Leakage protection circuit
By designing the power supply cable passing through the current transformer in the leakage current protection circuit and using a filtering module, the problem of leakage current protection malfunction during surge testing was solved, improving the reliability and response accuracy of the circuit.
Patent Information
- Application Number
- CN202423120645.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-17
- Publication Date
- 2025-11-18
- Estimated Expiration
- 2034-12-17
AI Technical Summary
In existing leakage current protection circuits, during surge testing, the common-mode surge voltage acts between the live wire, neutral wire, and ground wire, causing the current flowing to the ground wire to be mistakenly identified as residual current, triggering the leakage current protection to malfunction.
Design a leakage current protection circuit. By passing the power supply cable of the power supply module through the current transformer, the current flowing from the live wire and neutral wire to the ground wire is prevented from flowing through the current transformer. Combined with the filtering module to filter out interference, the control module determines the residual current and cuts off the power supply through the tripping module.
It improves the reliability of the leakage current protection circuit, avoids false triggering of tripping due to current flowing to the ground wire, and enhances response speed and accuracy.
Smart Images
Figure CN223567302U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the technical field of leakage protection, and particularly relates to a leakage protection circuit. BACKGROUND
[0002] A residual current circuit breaker (RCBO) usually controls the firewire and does not control the zero line, and has the following main functions:
[0003] Leakage protection: when detecting leakage current, RCBO will quickly cut off the power supply to prevent electric shock caused by current through the human body.
[0004] Overload protection: when the current in the circuit exceeds the set value, RCBO will automatically disconnect the circuit to prevent overheating of the wire and damage to the equipment.
[0005] Short circuit protection: when a short circuit fault occurs, RCBO can immediately cut off the circuit to reduce the risk of equipment damage and fire.
[0006] Common mode surge voltage acts between the firewire, zero line and PE line, and the current flowing to PE generated by the surge voltage is the residual current. For current transformers with high sensitivity, it is easy to detect the residual current generated by the surge voltage and trigger the tripping problem. SUMMARY
[0007] Therefore, the utility model provides a leakage protection circuit to solve the problem of leakage protection false triggering caused by the current flowing to the PE line during surge testing.
[0008] The utility model provides a leakage protection circuit, which comprises a transformer, a control module, a power supply module and a tripping module, wherein the transformer is connected in series between the firewire and the zero line of the power supply to be protected, the output end of the transformer is connected with the input end of the control module, and the transformer is used for collecting the residual current signal of the power supply to be protected; the power supply end of the control module is connected with the output end of the power supply module, the output end of the control module is connected with the control end of the tripping module, the first end of the control module is connected with the first power supply end of the power supply module and the first end of the tripping module, and then is connected with the ground wire of the power supply to be protected; the control module is used for outputting a trigger signal when determining that there is residual current in the power supply to be protected based on the output signal of the transformer; the second power supply end of the power supply module is connected with the second end of the tripping module, and the power supply module is used for supplying power to the control module; the third end of the tripping module is connected with the firewire after passing through the transformer, the output end of the tripping module is connected with the control end of the power supply to be protected, and the tripping module is used for cutting off the firewire of the power supply to be protected based on the trigger signal.
[0009] The power supply cable of the power supply module passes through the mutual inductor, and power supply of the front end of the mutual inductor is obtained, the current flowing from the fire wire and the zero wire to the PE wire no longer flows through the mutual inductor, the mutual inductor is prevented from triggering the tripping module after identifying the current flowing to the PE wire as the residual current, and the reliability of the electric leakage protection circuit is improved.
[0010] In an alternative embodiment, the tripping module comprises: a tripper and a trigger switch, wherein the control end of the trigger switch is connected with the output end of the control module, the first end of the trigger switch is connected with the first end of the control module, and the second end of the trigger switch is connected with the first end of the tripper and the second power supply end of the power supply module; the second end of the tripper is connected with the fire wire after passing through the mutual inductor, and the third end of the tripper is connected with the control end of the power supply to be protected.
