CN114079264A - Residual current circuit breaker and control method thereof - Google Patents

Abstract

The invention provides a residual current circuit breaker and a control method thereof, wherein the residual current circuit breaker comprises a leakage current transformer, a first driving circuit, a second driving circuit, a release and a release power supply circuit; the first driving circuit and the second driving circuit are used for conducting a power supply circuit of the release; the first driving circuit includes: the device comprises a sampling circuit, a main processing unit, a first power supply and a first controllable silicon; the second driving circuit comprises an amplifying circuit and a second silicon controlled rectifier; the controllable silicon of the two driving circuits are connected in series in the power supply circuit of the release and are in parallel connection, so that the double leakage protection of the leakage circuit breaker is realized; on the basis, an exit switch is also arranged, and the exit switch can be flexibly controlled by combining with a corresponding control scheme. The advantages are that: the dual leakage protection is realized by utilizing the two driving circuits, the reliability of the leakage protection is improved, and under the condition of ensuring the reliability, the leakage protection has certain flexibility by setting the exit switch and the corresponding control scheme.

Description

Residual current circuit breaker and control method thereof

Technical Field

The invention relates to the field of low-voltage electrical appliances, in particular to a double-leakage-protection leakage circuit breaker and a control method thereof.

Background

Traditional earth leakage circuit breaker, earth leakage trip circuit comprise a plurality of components, do not have logic control, when the leakage current reaches certain threshold value, can directly drive the supply circuit of release and switch on, let the release action, realize earth leakage protection's function.

The intelligent leakage circuit breaker utilizes current sampling, the CPU carries out operation processing, and when the intelligent leakage circuit breaker accords with a tripping condition, a control signal is sent to the controlled silicon, so that a power supply circuit of the release is conducted, the release acts, and the leakage protection function is realized.

Because the two circuit breakers have different schemes for realizing the leakage protection function, the traditional leakage protector adopts a direct driving mode, so that the reliability is high; the intelligent residual-current circuit breaker adopts a logic control mode, so that the flexibility is high. At present, many intelligent residual current circuit breakers only adopt a more flexible control mode so as to achieve the purpose of intelligence, and the reliability is reduced.

Simultaneously, in order to solve the problem of taking the emergent power consumption of electric leakage, no matter be ordinary electric leakage circuit breaker, still intelligent electric leakage circuit breaker, all increased the electric leakage and withdraw from the function, the increase of this function has certainly made things convenient for user's use, but also corresponding the risk that has improved the electric shock, withdraw from the function and open the back for example the electric leakage, carry out emergent power supply, fail in time to withdraw from the function after the end and close with the electric leakage.

Therefore, the intelligent residual current circuit breaker has reliability and flexibility in the aspect of leakage protection.

Disclosure of Invention

In order to solve the problem of insufficient reliability of the existing intelligent residual current circuit breaker and simultaneously reserve the problem of control flexibility, the invention provides a residual current circuit breaker, which comprises a residual current transformer, a first driving circuit, a second driving circuit, a release and a release power supply circuit; the first driving circuit and the second driving circuit are used for conducting a power supply circuit of the release; the first drive circuit includes: the device comprises a sampling circuit, a main processing unit, a first power supply and a first controllable silicon; the second driving circuit comprises an amplifying circuit and a second silicon controlled rectifier; the control electrode of the first silicon controlled rectifier, a first power supply and a sampling circuit are connected with the main processing unit, the sampling circuit is further connected with the output end of the leakage current transformer, and the first power supply is further connected with a live wire L and a zero line N at the upper end of a breaking point of the leakage current breaker; the input end of the amplifying circuit is connected with the output end of the leakage current transformer, and the output end of the amplifying circuit is connected with the control electrode of the second controllable silicon; the first silicon controlled rectifier and the second silicon controlled rectifier are connected in series in a power supply circuit of the release, and the first silicon controlled rectifier and the second silicon controlled rectifier are in parallel connection; and the release power supply circuit is connected with a live wire L and a zero line N at the lower end of a breaking point of the electric leakage circuit breaker.

