Detection protection device of power line, electric connection equipment and electric equipment

Abstract

The invention discloses a detection protection device of a power line, electric connection equipment and electric equipment. The power line comprises a first current-carrying wire and a second current-carrying wire. The detection protection device comprises a switch module, an electric leakage detection module, a fault response module, an overvoltage detection module and a trigger module. The electric leakage detection module comprises a first shielding conductor structure and a second shielding conductor structure. The fault response module obtains an electric leakage signal or an open circuit signal generated when the open circuit self-checking path is open, and outputs a tripping trigger signal to enable the switch module to disconnect power connection; the overvoltage detection module is used for generating an overvoltage signal and outputting the overvoltage signal to the fault response module when detecting that the voltage between the first current-carrying wire and the second current-carrying wire is too large, so that the fault response module outputs a tripping trigger signal, and feasibility and flexibility of electric leakage detection of a power line and open circuit detection of a shielding structure can be enriched. And the overvoltage input by the power supply is detected to trigger tripping, so that the power supply safety of the power line is improved.

Description

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

[0001] This invention relates to the field of electrical technology, and in particular to a power cord detection and protection device, an electrical connection device, and an electrical appliance. Background Technology

[0002] 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 disconnects the power supply to the appliance when a certain leakage current is detected, ensuring safe operation. In recent years, LCDIs have faced higher safety requirements beyond simply detecting leakage current in the power supply line. These include detecting open circuits in the leakage current detection lead and identifying situations where a product with a rated input voltage of 110V is mistakenly connected to 220V, which could easily damage the product, and taking appropriate corrective action. Summary of the Invention

[0003] The purpose of this invention is to at least solve one of the technical problems existing in the prior art, and to provide a power cord detection and protection device, electrical connection equipment and electrical equipment, which can enrich the feasibility and flexibility of power cord leakage detection and shielding structure open circuit detection, and can detect overvoltage of power input to trigger tripping, which is conducive to improving the power supply safety of power cord.

[0004] In a first aspect, embodiments of the present invention provide a power cord detection and protection device, wherein the power cord includes a first current-carrying wire and a second current-carrying wire, and the detection and protection device includes: a switching module, a leakage current detection module, a fault response module, an overvoltage detection module, and a triggering module, wherein: the switching module is used to control the power connection between the input end and the output end of the power cord; the leakage current detection module includes a first shielding conductor structure covering the first current-carrying wire and a second shielding conductor structure covering the second current-carrying wire; the first shielding conductor structure is used to collect leakage current signals of the first current-carrying wire, and the second shielding conductor structure is used to collect leakage current signals of the second current-carrying wire; the first shielding conductor structure includes a first end near the input end of the power cord, a second end near the output end of the power cord, and a third end located between the first end and the second end; the second shielding conductor structure includes: a first end near the input end of the power cord, a second end near the output end of the power cord, and a third end located between the first end and the second end; the second shielding conductor structure includes: a first shielding conductor structure ... The shielded conductor structure includes a fourth terminal near the input terminal, a fifth terminal near the output terminal, and a sixth terminal located between the fourth and fifth terminals; the third terminal and the sixth terminal are connected; the fault response module is electrically coupled to the leakage current detection module, and outputs a trip trigger signal in response to acquiring the leakage current signal or acquiring an open circuit signal generated when the leakage current detection module is open; the overvoltage detection module is electrically coupled to the fault response module, and is used to generate an overvoltage signal and output it to the fault response module when an excessive voltage is detected between the first current-carrying line and the second current-carrying line, so that the fault response module outputs the trip trigger 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.

[0005] The power line detection and protection device provided according to the embodiments of the present invention has at least the following beneficial effects: the first shielding conductor structure in the leakage detection module covers the first current-carrying line, thereby enabling the acquisition of the leakage signal of the first current-carrying line; the second shielding conductor structure in the leakage detection module covers the second current-carrying line, thereby enabling the acquisition of the leakage signal of the second current-carrying line; based on this, by connecting the third end of the middle part of the first shielding conductor structure to the sixth end of the second shielding conductor structure, the shielding conductor structures of the first and second current-carrying lines have an associated point, and the two shielding conductor structures are no longer independent and separate, allowing open-circuit detection for various different detection paths, such as the detection path from the first end to the third end of the first shielding conductor structure, then to the sixth end of the second shielding conductor structure, and finally to the fourth end of the second shielding conductor structure; the detection path from the first end to the third end of the first shielding conductor structure, then to the sixth end of the second shielding conductor structure, and finally to the fifth end of the second shielding conductor structure; the detection path from the second end to the third end of the first shielding conductor structure, then to the sixth end of the second shielding conductor structure, and finally to the fourth ... The detection path leads to the sixth end of the second shielding conductor structure and finally to the fifth end of the second shielding conductor structure. Additionally, the fault response module is electrically coupled to the leakage detection module. This allows it to acquire a leakage signal even when the leakage detection module is not open-circuited, and also to acquire an open-circuit signal when the leakage detection module is open-circuited. This triggers a tripping signal to the trigger module, causing the trigger module to drive the switch module to disconnect the power connection between the input and output ends of the power cord, ensuring the power supply safety of the power cord. Furthermore, an overvoltage detection module is included. If the voltage between the first and second current-carrying lines is too high, it outputs an overvoltage signal to the fault response module, causing the fault response module to output a tripping trigger signal to the trigger module, preventing overvoltage from burning out the product. In this embodiment of the power cord detection and protection device, the multiple detection segments formed by the first and second shielding conductor structures can be combined to construct a shielding network with various detection paths. This greatly enriches the feasibility and flexibility of power cord leakage detection and shielding structure open-circuit detection, and enables the detection of overvoltage at the power input to trigger tripping, thus improving the power supply safety of the power cord.

[0006] According to some embodiments of the present invention, the detection and protection device further includes a self-test path module, which includes a first self-test unit and a second self-test unit. The first self-test unit is electrically coupled between the first current-carrying line and the first shielding conductor structure, and the second self-test unit is electrically coupled between the second current-carrying line and the second shielding conductor structure, so that the electrically coupled first current-carrying line, first self-test unit, first shielding conductor structure, second shielding conductor structure, second self-test unit, and second current-carrying line constitute an open-circuit self-test path. The fault response module is electrically coupled to the connection point between the first self-test unit and the first shielding conductor structure to obtain the open-circuit signal generated when the open-circuit self-test path is open.

[0007] The detection and protection device provided according to some embodiments of the present invention further includes a test module, the test module including a test switch, one end of the test switch being connected to the second current-carrying line, and the other end being connected to the connection point between the second self-test unit and the second shielding conductor structure.

