CN204794014U - Take over -current protection's residual current action circuit breaker - Google Patents

Abstract

A residual current operated circuit breaker with overcurrent protection, comprising a tripping coil KA, a control circuit, a zero-sequence transformer TA, a power supply circuit and a signal acquisition and processing circuit; the input terminals of the power supply circuit are respectively connected to three-phase power lines For taking power, the output end of the power circuit is connected to the two ends of the tripping coil KA to form a tripping circuit; the input end of the signal acquisition and processing circuit is connected to the two ends of the secondary circuit lead wire of the zero-sequence transformer TA, and the signal The output terminal of the acquisition and processing circuit is connected to the control circuit, and the collected signal is fed back to the control circuit; the step-down circuit stabilizes the power supply voltage and outputs it to the control circuit, and the control circuit adopts a first-level thyristor VT1 and a second-level thyristor VT2 constitutes the secondary control circuit to control the tripping circuit, the design is reasonable, safe and stable, the tripping is more stable and reliable, and the performance of the product is improved.

Description

Residual current operated circuit breaker with overcurrent protection

technical field

The utility model relates to the field of low-voltage electrical appliances, in particular to a residual current operated circuit breaker with overcurrent protection.

Background technique

When the human body gets an electric shock or the leakage current of the power grid exceeds the specified value, the residual current operated circuit breaker can quickly cut off the faulty power supply in a very short time to protect the safety of people and electrical equipment.

At present, the working power of conventional leakage protection modules with residual current protection circuit breakers is sampled as single-phase leakage current protection, while the three-phase four-wire residual current protection circuit breakers on the market mainly only provide leakage current protection for two poles of the product, and cannot Realize the leakage current protection of phase voltage and line voltage at the same time, and it is impossible to realize normal operation without any phase.

Contents of the invention

The purpose of the utility model is to overcome the defects of the prior art and provide a residual current operated circuit breaker with overcurrent protection with reasonable structure and safe and stable performance.

In order to achieve the above object, the utility model adopts the following technical solutions:

A residual current operated circuit breaker with overcurrent protection, comprising a tripping coil KA, a control circuit, a zero-sequence transformer TA, a power supply circuit, and a signal acquisition and processing circuit; The L2 phase, the L3 phase of the power supply and the N phase of the power supply are connected to take power, and the output terminal of the power supply circuit is connected to the two ends of the tripping coil KA to form a tripping circuit; the input terminal of the signal acquisition and processing circuit is connected to the zero-sequence transformer TA The two ends of the secondary circuit lead are connected, the output end of the signal acquisition and processing circuit is connected with the control circuit, and the collected signal is fed back to the control circuit; it also includes a step-down circuit, the input end of the step-down circuit is connected to the tripping coil KA One end is connected, the output end of the step-down circuit is connected with the control circuit to provide working power for the control circuit; the control circuit includes a primary thyristor VT1 and a secondary thyristor VT2, a primary thyristor VT1 and a secondary thyristor The silicon VT2 is connected in series on the tripping circuit formed by the tripping coil KA and the power supply circuit. The output terminal of the step-down circuit is connected to the G pole of the first-level thyristor VT1 to trigger and control the first-level thyristor VT1. The control circuit according to the signal The signal collected by the acquisition and processing circuit triggers and controls the secondary thyristor VT2 through the G pole of the secondary thyristor VT2.

Further, the step-down circuit includes a resistor R5, a diode VD5, and a resistor R4; one end of the resistor R5 is connected to one end of the tripping coil KA, the other end is connected to the control circuit, the anode of the diode VD5 is connected to the other end of the resistor R5, and the diode The negative pole of VD5 is connected to the G pole of the primary thyristor VT1 after passing through the resistor R4; the primary thyristor VT1 and the secondary thyristor VT2 are connected in series, and the positive pole of the primary thyristor VT1 is connected to the tripping coil KA and One end of the resistor R5 is connected, the negative pole of the primary thyristor VT1 is connected to the positive pole of the secondary thyristor VT2, and the negative pole of the secondary thyristor VT2 is connected to the output terminal of the power circuit.

Further, the step-down circuit also includes a capacitor C5 and a varistor RV4, one end of the capacitor C5 is connected to the other end of the resistor R5, and the other end is grounded, and the varistor RV4 is connected in parallel with the primary thyristor VT1 and the secondary Both ends of SCR VT2.

