Detection and protection apparatus for power cord, electrical connection device, and electric device

Abstract

The present application discloses a detection and protection apparatus for a power cord, an electrical connection device, and an electric device. The detection and protection apparatus comprises a switch module (210), a leakage current detection module (220), a fault response module (230), a trigger module (240), a self-test current injection module (250), and a manual detection module (260). The leakage current detection module (220) comprises a first shielding conductor structure (221) and a second shielding conductor structure (222); the self-test current injection module (250) is used for generating a self-test current flowing from the second shielding conductor structure (222) to the first shielding conductor structure (221), and when the leakage current detection module (220) is open-circuited, generating an open-circuit signal flowing from a third end to the fault response module (230); and the manual detection module (260) is used for generating a simulated leakage current flowing from the first shielding conductor structure (221) to the second shielding conductor structure (222), the simulated leakage current being greater than the self-test current.

Description

Power cord detection and protection devices, electrical connection equipment and electrical equipment

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202422660387.5, filed on October 31, 2024, entitled "Power Line Detection and Protection Device, Electrical Connection Equipment and Electrical Equipment", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of electrical technology, and in particular to a power line detection and protection device, an electrical connection device, and an electrical appliance. Background Technology

[0004] A leakage circuit breaker (LCDI) is a power connection device for electrical appliances. It detects leakage current in the power supply line via a leakage current detection lead and trips the switch when a certain leakage current is detected, disconnecting the power supply to the appliance and ensuring safety. In recent years, LCDIs have faced higher safety detection requirements beyond simply detecting leakage current in the power supply line via the leakage current detection lead; for example, they need to detect whether the leakage current detection lead is open-circuited.

[0005] Currently, in power cord detection and protection devices, open-circuit detection of the leakage current detection line is generally performed continuously after the device is powered on. Once an open circuit is detected in the leakage current detection line, the switch is triggered to trip and disconnect the power supply. In addition, the detection and protection device is usually equipped with a test switch to simulate leakage current conditions to test whether the tripping device can work properly. However, existing power cord detection and protection devices cannot simultaneously achieve automatic and manual open-circuit detection of the leakage current detection line. Summary of the Invention

[0006] The purpose of this application is to at least solve one of the technical problems existing in the prior art, and to this end, to provide a power cord detection and protection device, an electrical connection device, and an electrical appliance.

[0007] In a first aspect, embodiments of this application provide a power line detection and protection device, wherein the power line includes a first current-carrying line and a second current-carrying line, and the detection and protection device includes: a switching module, a leakage current detection module, a fault response module, a triggering module, a self-test current injection module, and a manual detection module, wherein:

[0008] The switch module is used to control the power connection between the input and output ends of the power line.

[0009] The leakage current detection module includes a first shielding conductor structure covering the first current-carrying line and a second shielding conductor structure covering the second current-carrying line; the first shielding conductor structure is used to collect the leakage current signal of the first current-carrying line, and the second shielding conductor structure is used to collect the leakage current signal of the second current-carrying line; the first shielding conductor structure and the second shielding conductor structure are connected.

[0010] The fault response module is electrically coupled to the first shielding conductor structure and the second shielding conductor structure respectively, and outputs a trip trigger signal in response to the acquisition of the leakage signal;

[0011] The trigger module is electrically coupled to the fault response module and the switch module respectively, and is configured to drive the switch module to disconnect the power connection in response to receiving the trip trigger signal;

[0012] One end of the self-test current injection module is electrically coupled to the first current-carrying line, and the other end is electrically coupled to the connection point between the second shielding conductor structure and the fault response module. It is used to generate a self-test current flowing from the second shielding conductor structure to the first shielding conductor structure under the action of the voltage provided by the first current-carrying line, and to generate an open circuit signal flowing from the second shielding conductor structure to the fault response module when the leakage current detection module is open, so that the fault response module outputs the trip trigger signal.

[0013] The manual detection module has one end electrically coupled to the first current-carrying line and the other end electrically coupled to the connection point between the first shielding conductor structure and the fault response module. It is used to generate a simulated leakage current flowing from the first shielding conductor structure to the second shielding conductor structure under the action of the voltage provided by the first current-carrying line, and output the simulated leakage current from the second shielding conductor structure to the fault response module so that the fault response module outputs the trip trigger signal; wherein, the simulated leakage current is greater than the self-test current.