[0008] According to some embodiments of the present invention, the detection and protection device includes a first self-test unit comprising a first resistor and a second resistor, wherein the first resistor is connected between the first current-carrying line and the first terminal, and the second resistor is connected between the first current-carrying line and the second terminal.

[0009] According to some embodiments of the present invention, the fault response module includes a third resistor, a fourth resistor, and a first switching transistor. The third resistor and the fourth resistor are connected in series between the first current-carrying line and the second current-carrying line. The connection point of the third resistor and the fourth resistor is connected to the control pin of the first switching transistor. One switch pin of the first switching transistor is connected to the first terminal and the second terminal, and the other switch pin is connected to the trigger module.

[0010] According to some embodiments of the present invention, the overvoltage detection module includes a Zener diode, the positive terminal of which is connected to the second current-carrying line, and the negative terminal of which is connected to the connection point of the third resistor and the fourth resistor.

[0011] The detection and protection device provided according to some embodiments of the present invention further includes a first unidirectional conduction module, the first unidirectional conduction module including a first diode and a second diode, the first end being connected to the anode of the first diode, the second end being connected to the anode of the second diode, and the cathodes of the first diode and the second diode being connected to a switch pin of the first switching transistor.

[0012] According to some embodiments of the present invention, the detection and protection device includes a second self-test unit comprising a fifth resistor and a sixth resistor, wherein the fifth resistor is connected between the second current-carrying line and the fourth terminal, and the sixth resistor is connected between the second current-carrying line and the fifth terminal.

[0013] The detection and protection device provided according to some embodiments of the present invention further includes a second unidirectional conduction module, the second unidirectional conduction module including a third diode and a fourth diode, the test module further includes a seventh resistor, the other end of the test switch is connected to one end of the seventh resistor, the other end of the seventh resistor is connected to the anode of the third diode and the anode of the fourth diode, the cathode of the third diode is connected to the fourth terminal, and the cathode of the fourth diode is connected to the fifth terminal.

[0014] According to some embodiments of the present invention, the detection and protection device further includes a thyristor and a trip coil for generating electromagnetic force to drive the switching module to disconnect the power connection. The first 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 second current-carrying line, and the control electrode of the thyristor is connected to the output terminal of the fault response module.

[0015] According to some embodiments of the present invention, the detection and protection device further includes a fifth diode and a sixth diode. The cathode of the thyristor is connected to the anode of the fifth diode and the anode of the sixth diode. The cathode of the fifth diode is connected to the second current-carrying line. The cathode of the sixth diode is connected to the connection point between the trip coil and the thyristor.

[0016] According to some embodiments of the present invention, the triggering module further includes a thyristor driving module, which includes an eighth resistor, a ninth resistor, and a first capacitor. The output terminal of the fault response module is connected to one end of the eighth resistor, and the other end of the eighth resistor is connected to one end of the ninth resistor, one end of the first capacitor, and the control electrode of the thyristor. The other end of the ninth resistor and the other end of the first capacitor are both connected to the connection point between the thyristor and the fifth diode.

[0017] According to some embodiments of the present invention, the triggering module further includes a first varistor connected in parallel with the silicon controlled rectifier.

[0018] The detection and protection device provided according to some embodiments of the present invention further includes an indicator module connected in parallel with the silicon controlled rectifier, the indicator module including a tenth resistor and a light-emitting diode connected in series.

[0019] The detection and protection device provided according to some embodiments of the present invention 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.

[0020] In a second aspect, embodiments of the present invention provide an electrical connection device, including the detection and protection device, housing, and power cord as described in the first aspect embodiment above, wherein the power cord is connected to the housing, and the switch module, the self-test path module, the fault response module, and the trigger module are disposed in the housing.

[0021] Thirdly, embodiments of the present invention provide an electrical device, including a load device and an electrical connection device as described in the second aspect of the embodiments above, wherein the output end of the power line is connected to the load device.

[0022] Other features and advantages of the invention 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 invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the description, claims, and drawings. Attached Figure Description

[0023] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the technical solutions of the present invention, and do not constitute a limitation on the technical solutions of the present invention.

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments; Figure 1 is a block diagram of the module principle of the detection and protection device provided in the embodiment of the present invention; Figure 2 is a circuit diagram of the detection and protection device provided in the embodiment of the present invention; Figure 3 is a schematic diagram of the leakage signal flow when leakage occurs in the first current-carrying line provided in the embodiment of the present invention; Figure 4 is a schematic diagram of the leakage signal flow when leakage occurs in the second current-carrying line provided in the embodiment of the present invention; Figure 5 is a schematic diagram of the open-circuit signal flow when an open circuit occurs in the portion between the first and third ends of the first shielding conductor structure provided in the embodiment of the present invention; Figure 6 is a schematic diagram of the open-circuit signal flow when an open circuit occurs in the portion between the second and third ends of the first shielding conductor structure provided in the embodiment of the present invention; Figure 7 is a schematic diagram of the first current-carrying line provided in the embodiment of the present invention. Figure 8 is a schematic diagram of the open-circuit signal flow when an open circuit occurs in the connecting conductor between the third end of a shielded conductor structure and the sixth end of a second shielded conductor structure; Figure 9 is a schematic diagram of the open-circuit signal flow when a partial open circuit occurs between the fourth and sixth ends of the second shielded conductor structure provided in an embodiment of the present invention; Figure 10 is a schematic diagram of the simulated leakage current signal flow when the test switch is pressed, provided in an embodiment of the present invention; Figure 11 is a schematic diagram of the electrical signal flow when the voltage between the first current-carrying line and the second current-carrying line is too high, provided in an embodiment of the present invention; Figure 12 is a structural schematic diagram of the electrical connection device provided in an embodiment of the present invention. Detailed Implementation

[0025] This section will describe in detail specific embodiments of the present invention. Preferred embodiments of the present invention 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 overall technical solution of the present invention, but they should not be construed as limiting the scope of protection of the present invention.

[0026] In the description of the embodiments of the present invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," "exceeding," etc. are understood to exclude the number itself, while "above," "below," "within," etc. are understood to include the number itself. "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.

[0027] It should be noted that the terms "setting," "installing," and "connecting" in the embodiments of this invention should be interpreted broadly. Those skilled in the art can reasonably determine the specific meaning of the above terms in the embodiments of this invention 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.

[0028] It should be noted that the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0029] 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 disconnects the power supply to the appliance when a certain leakage current is detected, ensuring safe operation. In recent years, LCDIs have faced higher safety requirements beyond simply detecting leakage current in the power supply line. These include detecting open circuits in the leakage current detection lead and identifying situations where a product with a rated input voltage of 110V is mistakenly connected to 220V, which could easily damage the product, and taking appropriate corrective action.