[0011] In an alternative embodiment, the electric leakage protection circuit further comprises: a filtering module, wherein the first end of the filtering module is connected with the output end of the mutual inductor, the second end of the filtering module is connected with the input end of the control module, and the filtering module is used for filtering out the interference in the output signal of the mutual inductor.
[0012] The electric leakage protection circuit provided by the utility model improves the response speed and response accuracy of the control module by filtering out the interference of the input end of the control module.
[0013] In an alternative embodiment, the electric leakage protection circuit further comprises: a protection module, wherein the first end of the protection module is connected with the ground wire, the second end of the protection module is connected with the zero wire, the third end of the protection module is connected with the first end of the tripping module, and the protection module is used for limiting the current size and direction flowing through the ground wire.
[0014] In an alternative embodiment, the protection module comprises: an anti-reverse unit and a first surge protection unit, wherein the first end of the anti-reverse unit is connected with the first end of the first surge protection unit and then connected with the ground wire, and the second end of the anti-reverse unit is connected with the first end of the tripping module; the second end of the first surge protection unit is connected with the zero wire.
[0015] In an alternative embodiment, the first surge protection unit comprises: a pressure-sensitive resistor.
[0016] In an alternative embodiment, the anti-reverse unit comprises: a plurality of series-connected diodes.
[0017] In an alternative embodiment, the electric leakage protection circuit further comprises: a second surge protection unit, wherein the first end of the second surge protection unit is connected with the third end of the tripping module, and the second end of the second surge protection unit is connected with the second end of the protection module.
[0018] In an alternative embodiment, the leakage protection circuit further comprises a test module, wherein the test module is connected in series in the power supply to be protected, and the test module is configured to simulate a leakage test on the power supply to be protected. BRIEF DESCRIPTION OF DRAWINGS
[0019] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed in the specific embodiments or the prior art description will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.
[0020] Figure 1 is a component diagram of a leakage protection circuit according to the related art;
[0021] Figure 2 is a component diagram of a leakage protection circuit according to an embodiment of the present application;
[0022] Figure 3 is another component diagram of a leakage protection circuit according to an embodiment of the present application;
[0023] Figure 4 is a specific circuit structure diagram of a leakage protection circuit according to an embodiment of the present application. DETAILED DESCRIPTION
[0024] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.
[0025] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.
[0026] In the description of the utility model, it is necessary to explain that, unless there is definite stipulation and limitation, the terms "mount", "connect", "connection" should be understood broadly, for example, it can be fixed connection, also can be detachable connection, or integrally connected, it can be mechanical connection, also can be electrical connection, it can be direct connection, also can be indirect connection through intermediate medium, also can be the intercommunication of two elements, it can be wireless connection, also can be wired connection, for ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.
[0027] In addition, the technical features involved in the different embodiments of the utility model described below can be combined with each other as long as there is no conflict between them.
[0028] When surge test is carried out, common-mode surge voltage acts between the live wire L, the neutral wire N and the ground wire PE, the supply voltage of the existing leakage protection control chip is taken from the rear end of the transformer, as shown in Figure 1 When there is any current flowing from the live wire L or the neutral wire N to the ground wire PE, the current will flow through the transformer, the transformer captures the current and identifies it as a surge current, thereby causing the leakage protection to be triggered, especially the mA level leakage protection circuit has high sensitivity, and it is more likely to trigger the leakage protection to produce the tripping phenomenon.
[0029] Therefore, the embodiment provides a leakage protection circuit, as shown in Figure 2 The leakage protection circuit comprises a transformer 1, a control module 2, a power supply module 3 and a tripping module 4, wherein the transformer 1 is connected in series between the live wire L and the neutral wire N of the power supply to be protected, the output end of the transformer 1 is connected with the input end of the control module 2, the power supply end of the control module 2 is connected with the output end of the power supply module 3, the output end of the control module 2 is connected with the control end of the tripping module 4, the first end of the control module 2 is connected with the first power supply end of the power supply module and the first end of the tripping module 4, and then is connected with the ground wire PE of the power supply to be protected, the second power supply end of the power supply module 3 is connected with the second end of the tripping module 4, and the third end of the tripping module 4 is connected with the live wire after passing through the transformer 1, and the output end of the tripping module 4 is connected with the control end of the power supply to be protected.