[0014] According to the power line detection and protection device provided in the embodiments of this application, after the switch module is closed and powered on, since the two ends of the self-test current injection module are respectively connected to the first current-carrying line and the second shielding conductor structure, a self-test current is generated under the action of the voltage provided by the first current-carrying line, flowing from the self-test current injection module to the second shielding conductor structure and then to the first shielding conductor structure. When the leakage detection module is open-circuited, such as the first shielding conductor structure being open-circuited, the second shielding conductor structure being open-circuited, or the connection line between the first shielding conductor structure and the second shielding conductor structure being open-circuited, the self-test current cannot flow into the second shielding conductor structure and can only flow to the fault response module, thereby generating an open-circuit signal flowing from the second shielding conductor structure to the fault response module, causing the fault response module to output a trip trigger signal, which in turn drives the switch module to disconnect the power connection; when performing manual detection. Since the two ends of the manual detection module are connected to the first current-carrying line and the first shielding conductor structure respectively, a simulated leakage current is generated under the action of the voltage provided by the first current-carrying line, flowing from the manual detection module to the first shielding conductor structure and then to the second shielding conductor structure. Since the simulated leakage current is greater than the self-test current, it can cancel the existing self-test current. Finally, the current flows from the second shielding conductor structure to the fault response module, causing the fault response module to output a trip trigger signal, which in turn drives the switch module to disconnect the power connection. This detection and protection device can simultaneously realize automatic open-circuit detection and manual open-circuit detection of the shielding conductor structure in the leakage detection module. The direction and magnitude of the current flowing through the shielding conductor structure in the leakage detection module are different for the two cases, so the two different detection conditions can be further distinguished by detecting the current flowing through the leakage detection module.

[0015] According to some embodiments of the present application, the detection and protection device includes a first shielding conductor structure with a first end near the input end of the power line and a second end near the output end of the power line; the second shielding conductor structure includes a third end near the input end and a fourth end near the output end; the second end and the fourth end are connected; and the fault response module is connected to the first end and the third end respectively.

[0016] According to some embodiments of the present application, the detection protection device includes a manual detection module comprising a test switch and a first resistor. One end of the test switch is connected to the first current-carrying line, and the other end of the test switch is connected to one end of the first resistor. The other end of the first resistor is connected to the first end.

[0017] According to some embodiments of the present application, the detection and protection device includes a self-test current injection module comprising a second resistor, one end of which is connected to the first current-carrying line and the other end of which is connected to the third terminal, wherein the resistance value of the second resistor is greater than the resistance value of the first resistor.

[0018] According to some embodiments of the present application, the fault response module includes a third resistor, a fourth resistor, a first capacitor, and a Zener diode. One end of the third resistor is connected to the first terminal, one end of the fourth resistor is connected to the third terminal, the two ends of the first capacitor are respectively connected to the other ends of the third resistor and the fourth resistor, one end of the Zener diode is connected to the connection point of the first capacitor and the fourth resistor, and the other end of the Zener diode is connected to the trigger module to output the trip trigger signal to the trigger module when the Zener diode breaks down in the reverse direction.

[0019] According to some embodiments of the present application, the detection and protection device includes a triggering module comprising a silicon controlled rectifier (SCR) and a trip coil for generating electromagnetic force to drive the switching module to disconnect the power connection. A second current-carrying line is connected to one end of the trip coil, the other end of the trip coil is connected to the anode of the SCR, the cathode of the SCR is connected to the first current-carrying line, and the control electrode of the SCR is connected to the output terminal of the fault response module.

[0020] According to some embodiments of the present application, the detection and protection device includes a triggering module that further includes a thyristor driving module. The thyristor driving module includes a fifth resistor and a second capacitor. The output terminal of the fault response module is connected to one end of the fifth resistor, one end of the second capacitor, and the control electrode of the thyristor. The other end of the fifth resistor and the other end of the second capacitor are both connected to the cathode of the thyristor.

[0021] According to some embodiments of the present application, the detection and protection device further includes a first diode and a second diode. The cathode of the thyristor is connected to the anode of the first diode and the anode of the second diode. The cathode of the first diode is connected to the first current-carrying line, and the cathode of the second diode is connected to the connection point between the trip coil and the thyristor.

[0022] According to some embodiments of the present application, the triggering module of the detection and protection device further includes a first varistor connected in parallel with the silicon controlled rectifier.

[0023] The detection and protection device provided according to some embodiments of this application further includes an indicator module connected in parallel with the silicon controlled rectifier (SCR), the indicator module including a sixth resistor and a light-emitting diode connected in series.

[0024] The detection and protection device provided according to some embodiments of this application further includes a lightning protection module, wherein the lightning protection module includes a second varistor, and the two ends of the second varistor are respectively connected to the first current-carrying line and the second current-carrying line.

[0025] Secondly, embodiments of this application provide an electrical connection device, including the detection and protection device, housing, and power cord as described in the first aspect embodiment above. The power cord is connected to the housing, and the switch module, the fault response module, the trigger module, the self-test current injection module, and the manual detection module are disposed in the housing.

[0026] Thirdly, embodiments of this application provide an electrical device, including a load device and an electrical connection device as described in the second aspect of the embodiment above, wherein the output end of the power line is connected to the load device.

