CN205846698U - Earth leakage circuit breaker with overvoltage protection and undervoltage protection - Google Patents

Abstract

The utility model discloses a leakage circuit breaker with overvoltage protection and undervoltage protection. One end of the output end of the zero-sequence current transformer is connected to the negative pole of the output end of the rectifier bridge stack, and the other end is connected to the positive pole of the fourth diode. The negative pole of the pole tube is connected to one end of the fifth resistor, and the other end of the fifth resistor is connected to the control pole or grid of the first semiconductor switching element; the anode of the first conductor switching element is connected to the positive pole of the output terminal of the rectifier bridge stack, and the first semiconductor The cathode of the switching element is connected to the negative pole of the output terminal of the rectifier bridge stack; the two ends of the second capacitor are respectively connected to the cathode or source of the first semiconductor switching element and the control pole or delete; the second diode is connected in parallel with the fourth resistor, and the corresponding The parallel terminal of the anode of the second diode is connected to the cathode of the first semiconductor switching element. The utility model can not only cut off the power supply to protect personal safety when electric leakage occurs in the line, but also can cut off the power supply voltage when the voltage is overvoltage or undervoltage, so as to avoid accidents.

Description

Earth leakage circuit breaker with overvoltage protection and undervoltage protection

technical field

The utility model relates to a leakage circuit breaker, in particular to a leakage circuit breaker with overvoltage protection function and undervoltage protection function.

Background technique

Leakage circuit breakers (or leakage switches) are commonly used low-voltage power distribution switching devices to protect personal safety.

Due to power supply network failure, equipment switching, phase error, line resonance and other reasons, power frequency overvoltage faults often occur on power supply lines, and power frequency overvoltage will overload or even burn electrical equipment.

On the other hand, due to the load problem or failure of the power supply system itself, the power supply voltage may drop. When the power supply voltage drops below 80% of the rated voltage, the motor speed will drop significantly, so that it will be forced to stop, causing the motor to stop due to blockage. Burned instead. At the same time, the low power supply voltage will also cause the release of the switch contacts of low-voltage electrical appliances, so that the control circuit cannot work normally, resulting in personal accidents and damage to mechanical equipment.

Therefore, if the power supply is cut off when the overvoltage or undervoltage reaches a certain limit, the safety of power electronic equipment and personal safety can be protected, accidents can be avoided, and equipment reliability can be improved.

General leakage circuit breakers do not have overvoltage or undervoltage protection functions. Existing leakage circuit breakers with overvoltage/undervoltage protection functions or components with overvoltage/undervoltage protection functions generally use voltage comparison circuits based on operational amplifiers. The voltage is detected, but this circuit has the following disadvantages: it is susceptible to interference, and anti-interference design needs to be added; DC power supply needs to be configured; components with voltage/undervoltage protection functions need to increase the installation space, resulting in a product that is larger than ordinary leakage circuit breakers Much more; production costs are higher.

Utility model content

In order to overcome the above-mentioned shortcomings and deficiencies of the prior art, the purpose of this utility model is to provide a leakage circuit breaker with overvoltage and undervoltage protection functions, which not only has leakage protection functions, but also has overvoltage and undervoltage protection functions. The safety and reliability are much higher than the leakage circuit breaker in the prior art, and the leakage circuit breaker with overvoltage and undervoltage protection functions of the utility model is equivalent to the volume of the existing common leakage circuit breaker.

The purpose of this utility model is achieved through the following technical solutions:

A leakage circuit breaker with overvoltage protection and undervoltage protection, comprising a first semiconductor switching element, a second semiconductor switching element, a first voltage non-linear element, a second voltage non-linear element, a first diode, a first resistor, The second resistor, the first capacitor, the relay, the zero-sequence current transformer and the rectifier bridge; Copper wires, the two copper wires are connected to the load after passing through the zero-sequence current transformer; the coil of the relay is connected in series with the input end of the rectifier bridge stack, and after the series connection, the two ends are connected to the two terminals of the output end of the circuit breaker;

