Residual current circuit breaker

Abstract

The utility model discloses a residual current circuit breaker. According to the utility model, the internal simulation test trigger circuit and the remote simulation residual current test device are simultaneously arranged for the residual current simulation test, so that the simulation residual current test can be triggered locally or remotely according to actual needs, and the reliability of an electric leakage system can be diagnosed; when the circuit breaker is in a field, a high place or a cabinet door or other places where a manual triggering test is inconvenient, a user can be helped to solve the task of regularly simulating residual current function detection.

Description

Technical Field

[0001] The utility model discloses a residual current circuit breaker. Background Art

[0002] Residual current circuit breakers are a common type of protection device in power systems, used to detect residual current or ground fault current. Residual current circuit breakers need to use simulation test circuits regularly to check whether the residual current protection function is normal. A residual current is simulated in the test coil of the residual current transformer. After the residual current transformer measuring coil detects the signal, the control circuit identifies the residual current fault, thereby controlling the release to trip, thus realizing the simulation process.

[0003] The current residual current circuit breakers all use the test button on the residual current circuit breaker body to achieve on-site simulated residual current function; when the circuit breaker is installed in the field, high up or in a cabinet where it is inconvenient to manually trigger the test, the user cannot regularly perform simulated residual current function tests on the residual current circuit breaker. This will affect the safety and reliability of the residual current circuit breaker. Utility Model Content

[0004] The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art and provide a residual current circuit breaker capable of realizing a simulated residual current test in either a local or remote triggering mode.

[0005] The utility model specifically adopts the following technical solutions to solve the above technical problems:

[0006] A residual current circuit breaker comprises a residual current release, wherein the residual current release comprises a residual current transformer, a residual current sampling and amplifying circuit, a test circuit, a control circuit, a tripping circuit, a tripping mechanism, and a test trigger signal generating unit; the residual current transformer comprises a measuring coil and a test coil which are electromagnetically coupled to each other, the measuring coil is connected to the input end of the residual current sampling and amplifying circuit, the test coil is connected to the output end of the test circuit, and the output end of the residual current sampling and amplifying circuit and the input end of the test circuit are respectively connected to the control circuit; the control circuit responds to a test trigger signal output by the test trigger signal generating unit, excites the measuring coil through the test circuit to generate a simulated residual current signal, the measuring coil samples the simulated residual current signal and sends it to the control circuit through the residual current sampling and amplifying circuit, and the control circuit controls the tripping mechanism to perform a tripping action through the tripping circuit; the test trigger signal generating unit comprises an internal simulated test trigger circuit for generating a local test trigger signal; the test trigger signal generating unit also comprises a remote simulated residual current test device for generating a remote test trigger signal.

[0007] Preferably, the remote simulated residual current test device comprises a signal trigger circuit, an isolation transmission circuit, and a voltage divider filter circuit which are connected in sequence.

[0008] Further preferably, the signal trigger circuit includes a DC switch for connecting a 24V DC power supply, as well as a varistor, a filter capacitor, and two current limiting resistors; the positive output end of the DC switch is simultaneously connected to one end of the varistor and one end of the first current limiting resistor, the negative output end of the DC switch is simultaneously connected to the other end of the varistor, one end of the second current limiting resistor, one end of the filter capacitor, and an input end of the isolation transmission circuit and grounded, and the other end of the filter capacitor is simultaneously connected to the other end of the first current limiting resistor, the other end of the second current limiting resistor, and the other input end of the isolation transmission circuit.

[0009] Further preferably, the signal trigger circuit includes an AC switch for connecting an AC power supply, as well as a varistor, a rectifier circuit, a step-down resistor, first to third filter capacitors, a protection diode, and two current-limiting resistors; the two input ends of the AC switch are respectively connected to the two input ends of the rectifier circuit, the varistor is connected between the two input ends of the rectifier circuit, the positive output end of the rectifier circuit is connected to one end of the step-down resistor, and the other end of the step-down resistor is simultaneously connected to one end of the first filter capacitor, one end of the second filter capacitor, one end of the protection diode, and one end of the first current-limiting resistor, the negative output end of the rectifier circuit is commonly connected to the other end of the first filter capacitor, the other end of the second filter capacitor, the other end of the protection diode, one end of the second current-limiting resistor, one end of the third filter capacitor, and an input end of the isolation transmission circuit and grounded, and the other end of the third filter capacitor is commonly connected to the other end of the first current-limiting resistor, the other end of the second current-limiting resistor, and another input end of the isolation transmission circuit.