[0027] Other features and advantages of this application will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the description, claims and drawings. Attached Figure Description

[0028] The accompanying drawings are used to provide a further understanding of the technical solutions of this application and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of this application and do not constitute a limitation on the technical solutions of this application.

[0029] The embodiments of this application will be further described below with reference to the accompanying drawings and examples;

[0030] Figure 1 is a block diagram of the module principle of the detection and protection device provided in an embodiment of this application;

[0031] Figure 2 is a schematic diagram of the flow direction of the self-test current of the detection and protection device in the embodiment shown in Figure 1;

[0032] Figure 3 is a schematic diagram of the flow of the open-circuit signal of the detection and protection device in the embodiment shown in Figure 1;

[0033] Figure 4 is a schematic diagram of the simulated leakage current flow of the detection and protection device in the embodiment shown in Figure 1;

[0034] Figure 5 is a circuit diagram of the leakage current detection module, self-test current injection module and manual detection module of the detection and protection device provided in the embodiments of this application;

[0035] Figure 6 is a schematic diagram of the flow direction of the self-test current of the detection and protection device in the embodiment shown in Figure 5;

[0036] Figure 7 is a schematic diagram of the flow of the open-circuit signal of the detection and protection device in the embodiment shown in Figure 5;

[0037] Figure 8 is a schematic diagram of the simulated leakage current flow of the detection and protection device in the embodiment shown in Figure 5;

[0038] Figure 9 is a circuit diagram of the leakage current detection module and fault response module of the detection and protection device provided in the embodiments of this application;

[0039] Figure 10 is a circuit diagram of the switching module, triggering module, indicating module and lightning protection module of the detection and protection device provided in the embodiments of this application;

[0040] Figure 11 is a schematic diagram of the structure of the electrical connection device provided in an embodiment of this application. Detailed Implementation

[0041] This section will describe in detail the specific embodiments of this application. Preferred embodiments of this application are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of this application, but they should not be construed as limiting the scope of protection of this application.

[0042] In the description of the embodiments of this application, "several" means one or more, "multiple" means two or more, "greater than," "less than," "exceeding," etc. are understood to exclude the stated number, while "above," "below," "within," etc. are understood to include the stated number. "At least one" refers to one or more, and "at least one of the following" and similar expressions refer to any combination of these items, including any combination of single or multiple items. If "first," "second," etc., are used in the description, they are only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the number of indicated technical features or the order of the indicated technical features.

[0043] It should be noted that the terms "setting," "installing," and "connecting" in the embodiments of this application should be interpreted broadly. Those skilled in the art can reasonably determine the specific meaning of the above terms in the embodiments of this application in conjunction with the specific content of the technical solution. For example, the term "connection" can be a mechanical connection, an electrical connection, or a connection that allows for mutual communication; it can be a direct connection or an indirect connection through an intermediate medium.

[0044] It should be noted that the technical features involved in the various embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0045] A leakage circuit breaker (LCDI) is a power connection device for electrical appliances. It detects leakage current in the power supply line via a leakage current detection line and triggers a switch to trip when a certain leakage current is detected, disconnecting the power supply to the appliance and ensuring safety. In recent years, LCDIs have faced higher safety requirements beyond simply detecting leakage current in the power supply line via the leakage current detection line. For example, they need to detect whether the leakage current detection line is open-circuited. Currently, in power supply line detection and protection devices, open-circuit detection of the leakage current detection line is generally performed continuously after the device is powered on. Once an open circuit is detected, the switch is triggered to disconnect the power supply. Additionally, the detection and protection device usually includes a test switch to simulate leakage conditions and test whether the tripping device functions properly. However, existing power supply line detection and protection devices cannot simultaneously achieve automatic and manual open-circuit detection of the leakage current detection line.

[0046] Based on this, embodiments of this application provide a power cord detection and protection device, an electrical connection device, and an electrical appliance, which can simultaneously realize automatic open-circuit detection and manual open-circuit detection of the shielded conductor structure in the leakage current detection module, and can further distinguish between the two different detection situations by detecting the current flowing through the leakage current detection module.

[0047] The embodiments of this application will be further described below with reference to the accompanying drawings.

