of the power factor correction circuit 300, the neutral wire output terminal of the filter rectifier circuit 200 is connected to the neutral wire input terminal of the power factor correction circuit 300, the live wire output terminal of the power factor correction circuit 300 is connected to the live wire input terminal of the inverter circuit 400, the neutral wire output terminal of the power factor correction circuit 300 is connected to the neutral wire input terminal of the inverter circuit 400, and the neutral wire and live wire output terminals of the inverter circuit are connected to the load through the current detection unit 10 and the relay 20 in the leakage protection circuit.

[0036] Specifically, the input power supply in the power supply circuit of the above design can be a 115V / 400HZ power supply and then filtered through the filter rectifier circuit 200 in turn. Specifically, a surge suppression circuit is used to filter the input power signal to absorb surges outside the aircraft safety regulations, ensure the safe operation of the subsequent circuit, and remove line noise and interference. After filtering, the rectifier circuit performs rectification to convert the output DC voltage of about 150V, which is then transmitted to the power factor correction circuit 300 for power factor correction to maximize the efficiency of aircraft electricity consumption. After the power factor correction circuit 300 performs power factor correction, a high-voltage DC of 190V is output, and then the 190V high-voltage DC is converted into 110V / 60HZ AC through the inverter circuit 400 and then output to the load through the current detection unit 10 and the relay 20. In the above-designed circuit, the current detection unit 10 will detect the current difference between the live wire and the neutral wire at the output end of the inverter circuit 400 during the whole process, and then transmit it to the control unit 40 for control, thereby determining whether to cut off the power output. The self-test of the leakage protection circuit is consistent with the self-test process in the first embodiment, which will not be repeated here.

[0037] In an optional implementation of this embodiment, the power supply circuit may further include an output filter circuit 500 , and the neutral line and live line output ends of the inverter circuit 400 are connected to the load through the output filter circuit 500 , the current detection unit 10 and the relay 20 .

[0038] In an optional implementation manner of this embodiment, the filter rectifier circuit 200 may specifically include a filter circuit and a bridge rectifier circuit. The filter circuit and the bridge rectifier circuit may specifically be as follows: Figure 4The circuit shown in the figure includes a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7, an eighth capacitor C8, a ninth capacitor C9, a tenth capacitor C10, an eleventh capacitor C11, a twelfth capacitor C12, a thirteenth capacitor C13 and a fourteenth capacitor C14, a common-mode inductor L1, a first iron-core inductor L2, a second iron-core inductor L3, a bridge rectifier D1, a fourth resistor R4, a fifth resistor R5, a triac Q2 and a DC sensor M1. As can be seen from the figure, C4 is connected between the input neutral line and the live line, and the common-mode inductor L1 is connected to both ends of C4 and connected to the first end and The first end of C6 is connected, the second end of C5 and the second end of C6 are connected in series and the second ends of C5 and C6 are both grounded, the first end of C7 is connected to the first end of C5, the second end of C7 is connected to the first end of C6, the first end of C8 is connected to the first end of C7, the second end of C8 is connected to the second end of C7, the first end of L2 is connected to the first end of C8, the second end of L2 is connected to the first end of C9, the first end of L3 is connected to the second end of C8, the second end of L3 is connected to the second end of C9, the first end of C9 is connected to the first end of C10, and the second end of C10 is connected to the first end of the bridge rectifier D1, and the bridge rectifier The second end of D1 is connected to the first end of C10, the third end of the bridge rectifier D1 is the live line output end of the filter rectifier circuit 200, and the fourth end of the bridge rectifier D1 is the neutral line output end of the filter rectifier circuit 200; the second end of C9 is connected to the first terminal of the triac Q2 and is connected to the second terminal of the triac Q2 through the fourth resistor R4, the second end of C10 is also connected to the first terminal of the triac Q2, the gate of the triac Q2 is connected to the second end of C11 through the fifth resistor R5, and the first terminal of the triac Q2 is connected to the first terminal of C11. The first end of C11 is connected to the first end of C12, the second end of C11 is connected to the second end of C12, the first end of C12 is connected to the VO+ pin of the DC sensor M1; the second end of C12 is connected to the VO- of the DC sensor M1, the VIN+ pin of the DC sensor M1 is connected to the first end of C13, the VIN- pin of the DC sensor M1 is connected to the second end of C13, the first end of C13 is connected to the first end of C14, the second end of C13 is connected to the second end of C14, the first end of C14 is connected to a power supply voltage, and the second end of C14 is grounded.

[0039] The above-mentioned filter circuit has a surge suppression function and can filter the input power signal, absorb surges outside the safety range, ensure the safe operation of the subsequent circuit, and remove line noise and interference. The bridge rectifier circuit converts AC into DC.

[0040] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of the devices or units can be electrical, mechanical or other forms.

[0041] In addition, the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0042] Furthermore, the functional modules in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0043] It should be noted that if the function is implemented in the form of a software function module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can essentially be embodied in the form of a software product, or the part that contributes to the prior art or the part of the technical solution. The computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM) random access memory (RAM), disk or optical disk, and other media that can store program codes.