[0010] Preferably, the isolation transmission circuit is a relay or an optocoupler.

[0011] Preferably, the voltage divider filter circuit includes a capacitor C5, a capacitor C6, resistors R4 to R6, and a diode D3; the cathode of the diode D3 is simultaneously connected to one end of the capacitor C5 and the positive output end of the isolation transmission circuit, the anode of the diode D3 is simultaneously connected to the other end of the capacitor C5, one end of the resistor R4, and the negative output end of the isolation transmission circuit, the other end of the resistor R4 is simultaneously connected to one end of the resistor R5 and one end of the resistor R6, the other end of the resistor R5 is connected to one end of the capacitor C6 and is grounded, and the other end of the resistor R6 is simultaneously connected to the other end of the capacitor C6 and an I / O port of the control circuit.

[0012] Compared with the prior art, the utility model has the following beneficial effects:

[0013] The utility model is provided with an internal simulation test trigger circuit and a remote simulation residual current test device for the residual current simulation test, and can realize the simulation residual current test by either local or remote triggering according to actual needs, so as to diagnose the reliability of the leakage system; when the circuit breaker is in the field, at a high place or inside a cabinet door and other places where manual triggering test is inconvenient, it can help users solve the task of regular simulation residual current function detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a circuit principle block diagram of the residual current circuit breaker of the utility model;

[0015] Figure 2 A circuit diagram of a specific embodiment of a remote simulated residual current test device;

[0016] Figure 3 A circuit diagram of another specific embodiment of a remote simulated residual current test device;

[0017] Figure 4 This is a circuit connection diagram of the MCU circuit. DETAILED DESCRIPTION

[0018] In view of the deficiencies in the prior art, the solution of the utility model is to simultaneously set up an internal simulation test trigger circuit and a remote simulation residual current test device for the residual current simulation test, which can trigger the simulation residual current test locally or remotely according to actual needs.

[0019] The residual current circuit breaker proposed in the utility model comprises a residual current release, which comprises a residual current transformer, a residual current sampling and amplifying circuit, a test circuit, a control circuit, a tripping circuit, a tripping mechanism, and a test trigger signal generating unit; the residual current transformer comprises a measuring coil and a test coil which are electromagnetically coupled to each other, the measuring coil is connected to the input end of the residual current sampling and amplifying circuit, the test coil is connected to the output end of the test circuit, and the output end of the residual current sampling and amplifying circuit and the input end of the test circuit are respectively connected to the control circuit; the control circuit responds to the test trigger signal output by the test trigger signal generating unit, stimulates the measuring coil to generate a simulated residual current signal through the test circuit, the measuring coil samples the simulated residual current signal and sends it to the control circuit through the residual current sampling and amplifying circuit, and the control circuit controls the tripping mechanism to perform a tripping action through the tripping circuit; the test trigger signal generating unit comprises an internal simulated test trigger circuit for generating a local test trigger signal; the test trigger signal generating unit also comprises a remote simulated residual current test device for generating a remote test trigger signal.

[0020] Preferably, the remote simulated residual current test device comprises a signal trigger circuit, an isolation transmission circuit, and a voltage divider filter circuit which are connected in sequence.

[0021] Further preferably, the signal trigger circuit includes a DC switch for connecting a 24V DC power supply, as well as a varistor, a filter capacitor, and two current limiting resistors; the positive output end of the DC switch is simultaneously connected to one end of the varistor and one end of the first current limiting resistor, the negative output end of the DC switch is simultaneously connected to the other end of the varistor, one end of the second current limiting resistor, one end of the filter capacitor, and an input end of the isolation transmission circuit and grounded, and the other end of the filter capacitor is simultaneously connected to the other end of the first current limiting resistor, the other end of the second current limiting resistor, and the other input end of the isolation transmission circuit.