The second driving circuit further comprises an exit switch, an input end of the exit switch is connected to an output end of the amplifying circuit, an output end of the exit switch is connected to a reference ground of the circuit, or connected to a control electrode of the second controllable silicon, or simultaneously connected to the control electrode of the second controllable silicon and the reference ground of the circuit, and an output signal of the amplifying circuit is short-circuited to the ground, or the output end of the amplifying circuit is disconnected from the control electrode of the second controllable silicon and simultaneously short-circuited to the ground.

Further, the exit switch has an input terminal and an output terminal, the input terminal of the exit switch is connected to the output terminal of the amplifying circuit, and the output terminal of the exit switch is connected to the reference ground of the circuit.

Optionally, the exit switch has an input end and an output end, the input end of the exit switch is connected to the output end of the amplifying circuit, and the output end of the exit switch is connected to the control electrode of the second thyristor.

Optionally, the exit switch has an input end and two output ends, the input end of the exit switch is connected to the output end of the amplifying circuit, a first output end of the exit switch is connected to the control electrode of the second thyristor, and a second output end of the exit switch is connected to the reference ground of the circuit.

Optionally, the exit switch is provided with a remote signaling contact, and the remote signaling contact is connected to the main processing unit and used for the main processing unit to acquire the breaking state of the exit switch.

Furthermore, the control electrode of the second controllable silicon is also connected to the main processing unit, and the main processing unit collects signals of the control electrode of the second controllable silicon.

Further, the second driving circuit further comprises a second power supply, and the second power supply is connected to a live wire L at the upper end of a breaking point of the electric leakage circuit breaker and supplies power to the amplifying circuit.

Meanwhile, the control method of the residual current circuit breaker provided by the invention comprises the following steps:

step 1, signal acquisition: the main processing unit respectively collects a leakage current signal and a signal of a second silicon controlled control electrode through an AD sampling pin of the CPU;

step 2, signal comparison: the main processing unit compares the two collected signals through a CPU, and enters step 3 when the signal of the second silicon controlled rectifier control electrode is zero and the leakage current signal is not zero; when the two signals are consistent, step 4 is entered,

step 3, re-determining the protection threshold: and the main processing unit takes the current collected leakage current signal value as a basic value or takes 0 as the leakage current basic value to re-determine the protection threshold value.

And 4, continuously acquiring: the main processing unit continues to collect the leakage current signal through the AD sampling pin of the CPU, and when the leakage current signal is increased and the increment exceeds the threshold value, the step 5 is carried out;

and step 5, controlling output: the main processing unit sends a control signal to the first controlled silicon through an I/O pin of the CPU, so that the first controlled silicon is conducted, and the conduction of a power supply circuit of the release is realized.

The invention has the advantages that: the dual leakage protection is realized by utilizing the two driving circuits, the reliability of the leakage protection is improved, and the leakage protection has certain flexibility by arranging the exit switch and a corresponding control method under the condition of ensuring the reliability.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

FIG. 1: the principle of the invention is shown schematically;

FIG. 2: sampling and amplifying a leakage current transformer signal;

FIG. 3: a second power supply and its connection scheme;

FIG. 4: a first schematic diagram of an exit switch;

FIG. 5: a second schematic diagram of an exit switch;

FIG. 6: a third schematic diagram of an exit switch;

FIG. 7: a control schematic diagram of a release power supply circuit;

FIG. 8: a control method schematic diagram;

FIG. 9: schematic diagram of the remote signaling contacts of the exit switch.

Description of the reference numerals

1. The current leakage mutual inductor comprises a current leakage mutual inductor, 2-1 parts of a sampling circuit, 2-2 parts of a main processing unit, 2-3 parts of a first power supply, 2-4 parts of a first silicon controlled rectifier, 3-1 parts of an amplifying circuit, 3-2 parts of a second silicon controlled rectifier, 3-3 parts of a second power supply, 4 parts of a release, 5 parts of a release power supply circuit, 6 parts of an exit switch, 6-1 parts of a moving contact swing arm, 6-2 parts of a spring, 6-3 parts of a remote communication contact and 7 parts of a communication unit.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.