One end of the output end of the zero-sequence current transformer is connected to the negative pole of the output end of the rectifier bridge stack, the other end is connected to the positive pole of the fourth diode, the negative pole of the fourth diode is connected to one end of the fifth resistor, and the other end of the fifth resistor It is connected to the control pole or gate of the first semiconductor switching element; the anode of the first conductor switching element is connected to the positive pole of the output terminal of the rectifier bridge stack, and the cathode of the first semiconductor switching element is connected to the negative pole of the output terminal of the rectifier bridge stack; the two capacitors of the second capacitor Terminals are respectively connected with the cathode or source of the first semiconductor switch element and the control pole or delete; the second diode is connected in parallel with the fourth resistor, and the parallel terminal corresponding to the anode of the second diode is connected with the first semiconductor switch element. The cathode is connected, and the parallel terminal corresponding to the negative pole of the second diode is connected to the negative pole of the fourth diode; after the second voltage nonlinear element is connected in series with the second resistor, one end is connected to the positive pole of the output end of the rectifier bridge stack, and the other end is connected to the positive pole of the output end of the rectifier bridge stack. The negative pole of the fourth diode is connected; the cathode or source of the second semiconductor switching element is connected with the negative pole of the output terminal of the rectifier bridge stack, the anode or drain of the second semiconductor switching element is connected with one end of the third resistor, and the third resistor The other end is connected to the anode of the output end of the rectifier bridge stack; the anode of the third diode is connected to the anode or drain of the second semiconductor switching element, and the cathode of the third diode is connected to the cathode of the fourth diode; After a voltage non-linear element is connected in series with the first resistor, one end is connected to the positive pole of the output end of the rectifier bridge stack, and the other end is connected to the control pole or gate of the second semiconductor switching element; the first diode is connected in parallel with the first capacitor, corresponding to The parallel terminal of the negative pole of the first diode is connected with the control pole or the gate of the second semiconductor switch element, and the parallel terminal corresponding to the positive pole of the first diode is connected with the negative pole of the output terminal of the rectifier bridge stack.

In order to further realize the purpose of the utility model, preferably, the leakage circuit breaker also includes a test resistor and a test button; after the test resistor is connected in series with the test button, one end is directly connected to an output end of the circuit breaker, and the connecting line of the other end is connected to the circuit breaker. The other output terminal is connected.

Preferably, both the first semiconductor switch element and the second semiconductor switch element are unidirectional thyristors, bidirectional thyristors or field effect transistors. The first semiconductor switch element is preferably a one-way thyristor (thyristor); the second semiconductor switch element can be a one-way thyristor, or a low-voltage low-power field effect transistor.

Preferably, the first voltage nonlinear element and the second voltage nonlinear element are varistors or semiconductor transient voltage suppression diodes.

Preferably, both the first semiconductor switch element and the second semiconductor switch element are unidirectional thyristors, which are respectively the first unidirectional thyristor and the second unidirectional thyristor; the first unidirectional thyristor is resistant to The voltage index is greater than twice the peak value of the power supply voltage, and the second unidirectional thyristor selects a thyristor with a withstand voltage index greater than 25V; the resistance value of the third resistor is 10 times the resistance value of the fourth resistor; the first diode and Both the second diodes use 2.4V Zener diodes; the first resistor and the second resistor are current-limiting resistors, and the resistance value is 100K-500K low-power resistors; the fifth resistor is used as a current-limiting resistor, and a 330-ohm resistor is used; Both the first capacitor and the second capacitor are 0.1 microfarad capacitors.

Preferably, the first unidirectional thyristor is a thyristor with a withstand voltage of 800V.

Preferably, the first thyristor is used as the first semiconductor switching element, and the N-channel field effect transistor is used as the second semiconductor switching element; the first varistor and the second varistor are used as the first voltage nonlinear device and the second varistor respectively. Two-voltage nonlinear device.

Preferably, the N-channel field effect transistor selects a field effect transistor with a trigger voltage parameter V _T of 1V, a withstand voltage of 30V, and a maximum conduction current of 1A; the varistor voltage of the first varistor and the second varistor The parameters are 242V and 382V respectively; the resistance value of the third resistor is 10 times the resistance value of the fourth resistor; both the first diode and the second diode are 2.4V Zener diodes; the first resistor and the second resistor are The current-limiting resistor is a low-power resistor with a resistance value of 100k-500k; the fifth resistor is used as a current-limiting resistor, and a 330-ohm resistor is used; both the first capacitor and the second capacitor are 0.1 microfarad capacitors.

Preferably, the first semiconductor switch element and the second semiconductor switch element are respectively selected from unidirectional thyristors, which are respectively the first unidirectional thyristor and the second unidirectional thyristor; the first voltage nonlinear The element and the second voltage non-linear element are a first semiconductor TVS diode and a second semiconductor TVS diode.

Preferably, conduction voltage parameters of the first semiconductor TVS diode and the second semiconductor TVS diode are 240V and 380V respectively.

The trip linkage mechanism T of the utility model works through the pull-in action of the electromagnetic relay K, and when the relay K is energized and pull-in, the mechanical tripping device is pushed to disconnect the circuit breaker SW.

The leakage protection trigger circuit includes: zero-sequence current transformer L, rectifier bridge stack Z, first semiconductor switching element, fourth diode D4, fifth resistor R5, second diode D2, second capacitor C2, relay K and the trip linkage mechanism T connected with the relay K. When leakage occurs in the circuit connected to the leakage circuit breaker with overvoltage and undervoltage protection of the utility model, the total current passing through the zero-sequence current transformer L is not zero, and the output circuit of the zero-sequence current transformer L has current When the current reaches a predetermined current, the first semiconductor switching element is triggered to conduct, so that the relay K connected to it is energized, and the trip linkage mechanism T is triggered to open the circuit breaker. In order to detect whether the leakage protection circuit is working normally, a leakage test circuit is also set up, including a test resistor RT and a test button SK _. When the leakage circuit breaker with overvoltage and undervoltage protection of the utility model is working normally, press the test button SK , the test resistor R _T is connected to the power supply, and the resistor has a current flowing through it, so that the output terminal circuit of the zero-sequence current transformer L has a current flowing through it, and the current triggers the conduction of the first semiconductor switching element, thereby making the connected relay When energized, the trip linkage mechanism T is triggered to disconnect the circuit breaker.