[0022] Further preferably, the signal trigger circuit includes an AC switch for connecting an AC power supply, as well as a varistor, a rectifier circuit, a step-down resistor, first to third filter capacitors, a protection diode, and two current-limiting resistors; the two input ends of the AC switch are respectively connected to the two input ends of the rectifier circuit, the varistor is connected between the two input ends of the rectifier circuit, the positive output end of the rectifier circuit is connected to one end of the step-down resistor, and the other end of the step-down resistor is simultaneously connected to one end of the first filter capacitor, one end of the second filter capacitor, one end of the protection diode, and one end of the first current-limiting resistor, the negative output end of the rectifier circuit is commonly connected to the other end of the first filter capacitor, the other end of the second filter capacitor, the other end of the protection diode, one end of the second current-limiting resistor, one end of the third filter capacitor, and an input end of the isolation transmission circuit and grounded, and the other end of the third filter capacitor is commonly connected to the other end of the first current-limiting resistor, the other end of the second current-limiting resistor, and another input end of the isolation transmission circuit.

[0023] Preferably, the isolation transmission circuit is a relay or an optocoupler.

[0024] Preferably, the voltage divider filter circuit includes a capacitor C5, a capacitor C6, resistors R4 to R6, and a diode D3; the cathode of the diode D3 is simultaneously connected to one end of the capacitor C5 and the positive output end of the isolation transmission circuit, the anode of the diode D3 is simultaneously connected to the other end of the capacitor C5, one end of the resistor R4, and the negative output end of the isolation transmission circuit, the other end of the resistor R4 is simultaneously connected to one end of the resistor R5 and one end of the resistor R6, the other end of the resistor R5 is connected to one end of the capacitor C6 and is grounded, and the other end of the resistor R6 is simultaneously connected to the other end of the capacitor C6 and an I / O port of the control circuit.

[0025] In order to facilitate public understanding, the technical solution of the utility model is described in detail below with reference to the accompanying drawings:

[0026] The residual current release of the residual current circuit breaker of the utility model comprises a residual current transformer, a residual current sampling and amplifying circuit, an MCU circuit, a tripping circuit, a tripping mechanism, an internal simulation test trigger circuit, a test circuit, a remote residual current simulation test device, a residual current state indication circuit, an alarm circuit and a power supply circuit. When a residual current fault occurs in the main circuit, the residual current transformer in the main circuit senses a fault signal through a measuring coil and then sends it to the residual current sampling and amplifying circuit. The residual current sampling and amplifying circuit processes the fault signal and then sends it to the MCU circuit. The MCU circuit determines whether the fault signal exceeds a preset threshold value. If it exceeds, the tripping circuit is controlled to drive the tripping mechanism to drive the circuit breaker unit to operate, disconnecting the connection between the load and the main circuit. At the same time, the residual current state indication circuit and the alarm circuit indicate the residual current fault state and alarm when the residual current exceeds the preset threshold value.

[0027] When the user needs to simulate the internal circuit of the residual current circuit breaker, a test trigger signal is sent to the MCU circuit through the internal simulation test trigger circuit or the remote residual current simulation test device. When the MCU circuit receives the test trigger signal, a PWM signal is sent to the test coil in the residual current transformer that is electromagnetically coupled with the measuring coil through the test circuit, thereby generating a simulated residual current signal. At the same time, the measuring coil receives the simulated residual current signal, which is amplified by the residual current sampling and amplifier circuit and then transmitted to the MCU circuit to complete the subsequent tripping work, thereby realizing the simulated residual current test triggered locally or remotely.

[0028] Figure 2 A specific implementation circuit of a remote simulation residual current test device is shown. Figure 2 As shown, it includes a signal trigger circuit composed of a DC switch with external wiring terminals P1~P4, a varistor RV1, a filter capacitor C3, and current limiting resistors R2 and R3, an isolation transmission circuit composed of an isolation device K1, and a voltage divider filter circuit composed of a freewheeling diode D3, a filter capacitor C5, voltage divider resistors R4 and R5, and an RC filter circuit R6 and C6.