Further, the control circuit also includes a control chip, the other end of the resistor R5 is connected to the control chip to supply power for the control chip, and the G pole of the secondary thyristor VT2 is connected to the seventh pin of the control chip.

Further, the power supply circuit includes a rectification circuit; the rectification circuit includes a diode VD1, a diode VD2, a diode VD3 and a diode VD4. Connection, the cathodes of diode VD1, diode VD2 and diode VD3 are connected to one end of the tripping coil KA, the anode of diode VD4 is connected to the cathode of the secondary thyristor VT2, and the cathode of diode VD4 is connected to the power supply N.

Further, the power supply circuit includes a surge absorbing circuit; the surge absorbing circuit includes a varistor RV1, a varistor RV2, and a varistor RV3, and the varistor RV1 is connected between the power supply L1 phase and the power supply N phase, The varistor RV2 is connected between the L2 phase of the power supply and the N phase of the power supply, and the varistor RV3 is connected between the L3 phase of the power supply and the N phase of the power supply.

Further, the power supply circuit includes a rectification circuit; the rectification circuit includes diode VD1, diode VD2, diode VD3, diode VD4, diode VD5, diode VD6, diode VD7, diode VD8, diode VD1 and diode VD2, diode VD3 and diode VD4 , diode VD5 and diode VD6, diode VD7 and diode VD8 are respectively connected in series and then connected in parallel, one end of the parallel connection is connected to one end of trip coil KA, the middle node of diode VD1 and diode VD2 is connected to power supply L1, diode VD3 and diode VD4 The middle node of the diode VD5 is connected to the power supply L2, the middle node of the diode VD5 and the diode VD6 is connected to the power supply L3, the middle node of the diode VD7 and the diode VD8 is connected to the power supply N, the positive pole of the diode VD8 is connected to the negative pole of the secondary thyristor VT2 connect.

Further, the power supply circuit includes a surge absorbing circuit; the surge absorbing circuit includes a varistor RV1, a varistor RV2, a varistor RV3, a varistor RV4, a varistor RV5, and a varistor RV6, the voltage The varistor RV1 is connected between the L1 phase of the power supply and the N phase of the power supply, the varistor RV2 is connected between the L2 phase of the power supply and the N phase of the power supply, and the varistor RV3 is connected between the L3 phase of the power supply and the N phase of the power supply. RV4 is connected between the power L1 phase and the power L2 phase, the varistor RV5 is connected between the power L2 phase and the power L1 phase, and the varistor RV6 is connected between the power L1 phase and the power L3 phase.

Further, the signal acquisition and processing circuit also includes a bidirectional diode D1, a debugging resistor R1, a resistor R2, a resistor R3 and a capacitor C1; the power L1 phase, the power L2 phase, the power L3 phase and the power N phase wires all pass through the zero sequence The transformer TA and the two ends of the secondary circuit lead of the zero-sequence transformer TA are respectively connected to the first pin and the second pin of the control chip, and the debugging resistor R1, the bidirectional diode D1, and the capacitor C1 are connected in parallel to the secondary circuit lead in turn. One end of the resistor R2 is connected to one end of the capacitor C1, and the other end is connected to one end of the bidirectional diode D1; one end of the resistor R3 is connected to the other end of the capacitor C1, and the other end is connected to the other end of the bidirectional diode D1; Capacitor C2, capacitor C3, and capacitor C4. One end of capacitor C2 is connected to the fourth and fifth pins of the control chip, and the other end is grounded; one end of capacitor C3 is connected to the sixth pin of the control chip, and the other end is connected to the sixth pin of the control chip. The third pin of the control chip is connected, one end of the capacitor C4 is connected to the seventh pin of the control chip, the other end is connected to the third pin of the control chip, and one end of the capacitor C4 is connected to the control circuit.

Further, a test loop is also included, the test loop includes a normally open test switch S1 and a resistor R6, the normally open test switch S1 and the resistor R6 are connected in series to form a loop and pass through the zero-sequence transformer TA.