[0048] Figure 1 is a block diagram of the module principle of the detection and protection device provided in the embodiment of this application; Figure 5 is a circuit diagram of the leakage current detection module, self-test current injection module, and manual detection module of the detection and protection device provided in the embodiment of this application; Figure 9 is a circuit diagram of the leakage current detection module and fault response module of the detection and protection device provided in the embodiment of this application; Figure 10 is a circuit diagram of the switch module, trigger module, indicator module, and lightning protection module of the detection and protection device provided in the embodiment of this application. Referring to Figures 1, 5, 9, and 10, a first aspect embodiment of this application provides a power line detection and protection device, wherein:

[0049] The power supply line includes a first current-carrying wire 110 and a second current-carrying wire 120. It can be understood that when the power supply line supplies power to electrical equipment using two-phase AC power, it can be one of the following two cases: the first current-carrying wire 110 is the live wire L, and the second current-carrying wire 120 is the neutral wire N; or the first current-carrying wire 110 is the neutral wire N, and the second current-carrying wire 120 is the live wire L. When the power supply line supplies power to electrical equipment using three-phase AC power, it can be one of the following three cases: the first current-carrying wire 110 is the live wire L1, and the second current-carrying wire 120 is the neutral wire N; the first current-carrying wire 110 is the neutral wire N, and the second current-carrying wire 120 is the live wire L1; or the first current-carrying wire 110 is the live wire L1, and the second current-carrying wire 120 is the live wire L2. The following explanation uses the case shown in Figure 5, where the first current-carrying wire 110 is the live wire L and the second current-carrying wire 120 is the neutral wire N, as an example. The other cases can be understood similarly.

[0050] The detection and protection device includes: a switch module 210, a leakage current detection module 220, a fault response module 230, a trigger module 240, a self-test current injection module 250, and a manual detection module 260.

[0051] The switch module 210 is used to control the power connection between the input and output terminals of the power line. Referring to FIG10, the switch module 210 is provided with switch terminals on the first current-carrying line 110 and the second current-carrying line 120. When the switch terminals of the switch module 210 are closed, the power connection between the input and output terminals of the power line is conducted. When the switch terminals of the switch module 210 are open, the power connection between the input and output terminals of the power line is disconnected.

[0052] The leakage current detection module 220 includes a first shielded conductor structure 221 covering a first current-carrying line 110 and a second shielded conductor structure 222 covering a second current-carrying line 120. The first shielded conductor structure 221 is used to collect the leakage current signal of the first current-carrying line 110, and the second shielded conductor structure 222 is used to collect the leakage current signal of the second current-carrying line 120. The first shielded conductor structure 221 and the second shielded conductor structure 222 are connected. Specifically, the first shielded conductor structure 221 includes a first end a near the input end of the power line and a second end b near the output end of the power line; the second shielded conductor structure 222 includes a third end c near the input end and a fourth end d near the output end; the second end b and the fourth end d are connected. It can be understood that leakage current... The first shielding conductor structure 221 in the detection module 220 covers the first current-carrying line 110, thereby enabling the acquisition of the leakage current signal of the first current-carrying line 110. The second shielding conductor structure 222 in the leakage current detection module 220 covers the second current-carrying line 120, thereby enabling the acquisition of the leakage current signal of the second current-carrying line 120. Based on this, the second end b of the first shielding conductor structure 221 near the output end of the power line is connected to the fourth end d of the second shielding conductor structure 222 near the output end of the power line, so that the first shielding conductor structure 221 and the second shielding conductor structure 222 form a series detection loop. The integrity of the first shielding conductor structure 221 and the second shielding conductor structure 222 can be detected by determining whether the current can flow through the series detection loop.

[0053] The fault response module 230 is electrically coupled to the first shielded conductor structure 221 and the second shielded conductor structure 222 respectively. Specifically, the fault response module 230 is connected to the first terminal a and the third terminal c respectively, and outputs a trip trigger signal in response to the acquisition of the leakage signal.

[0054] The trigger module 240 is electrically coupled to the fault response module 230 and the switch module 210 respectively, and is configured to drive the switch module 210 to disconnect the power connection in response to receiving a trip trigger signal;

[0055] One end of the self-test current injection module 250 is electrically coupled to the first current-carrying line 110, and the other end is electrically coupled to the connection point between the second shielding conductor structure 222 and the fault response module 230. Specifically, it can be connected to the third terminal c. It is used to generate a self-test current flowing from the second shielding conductor structure 222 to the first shielding conductor structure 221 under the action of the voltage provided by the first current-carrying line 110, and to generate an open-circuit signal flowing from the third terminal c to the fault response module 230 when the leakage current detection module 220 is open, so that the fault response module 230 outputs a trip trigger signal.

[0056] The manual detection module 260 is electrically coupled to the first current-carrying line 110 at one end and electrically coupled to the connection point between the first shielding conductor structure 221 and the fault response module 230 at the other end. Specifically, it can be connected to the first end a. It is used to generate a simulated leakage current flowing from the first shielding conductor structure 221 to the second shielding conductor structure 222 under the action of the voltage provided by the first current-carrying line 110, and outputs the simulated leakage current from the third end c to the fault response module 230 so that the fault response module 230 outputs a trip trigger signal; wherein, the simulated leakage current is greater than the self-test current.