[0044] In this document, relational terms such as first and second, etc. are used merely to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0045] The above description is only an embodiment of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A leakage protection circuit for an aircraft, wherein the leakage protection circuit is arranged on the neutral line and the live line between the power supply and the load, and is characterized in that: The leakage protection circuit comprises: a current detection unit, whose input end is connected to the neutral line and the live line respectively, so as to detect the current difference between the neutral line and the live line; a relay and a first switch unit, wherein the first switch unit is connected to the relay, the relay is arranged between the live wire and the load, and the first switch unit is used to connect the power supply of the relay or cut off the power supply of the relay so that the relay connects the connection between the live wire and the load when the power supply is cut off or cuts off the connection between the live wire and the load when the power supply is turned on; a control unit, connected to the current detection unit and the first switch unit, respectively, for controlling the first switch unit to conduct when the current difference transmitted by the current detection unit is greater than a preset first current value so as to turn on the power supply of the coil of the relay, so that the relay disconnects the connection between the live wire and the load; a second switch unit, whose output end is respectively connected to the neutral line and the live line through at least one first resistor, and whose input end is respectively connected to the first power supply voltage and the external test device, so as to receive a test signal sent by the external test device, and control the second switch unit to be turned on according to the test signal, so that the at least one first resistor connects the neutral line and the live line so that the current difference between the neutral line and the live line is greater than the preset first current value; The second switch unit includes a packaged four-pin photoelectric relay, the input end of the packaged four-pin photoelectric relay includes a first wiring terminal and a second wiring terminal, and the output end includes a third wiring terminal and a fourth wiring terminal, the first wiring terminal is connected to the first power supply voltage, the second wiring terminal is connected to the external test device, the third wiring terminal is connected to the neutral line through the at least one first resistor, and the fourth wiring terminal is connected to the live line, wherein the packaged four-pin photoelectric relay includes a photoelectric relay with a model of AQY214S; The current detection unit comprises a zero-sequence current transformer, the primary side of which is connected to the neutral line and the live line respectively, and the secondary side of which is connected to the control unit; The control unit includes a ground fault circuit breaker controller, a VFB pin and a VREF pin of the ground fault circuit breaker controller are respectively connected to two ends of the secondary side of the zero-sequence current transformer, an AmpOut pin of the ground fault circuit breaker controller is connected in parallel with the VFB pin, an SCR pin of the ground fault circuit breaker controller is connected to the first switch unit, the first switch unit is connected to the Neutral pin of the ground fault circuit breaker controller and then grounded, and a Line pin of the ground fault circuit breaker controller is connected to a second power supply voltage; The first switch unit comprises a thyristor, a control stage of the thyristor is connected to an SCR pin of the ground fault circuit breaker controller, a cathode of the thyristor is connected to a Neutral pin of the ground fault circuit breaker controller and then grounded, and an anode of the thyristor is connected to the relay.

2. The leakage protection circuit according to claim 1, characterized in that: The first connecting terminal is connected to the first supply voltage via a second resistor.

3. The leakage protection circuit according to claim 1, characterized in that: The relay includes a coil and a contact group, the contact group includes a static contact, a normally closed moving contact and a normally open moving contact, one end of the coil is connected to the anode of the thyristor, the other end of the coil is connected to a third power supply voltage, the static contact is connected to the live wire, the normally closed moving contact is connected to the load, and the normally open moving contact is connected to the ground wire.

4. A power supply circuit, characterized in that: The power supply circuit comprises a leakage protection circuit, a filter rectifier circuit, a power factor correction circuit and an inverter circuit as claimed in any one of claims 1 to 3; The live wire input terminal and the neutral wire input terminal of the filtering and rectifying circuit are respectively connected to the power supply, the live wire output terminal of the filtering and rectifying circuit is connected to the live wire input terminal of the power factor correction circuit, the neutral wire output terminal of the filtering and rectifying circuit is connected to the neutral wire input terminal of the power factor correction circuit, the live wire output terminal of the power factor correction circuit is connected to the live wire input terminal of the inverter circuit, the neutral wire output terminal of the power factor correction circuit is connected to the neutral wire input terminal of the inverter circuit, and the neutral wire and live wire output terminals of the inverter circuit are connected to the load through the current detection unit in the leakage protection circuit and the relay.

5. The power supply circuit according to claim 4, characterized in that: The filtering and rectifying circuit comprises a filtering circuit and a bridge rectifier circuit, the live wire input terminal and the neutral wire input terminal of the filtering circuit are connected to the power supply, the filtering circuit is connected to the bridge rectifier circuit, the live wire output terminal of the bridge rectifier circuit is connected to the live wire input terminal of the power factor correction circuit, and the neutral wire output terminal of the bridge rectifier circuit is connected to the neutral wire input terminal of the power factor correction circuit.

6. The power supply circuit according to claim 4, characterized in that: The power supply circuit further includes an output filter circuit, and the neutral line and live line output ends of the inverter circuit are connected to the load through the output filter circuit, the current detection unit and the relay.

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