The power supply circuit of the residual current action circuit breaker with overcurrent protection of the utility model is divided into two circuits to supply power to the tripping coil and the control circuit after taking power from multiple poles, and can still work normally even when any phase is missing, ensuring power consumption Safe and improve product performance; the step-down circuit stabilizes the power supply voltage and outputs it to the control circuit. The control circuit uses a primary thyristor VT1 and a secondary thyristor VT2 to form a secondary control circuit to control the tripping circuit. The design is reasonable , safe and stable, the tripping is more stable and reliable, and the performance of the product is improved. The surge absorption circuit and the rectification circuit adopt two different embodiments. The first embodiment adopts three-way half-wave rectification, which can simultaneously realize leakage current protection for the phase voltage of the phase four-wire residual current operating circuit breaker; the second In this embodiment, four-way bridge-type full-wave rectification is adopted, which can realize leakage current protection for phase voltage and line voltage of a three-phase four-wire residual current operating circuit breaker at the same time, and in the absence of any phase, the product can work normally Work, to achieve all-round protection of power leakage.

Description of drawings

Fig. 1 is a frame diagram of the utility model;

Fig. 2 is a circuit diagram of Embodiment 1 of the power supply circuit of the present invention;

Fig. 3 is the circuit diagram of the second embodiment of the power supply circuit of the present invention;

Fig. 4 is the circuit diagram of the utility model embodiment three;

Fig. 5 is a circuit diagram of Embodiment 4 of the present utility model.

Detailed ways

The specific implementation of the residual current operated circuit breaker with overcurrent protection of the present invention will be further described below in conjunction with the embodiments given in accompanying drawings 1 to 5 . The residual current operated circuit breaker with overcurrent protection of the present invention is not limited to the description of the following embodiments.

As shown in Figures 1, 4, and 5, a residual current-operated circuit breaker with overcurrent protection includes a tripping coil KA, a control circuit, a zero-sequence transformer TA, a power supply circuit, and a signal acquisition and processing circuit. The input terminals of the power supply circuit are respectively connected with the power supply L1 phase, the power supply L2 phase, the power supply L3 phase and the power supply N phase for taking power, and the output terminals of the power supply circuit are connected with the two ends of the tripping coil KA to form a tripping circuit; The input end of the signal acquisition and processing circuit is connected to the two ends of the secondary loop lead wire of the zero sequence transformer TA, the output end of the signal acquisition and processing circuit is connected to the control circuit, and the collected signal is fed back to the control circuit; it also includes step-down circuit, the input end of the step-down circuit is connected to one end of the tripping coil KA, the output end of the step-down circuit is connected to the control circuit to provide working power for the control circuit; the control circuit includes a primary thyristor VT1 and a secondary controllable Silicon VT2, primary thyristor VT1 and secondary thyristor VT2 are connected in series on the trip circuit formed by the tripping coil KA and the power supply circuit, and the output terminal of the step-down circuit is connected to the G pole of the primary thyristor VT1. The primary thyristor VT1 performs trigger control, and the control circuit triggers and controls the secondary thyristor VT2 through the G pole of the secondary thyristor VT2 according to the signal collected by the signal acquisition and processing circuit. The power supply circuit of the residual current action circuit breaker with overcurrent protection of the utility model is divided into two circuits to supply power to the tripping coil and the control circuit after taking power from multiple poles, and can still work normally even when any phase is missing, ensuring power consumption Safe and improve product performance; the step-down circuit stabilizes the power supply voltage and outputs it to the control circuit. The control circuit uses a primary thyristor VT1 and a secondary thyristor VT2 to form a secondary control circuit to control the tripping circuit. The design is reasonable , safe and stable, the tripping is more stable and reliable, and the performance of the product is improved.