[0030] Based on this, embodiments of the present invention provide a power cord detection and protection device, an electrical connection device, and an electrical device, which can enrich the feasibility and flexibility of power cord leakage detection and shielding structure open circuit detection, and can detect overvoltage of power input to trigger tripping, which is beneficial to improving the power supply safety of the power cord.

[0031] The embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0032] Figure 1 is a block diagram of the detection and protection device provided in an embodiment of the present invention; Figure 2 is a circuit diagram of the detection and protection device provided in an embodiment of the present invention. Referring to Figures 1 and 2, a first aspect of the present invention provides a detection and protection device for a power line, wherein the power line includes a first current-carrying line 110 and a second current-carrying line 120.

[0033] It is understandable 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 line 110 is the live wire L, and the second current-carrying line 120 is the neutral wire N; or the first current-carrying line 110 is the neutral wire N, and the second current-carrying line 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 line 110 is the live wire L1, and the second current-carrying line 120 is the neutral wire N; the first current-carrying line 110 is the neutral wire N, and the second current-carrying line 120 is the live wire L1; or the first current-carrying line 110 is the live wire L1, and the second current-carrying line 120 is the live wire L2. The following explanation uses the case shown in Figure 2, i.e., the first current-carrying line 110 is the neutral wire N, and the second current-carrying line 120 is the live wire L, as an example. The other cases can be understood similarly.

[0034] The detection and protection device includes: a switch module 210, a leakage current detection module 220, a self-test path module 230, a fault response module 240, an overvoltage detection module 290, and a trigger module 250. The switch module 210 controls the power connection between the input and output terminals of the power line. Referring to Figure 2, the switch module 210 has 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 established; 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.

[0035] The leakage current detection module 220 includes a first shielding conductor structure 221 covering the first current-carrying line 110 and a second shielding conductor structure 222 covering the second current-carrying line 120. The first shielding conductor structure 221 is used to collect the leakage current signal of the first current-carrying line 110, and the second shielding conductor structure 222 is used to collect the leakage current signal of the second current-carrying line 120. The first shielding conductor structure 221 includes a first end a near the input end of the power line, a second end b near the output end of the power line, and a third end c located between the first end a and the second end b. The second shielding conductor structure 222 includes a fourth end d near the input end, a fifth end e near the output end, and a third end c located between the fourth end d and the fifth end e. The sixth terminal f; the third terminal c and the sixth terminal f are connected; it can be understood that the first shielding conductor structure 221 in the leakage current detection module 220 covers the first current-carrying line 110 so as to collect the leakage current signal of the first current-carrying line 110, and the second shielding conductor structure 222 in the leakage current detection module 220 covers the second current-carrying line 120 so as to collect the leakage current signal of the second current-carrying line 120. On this basis, by connecting the third terminal c in the middle of the first shielding conductor structure 221 with the sixth terminal f in the second shielding conductor structure 222, the shielding conductor structures of the first current-carrying line 110 and the second current-carrying line 120 have a connection point, and the two shielding conductor structures are no longer independent and separate.

[0036] The self-test path module 230 includes a first self-test unit 231 and a second self-test unit 232. The first self-test unit 231 is electrically coupled between the first current-carrying line 110 and the first shielding conductor structure 221, and the second self-test unit 232 is electrically coupled between the second current-carrying line 120 and the second shielding conductor structure 222. This arrangement, where the first current-carrying line 110, the first self-test unit 231, the first shielding conductor structure 221, the second shielding conductor structure 222, the second self-test unit 232, and the second current-carrying line 120 are sequentially electrically coupled, constitutes an open-circuit self-test path. It can be understood that the open-circuit self-test path formed by the first self-test unit 231 and the second self-test unit 232, along with the first shielding conductor structure 221, the second shielding conductor structure 222, the first current-carrying line 110, and the second current-carrying line 120, can handle various different detection paths. Open-circuit detection can be performed on the following paths: from the first end a of the first shielding conductor structure 221 to the third end c, then to the sixth end f of the second shielding conductor structure 222, and finally to the fourth end d of the second shielding conductor structure 222; from the first end a of the first shielding conductor structure 221 to the third end c, then to the sixth end f of the second shielding conductor structure 222, and finally to the fifth end e of the second shielding conductor structure 222; from the second end b of the first shielding conductor structure 221 to the third end c, then to the sixth end f of the second shielding conductor structure 222, and finally to the fourth end d of the second shielding conductor structure 222; and from the second end b of the first shielding conductor structure 221 to the third end c, then to the sixth end f of the second shielding conductor structure 222, and finally to the fifth end e of the second shielding conductor structure 222.

[0037] The fault response module 240 is electrically coupled to the leakage current detection module 220. More specifically, the fault response module 240 is electrically coupled to the connection point between the first self-test unit 231 and the first shielding conductor structure 221. In response to the acquisition of a leakage current signal or an open circuit signal generated when the open circuit self-test path is open, it outputs a trip trigger signal. The overvoltage detection module 290 is electrically coupled to the fault response module 240. When an excessive voltage is detected between the first current-carrying line 110 and the second current-carrying line 120, it generates an overvoltage signal and outputs it to the fault response module 240, so that the fault response module 240 outputs a trip trigger signal. The trigger module 250 is electrically coupled to the fault response module 240 and the switch module 210 respectively, and is configured to drive the switch module 210 to disconnect the power connection in response to receiving the trip trigger signal.

[0038] According to the power cord detection and protection device provided in the embodiment of the present invention, the fault response module 240 is electrically coupled to the connection point between the first self-test unit 231 and the first shielding conductor structure 221. It can obtain a leakage signal when there is no open circuit in the first shielding conductor structure 221 and the second shielding conductor structure 222, and it can also obtain an open circuit signal when an open circuit occurs in any detection path of the open circuit self-test path. This outputs a trip trigger signal to the trigger module 250, causing the trigger module 250 to drive the switch module 210 to disconnect the power connection between the input and output terminals of the power cord, ensuring the power supply safety of the power cord. Furthermore, an overvoltage detection module 290 is also provided to detect overvoltages in the first self-test unit 231. If the voltage between the first current-carrying line 110 and the second current-carrying line 120 is too high, an overvoltage signal is output to the fault response module 240, causing the fault response module 240 to output a trip trigger signal to the trigger module, thus preventing the product from burning out due to overvoltage. In the power cord detection and protection device of this embodiment, the first shielding conductor structure 221 and the second shielding conductor structure 222 form a shielding network with multiple detection segments that can be combined to construct a variety of different detection paths. This greatly enriches the feasibility and flexibility of power cord leakage detection and shielding structure open circuit detection, and enables the detection of power input overvoltage to trigger tripping, which is beneficial to improving the power supply safety of the power cord.