[0030] Specifically, Figure 2 In the embodiment, the power supply cable of the power supply module 3 is connected with the live wire L through the tripping module 4 and the transformer 1, and the ground wire PE is connected with the neutral wire N through a diode and the transformer 1, when the current in the live wire L or the neutral wire N flows through the ground wire PE, the bidirectional current cancels each other out, the transformer 1 will not identify the current, and the current will not affect the transformer 1, therefore, Figure 2 The power supply cable in the embodiment passes through the transformer 1, which is equivalent to Figure 3 Taking power at the front end of the transformer in the embodiment.
[0031] Specifically,Figure 3 In the embodiment, the current transformer 1 is configured to collect a residual current signal of a power supply to be protected, the control module 2 is configured to output a trigger signal when determining that there is a residual current in the power supply to be protected based on an output signal of the current transformer 1, the power supply module 3 is configured to supply power to the control module 2, and the tripping module 4 is configured to cut off a fire wire of the power supply to be protected based on the trigger signal.
[0032] Optionally, Figure 1 The current transformer in the embodiment is a current transformer.
[0033] The power supply cable of the power supply module passes through the current transformer in the leakage protection circuit provided by the embodiment, which is equivalent to obtaining power supply at the front end of the current transformer. The current flowing from the fire wire and the zero wire to the PE wire no longer flows through the current transformer, so that the current transformer is prevented from triggering the tripping module to trip when identifying the current flowing to the PE wire as a residual current, and the reliability of the leakage protection circuit is improved.
[0034] In some optional embodiments, the leakage protection circuit further comprises a filtering module 5, wherein a first end of the filtering module 5 is connected to an output end of the current transformer 1, a second end of the filtering module 5 is connected to an input end of the control module 2, and the filtering module 5 is configured to filter out interference in the output signal of the current transformer 1.
[0035] Specifically, as shown in Figure 4 The tripping module 4 comprises a tripper T2 and a trigger switch Q1, wherein a control end of the trigger switch Q1 is connected to an output end of the control module 2, a first end of the trigger switch Q1 is connected to a first end of the control module 2, a second end of the trigger switch Q1 is connected to a first end of the tripper T2 and a second power supply end of the power supply module 3, a second end of the tripper T2 is connected to the fire wire L after passing through the current transformer 1, and a third end of the tripper T2 is connected to a control end of a switch K on the fire wire L in the power supply to be protected.
[0036] Specifically, Figure 4 In the embodiment, when the control module 2 identifies that there is a residual current in the fire wire L or the zero wire N through the current transformer 1, the control module 2 outputs a trigger signal to make the trigger switch Q1 conductive, so that the tripping current generated by the tripper T2 coil makes the switch K on the fire wire L open, thereby cutting off the fire wire L in the power supply to be protected.
[0037] Optionally, Figure 4 In the embodiment, the filtering module can be an RC filtering circuit.
[0038] In some optional embodiments, the leakage protection circuit further comprises a protection module 6, wherein a first end of the protection module 6 is connected to a ground wire PE, a second end of the protection module 6 is connected to a zero wire N, a third end of the protection module 6 is connected to a first end of the tripping module 4, and the protection module 6 is configured to limit the size and direction of the current flowing through the ground wire PE.
[0039] Specifically, the protection module 6 comprises an anti-reverse unit 61 and a first surge protection unit 62, wherein a first end of the anti-reverse unit 61 is connected with a first end of the first surge protection unit 62 and then connected with the ground wire PE, and a second end of the anti-reverse unit 61 is connected with a first end of the tripping module 4; a second end of the first surge protection unit 62 is connected with the zero wire N.
[0040] Specifically, Figure 4 In particular, the anti-reverse unit 61 comprises a plurality of diodes connected in series, i.e. diodes D5 and D6. The first surge protection unit 62 comprises a pressure-sensitive resistor RV2.
[0041] It should be noted that the number of diodes in the anti-reverse unit is not limited.