[0029] The P1 and P2 terminals of the DC switch are connected to an external 24V DC power supply, and the P3 and P4 terminals of the DC switch are connected to a push button switch for turning on the power supply, and the terminal contact capacity is 24V / 1A. When remote simulation is required, press the push button switch connected to P3 and P4, and the remote residual current simulation test device obtains a 24V DC power supply. After the power supply is protected by the varistor RV1 overvoltage protection, C3 filtering, and R8 and R9 current limiting, a current signal is given to the isolation device K1, thereby transmitting the external control signal to the receiving end through the isolation device K1, and the internal voltage signal Vdd is sent to the I / O2 port of the MCU circuit after the diode D3 continues to flow, the capacitor C5 filters, the resistors R4 and R5 divide the voltage, and the RC filter circuit R6 and C6 filters. Thus, the transmission of the external remote residual current simulation test signal is realized. When the MCU circuit receives the local simulation test signal from the internal simulation test trigger circuit, or the remote simulation test signal from the remote residual current simulation test device, a PWM signal is sent to the test coil of the residual current transformer through the test circuit. At the same time, the residual current transformer receives the simulated fault signal and completes the subsequent tripping work, thus realizing the simulated residual current test triggered locally or remotely.

[0030] The isolation device K1 may be a photocoupler, a relay or other device, and the isolation voltage is greater than or equal to 3000V.

[0031] The remote residual current simulation test device can be placed outside, on the side or even inside the residual current circuit breaker. To perform remote control, just lead the push button switch connected to the P3 and P4 terminals to a place that is convenient for users to operate.

[0032] Figure 3 Another specific implementation circuit of the remote simulation residual current test device is shown. Figure 3 As shown, it includes a signal trigger circuit consisting of an AC switch with external wiring terminals P1~P4, a varistor RV2, a rectifier bridge D1, a voltage-dropping resistor R1, filter capacitors C1, C2, C4, a protection diode D2, and current-limiting resistors R8 and R9, an isolation transmission circuit consisting of an isolation device N1, and a voltage-dividing filter circuit consisting of a freewheeling diode D3, a filter capacitor C5, voltage-dividing resistors R4, R5, and an RC filter circuit R6 and C6.

[0033] The P5 and P6 terminals of the AC switch are connected to an external 230V AC power supply, and the P7 and P8 terminals of the AC switch are connected to a push button switch for turning on the power supply, and the terminal contact capacity can be 230V / 3A. When remote simulation is required, press the push button switch connected to P7 and P8, and the remote residual current simulation test device obtains a 230V AC power supply. The power supply is protected by overvoltage of the varistor RV2, rectified by the rectifier bridge D1, stepped down by the resistor R1, filtered by C1, C2, C4, and limited by R8 and R9, and then a current signal is given to the isolation device N1, thereby transmitting the external control signal to the receiving end through the isolation device N1; the internal voltage signal Vdd is sent to the I / O2 port of the MCU after continuous current through the diode D3, filtering by the capacitor C5, voltage division by the resistors R4 and R5, and filtering by the RC filter circuit R6 and C6, thereby realizing the transmission of the external remote residual current simulation test signal. When the MCU circuit receives the local simulation test signal from the internal simulation test trigger circuit, or the remote simulation test signal from the remote residual current simulation test device, a PWM signal is sent to the test coil of the residual current transformer through the test circuit. At the same time, the residual current transformer receives the simulated fault signal and completes the subsequent tripping work, thus realizing the simulated residual current test triggered locally or remotely.

[0034] The external AC power connected to the P5 and P6 terminals can be obtained from the upper or lower end of the main circuit; the power supply can be 230V, or even increased to 400V or 690V. The isolation device N1 can be an optocoupler, relay or other device, and the isolation voltage is greater than or equal to 3000V.

[0035] The remote residual current simulation test device can be placed outside, on the side or even inside the residual current circuit breaker. To perform remote control, just lead the push button switch connected to the P7 and P8 terminals to a place where it is convenient for users to operate.

[0036] Figure 4 The specific connection status of the MCU circuit is shown. The internal simulation test trigger circuit is composed of a button switch S1 and a resistor R7. When the button switch S1 is pressed, the I / O1 interface of the MCU circuit receives the internal test trigger signal; the I / O2 interface of the MCU circuit receives the remote test trigger signal output by the remote residual current simulation test device, the I / O3 interface of the MCU circuit receives the residual current signal, and the I / O4 interface of the MCU circuit sends a PWM signal.