[0039] Referring to Figures 1 and 2, the detection and protection device provided in some embodiments of the present invention further includes a test module 260. The test module 260 includes a test switch TEST. One end of the test switch TEST is connected to the second current-carrying line 120, and the other end is connected to the connection point between the second self-test unit 232 and the second shielding conductor structure 222.

[0040] In this embodiment, when the test switch TEST in the test module 260 is pressed, it is equivalent to directly connecting the second current-carrying line 120 to the second shielding conductor structure 222, that is, simulating the leakage current signal of the second current-carrying line 120 to be transmitted to the second shielding conductor structure 222, thereby testing whether the leakage current detection function of the protection device is intact.

[0041] It should also be noted that since the fault response module 240 is connected to the connection point between the first self-test unit 231 and the first shielded conductor structure 221, and the other end of the test switch TEST is connected to the connection point between the second self-test unit 232 and the second shielded conductor structure 222, the simulated leakage signal generated when the test switch TEST is pressed flows from the other end of the test switch TEST through the second shielded conductor structure 222, then through the sixth end f of the second shielded conductor structure 222 to the third end c of the first shielded conductor structure 221, then through the first shielded conductor structure 221, and finally to the fault response module 240. That is, the simulated leakage signal flows completely through the leakage detection module 220. Therefore, whether the fault response module 240 receives the simulated leakage signal after the test switch TEST is pressed can be used to determine whether the first shielded conductor structure 221 and the second shielded conductor structure 222 are open circuits.

[0042] Referring to FIG2, in the detection and protection device provided in some embodiments of the present invention, the first self-test unit 231 includes a first resistor R1 and a second resistor R2. The first resistor R1 is connected between the first current-carrying line 110 and the first terminal a, and the second resistor R2 is connected between the first current-carrying line 110 and the second terminal b.

[0043] In this embodiment, the first end a of the first shielding conductor structure 221 is separated from the first current-carrying line 110 by the first resistor R1, and the second end b of the first shielding conductor structure 221 is separated from the first current-carrying line 110 by the second resistor R2, thereby reducing the potential of the first shielding conductor structure 221 in the open-circuit self-test path. This ensures that under normal circumstances, the potential of the first shielding conductor structure 221 will not trigger the fault response module 240 to output a trip trigger signal.

[0044] It should be noted that when the first shielding conductor structure 221 is not open-circuited, the first end a and the second end b of the first shielding conductor structure 221 are at the same potential, and the first resistor R1 and the second resistor R2 are equivalent to being in parallel.

[0045] Referring to FIG2, in the detection and protection device provided in some embodiments of the present invention, the second self-test unit 232 includes a fifth resistor R5 and a sixth resistor R6. The fifth resistor R5 is connected between the second current-carrying line 120 and the fourth terminal d, and the sixth resistor R6 is connected between the second current-carrying line 120 and the fifth terminal e.

[0046] In this embodiment, the fourth terminal d of the second shielding conductor structure 222 is separated from the second current-carrying line 120 by the fifth resistor R5, and the fifth terminal e of the second shielding conductor structure 222 is separated from the second current-carrying line 120 by the sixth resistor R6, thereby reducing the potential of the second shielding conductor structure 222 in the open-circuit self-test path. This ensures that under normal circumstances, the potential of the second shielding conductor structure 222 will not trigger the fault response module 240 to output a trip trigger signal.

[0047] It should be noted that when the second shielding conductor structure 222 is not open-circuited, the fourth terminal d and the fifth terminal e of the second shielding conductor structure 222 are at the same potential. At this time, the fifth resistor R5 and the sixth resistor R6 are in parallel.

[0048] It should also be noted that, since the third end c of the first shielding conductor structure 221 is connected to the sixth end f of the second shielding conductor structure 222, and there are no open circuits in the connection lines between the first shielding conductor structure 221, the second shielding conductor structure 222, and the third end c and the sixth end f, any point of the first shielding conductor structure 221 and any point of the second shielding conductor structure 222 are at the same potential. At this time, the potentials of the first shielding conductor structure 221 and the second shielding conductor structure 222 are determined by the voltage division ratio of the first parallel resistor and the second parallel resistor, wherein: the first parallel resistor is the resistance obtained by connecting the first resistor R1 and the second resistor R2 in parallel, and the second parallel resistor is the resistance obtained by connecting the fifth resistor R5 and the sixth resistor R6 in parallel.

[0049] Referring to Figure 2, in the detection and protection device provided in some embodiments of the present invention, the fault response module 240 includes a third resistor R3, a fourth resistor R4, and a first switching transistor Q1. The third resistor R3 and the fourth resistor R4 are connected in series between the first current-carrying line 110 and the second current-carrying line 120. The connection point of the third resistor R3 and the fourth resistor R4 is connected to the control pin of the first switching transistor Q1. One switching pin of the first switching transistor Q1 is connected to the first terminal a and the second terminal b, and the other switching pin is connected to the trigger module 250. Specifically, the first switching transistor Q1 is a transistor Q1. The connection point of the third resistor R3 and the fourth resistor R4 is connected to the base of the transistor Q1. The emitter of the transistor Q1 is connected to the first terminal a and the second terminal b, and the collector of the transistor Q1 is connected to the trigger module 250.

[0050] In this embodiment, the third resistor R3 and the fourth resistor R4 are connected in series between the first current-carrying line 110 and the second current-carrying line 120. The connection point of the third resistor R3 and the fourth resistor R4 provides a voltage divider to the base of the transistor Q1. When the voltage received at the emitter of the transistor Q1 is greater than the voltage divider at the base, the emitter junction of the transistor Q1 is forward biased and thus conducts. In turn, a trip trigger signal is output to the trigger module 250 through the collector of the transistor Q1.

[0051] Referring to FIG2, in the detection and protection device provided in some embodiments of the present invention, the overvoltage detection module 290 includes a Zener diode DZ1, the positive terminal of which is connected to the second current-carrying line 120, and the negative terminal is connected to the connection point of the third resistor R3 and the fourth resistor R4.