[0057] According to the power line detection and protection device provided in this application embodiment, after the switch module 210 is closed and energized, since the two ends of the self-test current injection module 250 are respectively connected to the third end c of the first current-carrying line 110 and the second shielding conductor structure 222, a self-test current is generated under the action of the voltage provided by the first current-carrying line 110, flowing from the self-test current injection module 250 to the second shielding conductor structure 222 and then to the first shielding conductor structure 221. The flow direction of the self-test current is shown by the arrow in FIG2. When the leakage detection module 220 is open-circuited... In cases where, for example, the first shielding conductor structure 221 is open, the second shielding conductor structure 222 is open, or the connection line between the second terminal b and the fourth terminal d is open, the self-test current cannot flow from the third terminal c of the second shielding conductor structure 222 into the second shielding conductor structure 222. Instead, it flows to the fault response module 230, thus generating an open-circuit signal flowing from the third terminal c to the fault response module 230. The direction of the open-circuit signal is shown by the arrow in Figure 3, causing the fault response module 230 to output a trip trigger signal, which in turn drives the switch module 240. 10. Disconnect the power connection; During manual testing, since the two ends of the manual testing module 260 are connected to the first current-carrying line 110 and the first end a of the first shielding conductor structure 221 respectively, a simulated leakage current is generated under the action of the voltage provided by the first current-carrying line 110, flowing from the manual testing module 260 to the first shielding conductor structure 221 and then to the second shielding conductor structure 222. Since the simulated leakage current is greater than the self-test current, it can cancel the existing self-test current. Finally, it flows from the third end c to the fault response module 230. The direction of the simulated leakage current is shown by the arrow in Figure 4, which causes the fault response module 230 to output a trip trigger signal, which in turn drives the switch module 210 to disconnect the power connection by the trigger module 240. This detection and protection device can simultaneously realize automatic open-circuit detection and manual open-circuit detection of the shielding conductor structure in the leakage detection module 220. The direction and magnitude of the current flowing through the shielding conductor structure in the leakage detection module 220 are different, so the two different detection situations can be further distinguished by detecting the current flowing through the leakage detection module 220.

[0058] It should be noted that detection and protection devices with leakage current detection and open circuit detection functions need to be sent for testing to determine whether they meet the requirements of national standards. After the power cord detection and protection device provided in the embodiments of this application is sent for testing, in order to verify the automatic open-circuit detection and manual open-circuit detection functions of the detection and protection device, ammeters can be set at different positions to detect the magnitude of the current signal flowing through the leakage current detection module 220 and the magnitude of the current signal flowing from the third end c of the second shielding conductor structure 222 to the fault response module 230. When the manual detection module 260 is not conducting and the leakage current detection module 220 is not open-circuited, a small self-test current can be detected, flowing through the leakage current detection module 220 in a counterclockwise direction as shown in Figure 2. It can be understood that at this time, current can also flow directly from the self-test current injection module 250 to the fault response module 230. When the manual detection module 260 is conducting and the leakage current detection module 220 is not open-circuited, a large simulated leakage current can be detected, flowing through the leakage current detection module 220 in a clockwise direction as shown in Figure 4 and flowing from the third end c to the fault response module 230. Therefore, the automatic open-circuit detection and manual open-circuit detection functions of the protection device can be demonstrated by detecting the current flowing through the leakage current detection module 220.

[0059] Referring to FIG5, in the detection protection device provided in some embodiments of this application, the manual detection module 260 includes a test switch TEST and a first resistor R1. One end of the test switch TEST is connected to the first current-carrying line 110, and the other end of the test switch TEST is connected to one end of the first resistor R1. The other end of the first resistor R1 is connected to the first terminal a.

[0060] In this embodiment, during manual testing, pressing the test switch TEST closes the switch, generating a simulated leakage current under the voltage provided by the first current-carrying line 110. This simulated leakage current flows sequentially through the test switch TEST, the first resistor R1, the first shielding conductor structure 221, and the second shielding conductor structure 222, finally flowing from the third end c of the second shielding conductor structure 222 to the fault response module 230. The simulated leakage current is shown by the arrow in Figure 8. It can be understood that pressing the test switch TEST can also result in current flowing directly from the connection point between the first resistor R1 and the first shielding conductor structure 221, i.e., the first end a, to the fault response module 230.

[0061] Referring to Figure 5, in the detection and protection device provided in some embodiments of this application, the self-test current injection module 250 includes a second resistor R2. One end of the second resistor R2 is connected to the first current-carrying line 110, and the other end of the second resistor R2 is connected to the third terminal c. The resistance value of the second resistor R2 is greater than the resistance value of the first resistor R1.