Claims

1. A residual current circuit breaker, comprising a residual current release, the residual current release comprising a residual current transformer, a residual current sampling and amplifying circuit, a test circuit, a control circuit, a tripping circuit, a tripping mechanism, and a test trigger signal generating unit; the residual current transformer comprises a measuring coil and a test coil which are electromagnetically coupled to each other, the measuring coil is connected to the input end of the residual current sampling and amplifying circuit, the test coil is connected to the output end of the test circuit, the output end of the residual current sampling and amplifying circuit and the input end of the test circuit are respectively connected to the control circuit; the control circuit responds to a test trigger signal output by the test trigger signal generating unit, stimulates the measuring coil through the test circuit to generate an analog residual current signal, the measuring coil samples the analog residual current signal and sends it to the control circuit through the residual current sampling and amplifying circuit, and the control circuit controls the tripping mechanism through the tripping circuit to perform a tripping action; the test trigger signal generating unit comprises an internal analog test trigger circuit for generating a local test trigger signal; it is characterized in that The test trigger signal generating unit further comprises a remote simulated residual current test device for generating a remote test trigger signal.

2. The residual current circuit breaker according to claim 1, characterized in that: The remote simulated residual current test device comprises a signal trigger circuit, an isolation transmission circuit and a voltage dividing filter circuit which are connected in sequence.

3. The residual current circuit breaker according to claim 2, characterized in that: The signal trigger circuit includes a DC switch for connecting a 24V DC power supply, as well as a varistor, a filter capacitor, and two current-limiting resistors; the positive output end of the DC switch is simultaneously connected to one end of the varistor and one end of the first current-limiting resistor, the negative output end of the DC switch is simultaneously connected to the other end of the varistor, one end of the second current-limiting resistor, one end of the filter capacitor, and an input end of the isolation transmission circuit and grounded, and the other end of the filter capacitor is simultaneously connected to the other end of the first current-limiting resistor, the other end of the second current-limiting resistor, and the other input end of the isolation transmission circuit.

4. The residual current circuit breaker according to claim 2, characterized in that: The signal trigger circuit includes an AC switch for connecting an AC power supply, as well as a varistor, a rectifier circuit, a step-down resistor, first to third filter capacitors, a protection diode, and two current-limiting resistors; the two input ends of the AC switch are respectively connected to the two input ends of the rectifier circuit, the varistor is connected between the two input ends of the rectifier circuit, the positive output end of the rectifier circuit is connected to one end of the step-down resistor, the other end of the step-down resistor is simultaneously connected to one end of the first filter capacitor, one end of the second filter capacitor, one end of the protection diode, and one end of the first current-limiting resistor, the negative output end of the rectifier circuit is commonly connected to the other end of the first filter capacitor, the other end of the second filter capacitor, the other end of the protection diode, one end of the second current-limiting resistor, one end of the third filter capacitor, and an input end of the isolation transmission circuit and grounded, and the other end of the third filter capacitor is commonly connected to the other end of the first current-limiting resistor, the other end of the second current-limiting resistor, and another input end of the isolation transmission circuit.

5. The residual current circuit breaker according to any one of claims 2 to 4, characterized in that: The isolation transmission circuit is a relay or an optical coupler.

6. The residual current circuit breaker according to any one of claims 2 to 4, characterized in that: The voltage divider filter circuit includes a capacitor C5, a capacitor C6, resistors R4 to R6, and a diode D3; the cathode of the diode D3 is simultaneously connected to one end of the capacitor C5 and the positive output end of the isolation transmission circuit, the anode of the diode D3 is simultaneously connected to the other end of the capacitor C5, one end of the resistor R4, and the negative output end of the isolation transmission circuit, the other end of the resistor R4 is simultaneously connected to one end of the resistor R5 and one end of the resistor R6, the other end of the resistor R5 is connected to one end of the capacitor C6 and is grounded, and the other end of the resistor R6 is simultaneously connected to the other end of the capacitor C6 and an I / O port of the control circuit.

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