[0052] In this embodiment, the third resistor R3 and the fourth resistor R4 divide the voltage between the first current-carrying line 110 and the second current-carrying line 120, and output the divided voltage to the negative terminal of the Zener diode DZ1. When the voltage between the first current-carrying line 110 and the second current-carrying line 120 is normal and not too high, the voltage across the Zener diode DZ1 is insufficient to cause it to break down, and the Zener diode DZ1 is in the off state. When the voltage between the first current-carrying line 110 and the second current-carrying line 120 is abnormally high, the voltage across the fourth resistor R4 is greater than the threshold voltage of the Zener diode DZ1, and the Zener diode DZ1 breaks down in reverse and conducts, thereby pulling down the base voltage of the transistor Q1, causing the transistor Q1 to conduct, and then outputting a trip trigger signal to the trigger module 250 through the collector of the transistor Q1.

[0053] Referring to FIG2, in some embodiments of the detection and protection device provided by the present invention, a first unidirectional conduction module 241 is further included. The first unidirectional conduction module 241 includes a first diode D1 and a second diode D2. A first end a is connected to the anode of the first diode D1, and a second end b is connected to the anode of the second diode D2. The cathodes of the first diode D1 and the second diode D2 are both connected to a switch pin of the first switch transistor Q1.

[0054] In this embodiment, the first diode D1 in the first unidirectional conduction module 241 enables the leakage signal on the first shielding conductor structure 221 and the open-circuit signal generated when the open-circuit self-test path is open to be transmitted unidirectionally from the first terminal a to the emitter of the transistor Q1; similarly, the second diode D2 in the first unidirectional conduction module 241 enables the leakage signal on the first shielding conductor structure 221 and the open-circuit signal generated when the open-circuit self-test path is open to be transmitted unidirectionally from the second terminal b to the emitter of the transistor Q1.

[0055] Referring to Figure 2, in some embodiments of the detection and protection device provided by the present invention, a second unidirectional conduction module 261 is further included. The second unidirectional conduction module 261 includes a third diode D3 and a fourth diode D4. The test module 260 also includes a seventh resistor R7. The other end of the test switch TEST is connected to one end of the seventh resistor R7. The other end of the seventh resistor R7 is connected to the anode of the third diode D3 and the anode of the fourth diode D4. The cathode of the third diode D3 is connected to the fourth terminal d, and the cathode of the fourth diode D4 is connected to the fifth terminal e.

[0056] In this embodiment, the third diode D3 in the second unidirectional conduction module 261 ensures that when the test switch TEST is pressed, the analog leakage signal from the second current-carrying line 120 can only be transmitted unidirectionally to the fourth terminal d of the second shielding conductor structure 222 via the seventh resistor R7; similarly, the fourth diode D4 in the second unidirectional conduction module 261 ensures that when the test switch TEST is pressed, the analog leakage signal from the second current-carrying line 120 can only be transmitted unidirectionally to the fifth terminal e of the second shielding conductor structure 222 via the seventh resistor R7.

[0057] Referring to FIG2, in the detection and protection device provided in some embodiments of the present invention, the trigger module 250 further includes a thyristor Q2 and a trip coil Lx for generating electromagnetic force to drive the switch module 210 to disconnect the power connection. The first current-carrying line 110 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 Q2, the cathode of the thyristor Q2 is connected to the second current-carrying line 120, and the control electrode of the thyristor Q2 is connected to the output terminal of the fault response module 240.

[0058] It should be noted that the first self-test unit 231 mentioned above includes a first resistor R1 and a second resistor R2. The first resistor R1 is connected between the first current-carrying line 110 and the first terminal a, and the second resistor R2 is connected between the first current-carrying line 110 and the second terminal b. The first resistor R1 and the second resistor R2 can be directly connected to the first current-carrying line 110 or indirectly connected to the first current-carrying line 110. For example, as shown in FIG2, the first resistor R1 is used to connect to one end of the first current-carrying line 110, and after being connected together with the second resistor R2 to one end of the first current-carrying line 110, they are connected to the first current-carrying line 110 via the trip coil Lx. That is, the connection point of the first resistor R1 and the second resistor R2 is connected to the connection point of the trip coil Lx and the thyristor Q2. This setting can reduce the number of connection points led out from the first current-carrying line 110.

[0059] Referring to FIG2, in the detection and protection device provided in some embodiments of the present invention, the trigger module 250 further includes a fifth diode D5 and a sixth diode D6. The cathode of the thyristor Q2 is connected to the anode of the fifth diode D5 and the anode of the sixth diode D6. The cathode of the fifth diode D5 is connected to the second current-carrying line 120. The cathode of the sixth diode D6 is connected to the connection point between the trip coil Lx and the thyristor Q2.

[0060] It should be noted that the second self-test unit 232 mentioned above includes a fifth resistor R5 and a sixth resistor R6. The fifth resistor R5 is connected between the second current-carrying line 120 and the fourth terminal d, and the sixth resistor R6 is connected between the second current-carrying line 120 and the fifth terminal e. The fifth resistor R5 and the sixth resistor R6 can be directly connected to the second current-carrying line 120 or indirectly connected to the second current-carrying line 120. For example, as shown in FIG2, the fifth resistor R5 is used to connect to one end of the second current-carrying line 120, and after being connected together with the sixth resistor R6 to one end of the second current-carrying line 120, they are connected to the second current-carrying line 120 via the fifth diode D5. That is, the connection point of the fifth resistor R5 and the sixth resistor R6 is connected to the connection point of the fifth diode D5 and the sixth diode D6. This setting can reduce the number of connection points led out from the second current-carrying line 120.

[0061] It should also be noted that the positive terminal of the Zener diode DZ1 in the overvoltage detection module 290 needs to be connected to the second current-carrying line 120. The positive terminal of the Zener diode DZ1 can be directly connected to the second current-carrying line 120, or it can be connected to the second current-carrying line 120 through the fifth diode D5. For example, as shown in Figure 2, the positive terminal of the Zener diode DZ1 is connected to the positive terminal of the fifth diode D5, and the negative terminal of the fifth diode D5 is then connected to the second current-carrying line 120. This allows overvoltage detection to be performed during half a cycle when the voltage of the first current-carrying line 110 is greater than the voltage of the second current-carrying line 120.

[0062] Referring to Figure 2, in some embodiments of the detection and protection device provided by the present invention, the trigger module 250 further includes a thyristor drive module 251. The thyristor drive module 251 includes an eighth resistor R8, a ninth resistor R9, and a first capacitor C1. The output terminal of the fault response module 240 is connected to one end of the eighth resistor R8. The other end of the eighth resistor R8 is connected to one end of the ninth resistor R9, one end of the first capacitor C1, and the control electrode of the thyristor Q2. The other ends of the ninth resistor R9 and the first capacitor C1 are both connected to the connection point between the thyristor Q2 and the fifth diode D5. In addition, the thyristor drive module 251 also includes a second capacitor C2 connected in parallel with the first capacitor C1.

