Electric leakage detection protection device for preventing high-voltage damage

Abstract

The utility model relates to the technical field of electric control, in particular to an electric leakage detection protection device capable of preventing high-voltage damage, which comprises a power supply circuit, a release, a step-down rectifying circuit, an electric leakage detection circuit, a silicon controlled switch circuit and an electric leakage induction circuit, and is characterized in that the power supply circuit comprises a phase line and a zero line which are respectively connected with the step-down rectifying circuit; the release comprises a main tap, an auxiliary tap and a shunt tap, the main tap is connected with the phase line, and the shunt tap is connected with the zero line and the step-down rectifying circuit; when the silicon-controlled switch circuit is switched on, the anode and the cathode of the silicon-controlled switch are triggered to be switched on, so that the release is switched on to the ground and forms a loop with the silicon-controlled switch, and an external mechanism is triggered to be switched off through the release coil. The protection device is additionally arranged in front of the release, so that the release and the product are not easy to damage and can stably run for a long time, and the reliability of the product is greatly improved.

Description

Technical Field

[0001] This utility model relates to the field of electrical control technology, and in particular to a leakage current detection and protection device to prevent high voltage damage. Background Technology

[0002] Currently, with the widespread application of current converters, switching devices, and energy-saving equipment in daily life and production, residual current devices (RCDs) are easily damaged by excessive voltage during use. To address the issue of products failing to protect personal safety when excessive voltage occurs, a more reliable and stable leakage current detection and protection device is needed at the power supply point to protect personal and property safety. This circuit adds protection to the easily damaged electromagnet, making the product more stable and safe. However, most leakage current circuits on the market can only operate under normal voltage; when excessive voltage or current passes through, they are easily damaged, failing to protect electrical products and personal safety.

[0003] Therefore, a new technical solution is urgently needed to solve the above-mentioned technical problems. Utility Model Content

[0004] The purpose of this utility model is to overcome the problems of the prior art and provide a leakage current detection and protection device to prevent high voltage damage. This solves the technical problem that most leakage current circuits in the prior art can only work under normal voltage. When excessive voltage or current passes through, they are easily damaged and cannot protect electrical products and personal safety.

[0005] The above objectives are achieved through the following technical solutions:

[0006] A leakage current detection and protection device for preventing high-voltage damage includes a power supply circuit, a trip unit, a step-down rectifier circuit, a leakage current detection circuit, and a thyristor switch circuit connected in sequence, and also includes a leakage current sensing circuit connected to the power supply circuit, the step-down rectifier circuit, and the leakage current detection circuit. The power supply circuit includes a phase line and a neutral line, which are respectively connected to the step-down rectifier circuit. The trip unit includes a main tap, an auxiliary tap, and a shunt tap. The main tap is connected to the phase line, and the shunt tap is connected to the neutral line and the step-down rectifier circuit. A varistor is also provided between the main tap and the shunt tap. When the thyristor switch circuit is turned on, it triggers the conduction between the anode and cathode of the thyristor switch, causing the trip unit to conduct to ground and forming a circuit with the thyristor switch, triggering an external mechanism to trip through the trip coil.

[0007] Further, the step-down rectifier circuit includes a bridge rectifier circuit composed of the first diode, the second diode, the third diode, and the fourth diode; the anode of the first diode and the cathode of the second diode are connected as the first terminal of the bridge rectifier circuit, the anode of the second diode and the anode of the fourth diode are connected as the second terminal of the bridge rectifier circuit, the cathode of the fourth diode and the anode of the third diode are connected as the third terminal of the bridge rectifier circuit, and the cathode of the third diode and the cathode of the first diode are connected as the fourth terminal of the bridge rectifier circuit; the first terminal of the bridge rectifier circuit is connected to the shunt tap, and the fourth terminal of the bridge rectifier circuit is connected to the leakage current detection circuit via a first resistor.

[0008] Furthermore, the thyristor switch circuit includes a thyristor switch, the cathode of which is connected to the second terminal of the bridge rectifier circuit, the anode of which is connected to the fourth terminal of the bridge rectifier circuit, and the gate of which is connected to the leakage current detection circuit.

[0009] Furthermore, the model number of the thyristor switch is JX014.