As shown in Figures 4 and 5, the residual current operated circuit breaker with overcurrent protection of the present invention also includes a signal acquisition and processing circuit, and the control circuit also includes a control chip; the signal acquisition and processing circuit includes a bidirectional diode D1, a debugging resistor R1, resistor R2, resistor R3 and capacitor C1; the wires of the power L1 phase, power L2 phase, power L3 phase and power N phase all pass through the zero-sequence transformer TA, and the two secondary circuit leads of the zero-sequence transformer TA The terminals are respectively connected to the first and second pins of the control chip, the debugging resistor R1, the bidirectional diode D1, and the capacitor C1 are connected in parallel at both ends of the secondary circuit lead in turn, one end of the resistor R2 is connected to one end of the capacitor C1, and the other One end is connected to one end of bidirectional diode D1; one end of resistor R3 is connected to the other end of capacitor C1, and the other end is connected to the other end of bidirectional diode D1; it also includes capacitor C2, capacitor C3, capacitor C4, and one end of capacitor C2 is respectively connected to the control The fourth pin of the chip is connected to the fifth pin, and the other end is grounded; one end of the capacitor C3 is connected to the sixth pin of the control chip, the other end is connected to the third pin of the control chip, and one end of the capacitor C4 is connected to the control chip The seventh pin of the capacitor C4 is connected, the other end is connected to the third pin of the control chip, and one end of the capacitor C4 is connected to the control circuit. Power supply L1 phase, power supply L2 phase, power supply L3 phase and power supply N-phase wires pass through the zero-sequence transformer. When there is leakage current, it is adjusted by debugging resistor R1, bidirectional diode D1, resistor R2, resistor R3, and capacitor C1. After that, the signal is collected to the control chip. After the control chip and the capacitor C2, capacitor C3, and capacitor C4, the signal is processed and judged, and the signal is output to the thyristor VT2 for control. It also includes a test loop, the test loop includes a normally open test switch S1 and a resistor R6, the normally open test switch S1 and the resistor R6 are connected in series to form a loop and pass through the zero-sequence transformer TA. The normally open test switch S1 of the test circuit is closed to simulate a short circuit, and the leakage trip test is performed on the trip circuit.

Figures 2 and 4 show two embodiments of the residual current operated circuit breaker for overcurrent protection of the present invention. Three-way half-wave rectification is used to simultaneously realize leakage current protection for the phase voltage of the four-wire residual current operated circuit breaker.

As shown in Figure 4, the step-down circuit includes a resistor R5, a diode VD5, and a resistor R4; one end of the resistor R5 is connected to one end of the tripping coil KA, the other end is connected to the control circuit, and the positive pole of the diode VD5 is connected to the other end of the resistor R5 , the cathode of the diode VD5 is connected to the G pole of the primary thyristor VT1 after passing through the resistor R4; the primary thyristor VT1 and the secondary thyristor VT2 are connected in series, and the positive pole of the primary thyristor VT1 is connected to the tripping coil One end of KA connected to the resistor R5, the negative pole of the primary thyristor VT1 is connected to the positive pole of the secondary thyristor VT2, and the negative pole of the secondary thyristor VT2 is connected to the output terminal of the power circuit. The step-down circuit also includes a capacitor C5 and a varistor RV4, one end of the capacitor C5 is connected to the other end of the resistor R5, and the other end is grounded, and the varistor RV4 is connected in parallel with the primary thyristor VT1 and the secondary thyristor VT1 in series. silicon across VT2. The control circuit also includes a control chip, the other end of the resistor R5 is connected to the control chip to supply power for the control chip, and the G pole of the secondary thyristor VT2 is connected to the seventh pin of the control chip. The step-down circuit sets the resistor R5 to step down the power supply voltage flowing out of the tripping coil KA and output it to the control chip. At the same time, the diode triggers and controls the G pole of the primary thyristor VT1 of the control circuit through VD5 and resistor R4. The first-level thyristor VT1 is controlled by resistor divider or other trigger methods. The capacitor C5 stabilizes the power supply voltage flowing out of the trip coil KA and outputs it to the control chip. The varistor RV4 is connected in parallel at both ends of the control circuit. Surge absorbing protection. In the embodiment shown in FIG. 2, the step-down circuit further includes a resistor R6 connected in series with the resistor R5.

As shown in Figures 2 and 4, the power supply circuit includes a rectifier circuit; the rectifier circuit includes a diode VD1, a diode VD2, a diode VD3 and a diode VD4. The L2 phase is connected to the power supply L3, the cathodes of diode VD1, diode VD2 and diode VD3 are connected to one end of the tripping coil KA, the anode of diode VD4 is connected to the cathode of the secondary thyristor VT2, and the cathode of diode VD4 is connected to the N phase of the power supply connect. The rectification circuit respectively rectifies the current of each phase of the power supply, and converts the alternating current of each phase of the power supply into direct current. The rectifier circuit can also use a bridge rectifier device to rectify the power circuit.