[0063] In this embodiment, when the first switch Q1 is turned on, the current signal flowing through the first switch Q1 charges the first capacitor C1 and the second capacitor C2 after passing through the eighth resistor R8. The potential of the control electrode of the thyristor Q2 rises. When the negative half-cycle of the AC power supply arrives, that is, when the level of the first current-carrying line 110 is greater than the level of the second current-carrying line 120, the thyristor Q2 is turned on, forming a strong current path of the first current-carrying line 110 - trip coil Lx - thyristor Q2 - fifth diode D5 - second current-carrying line 120. 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 supply line.

[0064] Referring to Figure 2, in some embodiments of the detection and protection device provided by the present invention, the trigger module 250 further includes a first varistor ZR1 connected in parallel with the silicon controlled rectifier Q2. 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 silicon controlled rectifier Q2 can protect the silicon controlled rectifier Q2 from damage.

[0065] Referring to FIG2, in some embodiments of the present invention, the detection and protection device further includes an indicator module 270 connected in parallel with the silicon controlled rectifier Q2. The indicator module 270 includes an eleventh resistor R11, a tenth resistor R10 and a light-emitting diode LED1 connected in series.

[0066] Referring to Figure 2, the detection and protection device provided in some embodiments of the present invention 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, placing the second varistor ZR2 before the first current-carrying line 110 and the second current-carrying line 120 can protect subsequent components in the detection and protection device from damage caused by lightning strike voltage.

[0067] The following describes the operation of the detection and protection device provided in this embodiment under various leakage and open circuit conditions, using the embodiment shown in Figure 2 as an example: 1. When the leakage signal of the first current-carrying line 110 is transmitted to the first shielding conductor structure 221: After the first shielding conductor structure 221 obtains the leakage signal, as shown in Figure 3, it is transmitted from the first terminal a through the first diode D1 to the emitter of the transistor Q1, and from the second terminal b through the second diode D2 to the emitter of the transistor Q1, and the transistor Q1 is turned on; the transistor Q1 After conduction, the leakage signal charges the first capacitor C1 and the second capacitor C2, and the voltage of the control electrode of the thyristor Q2 increases. When the negative half-cycle of the AC power supply arrives, that is, when the level of the first current-carrying line 110 is greater than the level of the second current-carrying line 120, the thyristor Q2 conducts, forming a strong current path of the first current-carrying line 110-trip coil Lx-thyristor Q2-fifth diode D5-second current-carrying line 120. 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 supply line.

[0068] 2. When the leakage signal of the second current-carrying line 120 is transmitted to the second shielding conductor structure 222: After the second shielding conductor structure 222 receives the leakage signal, as shown in Figure 4, it is transmitted from the sixth terminal f to the third terminal c of the first shielding conductor structure 221. On one hand, it is transmitted from the first terminal a through the first diode D1 to the emitter of the transistor Q1, and on the other hand, it is transmitted from the second terminal b through the second diode D2 to the emitter of the transistor Q1, and the transistor Q1 is turned on. After the transistor Q1 is turned on, the leakage signal is transmitted to the first... As capacitors C1 and C2 charge, the voltage at the control electrode of thyristor Q2 increases. When the negative half-cycle of the AC power supply arrives, i.e., the level of the first current-carrying line 110 is greater than the level of the second current-carrying line 120, thyristor Q2 turns on, forming a strong current path from the first current-carrying line 110 to the trip coil Lx, thyristor Q2, the fifth diode D5, and the second current-carrying line 120. 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 supply line.

[0069] 3. When the first shielding conductor structure 221 is partially open between the first terminal a and the third terminal c: the first resistor R1 is no longer connected in parallel with the second resistor R2. When the negative half-cycle of the AC power supply arrives, that is, when the level of the first current-carrying line 110 is greater than the level of the second current-carrying line 120, as shown in Figure 5, an open-circuit signal is generated at the connection point of the first resistor R1 and the first diode D1, and is transmitted to the emitter of the transistor Q1 via the first diode D1. After the transistor Q1 is turned on, the open-circuit signal charges the first capacitor C1 and the second capacitor C2, and the voltage of the control electrode of the thyristor Q2 increases. When the negative half-cycle of the AC power supply arrives, that is, when the level of the first current-carrying line 110 is greater than the level of the second current-carrying line 120, the thyristor Q2 is turned on, forming a strong current path of first current-carrying line 110 - trip coil Lx - thyristor Q2 - fifth diode D5 - second current-carrying line 120. 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.

[0070] 4. When the first shielding conductor structure 221 is partially open between the second end b and the third end c: the second resistor R2 is no longer connected in parallel with the first resistor R1. When the negative half-cycle of the AC power supply arrives, that is, when the level of the first current-carrying line 110 is greater than the level of the second current-carrying line 120, as shown in Figure 6, an open-circuit signal is generated at the connection point of the second resistor R2 and the second diode D2, and is transmitted to the emitter of the transistor Q1 via the second diode D2. After the transistor Q1 is turned on, the open-circuit signal charges the first capacitor C1 and the second capacitor C2, and the voltage of the control electrode of the thyristor Q2 increases. When the negative half-cycle of the AC power supply arrives, that is, when the level of the first current-carrying line 110 is greater than the level of the second current-carrying line 120, the thyristor Q2 is turned on, forming a strong current path of first current-carrying line 110 - trip coil Lx - thyristor Q2 - fifth diode D5 - second current-carrying line 120. 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 ends of the power line.

[0071] 5. When the conductor connecting the third terminal c and the sixth terminal f is open-circuited: The first parallel resistor obtained by connecting the first resistor R1 and the second resistor R2 in parallel is no longer connected to the second parallel resistor obtained by connecting the fifth resistor R5 and the sixth resistor R6 in parallel. When the negative half-cycle of the AC power supply arrives, that is, when the level of the first current-carrying line 110 is greater than the level of the second current-carrying line 120, as shown in Figure 7, this is equivalent to generating an open-circuit signal at the connection point of the first resistor R1 and the first diode D1, which is transmitted to the emitter of the transistor Q1 via the first diode D1, and an open-circuit signal is also generated at the connection point of the second resistor R2 and the second diode D2. The signal is transmitted to the emitter of transistor Q1 via the second diode D2. After transistor Q1 is turned on, the open-circuit signal charges the first capacitor C1 and the second capacitor C2, and the voltage of the control electrode of thyristor Q2 increases. When the negative half-cycle of the AC power supply arrives, that is, when the level of the first current-carrying line 110 is greater than the level of the second current-carrying line 120, thyristor Q2 is turned on, forming a strong current path of first current-carrying line 110-trip coil Lx-thyristor Q2-fifth diode D5-second current-carrying line 120. 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 supply line.