[0042] In some optional embodiments, as shown in Figure 4 The leakage protection circuit further comprises a second surge protection unit 7, wherein a first end of the second surge protection unit 7 is connected with a third end of the tripping module 4, and a second end of the second surge protection unit 7 is connected with a second end of the protection module 6.
[0043] Optionally, Figure 4 In particular, the second surge protection unit 7 can be a pressure-sensitive resistor.
[0044] In some optional embodiments, as shown in Figure 4 The leakage protection circuit further comprises a test module 8, wherein the test module 8 is connected in series in the power supply to be protected, and the test module 8 is used for leakage simulation test on the power supply to be protected.
[0045] Specifically, Figure 4 In particular, the leakage simulation test is realized by controlling the on-off of a test switch TEST in the test module 8, and the specific test method is not described herein.
[0046] Although the embodiments of the utility model are described in combination with the drawings, various modifications and variations can be made by those skilled in the art without departing from the spirit and scope of the utility model, and such modifications and variations all fall within the scope defined by the appended claims.
Claims
1. An electric leakage protection circuit, characterized by comprising: The application relates to a residual current circuit breaker, which comprises a mutual inductor, a control module, a power supply module and a tripping module, wherein the mutual inductor is connected in series with a live wire and a zero wire of a power supply to be protected, the output end of the mutual inductor is connected with the input end of the control module, and the mutual inductor is used for collecting a residual current signal of the power supply to be protected; the power supply end of the control module is connected with the output end of the power supply module, the output end of the control module is connected with the control end of the tripping module, the first end of the control module is connected with the first power supply end of the power supply module and the first end of the tripping module, and then the first end is connected with the ground wire of the power supply to be protected; the control module is used for outputting a trigger signal when the power supply to be protected has a residual current based on the output signal of the mutual inductor; the second power supply end of the power supply module is connected with the second end of the tripping module, and the power supply module is used for supplying power to the control module; the third end of the tripping module penetrates through the mutual inductor and is connected with the live wire, the output end of the tripping module is connected with the control end of the power supply to be protected, and the tripping module is used for cutting off the live wire of the power supply to be protected based on the trigger signal. The tripping module comprises a tripping device and a trigger switch, wherein the control end of the trigger switch is connected with the output end of the control module, the first end of the trigger switch is connected with the first end of the control module, and the second end of the trigger switch is connected with the first end of the tripping device and the second power supply end of the power supply module; the second end of the tripping device penetrates through the mutual inductor and is connected with the live wire, and the third end of the tripping device is connected with the control end of the power supply to be protected. The application further comprises a filter module, wherein the first end of the filter module is connected with the output end of the mutual inductor, the second end of the filter module is connected with the input end of the control module, and the filter module is used for filtering out interference in the output signal of the mutual inductor. The application further comprises a protection module, wherein the first end of the protection module is connected with the ground wire, the second end of the protection module is connected with the zero wire, the third end of the protection module is connected with the first end of the tripping module, and the protection module is used for limiting the size and direction of the current flowing through the ground wire. The protection module comprises an anti-reverse unit and a first surge protection unit, wherein the first end of the anti-reverse unit is connected with the first end of the first surge protection unit and then connected with the ground wire, the second end of the anti-reverse unit is connected with the first end of the tripping module; the second end of the first surge protection unit is connected with the zero wire. The first surge protection unit comprises a pressure-sensitive resistor.
2. The ground-fault circuit of claim 1, wherein, The anti-reverse unit comprises a plurality of diodes connected in series. The application further comprises a second surge protection unit, wherein the first end of the second surge protection unit is connected with the third end of the tripping module, and the second end of the second surge protection unit is connected with the second end of the protection module. The application further comprises a test module, wherein the test module is connected in series in the power supply to be protected, and the test module is used for simulating a leakage test on the power supply to be protected.
3. The ground-fault circuit of claim 1, wherein, 4. The ground-fault circuit of claim 1, wherein, 5. The ground-fault circuit of claim 4, wherein, 6. The ground-fault circuit of claim 5, wherein, 7. The ground fault protection circuit of claim 5, wherein, 8. The ground fault protection circuit of claim 4, wherein, 9. The ground fault protection circuit of claim 1, wherein,