As shown in Figures 2 and 4, the power supply circuit also includes a surge absorbing circuit; the surge absorbing circuit includes a varistor RV1, a varistor RV2 and a varistor RV3, and the varistor RV1 is connected to the phase of the power supply L1 Between the power supply N phase and the power supply N phase, the varistor RV2 is connected between the power supply L2 phase and the power supply N phase, and the varistor RV3 is connected between the power supply L3 phase and the power supply N phase. The surge absorbing circuit absorbs the surge voltage formed between the power supply L1 phase, the power supply L2 phase, the power supply L3 phase and the power supply N phase by setting the varistor RV1, the varistor RV2 and the varistor RV3, so as to effectively protect the circuit . The surge absorbing circuit can also use a TVS tube or a resistance-capacitance module or other surge absorbing modules to protect the thyristor.

Figures 3 and 5 are two other embodiments of the residual current-operated circuit breaker for over-current protection of the present invention, which adopts four-way bridge full-wave rectification, and can control the phase voltage and line voltage of the residual current-operated circuit breaker in the three-phase four-wire system At the same time, leakage current protection is realized, and in the absence of any phase, the product can work normally, realizing all-round protection of power leakage.

As shown in Figure 5, the step-down circuit includes a resistor R5, a resistor R6, a diode VD9, and a resistor R4. One end of the series connection of the resistor R5 and the resistor R6 is connected to one end of the tripping coil KA, and the other end is connected to the control circuit. The positive pole of VD9 is connected to the other end of resistor R6, and the negative pole of diode VD9 is connected to the G pole of the primary thyristor VT1 after passing through resistor R4; the primary thyristor VT1 and the secondary thyristor VT2 are connected in series, and the primary thyristor VT1 The positive pole of the thyristor VT1 is connected to one end of the trip coil KA connected to the resistor R5, the negative pole of the primary thyristor VT1 is connected to the positive pole of the secondary thyristor VT2, and the negative pole of the secondary thyristor VT2 is connected to the output of the power circuit Terminal connection, the G pole of the secondary thyristor VT2 is connected to the control circuit; it also includes a capacitor C5 and a varistor RV7, one end of the capacitor C5 is connected to the other end of the series connection of the resistor R5 and the resistor R6, and the other end is grounded, the varistor Resistor RV7 is connected in parallel at both ends of the series-connected primary thyristor VT1 and secondary thyristor VT2. The control circuit also includes a control chip, the other end of which the resistors R5 and R6 are connected in series is connected to the control chip to supply power for the control chip, and the G pole of the secondary thyristor VT2 is connected to the seventh pin of the control chip. The step-down circuit sets resistors R5 and R6 to step down the power supply voltage flowing out of the tripping coil KA and output it to the control chip, and at the same time trigger and control the G pole of the primary thyristor VT1 of the control circuit through the diode VD9 and resistor R4 , can also use resistor divider or other trigger methods to control the first-stage thyristor VT1, capacitor C5 stabilizes the power supply voltage flowing out of the trip coil KA and outputs it to the control chip, and varistor RV4 is connected in parallel to the control circuit. Both ends are protected by surge absorption.

As shown in Figures 3 and 5, the power supply circuit includes a rectification circuit; the power supply circuit includes a rectification circuit; the rectification circuit includes a diode VD1, a diode VD2, a diode VD3, a diode VD4, a diode VD5, a diode VD6, a diode VD7, Diode VD8, diode VD1 and diode VD2, diode VD3 and diode VD4, diode VD5 and diode VD6, diode VD7 and diode VD8 are respectively connected in series and connected in parallel, one end of the parallel connection is connected to one end of tripping coil KA, diode VD1 and diode VD2 The middle node of diode VD3 and diode VD4 is connected to power supply L2, the middle node of diode VD5 and diode VD6 is connected to power supply L3, and the middle node of diode VD7 and diode VD8 is connected to power supply N , The anode of the diode VD8 is connected to the cathode of the secondary thyristor VT2. The rectifier circuit can also use a bridge rectifier device to rectify the power circuit. In this embodiment, the diode VD7 and the diode VD8 may not be provided, and only three-way full-wave rectification is used.