[0072] 6. When the second shielding conductor structure 222 is partially open between the fourth terminal d and the sixth terminal f: the fifth resistor R5 is no longer connected in parallel with the sixth resistor R6, causing the voltage at the first terminal a, the second terminal b, the third terminal c of the first shielding conductor structure 221, and the fifth terminal e and the sixth terminal f of the second shielding conductor structure 222 to rise. Referring to Figure 8, this is equivalent to generating an open-circuit signal at the connection point of the first resistor R1 and the first diode D1, which is transmitted to the emitter of the transistor Q1 via the first diode D1. Similarly, an open-circuit signal is generated at the connection point of the second resistor R2 and the second diode D2, which is transmitted to the emitter of the transistor Q1 via the second diode D1. The voltage from diode D2 is transmitted to the emitter of transistor Q1. After transistor Q1 is turned on, the open-circuit signal charges the first capacitor C1 and the second capacitor C2, and the voltage at the control electrode of thyristor Q2 increases. When the negative half-cycle of the AC power supply arrives, that is, when the level of the first current-carrying line 110 is greater than the level of the second current-carrying line 120, thyristor Q2 is turned on, forming a strong current path of first current-carrying line 110 - trip coil Lx - thyristor Q2 - fifth diode D5 - second current-carrying line 120. 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 supply line.

[0073] 7. When the second shielding conductor structure 222 is partially open between the fifth terminal e and the sixth terminal f: the sixth resistor R6 is no longer connected in parallel with the fifth resistor R5, causing the voltage at the first terminal a, the second terminal b, the third terminal c of the first shielding conductor structure 221, the fourth terminal d, and the sixth terminal f of the second shielding conductor structure 222 to rise. Referring to Figure 9, this is equivalent to generating an open-circuit signal at the connection point of the first resistor R1 and the first diode D1, which is transmitted to the emitter of the transistor Q1 via the first diode D1. Similarly, an open-circuit signal is generated at the connection point of the second resistor R2 and the second diode D2, which is transmitted to the emitter of the transistor Q1 via the second diode D1. The voltage from diode D2 is transmitted to the emitter of transistor Q1. After transistor Q1 is turned on, the open-circuit signal charges the first capacitor C1 and the second capacitor C2, and the voltage at the control electrode of thyristor Q2 increases. When the negative half-cycle of the AC power supply arrives, that is, when the level of the first current-carrying line 110 is greater than the level of the second current-carrying line 120, thyristor Q2 is turned on, forming a strong current path of first current-carrying line 110 - trip coil Lx - thyristor Q2 - fifth diode D5 - second current-carrying line 120. 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 supply line.

[0074] 8. When the test switch TEST is pressed: During the positive half-cycle of the AC power supply, that is, when the level of the second current-carrying line 120 is greater than the level of the first current-carrying line 110, as shown in Figure 10, the analog leakage signal from the second current-carrying line 120 first passes through the test switch TEST, then through the seventh resistor R7. On one hand, it is transmitted to the fourth terminal d of the second shielding conductor structure 222 via the third diode D3, and then flows sequentially through the sixth terminal f of the second shielding conductor structure 222, the third terminal c of the first shielding conductor structure 221, the first terminal a, and the first diode D1 to reach the emitter of the transistor Q1. On the other hand, it is transmitted to the fifth terminal e of the second shielding conductor structure 222 via the fourth diode D4, and then flows sequentially through the sixth terminal f of the second shielding conductor structure 222, the third terminal c of the first shielding conductor structure 221, and the fifth terminal e of the second shielding conductor structure 222. The second terminal b and the second diode D2 reach the emitter of transistor Q1; after transistor Q1 is turned on, a conduction path is formed from transistor Q1 - eighth resistor R8 - ninth resistor R9 - sixth diode D6 - trip coil Lx - second current-carrying line 120. This simulated leakage signal charges the first capacitor C1 and the second capacitor C2, and the voltage of the control electrode of thyristor Q2 increases; when the negative half-cycle of the AC power supply arrives, that is, when the level of the first current-carrying line 110 is greater than the level of the second current-carrying line 120, thyristor Q2 is turned on, forming a strong current path from the first current-carrying line 110 - trip coil Lx - thyristor Q2 - fifth diode D5 - second current-carrying line 120; 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 supply line.

[0075] 9. When the voltage between the first current-carrying line 110 and the second current-carrying line 120 is too high: During the negative half-cycle of the AC power supply, that is, when the level of the first current-carrying line 110 is greater than the level of the second current-carrying line 120, as shown in Figure 11, in the current path from the first current-carrying line 110 - trip coil Lx - third resistor R3 - fourth resistor R4 - fifth diode D5 - second current-carrying line 120, the voltage across the fourth resistor R4 is greater than the threshold voltage of the Zener diode DZ1. The Zener diode DZ1 reverse-breaks down and conducts, thereby lowering the base voltage of the transistor Q1, causing the transistor Q1 to conduct. After the transistor Q1 conducts, a current path is formed from the first current-carrying line 110 - trip coil Lx - third resistor R1 / fourth resistor R2 - first diode D5. 1 / The conduction path of the second diode D2-transistor Q1-eighth resistor R8-ninth resistor R9-sixth diode D6-trip coil Lx-second current-carrying line 120 is formed. This simulated leakage signal charges the first capacitor C1 and the second capacitor C2, and the voltage of the control electrode of the thyristor Q2 increases. When the negative half-cycle of the AC power supply arrives, that is, when the level of the first current-carrying line 110 is greater than the level of the second current-carrying line 120, the thyristor Q2 is turned on, forming a strong current path of the first current-carrying line 110-trip coil Lx-thyristor Q2-fifth diode D5-second current-carrying line 120. 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 supply line.

[0076] The detection and protection device provided in this embodiment of the invention can detect leakage signals on the current-carrying line through the leakage detection module 220, and can also construct an open-circuit self-test path with the leakage detection module 220 and the current-carrying line through the self-test path module 230, thereby realizing leakage detection of the power line and automatic open-circuit detection of the shielding structure of the power line; it can also realize manual open-circuit detection of the shielding structure of the power line by pressing the test switch TEST of the test module 260; moreover, the first shielding conductor structure 221 and the second shielding conductor structure 222, which form multiple detection segments, can be combined to construct a shielding network with various detection paths, greatly enriching the feasibility and flexibility of leakage detection of the power line and open-circuit detection of the shielding structure, which is conducive to improving the power supply safety of the power line.