The undervoltage protection trigger circuit includes: a bridge rectifier stack Z, a first semiconductor switching element, a first voltage non-linear element, a first capacitor C1, a first resistor R1, a third resistor R3, a fourth resistor R4, and a fifth resistor R5, The first diode D1, the second diode D2, the third diode D3, the second semiconductor switching element, the relay K and the trip linkage mechanism T connected with the relay K. When the power supply voltage connected to the leakage circuit breaker of the present utility model is lower than the designed lower limit voltage, the first voltage nonlinear element is not conducting, the second semiconductor switching element is not conducting, the third resistor R3, the third diode D3 and the fourth resistor R4 form a series circuit, the series circuit is connected in parallel to the output terminal of the rectifier bridge stack Z, the voltage division on the fourth resistor R4 triggers the conduction of the first semiconductor switching element, so that the relay K connected to it is energized and triggers The trip linkage mechanism disconnects the circuit breaker; when the power supply voltage connected to the leakage circuit breaker of the present invention is higher than the designed lower limit voltage, the first voltage nonlinear element is turned on, and the conduction current triggers the second semiconductor switching element, After the second semiconductor switch element is turned on, the voltage division ratio of the series circuit formed by the third resistor R3, the third diode D3 and the fourth resistor R4 is changed, and the voltage division on the fourth resistor R4 is greatly reduced, so that the first semiconductor switch The element is in the cut-off state, and the trip linkage mechanism T does not act.

The overvoltage protection trigger circuit includes: a rectifier bridge stack Z, a first semiconductor switching element, a second voltage non-linear element, a second resistor R2, a fourth resistor R4, a fifth resistor R5, a second diode D2 (zener diode ), the second capacitor C2, the relay K and the trip linkage mechanism T connected to the relay K. When the power supply voltage connected to the leakage circuit breaker of the utility model exceeds the design upper limit voltage, the second voltage non-linear element is turned on, and the divided voltage of the conduction current on the fourth resistor R4 triggers the first semiconductor switch element to be turned on, so that The relay K connected to it is energized, triggering the trip linkage mechanism T to disconnect the circuit breaker.

Compared with the prior art, the utility model has the following advantages and beneficial effects:

1) The leakage circuit breaker with overvoltage and undervoltage protection functions of the utility model can not only disconnect the power supply to protect personal safety when the line leakage occurs, but also disconnect it when the power supply voltage is overvoltage or undervoltage to avoid accidents. ACCIDENT;

2) The leakage circuit breaker with overvoltage and undervoltage protection functions of the utility model does not need external overvoltage and undervoltage protection components, which saves installation space, and the product volume is equivalent to that of existing ordinary leakage circuit breakers;

3) The leakage circuit breaker with overvoltage and undervoltage protection functions of the utility model adopts voltage nonlinear elements to realize overvoltage and undervoltage detection and control, and has higher reliability and lower manufacturing cost than the overvoltage and undervoltage protectors of the prior art. Low.

Description of drawings

Fig. 1 is a schematic diagram of circuit connection of an earth leakage circuit breaker with overvoltage and undervoltage protection functions according to Embodiment 1 of the present utility model.

Fig. 2 is a schematic diagram of the circuit connection of the leakage circuit breaker with overvoltage and undervoltage protection functions according to the second embodiment of the present invention.

Fig. 3 is a schematic diagram of circuit connection of the leakage circuit breaker with overvoltage and undervoltage protection functions according to Embodiment 3 of the present invention.

The figure shows: first thyristor SCR1, second thyristor SCR2, N-channel field effect transistor NMOS, first varistor R _V 1, second varistor R _V 2, first semiconductor transient suppression Diode TVS1, second semiconductor transient suppressor diode TVS2, first diode D1, second diode D2, third diode D3, fourth diode D4, first resistor R1, second resistor R2, The third resistor R3, the fourth resistor R4, the fifth resistor R5, the first capacitor C1, the second capacitor C2, the relay K, the trip linkage mechanism T, the zero-sequence current transformer L, the rectifier bridge stack Z, and the circuit breaker SW. Wherein the first diode D1 and the second diode D2 are zener diodes, a test resistor _RT and a test button SK.

detailed description

In order to better understand the utility model, the utility model will be further described below in conjunction with the accompanying drawings and examples, but the implementation of the utility model is not limited thereto.

Example 1

In this embodiment, the first thyristor SCR1 and the second thyristor SCR2 are used as the first semiconductor switching element and the second semiconductor switching element; the first varistor R _V 1 and the second varistor R _V 2 are respectively used as A first voltage nonlinear device and a second voltage nonlinear device.