As shown in Figures 3 and 5, the power supply circuit also includes a surge absorbing circuit; the surge absorbing circuit includes a varistor RV1, a varistor RV2, a varistor RV3, a varistor RV4, and a varistor RV5 And the varistor RV6, the varistor RV1 is connected between the L1 phase of the power supply and the N phase of the power supply, the varistor RV2 is connected between the L2 phase of the power supply and the N phase of the power supply, and the varistor RV3 is connected between the L3 phase of the power supply and the N phase of the power supply Between the phases, the varistor RV4 is connected between the power supply L1 phase and the power supply L2 phase, the varistor RV5 is connected between the power supply L2 phase and the power supply L1 phase, and the varistor RV6 is connected between the power supply L1 phase and the power supply L3 phase between. The surge absorbing circuit absorbs and protects the surge voltage between each phase and each line respectively. The surge absorbing circuit can also use a TVS tube or a resistance-capacitance module or other surge absorbing modules to protect the thyristor.

The above content is a further detailed description of the utility model in combination with specific preferred embodiments, and it cannot be assumed that the specific implementation of the utility model is only limited to these descriptions. For a person of ordinary skill in the technical field to which the utility model belongs, without departing from the concept of the utility model, some simple deduction or substitutions can also be made, which should be regarded as belonging to the protection scope of the utility model.

Claims (10)