[0010] Furthermore, the gate of the thyristor switch is also provided with a first capacitor.

[0011] Furthermore, the leakage current detection circuit includes a leakage current detection chip, which includes a first pin, a second pin, a third pin, a fourth pin, a fifth pin, a sixth pin, a seventh pin, and an eighth pin; the eighth pin is connected to the first resistor; the fifth pin is connected to the gate of the thyristor switch; and the second pin and the third pin are respectively connected to the leakage current sensing circuit.

[0012] Furthermore, the leakage current detection chip is model CS54123.

[0013] Furthermore, the leakage current sensing circuit includes a zero-sequence current transformer (ZCT), a first inductor, a second inductor, a bidirectional diode, a sixth resistor, a seventh resistor, an eighth resistor, a fifth capacitor, a seventh capacitor, a ninth capacitor, and a tenth capacitor connected to each other. The zero-sequence current transformer (ZCT) clamps the sensed leakage current through the bidirectional diode, filters it through the seventh capacitor, and then inputs it to the second and third pins of the leakage current detection chip after conversion by the seventh resistor.

[0014] Furthermore, it also includes a test button circuit, which is connected to the power supply circuit and the leakage current sensing circuit, and is used to test the working state of the circuit.

[0015] Furthermore, the test button circuit includes a test button, one end of which is connected to the leakage current sensing circuit through a second resistor, a third resistor, a fourth resistor, a fifth resistor, and a ninth resistor, and the other end is connected to the phase line.

[0016] This utility model provides a leakage current detection and protection device to prevent high voltage damage. The device has a simple structure and uses a brand-new circuit to detect leakage current. It has high trigger sensitivity for different types of leakage current signals and can detect leakage current signals including AC type. The leakage current signal detection consistency is high. In addition, the product adds a protection device before the trip unit, which can make the trip unit and the product less susceptible to damage and can operate stably for a long time, greatly improving the reliability of the product. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a leakage current detection and protection device for preventing high voltage damage according to the present invention;

[0018] Figure 2 This is a circuit diagram of a leakage current detection and protection device for preventing high voltage damage as described in this utility model. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to the figures and embodiments.

[0020] like Figure 1 As shown, a leakage current detection and protection device for preventing high voltage damage includes a power supply circuit, a trip unit, a step-down rectifier circuit, a leakage current detection circuit, and a thyristor switch circuit connected in sequence, and also includes a leakage current sensing circuit, which is connected to the power supply circuit, the step-down rectifier circuit, and the leakage current detection circuit.

[0021] The power supply circuit includes a phase line L and a neutral line N, which are respectively connected to the step-down rectifier circuit;

[0022] The trip unit includes a main tap, an auxiliary tap, and a shunt tap. The main tap is connected to the phase line L, and the shunt tap is connected to the neutral line N and the step-down rectifier circuit.

[0023] A varistor MOV1 is also provided between the main tap and the shunt tap to protect the circuit from high voltage breakdown.

[0024] When the thyristor switch circuit is turned on, it triggers the connection between the anode and cathode of the thyristor switch, causing the trip unit to be connected to ground and forming a circuit with the thyristor switch, triggering the external mechanism to open the circuit through the trip coil.

[0025] This embodiment uses a varistor MOV1 at the front end of the trip unit. When the voltage exceeds the mains power, the high voltage first forms a circuit through the varistor MOV1, thus preventing damage to subsequent products and effectively ensuring the safety of the electromagnet and circuit.

[0026] like Figure 2 As shown, the step-down rectifier circuit in this embodiment includes a bridge rectifier circuit composed of the first diode 1, the second diode D2, the third diode D3, and the fourth diode D4, specifically:

[0027] The anode of the first diode D1 and the cathode of the second diode D2 are connected as the first terminal of the bridge rectifier circuit; the anode of the second diode D2 and the anode of the fourth diode D4 are connected as the second terminal of the bridge rectifier circuit; the cathode of the fourth diode D4 and the anode of the third diode D3 are connected as the third terminal of the bridge rectifier circuit; and the cathode of the third diode D3 and the cathode of the first diode D1 are connected as the fourth terminal of the bridge rectifier circuit.

[0028] The first terminal of the bridge rectifier circuit is connected to the shunt tap, and the fourth terminal of the bridge rectifier circuit is connected to the leakage current detection circuit via the first resistor R1.