As shown in Figure 1, a leakage circuit breaker with overvoltage protection and undervoltage protection includes a first thyristor SCR1, a second thyristor SCR2, a first varistor R _V 1, a second varistor R _V 2, first diode D1, second diode D2, third diode D3, fourth diode D4, first resistor R1, second resistor R2, third resistor R3, fourth resistor R4, fifth resistor R5, first capacitor C1, second capacitor C2, relay K, trip linkage mechanism T, zero-sequence current transformer L, rectifier bridge stack Z, circuit breaker SW, test resistor R _T , test button SK .

The relay K is connected to the circuit breaker SW through the trip linkage mechanism T, the input terminal of the circuit breaker SW is connected to the power supply, and the output terminal of the circuit breaker SW is connected to two copper wires, after the two copper wires pass through the zero-sequence current transformer L Connect the load; the relay K controls the circuit breaker SW through the trip linkage mechanism T, and when the coil of the relay K is energized, the trip linkage mechanism T is pushed to disconnect the circuit breaker SW; the end of the test resistor R _T is connected in series with the test button SK It is directly connected to one output terminal of the circuit breaker SW, and the other terminal is connected to the other output terminal of the circuit breaker SW passing through the zero-sequence current transformer L; the coil of the relay K is connected in series with the input terminal of the rectifier bridge stack Z, and after series connection Both ends are connected with two terminals of the output end of the circuit breaker SW, because whether the two connecting lines pass through the zero-sequence current transformer L has no influence on the effect of the circuit of the utility model, for the convenience of connection, the present embodiment connects the two connection points Correspondingly connected to both ends of the above _- mentioned test resistor RT and the test button SK series circuit.

One end of the output terminal of the zero-sequence current transformer L is connected to the negative pole of the output terminal of the rectifier bridge stack Z, the other end is connected to the positive pole of the fourth diode D4, the negative pole of the fourth diode D4 is connected to one end of the fifth resistor R5, and the fifth resistor The other end of R5 is connected to the control electrode of the first thyristor SCR1. The anode of the first thyristor SCR1 is connected to the positive pole of the output end of the rectifier bridge stack Z, and the cathode of the first thyristor SCR1 is connected to the negative pole of the output end of the rectifier bridge stack Z. Both ends of the second capacitor C2 are respectively connected to the cathode and the control electrode of the first thyristor SCR1; the second diode D2 is connected in parallel with the fourth resistor R4, and the parallel terminal corresponding to the anode of the second diode D2 is connected to the first The cathode of the thyristor SCR1 is connected, and the parallel terminal corresponding to the cathode of the second diode D2 is connected to the cathode of the fourth diode D4; the second varistor R _V 2 is connected in series with the second resistor R2, and one end is connected to the rectifier bridge The output end of the stack Z is connected to the positive pole, and the other end is connected to the negative pole of the fourth diode D4; the cathode of the second thyristor SCR2 is connected to the negative pole of the output end of the rectifier bridge stack Z, and the anode of the second thyristor SCR2 is connected to the third thyristor SCR2 One end of the resistor R3 is connected, and the other end of the third resistor R3 is connected to the anode of the output terminal of the rectifier bridge stack Z; the anode of the third diode D3 is connected to the anode of the second thyristor SCR2, and the anode of the third diode D3 The negative pole is connected to the negative pole of the fourth diode D4; the first varistor R _V 1 is connected in series with the first resistor R1, and one end is connected to the positive pole of the output end of the rectifier bridge stack Z, and the other end is connected to the control of the second thyristor SCR2 The first diode D1 is connected in parallel with the first capacitor C1, the parallel terminal corresponding to the negative pole of the first diode D1 is connected to the control pole of the second thyristor SCR2, and the parallel terminal corresponding to the positive pole of the first diode D1 It is connected to the negative pole of the output end of the rectifier bridge stack Z.

The leakage protection trigger circuit includes: zero-sequence current transformer L, rectifier bridge stack Z, first thyristor SCR1, fourth diode D4, fifth resistor R5, second diode D2, second capacitor C2, relay K, trip linkage mechanism T and circuit breaker SW. When leakage occurs in the circuit connected to the leakage circuit breaker with overvoltage and undervoltage protection of the utility model, the total current passing through the zero-sequence current transformer L is not zero, and the output circuit of the zero-sequence current transformer L has current The current is rectified by the fourth diode, and then flows to the control electrode of the first thyristor SCR1 through the fifth resistor R5. When the current reaches the predetermined leakage circuit breaker specification current, the first thyristor SCR1 is triggered to conduct. The output end of rectifier bridge stack Z is short-circuited, causing the relay K connected in series with the input end of rectifier bridge stack Z to be energized, triggering the trip linkage mechanism T to turn off the circuit breaker SW. During the above working process, the fourth diode rectifies the loop current at the output terminal of the zero-sequence current transformer L, and triggers the first thyristor SCR1 after the current is limited by the fifth resistor R5; the second diode D2 is used for voltage regulation The diode is used to protect the first thyristor SCR1 from being damaged by the high input voltage of the first thyristor SCR1; the second capacitor C2 is used to absorb interference signals and prevent the first thyristor SCR1 from false triggering.