1. A residual current operated circuit breaker with overcurrent protection, comprising a tripping coil KA, a control circuit, a zero-sequence transformer TA, a power supply circuit and a signal acquisition and processing circuit, characterized in that: The input terminals of the power supply circuit are respectively connected with the power supply L1 phase, the power supply L2 phase, the power supply L3 phase and the power supply N phase for taking power, and the output terminals of the power supply circuit are connected with the two ends of the tripping coil KA to form a tripping circuit; The input end of the signal acquisition processing circuit is connected to the two ends of the secondary loop lead of the zero sequence transformer TA, the output end of the signal acquisition processing circuit is connected to the control circuit, and the collected signal is fed back to the control circuit; It also includes a step-down circuit, the input end of the step-down circuit is connected to one end of the tripping coil KA, and the output end of the step-down circuit is connected to the control circuit to provide working power for the control circuit; The control circuit includes a primary thyristor VT1 and a secondary thyristor VT2, the primary thyristor VT1 and the secondary thyristor VT2 are connected in series on the tripping loop formed by the tripping coil KA and the power supply circuit, and the step-down The output terminal of the circuit is connected to the G pole of the first-level thyristor VT1 to trigger and control the first-level thyristor VT1, and the control circuit passes the G pole of the second-level thyristor VT2 to the second-level SCR VT2 triggers the control. 2. The residual current operated circuit breaker with overcurrent protection according to claim 1, characterized in that: the step-down circuit includes a resistor R5, a diode VD5, and a resistor R4; one end of the resistor R5 and one end of the tripping coil KA The other end is connected to the control circuit, the positive pole of the diode VD5 is connected to the other end of the resistor R5, the negative pole of the diode VD5 is connected to the G pole of the primary thyristor VT1 after passing through the resistor R4; the primary thyristor VT1 and the secondary The thyristor VT2 is connected in series, the positive pole of the primary thyristor VT1 is connected to one end of the tripping coil KA connected to the resistor R5, the negative pole of the primary thyristor VT1 is connected to the positive pole of the secondary thyristor VT2, and the secondary thyristor VT2 is connected to the positive pole of the secondary thyristor. The negative pole of the silicon controlled silicon VT2 is connected with the output terminal of the power supply circuit. 3. The residual current operated circuit breaker with overcurrent protection according to claim 2, wherein the step-down circuit further includes a capacitor C5 and a varistor RV4, one end of the capacitor C5 is connected to the other end of the resistor R5 , the other end is grounded, and the varistor RV4 is connected in parallel at both ends of the series-connected primary thyristor VT1 and secondary thyristor VT2. 4. The residual current operated circuit breaker with overcurrent protection according to claim 2 or 3, characterized in that: the control circuit also includes a control chip, the other end of the resistor R5 is connected to the control chip to supply power for the control chip, two The G pole of the level thyristor VT2 is connected to the seventh pin of the control chip. 5. The residual current operated circuit breaker with overcurrent protection according to claim 1, characterized in that: the power supply circuit includes a rectification circuit; the rectification circuit includes a diode VD1, a diode VD2, a diode VD3 and a diode VD4, and the diode The anodes of VD1, diode VD2 and diode VD3 are respectively connected to the power supply L1 phase, power supply L2 phase and power supply L3, the cathodes of diode VD1, diode VD2 and diode VD3 are connected to one end of the tripping coil KA, the anode of diode VD4 is connected to the secondary The cathode of the thyristor VT2 is connected, and the cathode of the diode VD4 is connected with the power supply N. 6. The residual current operated circuit breaker with overcurrent protection according to claim 5, characterized in that: the power supply circuit includes a surge absorbing circuit; the surge absorbing circuit includes a varistor RV1, a varistor RV2 And varistor RV3, varistor RV1 is connected between power supply L1 phase and power supply N phase, varistor RV2 is connected between power supply L2 phase and power supply N phase, varistor RV3 is connected between power supply L3 phase and power supply N phase Between phases. 7. The residual current operated circuit breaker with overcurrent protection according to claim 1, characterized in that: the power supply circuit includes a rectifier circuit; the rectifier circuit includes a diode VD1, a diode VD2, a diode VD3, a diode VD4, a diode VD5, diode VD6, diode VD7, diode VD8, diode VD1 and diode VD2, diode VD3 and diode VD4, diode VD5 and diode VD6, diode VD7 and diode VD8 are respectively connected in series and connected in parallel. One end is connected, the middle node of diode VD1 and diode VD2 is connected to power supply L1, the middle node of diode VD3 and diode VD4 is connected to power supply L2, the middle node of diode VD5 and diode VD6 is connected to power supply L3, diode VD7 is connected to diode VD8 The middle node of the diode VD8 is connected to the power supply N, and the anode of the diode VD8 is connected to the cathode of the secondary thyristor VT2. 8. The residual current operated circuit breaker with overcurrent protection according to claim 7, characterized in that: the power supply circuit includes a surge absorbing circuit; the surge absorbing circuit includes a varistor RV1, a varistor RV2 , varistor RV3, varistor RV4, varistor RV5 and varistor RV6, varistor RV1 is connected between the power supply L1 phase and the power supply N phase, and the varistor RV2 is connected between the power supply L2 phase and the power supply N phase Between, the varistor RV3 is connected between the L3 phase of the power supply and the N phase of the power supply, the varistor RV4 is connected between the L1 phase of the power supply and the L2 phase of the power supply, and the varistor RV5 is connected between the L2 phase of the power supply and the L1 phase of the power supply , The piezoresistor RV6 is connected between the power L1 phase and the power L3 phase. 9. The residual current operated circuit breaker with overcurrent protection according to claim 4, characterized in that: the signal acquisition and processing circuit also includes a bidirectional diode D1, a debugging resistor R1, a resistor R2, a resistor R3 and a capacitor C1; The power L1 phase, power L2 phase, power L3 phase and power N phase wires all pass through the zero-sequence transformer TA, and the two ends of the secondary circuit lead of the zero-sequence transformer TA are respectively connected to the first pin and the second pin of the control chip. The two pins are connected, the debugging resistor R1, the bidirectional diode D1, and the capacitor C1 are sequentially connected in parallel at both ends of the secondary circuit lead, one end of the resistor R2 is connected to one end of the capacitor C1, and the other end is connected to one end of the bidirectional diode D1; the resistor R3 One end is connected to the other end of the capacitor C1, and the other end is connected to the other end of the bidirectional diode D1; it also includes capacitor C2, capacitor C3, and capacitor C4, and one end of the capacitor C2 is respectively connected to the fourth pin and the fifth pin of the control chip , the other end is grounded; one end of capacitor C3 is connected to the sixth pin of the control chip, the other end is connected to the third pin of the control chip, one end of capacitor C4 is connected to the seventh pin of the control chip, and the other end is connected to the control chip The third pin of the capacitor C4 is connected to the control circuit. 10. The residual current operated circuit breaker with overcurrent protection according to claim 1, characterized in that it also includes a test circuit, the test circuit includes a normally open test switch S1 and a resistor R6, and the normally open test switch S1 and resistor R6 are connected in series Form a loop and pass through the zero sequence transformer TA.