[0029] The thyristor switch circuit described in this embodiment includes a thyristor switch SCR1. The cathode of the thyristor switch SCR1 is connected to the second terminal of the bridge rectifier circuit, the anode of the thyristor switch SCR1 is connected to the fourth terminal of the bridge rectifier circuit, and the gate of the thyristor switch SCR1 is connected to the leakage current detection circuit.

[0030] The model number of the SCR1 thyristor switch is JX014.

[0031] In this embodiment, a first capacitor C1 is also provided at the gate of the silicon controlled rectifier switch SCR1 for filtering the connection to ground.

[0032] like Figure 2 As shown, the leakage current detection circuit in this embodiment includes a leakage current detection chip U1, which includes a first pin NC, a second pin OPI1, a third pin OPI2, a fourth pin GND, a fifth pin SCRT, a sixth pin DLYC, a seventh pin OPAO, and an eighth pin VDD.

[0033] The eighth pin VDD is connected to the first resistor R1;

[0034] The fifth pin SCRT is connected to the gate of the thyristor switch SCR1;

[0035] The second pin OPI1 and the third pin OPI2 are respectively connected to the leakage current sensing circuit.

[0036] The leakage current detection chip U1 mentioned in this solution is model CS54123.

[0037] like Figure 2 As shown, the leakage current sensing circuit in this embodiment includes a zero-sequence current transformer ZCT, a first inductor L1, a second inductor L2, a bidirectional diode CR5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a fifth capacitor C5, a seventh capacitor C7, a ninth capacitor C9, and a tenth capacitor C10 that are connected to each other.

[0038] The zero-sequence current transformer ZCT clamps the sensed leakage current through the bidirectional diode CR5, filters it through the seventh capacitor C7, and after conversion by the seventh resistor R7, inputs it to the second pin OPI1 and the third pin OPI2 of the leakage current detection chip U1.

[0039] In this process, the first inductor L1, the second inductor L2, the fifth capacitor C5, the tenth capacitor C10, the sixth resistor R6, and the eighth resistor R8 undergo secondary filtering to remove noise from the leakage signal and obtain a smoother waveform.

[0040] Then, the leakage current detection chip U1 amplifies and rectifies the sensed leakage current signal to obtain a DC voltage, which is then input to the thyristor switch SCR1 through the fifth pin SCRT.

[0041] It should be noted that in this embodiment, the sixth resistor R6, the eighth resistor R8, and the ninth capacitor C9 together form a resistive-capacitive filter; among them, the capacitor plays the main filtering role, while the resistor limits the current and stabilizes the voltage. The capacitor can store charge and charge and discharge when the voltage changes, thereby reducing voltage fluctuations. The resistor further stabilizes the voltage by limiting the current, preventing excessive current from damaging other components in the circuit.

[0042] like Figure 1 and Figure 2 As shown, this solution also includes a test button circuit, which is connected to the power supply circuit and the leakage current sensing circuit, and is used to test the working state of the circuit.

[0043] Specifically, the test button circuit includes a test button SW2. One end of the test button SW2 is connected to the leakage current sensing circuit through a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a ninth resistor R9, and the other end is connected to the phase line L.

[0044] The above description is merely a preferred embodiment of this utility model, but the scope of protection of this utility model is not limited thereto. Any variations or substitutions that can be conceived by those skilled in the art within the scope of the technology disclosed in this utility model are included within the scope of protection of this utility model. Therefore, the scope of protection of this utility model should be determined by the scope of the claims.

Claims

1. A leakage detection protection device for preventing damage from high voltage, characterized by, The power supply circuit, the tripping device, the step-down rectifier circuit, the leakage detection circuit and the silicon controlled switch circuit are sequentially connected, and the leakage induction circuit is connected with the power supply circuit, the step-down rectifier circuit and the leakage detection circuit. The power supply circuit includes a phase line (L) and a zero line (N) connected with the step-down rectifier circuit. The tripping device includes a main tap, an auxiliary tap and a shunt tap, the main tap is connected with the phase line (L), and the shunt tap is connected with the zero line (N) and the step-down rectifier circuit. A pressure sensitive resistor (MOV1) is arranged between the main tap and the shunt tap. When the silicon controlled switch circuit is turned on, the silicon controlled switch anode and cathode are triggered to be turned on, the tripping device is turned on to the ground, and a loop is formed with the silicon controlled switch, so that the external mechanism is triggered to be tripped by the tripping coil.