In order to verify whether the leakage protection circuit is working normally, a leakage test circuit is also set up, including the test resistor _RT and the test button SK; when the leakage circuit breaker with overvoltage and undervoltage protection of the utility model is working normally, press the test button SK , there is current flowing through the test resistance R _T , because the current path passes through the zero-sequence current transformer in one direction, so that the total current passing through the zero-sequence current transformer L is not zero, and the output terminal circuit of the zero-sequence current transformer L A current flows, and the current triggers the conduction of the first thyristor SCR1, thereby energizing the relay K connected to it, and triggering the trip linkage mechanism T to turn off the circuit breaker SW.

The undervoltage protection trigger circuit includes: rectifier bridge stack Z, first thyristor SCR1, first varistor R _V 1, first resistor R1, third resistor R3, fourth resistor R4, first capacitor C1, fifth Resistor R5, first diode D1, second diode D2, third diode D3, second thyristor SCR2, relay K and trip linkage mechanism T connected to relay K, circuit breaker SW.

The working principle of undervoltage protection is: when the power supply voltage connected to the leakage circuit breaker of the utility model is lower than the designed lower limit voltage, the first piezoresistor R _V1 is not conducting, the second thyristor SCR2 is not conducting, and the second thyristor SCR2 is not conducting. The three resistors R3, the third diode D3 and the fourth resistor R4 are connected in series and connected in parallel to the output end of the rectifier bridge stack Z, and the voltage division on the fourth resistor R4 triggers the conduction of the first thyristor SCR1, so that the rectifier bridge stack Z The output terminal of the rectifier bridge stack Z is short-circuited, causing the relay K connected in series with the input terminal of the rectifier bridge stack Z to be energized, triggering the trip linkage mechanism T to disconnect the circuit breaker SW, that is, when the power supply voltage is too low (undervoltage), the circuit breaker Tripping, thus playing the role of undervoltage protection. When the power supply voltage connected to the leakage circuit breaker of the utility model is higher than the designed lower limit voltage, the first piezoresistor R _V1 is turned on, and the conduction current triggers the second thyristor SCR2, and the second thyristor SCR2 conducts After the connection, the divided voltage on the fourth resistor R4 is reduced, so that the first thyristor SCR1 is in the cut-off state, and the trip linkage mechanism T does not operate. In the above working process, the first resistor R1 is used to limit the conduction current of the first varistor R _V1 ; the first diode D1 is a Zener diode, which is used to protect the second thyristor SCR2 and avoid inputting the second thyristor. The trigger voltage of the silicon controlled silicon SCR2 is too high to damage it; the first capacitor C1 is used to absorb interference signals to prevent the second silicon controlled silicon SCR2 from false triggering. The second diode D2 is a voltage stabilizing diode, which is used to protect the first thyristor SCR1 and prevent the first thyristor SCR1 from being damaged by an excessively high input voltage.

The overvoltage protection trigger circuit includes: rectifier bridge stack Z, first thyristor SCR1, second varistor R _V2 , second resistor R2, fourth resistor R4, fifth resistor R5, second diode D2, The second capacitor C2, the relay K and the trip linkage mechanism T connected with the relay K.

The working principle of the overvoltage protection is: when the power supply voltage connected to the leakage circuit breaker of the utility model exceeds the design upper limit voltage, the second piezoresistor R _V 2 is turned on, although the second thyristor SCR2 is also turned on at this time, but Due to the isolation effect of the third diode D3, the divided voltage of the conduction current of the second varistor R _V2 on the fourth resistor R4 triggers the conduction of the first thyristor SCR1, so that the relay connected to it K is electrified and acts, triggering the trip linkage mechanism T to turn off the circuit breaker SW. That is, when the power supply voltage is too high (overvoltage), the circuit breaker trips, thus playing the role of overvoltage protection. The second resistor R2 is a current-limiting resistor, which limits the conduction current of the second varistor R _V 2 when the voltage is too high to protect the first thyristor SCR1; the second capacitor C2 is used to absorb interference signals to prevent the first thyristor SCR1 triggers by mistake.

The varistor voltage parameters of the first varistor R _V 1 and the second varistor R _V 2 adopted in this embodiment are 235V and 375V respectively.

In order to verify the working status of the leakage circuit breaker with overvoltage and undervoltage protection functions of the utility model, the power supply terminal of the leakage circuit breaker with overvoltage and undervoltage protection functions of the utility model is connected to the power frequency power supply with adjustable voltage.

When the power frequency adjustable power supply voltage is adjusted below 165VAC, the leakage current of the first varistor R _V 1 is very small (non-conductive) at this voltage, the second thyristor SCR2 is non-conductive, and the fourth resistor The divided voltage on R4 is greater than the trigger voltage of the first thyristor SCR1, so that the first thyristor SCR1 is turned on. After the first thyristor SCR1 is turned on, it is equivalent to short-circuiting the Z output terminal of the rectifier bridge stack, and the rectifier bridge stack The K coil of the relay connected in series at the Z input terminal is energized and acts, triggering the trip linkage mechanism T to turn off the circuit breaker SW.