[0077] Referring to FIG12, a second aspect embodiment of the present invention 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, wherein the power cord is connected to the housing 310, and a switch module 210, a self-test path module 230, a fault response module 240 and a trigger module 250 are disposed in the housing 310.

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

[0079] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention 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 the present invention.

Claims

1. A power cord detection and protection device, characterized in that, The power cord includes a first current-carrying wire and a second current-carrying wire. The detection and protection device includes: a switching module for controlling the power connection between the input and output ends of the power cord; and a leakage current detection module, including a first shielding conductor structure covering the first current-carrying wire and a second shielding conductor structure covering the second current-carrying wire. The first shielding conductor structure is used to collect leakage current signals from the first current-carrying wire, and the second shielding conductor structure is used to collect leakage current signals from the second current-carrying wire. The first shielding conductor structure includes a first end near the input end of the power cord, a second end near the output end of the power cord, and a third end located between the first end and the second end. The second shielding conductor structure includes a fourth end near the input end and a fifth end near the output end. And a sixth terminal located between the fourth terminal and the fifth terminal; the third terminal and the sixth terminal are connected; a fault response module, electrically coupled to the leakage current detection module, outputs a trip trigger signal in response to acquiring the leakage current signal or acquiring an open circuit signal generated when the leakage current detection module is open; an overvoltage detection module, electrically coupled to the fault response module, generates an overvoltage signal and outputs it to the fault response module when an excessive voltage is detected between the first current-carrying line and the second current-carrying line, so that the fault response module outputs the trip trigger signal; a trigger module, electrically coupled to the fault response module and the switch module respectively, and configured to drive the switch module to disconnect the power connection in response to receiving the trip trigger signal.

2. The detection and protection device according to claim 1, characterized in that, It also includes a self-test path module, which includes a first self-test unit and a second self-test unit. The first self-test unit is electrically coupled between the first current-carrying line and the first shielding conductor structure, and the second self-test unit is electrically coupled between the second current-carrying line and the second shielding conductor structure, so that the electrically coupled first current-carrying line, first self-test unit, first shielding conductor structure, second shielding conductor structure, second self-test unit, and second current-carrying line constitute an open-circuit self-test path. The fault response module is electrically coupled to the connection point between the first self-test unit and the first shielded conductor structure to obtain the open-circuit signal generated when the open-circuit self-test path is open.

3. The detection and protection device according to claim 2, characterized in that, It also includes a test module, which includes a test switch. One end of the test switch is connected to the second current-carrying line, and the other end is connected to the connection point between the second self-test unit and the second shielded conductor structure.

4. The detection and protection device according to claim 2, characterized in that, The first self-test unit includes a first resistor and a second resistor. The first resistor is connected between the first current-carrying line and the first terminal, and the second resistor is connected between the first current-carrying line and the second terminal.

5. The detection and protection device according to claim 4, characterized in that, The fault response module includes a third resistor, a fourth resistor, and a first switching transistor. The third resistor and the fourth resistor are connected in series between the first current-carrying line and the second current-carrying line. The connection point of the third resistor and the fourth resistor is connected to the control pin of the first switching transistor. One switch pin of the first switching transistor is connected to the first terminal and the second terminal, and the other switch pin is connected to the trigger module.

6. The detection and protection device according to claim 5, characterized in that, The overvoltage detection module includes a Zener diode, the positive terminal of which is connected to the second current-carrying line, and the negative terminal is connected to the connection point of the third resistor and the fourth resistor.

7. The detection and protection device according to claim 5, characterized in that, It also includes a first unidirectional conduction module, which includes a first diode and a second diode. The first end is connected to the anode of the first diode, the second end is connected to the anode of the second diode, and the cathodes of the first diode and the second diode are both connected to a switch pin of the first switching transistor.

8. The detection and protection device according to claim 3, characterized in that, The second self-test unit includes a fifth resistor and a sixth resistor. The fifth resistor is connected between the second current-carrying line and the fourth terminal, and the sixth resistor is connected between the second current-carrying line and the fifth terminal.

9. The detection and protection device according to claim 8, characterized in that, It also includes a second unidirectional conduction module, which includes a third diode and a fourth diode. The test module also includes a seventh resistor. The other end of the test switch is connected to one end of the seventh resistor. The other end of the seventh resistor is connected to the anode of the third diode and the anode of the fourth diode. The cathode of the third diode is connected to the fourth terminal, and the cathode of the fourth diode is connected to the fifth terminal.

10. The detection and protection device according to claim 1, characterized in that, The triggering module further includes a thyristor and a trip coil for generating electromagnetic force to drive the switching module to disconnect the power connection. The first 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 second current-carrying line, and the control electrode of the thyristor is connected to the output terminal of the fault response module.

11. The detection and protection device according to claim 10, characterized in that, The trigger module further includes a fifth diode and a sixth diode. The cathode of the thyristor is connected to the anode of the fifth diode and the anode of the sixth diode. The cathode of the fifth diode is connected to the second current-carrying line. The cathode of the sixth diode is connected to the connection point between the trip coil and the thyristor.

12. The detection and protection device according to claim 11, characterized in that, The triggering module further includes a thyristor driving module, which includes an eighth resistor, a ninth resistor, and a first capacitor. The output terminal of the fault response module is connected to one end of the eighth resistor, and the other end of the eighth resistor is connected to one end of the ninth resistor, one end of the first capacitor, and the control electrode of the thyristor. The other end of the ninth resistor and the other end of the first capacitor are both connected to the connection point between the thyristor and the fifth diode.

13. The detection and protection device according to claim 10, characterized in that, The triggering module also includes a first varistor connected in parallel with the thyristor.

14. The detection and protection device according to claim 10, characterized in that, It also includes an indicator module connected in parallel with the silicon controlled rectifier, the indicator module comprising a tenth resistor and a light-emitting diode connected in series.

15. The detection and protection device according to claim 1, characterized in that, It also includes a lightning protection module, which includes a second varistor, the two ends of which are respectively connected to the first current-carrying line and the second current-carrying line.

16. An electrical connection device, characterized in that, The device includes the detection and protection device, housing, and power cord as described in any one of claims 1 to 15, wherein the power cord is connected to the housing, and the switch module, the self-test path module, the fault response module, and the trigger module are disposed in the housing.

17. An electrical appliance, characterized in that, It includes a load device and the electrical connection device as described in claim 16, wherein the output end of the power line is connected to the load device.

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