2. The leakage current detection and protection device for preventing high voltage damage according to claim 1, characterized in that, The step-down rectifier circuit includes a bridge rectifier circuit composed of a first diode (D1), a second diode (D2), a third diode (D3) and a fourth diode (D4). The anode of the first diode (D1) and the cathode of the second diode (D2) are connected as the first end of the bridge rectifier circuit, the anode of the second diode (D2) and the anode of the fourth diode (D4) are connected as the second end of the bridge rectifier circuit, the cathode of the fourth diode (D4) and the anode of the third diode (D3) are connected as the third end of the bridge rectifier circuit, and the cathode of the third diode (D3) and the cathode of the first diode (D1) are connected as the fourth end of the bridge rectifier circuit. The first end of the bridge rectifier circuit is connected with the shunt tap, and the fourth end of the bridge rectifier circuit is connected with the leakage detection circuit through the first resistor (R1).

3. The ground fault circuit interrupter of claim 2, wherein the ground fault circuit interrupter is configured to: The silicon controlled switch circuit includes a silicon controlled switch (SCR1), the cathode of the silicon controlled switch (SCR1) is connected with the second end of the bridge rectifier circuit, the anode of the silicon controlled switch (SCR1) is connected with the fourth end of the bridge rectifier circuit, and the gate of the silicon controlled switch (SCR1) is connected with the leakage detection circuit.

4. The ground fault circuit interrupter of claim 3, wherein the ground fault circuit interrupter is configured to: The model of the silicon controlled switch (SCR1) is JX014.

5. A leakage current detection and protection device for preventing high voltage damage according to claim 3, characterized in that, The gate of the silicon controlled switch (SCR1) is further provided with a first capacitor (C1).

6. The ground fault circuit interrupter of claim 3 or 5, wherein the ground fault circuit interrupter further comprises a ground fault detection circuit configured to detect a ground fault in the ground fault circuit interrupter. The leakage detection circuit includes a leakage detection chip (U1), and the leakage detection chip (U1) includes a first pin (NC), a second pin (OPI1), a third pin (OPI2), a fourth pin (GND), a fifth pin (SCRT), a sixth pin (DLYC), a seventh pin (OPAO) and an eighth pin (VDD). The eighth pin (VDD) is connected with the first resistor (R1). The fifth pin (SCRT) is connected with the gate of the silicon controlled switch (SCR1). The second pin (OPI1) and the third pin (OPI2) are respectively connected with the leakage induction circuit.

7. A leakage current detection and protection device for preventing high voltage damage according to claim 6, characterized in that, The model of the leakage detection chip (U1) is CS54123.

8. A leakage current detection and protection device for preventing high voltage damage according to claim 6, characterized in that, The leakage induction circuit comprises a zero sequence current transformer (ZCT), a first inductor (L1), a second inductor (L2), a bidirectional diode (CR5), a sixth resistor (R6), a seventh resistor (R7), an eighth resistor (R8), a fifth capacitor (C5), a seventh capacitor (C7), a ninth capacitor (C9), and a tenth capacitor (C10) connected with each other. The zero sequence current transformer ZCT clamps the sensed leakage current through the bidirectional diode (CR5) and filters the leakage current through the seventh capacitor (C7), and converts the leakage current through the seventh resistor (R7) and inputs the leakage current to the second pin (OPI1) and the third pin (OPI2) of the leakage detection chip (U1).

9. A leakage current detection and protection device for preventing high voltage damage according to claim 1, characterized in that, The test button circuit is connected with the power supply circuit and the leakage induction circuit, and is used for testing the working state of the circuit.

10. A leakage current detection and protection device for preventing high voltage damage according to claim 9, characterized in that, The test button circuit comprises a test button (SW2), one end of the test button (SW2) is connected with the leakage induction circuit through a second resistor (R2), a third resistor (R3), a fourth resistor (R4), a fifth resistor (R5), and a ninth resistor (R9), and the other end of the test button (SW2) is connected with the phase line (L).

Images