When the power frequency adjustable power supply voltage is adjusted to the range of 165-265VAC, the leakage current of the first varistor R _V 1 is relatively large (conduction), which triggers the conduction of the second thyristor SCR2, and the second thyristor SCR2 conducts Finally, the divided voltage on the fourth resistor R4 is reduced, so that the first thyristor SCR1 is in the cut-off state, and the trip linkage mechanism T does not act. In this power supply voltage range (165～265VAC), the utility model has overvoltage protection and The leakage circuit breaker for undervoltage protection is in normal working condition.

When the power frequency adjustable power supply voltage is adjusted above 265VAC, the first varistor R _V 1 is turned on, triggering the second thyristor SCR2 to be turned on, and at this time the second varistor R _V 2 is also turned on, and There is a third diode D3 for isolation, and the divided voltage on the fourth resistor R4 is enough to trigger the first thyristor SCR1. After the first thyristor SCR1 is turned on, it is equivalent to short-circuiting the output terminal of the rectifier bridge stack Z, and the rectifier bridge stack The K coil of the relay connected in series at the Z input terminal is energized and acts, triggering the trip linkage mechanism T to turn off the circuit breaker SW.

In this embodiment, the withstand voltage index of the first thyristor SCR1 should be greater than 2.0 times the peak value of the power supply voltage. This embodiment adopts a thyristor with a withstand voltage of 800V; the second thyristor SCR2 selects a thyristor with a withstand voltage index greater than 25V ; The resistance value of the third resistor R3 is 10 times the resistance value of the fourth resistor R4; the first diode D1 and the second diode D2 are both 2.4V Zener diodes; the third diode D3 and the fourth two The pole tube D4 has no special requirements. The first resistor R2 and the second resistor R2 are current-limiting resistors, and low-power resistors with a resistance value of 100k to 500k can be used; the fifth resistor R5 is used as a current-limiting resistor, but its resistance value and leakage operating current Relatedly, in this embodiment, a 330 ohm resistor is used to adjust the leakage operating current to 30 mA; both the first capacitor C1 and the second capacitor C2 are 0.1 microfarad capacitors. Both the first thyristor SCR1 and the second thyristor SCR2 are unidirectional thyristors.

Example 2

In Embodiment 2, the first thyristor SCR1 is used as the first semiconductor switching element, and the N-channel field effect transistor (NMOS) is used as the second semiconductor switching element; the first piezoresistor R _V1 , the second piezoresistor R _V 2 as the first voltage nonlinear device and the second voltage nonlinear device respectively.

As shown in Figure 2, a leakage circuit breaker with overvoltage protection and undervoltage protection, compared with Embodiment 1, this embodiment uses an N-channel field effect transistor (NMOS) to replace the second thyristor in Embodiment 1 SCR2, the connection method of each component is the same as that of embodiment 1, and the working principle is the same as that of embodiment 1. The source S, drain D, and gate G of the N-channel field effect transistor NMOS in this embodiment correspond to the cathode, anode, and control electrode of the second thyristor SCR2 in Embodiment 1, respectively.

The varistor voltage parameters of the first varistor R _V 1 and the second varistor R _V 2 used in this embodiment are 242V and 382V respectively.

In order to verify the working status of the leakage circuit breaker with overvoltage and undervoltage protection functions of the utility model, the power supply terminal of the leakage circuit breaker with overvoltage and undervoltage protection functions of the utility model is connected to the power frequency power supply with adjustable voltage.

When the power frequency adjustable power supply voltage is adjusted below 170VAC, the leakage current of the first varistor RV1 is very small (non-conductive) under this voltage, the field effect transistor NMOS is non-conductive, and the branch on the fourth resistor R4 The voltage is greater than the trigger voltage of the first thyristor SCR1. After the first thyristor SCR1 is turned on, it is equivalent to short-circuiting the output end of the rectifier bridge stack Z, and the relay K coil connected in series with the input end of the rectifier bridge stack Z is energized and acts, triggering The trip linkage mechanism T opens the circuit breaker SW.

When the power frequency adjustable power supply voltage is adjusted to the range of 170-270VAC, the leakage current of the first piezoresistor R _V 1 is relatively large (turned on), which triggers the conduction of the field effect transistor NMOS, and after the field effect transistor NMOS is turned on, the second The voltage division on the four resistors R4 makes the first thyristor SCR1 in cut-off state, the trip linkage mechanism T does not act, and the leakage circuit breaker with over-voltage protection and under-voltage protection of the utility model is in normal working state.