[0062] In this embodiment, since the two ends of the second resistor R2 are respectively connected to the third end c of the first current-carrying line 110 and the second shielding conductor structure 222, a self-test current is generated under the action of the voltage provided by the first current-carrying line 110. This self-test current flows through the second resistor R2, the second shielding conductor structure 222, and the first shielding conductor structure 221, and finally flows from the first end a of the first shielding conductor structure 221 to the fault response module 230. The direction of the self-test current is shown by the arrow in Figure 6. It can be understood that, at this time, it is also possible for the self-test current to flow directly from the connection point between the second resistor R2 and the second shielding conductor structure 222, i.e., the third end c, to the fault response module 230. The current of block 230; when the leakage detection module 220 is open-circuited, such as the first shielding conductor structure 221 being open-circuited, the second shielding conductor structure 222 being open-circuited, or the connection line between the second terminal b and the fourth terminal d being open-circuited, the self-test current cannot flow from the third terminal c of the second shielding conductor structure 222 into the second shielding conductor structure 222, but can only flow to the fault response module 230, thereby generating an open-circuit signal flowing from the third terminal c to the fault response module 230. The direction of the open-circuit signal is shown by the arrow in Figure 7, which causes the fault response module 230 to output a trip trigger signal, which in turn drives the switch module 210 to disconnect the power connection by the trigger module 240.

[0063] It should also be noted that since the second end b of the first shielding conductor structure 221 and the fourth end d of the second shielding conductor structure 222 are connected together, the first shielding conductor structure 221 and the second shielding conductor structure 222 are at the same potential. The resistance of the second resistor R2 is greater than that of the first resistor R1, that is, the resistance of the second resistor R2 is larger. Therefore, the self-test current injected from the second resistor R2 into the second shielding conductor structure 222 is smaller. Since the resistance of the first resistor R1 is smaller, when the test switch TEST is pressed, the leakage current simulation current injected from the first resistor R1 into the first shielding conductor structure 221 is larger, which can cancel the existing self-test current. Finally, it flows from the third end c of the second shielding conductor structure 222 to the fault response module 230, so that the fault response module 230 outputs a trip trigger signal, which in turn drives the switch module 210 to disconnect the power connection by the trigger module 240.

[0064] Referring to FIG9, in the detection and protection device provided in some embodiments of this application, the fault response module 230 includes a third resistor R3, a fourth resistor R4, a first capacitor C1, and a Zener diode ZD1. One end of the third resistor R3 is connected to the first terminal a, one end of the fourth resistor R4 is connected to the third terminal c, the two ends of the first capacitor C1 are respectively connected to the other ends of the third resistor R3 and the fourth resistor R4, one end of the Zener diode ZD1 is connected to the connection point of the first capacitor C1 and the fourth resistor R4, and the other end of the Zener diode ZD1 is connected to the trigger module 240 so as to output a trip trigger signal to the trigger module 240 when the Zener diode ZD1 breaks down in reverse.

[0065] In this embodiment, the Zener diode ZD1 will break down in reverse under the following four conditions, thereby outputting a trip trigger signal to the trigger module 240: The first condition is that the first shielding conductor structure 221 detects a leakage signal from the first current-carrying line 110 and transmits it to the fault response module 230; the second condition is that the second shielding conductor structure 222 detects a leakage signal from the second current-carrying line 120 and transmits it to the fault response module 230; the third condition is that the leakage detection module 220 is open-circuited, for example, the first shielding conductor structure 221 is open-circuited, the second shielding conductor structure 222 is open-circuited, or the connection line between the second terminal b and the fourth terminal d is open-circuited, generating an open-circuit signal flowing from the third terminal c to the fault response module 230; the fourth condition is that the test switch TEST is manually pressed, generating a simulated leakage current, which flows from the third terminal c of the second shielding conductor structure 222 to the fault response module 230.

[0066] Additionally, it should be noted that the connection point between the third resistor R3 and the first capacitor C1 is also connected to the trigger module 240 so that a complete current loop can be formed.

[0067] Referring to FIG10, in the detection and protection device provided in some embodiments of this application, the trigger module 240 includes a thyristor Q1 and a trip coil Lx for generating electromagnetic force to drive the switch module 210 to disconnect the power connection. The second current-carrying line 120 is connected to one end of the trip coil Lx, the other end of the trip coil Lx is connected to the anode of the thyristor Q1, the cathode of the thyristor Q1 is connected to the first current-carrying line 110, and the control electrode of the thyristor Q1 is connected to the output terminal of the fault response module 230.

[0068] In this embodiment, when the output terminal of the fault response module 230 outputs a trip trigger signal to the control electrode of the thyristor Q1, the thyristor Q1 is turned on, forming a strong current path of the second current-carrying line 120-trip coil Lx-thyristor Q1-first diode D1-first current-carrying line 110; the trip coil Lx generates a strong electromagnetic force, thereby driving the switch module 210 to disconnect the power connection between the input and output terminals of the power line.