When the power frequency adjustable power supply voltage is adjusted above 270VAC, although the first varistor R _V 1 is turned on at this time, the trigger field effect transistor NMOS is turned on, because the second varistor R _V 2 is also turned on at this time , and is isolated by the third diode D3, the divided voltage on the fourth resistor R4 is enough to trigger the first thyristor SCR1. The coil of the relay K connected in series with the input terminal of the bridge stack Z is energized, triggering the trip linkage mechanism T to turn off the circuit breaker SW.

Component parameter selection: In this embodiment, an N-channel field effect transistor NMOS is used to replace the second thyristor SCR2 in Embodiment 1. Since the N-channel field effect transistor NMOS withstands a very small voltage and current when the circuit is in operation, the trigger voltage is selected NMOS with parameter V _T =1V, withstanding voltage of 30V, and maximum conduction current of 1A; the selection of other component parameters is the same as that of Embodiment 1.

Example 3

In this embodiment, the first thyristor SCR1 is used as the semiconductor switching element 1, and the second thyristor SCR2 is used as the semiconductor switching element 2; the first semiconductor transient suppressor diode TVS1 and the second semiconductor transient suppressor diode TVS2 are respectively used as the voltage non-conductor Linear device 1 and voltage nonlinear device 2.

As shown in Figure 3, a leakage circuit breaker with overvoltage protection and undervoltage protection, compared with Embodiment 1, this embodiment uses the first semiconductor transient suppression diode TVS1 and the second semiconductor transient suppression diode TVS2 to replace The first varistor R _V 1 and the second varistor R _V 2 in the first embodiment are connected in the same way as in the first embodiment, and the working principle is the same as that in the first embodiment.

The turn-on voltage parameters of the first semiconductor transient suppressor diode TVS1 and the second semiconductor transient suppressor diode TVS2 used in this embodiment are 240V and 380V respectively, because the first semiconductor transient suppressor diode TVS1 and the second semiconductor transient suppressor diode TVS1 When the diode TVS2 is turned on, it only passes a small current (in the order of mA), so there is no need to consider other parameters except for the appropriate conduction voltage parameter. The selection of other component parameters in this embodiment is the same as that in Embodiment 1.

In order to verify the working status of the leakage circuit breaker with overvoltage and undervoltage protection functions of the utility model, the power supply terminal of the leakage circuit breaker with overvoltage and undervoltage protection functions of the utility model is connected to the power frequency power supply with adjustable voltage.

When the power frequency adjustable power supply voltage is adjusted below 170VAC, the leakage current of the first semiconductor transient suppression diode TVS1 is very small (non-conductive) at this voltage, the second thyristor SCR2 is non-conductive, and the fourth resistor The divided voltage on R4 is greater than the trigger voltage of the first thyristor SCR1. After the first thyristor SCR1 is turned on, it is equivalent to short-circuiting the output end of the rectifier bridge stack Z, and the relay K coil connected in series with the input end of the rectifier bridge stack Z is energized. And the action triggers the trip linkage mechanism T to open the circuit breaker SW.

When the power frequency adjustable power supply voltage is adjusted to the range of 170-270VAC, the leakage current of the first semiconductor transient suppression diode TVS1 is large (turned on), triggering the conduction of the second thyristor SCR2, and the second thyristor SCR2 is turned on Finally, the divided voltage on the fourth resistor R4 is reduced, so that the first thyristor SCR1 is in the cut-off state, the trip linkage mechanism T does not act, and the leakage circuit breaker with over-voltage protection and under-voltage protection of the utility model is in a normal working state .

When the power frequency adjustable power supply voltage is adjusted above 270VAC, although the first semiconductor transient suppression diode TVS1 is turned on at this time, triggering the second thyristor SCR2 to be turned on, because the second semiconductor transient suppression diode TVS2 is also turned on at this time. conduction, and is isolated by the third diode D3, the divided voltage on the fourth resistor R4 is enough to trigger the first thyristor SCR1, after the first thyristor SCR1 is turned on, it is equivalent to short-circuiting the output terminal of the rectifier bridge stack Z, The coil of the relay K connected in series with the input terminal of the rectifier bridge stack Z is energized, and the trip linkage mechanism T is triggered to turn off the circuit breaker SW.

The implementation of the utility model is not limited by the examples, and any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the utility model should be equivalent replacement methods , are all included within the protection scope of the present utility model.

Claims (10)

1. there is the RCCB of overvoltage protection and low-voltage protection, it is characterised in that include the first semiconductor switch unit Part, the second thyristor, the first non-linear to voltage element, the second non-linear to voltage element, the first diode, the first electricity Resistance, the second resistance, the first capacitor, relay, zero sequence current mutual inductor and rectifier bridge stack；Described relay is linked by dropout Mechanism is connected with disconnect switch, and the input of disconnect switch is connected with power supply, and the outfan of disconnect switch connects two copper cash, should Article two, copper cash connects load after zero sequence current mutual inductor；The coil of relay is connected with the input of rectifier bridge stack, string After connection, two ends are connected with two terminals of outfan of disconnect switch；

Described zero sequence current mutual inductor outfan one end is connected to rectifier bridge stack negative pole of output end, and the other end connects the 4th diode Positive pole, the negative pole of the 4th diode and the 5th resistance one end be connected, and the other end of the 5th resistance is first with the first semiconductor switch The control pole of part or grid are connected；The anode of the first conductor switch element is connected with rectifier bridge stack output head anode, and the first half lead The negative electrode of body switch element is connected with rectifier bridge stack negative pole of output end；Second capacitor two ends are first with the first semiconductor switch respectively The negative electrode of part or source electrode and control pole or delete and be connected；Second diode and the 4th resistor coupled in parallel, and corresponding second diode The parallel connected end of positive pole be connected with the negative electrode of the first thyristor, the parallel connected end of the negative pole of corresponding second diode and the The negative pole of four diodes connects；After second non-linear to voltage element and the second resistant series, one end is rectified with the output of rectifier bridge stack The most connected, the negative pole of the other end and the 4th diode connects；The negative electrode of the second thyristor or source electrode and rectifier bridge stack Negative pole of output end is connected, and anode or the drain electrode of the second thyristor are connected with one end of the 3rd resistance, the 3rd resistance The other end is connected with the output head anode of rectifier bridge stack；The positive pole of the 3rd diode and the anode of the second thyristor or Drain electrode is connected, and the negative pole of the 3rd diode and the negative pole of the 4th diode connect；First non-linear to voltage element and the first resistance After series connection, one end is connected with the output head anode of rectifier bridge stack, the control pole of the other end and the second thyristor or grid It is connected；First diode and the first capacitor are in parallel, the parallel connected end of corresponding first diode cathode and the second semiconductor switch unit The control pole of part or grid are connected, and the corresponding parallel connected end of the first diode cathode is connected with the negative pole of output end of rectifier bridge stack.

The RCCB with overvoltage protection and low-voltage protection the most according to claim 1, it is characterised in that institute State RCCB and also include test resistance and test button；Test resistance connect with test button after one end and disconnect switch One outfan is directly connected to, and the line of the other end is connected with another outfan of disconnect switch.

The RCCB with overvoltage protection and low-voltage protection the most according to claim 1, it is characterised in that Described first thyristor and the second thyristor are all one-way SCR, bidirectional triode thyristor or field effect Pipe.

The RCCB with overvoltage protection and low-voltage protection the most according to claim 1, it is characterised in that institute State the first non-linear to voltage element and the second non-linear to voltage element is varistor or quasiconductor transient voltage suppressor diode.

The RCCB with overvoltage protection and low-voltage protection the most according to claim 3, it is characterised in that institute State the first thyristor and the second thyristor all selects one-way SCR, the respectively first one-way SCR With the second one-way SCR；The first resistance to forcing up the targets of one-way SCR is more than 2 times of supply voltage peak value, and the second one-way SCR selects Take the resistance to forcing up the targets controllable silicon more than 25V；3rd resistance is 10 times of the resistance of the 4th resistance；First diode and second Diode all uses 2.4V Zener diode；First resistance and the second resistance are current-limiting resistance, and using resistance is that 100k 500k is low Power resistor；5th resistance, as current-limiting resistance, uses 330 ohmages；First capacitor and the second capacitor all use 0.1 Micro farad capacitor.

The RCCB with overvoltage protection and low-voltage protection the most according to claim 5, it is characterised in that institute State the first one-way SCR and use pressure 800V controllable silicon.

The RCCB with overvoltage protection and low-voltage protection the most according to claim 1, it is characterised in that adopt With the first controllable silicon as the first thyristor, N-channel field effect transistor is as the second thyristor；Use the One varistor and the second varistor are respectively as the first non-linear to voltage device and the second non-linear to voltage device.

The RCCB with overvoltage protection and low-voltage protection the most according to claim 7, it is characterised in that institute State N-channel field effect transistor and select trigger voltage parameter V_TFor 1V, pressure 30V, the field effect transistor of maximum conducting electric current 1A；Described The pressure sensitive voltage parameter of one varistor and the second varistor is respectively 242V and 382V；3rd resistance is the 4th resistance 10 times of resistance；First diode and the second diode all use 2.4V Zener diode；First resistance and the second resistance are Current-limiting resistance, using resistance is 100K 500K low-power resistance；5th resistance, as current-limiting resistance, uses 330 ohmages； First capacitor and the second capacitor all use 0.1 micro farad capacitor.

The RCCB with overvoltage protection and low-voltage protection the most according to claim 1, it is characterised in that institute State the first thyristor and one-way SCR the most all selected by the second thyristor, respectively first unidirectional can Control silicon and the second one-way SCR；Described first non-linear to voltage element and the second non-linear to voltage element were the first quasiconductor wink State suppression diode and the second quasiconductor Transient Suppression Diode.

The RCCB with overvoltage protection and low-voltage protection the most according to claim 9, it is characterised in that The conducting voltage parameter of described first quasiconductor Transient Suppression Diode and the second quasiconductor Transient Suppression Diode is respectively 240V and 380V.