[0069] Referring to FIG10, in the detection and protection device provided in some embodiments of this application, the trigger module 240 further includes a thyristor drive module 241. The thyristor drive module 241 includes a fifth resistor R5 and a second capacitor C2. The output terminal of the fault response module 230 is connected to one end of the fifth resistor R5, one end of the second capacitor C2 and the control electrode of the thyristor Q1. The other end of the fifth resistor R5 and the other end of the second capacitor C2 are both connected to the cathode of the thyristor Q1.

[0070] In this embodiment, when the fault response module 230 outputs a trip trigger signal, the trip trigger signal charges the second capacitor C2 through the fifth resistor R5, and the potential of the control electrode of the thyristor Q1 rises. When the negative half-cycle of the AC power supply arrives, that is, when the level of the second current-carrying line 120 is greater than the level of the first current-carrying line 110, the thyristor Q1 is turned on, forming a strong current path of the second current-carrying line 120-trip coil Lx-thyristor Q1-first diode D1-first current-carrying line 110; the trip coil Lx generates a strong electromagnetic force, thereby driving the switch module 210 to disconnect the power connection between the input and output terminals of the power line.

[0071] Referring to FIG10, in the detection and protection device provided in some embodiments of this application, the trigger module 240 further includes a first diode D1 and a second diode D2. The cathode of the thyristor Q1 is connected to the anode of the first diode D1 and the anode of the second diode D2. The cathode of the first diode D1 is connected to the first current-carrying line 110, and the cathode of the second diode D2 is connected to the connection point between the trip coil Lx and the thyristor Q1.

[0072] In this embodiment, the first diode D1 and the second diode D2 in the trigger module 240 can enable the current signal transmitted to the cathode of the thyristor Q1 to form a complete current loop and flow back to the first current-carrying line 110 or the second current-carrying line 120.

[0073] Referring to Figure 10, in some embodiments of the detection and protection device provided in this application, the trigger module 240 further includes a first varistor ZR1 connected in parallel with the silicon controlled rectifier (SCR) Q1. It is understood that a varistor is a resistor with nonlinear current-voltage characteristics, mainly used for voltage clamping when the circuit is subjected to overvoltage, absorbing excess current to protect sensitive devices. Therefore, setting the first varistor ZR1 in parallel with the SCR Q1 can protect the SCR Q1 from damage.

[0074] Referring to FIG10, in some embodiments of the detection and protection device provided in this application, an indicator module 270 connected in parallel with the silicon controlled rectifier Q1 is also included. The indicator module 270 includes a sixth resistor R6 and a light-emitting diode LED1 connected in series.

[0075] In this embodiment, after the switch module 210 is closed, a conduction path is formed from the second current-carrying line 120 to the trip coil Lx, the sixth resistor R6, the light-emitting diode LED1, the first diode D1, and the first current-carrying line 110, and the light-emitting diode LED1 is lit. After the trigger module 240 drives the switch module 210 to disconnect the power connection, the light-emitting diode LED1 is turned off. The user can intuitively see the working status of the detection and protection device.

[0076] Referring to Figure 10, the detection and protection device provided in some embodiments of this application further includes a lightning protection module 280. The lightning protection module 280 includes a second varistor ZR2, with its two ends connected to the first current-carrying line 110 and the second current-carrying line 120, respectively. It is understood that a varistor is a resistor with nonlinear volt-ampere characteristics, mainly used for voltage clamping when a circuit is subjected to overvoltage, absorbing excess current to protect sensitive devices. Therefore, by placing the second varistor ZR2 between the first current-carrying line 110 and the second current-carrying line 120, the subsequent components in the detection and protection device can be protected from damage caused by lightning voltage.

[0077] Referring to FIG11, a second aspect embodiment of this application provides an electrical connection device 300, including a detection and protection device as described in the first aspect embodiment above, a housing 310, and a power cord. The power cord is connected to the housing 310. A switch module 210, a fault response module 230, a trigger module 240, a self-test current injection module 250, and a manual detection module 260 are disposed in the housing.

[0078] In addition, a third aspect of this application provides an electrical device, including a load device and an electrical connection device 300 as described in the second aspect of the embodiment above, wherein the output end of a power cord is connected to the load device.

[0079] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application.

Claims

1. A power cord detection and protection device, wherein, The power line includes a first current-carrying line and a second current-carrying line, and the detection and protection device includes: The switching module is used to control the power connection between the input and output terminals of the power line; A leakage current detection module includes a first shielding conductor structure covering the first current-carrying line and a second shielding conductor structure covering the second current-carrying line; the first shielding conductor structure is used to collect the leakage current signal of the first current-carrying line, and the second shielding conductor structure is used to collect the leakage current signal of the second current-carrying line; the first shielding conductor structure and the second shielding conductor structure are connected. The fault response module is electrically coupled to the first shielding conductor structure and the second shielding conductor structure respectively, and outputs a trip trigger signal in response to the acquisition of the leakage current signal; The trigger module is electrically coupled to the fault response module and the switch module respectively, and is configured to drive the switch module to disconnect the power connection in response to receiving the trip trigger signal; The self-test current injection module, with one end electrically coupled to the first current-carrying line and the other end electrically coupled to the connection point between the second shielded conductor structure and the fault response module, generates a self-test current flowing from the second shielded conductor structure to the first shielded conductor structure under the voltage provided by the first current-carrying line, and generates an open-circuit signal flowing from the second shielded conductor structure to the fault response module when the leakage current detection module is open-circuited, so that the fault response module outputs the trip trigger signal; and The manual detection module has one end electrically coupled to the first current-carrying line and the other end electrically coupled to the connection point between the first shielding conductor structure and the fault response module. It is used to generate a simulated leakage current flowing from the first shielding conductor structure to the second shielding conductor structure under the action of the voltage provided by the first current-carrying line, and output the simulated leakage current from the second shielding conductor structure to the fault response module so that the fault response module outputs the trip trigger signal; wherein, the simulated leakage current is greater than the self-test current.

2. The detection and protection device according to claim 1, wherein, The first shielding conductor structure includes a first end near the input end of the power line and a second end near the output end of the power line; the second shielding conductor structure includes a third end near the input end and a fourth end near the output end; the second end and the fourth end are connected; the fault response module is connected to the first end and the third end respectively.

3. The detection and protection device according to claim 2, wherein, The manual testing module includes a test switch and a first resistor. One end of the test switch is connected to the first current-carrying line, and the other end of the test switch is connected to one end of the first resistor. The other end of the first resistor is connected to the first end.

4. The detection and protection device according to claim 3, wherein, The self-test current injection module includes a second resistor, one end of which is connected to the first current-carrying line and the other end of which is connected to the third terminal. The resistance value of the second resistor is greater than that of the first resistor.

5. The detection and protection device according to any one of claims 2 to 4, wherein, The fault response module includes a third resistor, a fourth resistor, a first capacitor, and a Zener diode. One end of the third resistor is connected to the first terminal, and one end of the fourth resistor is connected to the third terminal. The two ends of the first capacitor are respectively connected to the other ends of the third resistor and the fourth resistor. One end of the Zener diode is connected to the connection point of the first capacitor and the fourth resistor, and the other end of the Zener diode is connected to the trigger module to output the trip trigger signal to the trigger module when the Zener diode breaks down in the reverse direction.

6. The detection and protection device according to any one of claims 2 to 5, wherein, The triggering module includes a thyristor and a trip coil for generating electromagnetic force to drive the switching module to disconnect the power connection. The second current-carrying line is connected to one end of the trip coil, the other end of the trip coil is connected to the anode of the thyristor, the cathode of the thyristor is connected to the first current-carrying line, and the control electrode of the thyristor is connected to the output terminal of the fault response module.

7. The detection and protection device according to claim 6, wherein, The triggering module also includes a thyristor driving module, which includes a fifth resistor and a second capacitor. The output terminal of the fault response module is connected to one end of the fifth resistor, one end of the second capacitor, and the control electrode of the thyristor. The other end of the fifth resistor and the other end of the second capacitor are both connected to the cathode of the thyristor.

8. The detection and protection device according to claim 6 or 7, wherein, The trigger module further includes a first diode and a second diode. The cathode of the thyristor is connected to the anode of the first diode and the anode of the second diode. The cathode of the first diode is connected to the first current-carrying line, and the cathode of the second diode is connected to the connection point between the trip coil and the thyristor.

9. The detection and protection device according to any one of claims 6 to 8, wherein, The triggering module also includes a first varistor connected in parallel with the thyristor.

10. The detection and protection device according to any one of claims 6 to 9 further includes an indicator module connected in parallel with the silicon controlled rectifier, wherein the indicator module includes a sixth resistor and a light-emitting diode connected in series.

11. The detection and protection device according to any one of claims 1 to 10, further comprising a lightning protection module, wherein, The lightning protection module includes a second varistor, the two ends of which are respectively connected to the first current-carrying line and the second current-carrying line.

12. An electrical connection device, comprising the detection and protection device according to any one of claims 1 to 11, a housing, and the power cord, wherein, The power cord is connected to the housing, and the switch module, the fault response module, the trigger module, the self-test current injection module, and the manual detection module are disposed in the housing.

13. An electrical appliance comprising a load device and the electrical connection device of claim 12, wherein the output end of the power line is connected to the load device.

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