In the present invention, unless otherwise explicitly specified or limited, the term "connected" is to be understood broadly, and may be either mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

The invention provides a residual current circuit breaker, which refers to fig. 1 and comprises a leakage current transformer 1, a first driving circuit, a second driving circuit, a release 4 and a release power supply circuit 5; the first driving circuit and the second driving circuit are used for conducting the tripper power supply circuit 5; the first driving circuit includes: the device comprises a sampling circuit 2-1, a main processing unit 2-2, a first power supply 2-3 and a first controllable silicon 2-4; the second driving circuit comprises an amplifying circuit 3-1 and a second controllable silicon 3-2; the first power supply 2-3, the sampling circuit 2-1 and the control electrode of the first silicon controlled rectifier 2-4 are connected with the main processing unit 2-2, the sampling circuit 2-1 is also connected with the output end of the leakage current transformer 1, and the first power supply 2-3 is also connected with a live wire L and a zero wire N at the upper end of a breaking point of the leakage current circuit breaker; the input end of the amplifying circuit 3-1 is connected with the output end of the leakage current transformer 1, and the output end of the amplifying circuit 3-1 is connected with the control electrode of the second controllable silicon 3-2; the first controllable silicon 2-4 and the second controllable silicon 3-2 are connected in series in the power supply circuit 5 of the release, and the first controllable silicon 2-4 and the second controllable silicon 3-2 are in parallel connection; and the release power supply circuit 5 is connected with a live wire L and a zero line N at the lower end of a breaking point of the residual current circuit breaker.

Further, the second driving circuit also comprises an exit switch 6, the exit switch 6 is connected between the output end of the amplifying circuit 3-1 and the circuit of the control electrode of the second controllable silicon 3-2, the output signal of the amplifying circuit 3-1 is short-circuited to the ground, or the output end of the amplifying circuit 3-1 is disconnected with the control electrode of the second controllable silicon 3-2 and the output signal of the amplifying circuit 3-1 is short-circuited to the ground at the same time.

Referring to fig. 2, the amplifying circuit 3-1 is composed of an operational amplifier a4 and resistors R19, R20, R21; the sampling circuit 2-1 is composed of an operational amplifier A3 and resistors R16, R17, R18.

Specifically, the method comprises the following steps: an output end S2 of the leakage current transformer 1 is connected with a reference ground GND of the circuit after being connected with a resistor R12, the other output end S1 is connected with a resistor R12 and then connected with a resistor R18, and the other end of the resistor R18 is connected with a pin 3 of an operational amplifier A3 and a pin 3 of an operational amplifier A4; pin 2 of the operational amplifier A3 is connected to a resistor R16 and a resistor R17, the other end of the resistor R16 is connected to the ground GND, the other end of the resistor R17 is connected to pin 1 of the operational amplifier A3, and pin 1 of the operational amplifier A3 is connected to the AD sampling pin of the CPU of the main processing unit; pin 2 of the operational amplifier a4 is connected to the resistor R19 and the resistor R20, the other end of the resistor R19 is connected to the ground GND, the other end of the resistor R20 is connected to pin 1 of the operational amplifier a4, pin 1 of the operational amplifier a4 is connected to the resistor R21, and the other end of the resistor R21 is connected to the gate G of the second thyristor Q2.

After the connection, the signal of the leakage current transformer 1 can be amplified by the operational amplifier A3 and then output to the AD sampling pin of the CPU for sampling, so that the first driving circuit samples the leakage current signal; after being amplified by the operational amplifier A4, the signal is output to the control electrode G of the second controllable silicon Q2, so that the conduction of the power supply circuit 5 of the direct drive release is realized.

For the electric leakage circuit breaker, the first power supply 2-3 supplies power to all components needing power supply in the whole circuit system, and in the technical scheme of the invention, in order to more thoroughly embody the purpose of electric leakage double protection, the second power supply 3-3 is also arranged to independently supply power to the amplifying circuit 3-1 in the second driving circuit so as to realize the dual-power supply of the amplifying circuit 3-1. Specifically referring to fig. 3, the second power supply is a resistance voltage-dropping type power supply, one end of the power supply is connected to the live wire L at the upper end of the breaking point of the leakage breaker, and after being serially connected with resistors R25, R26, R27, R28 and R29 for voltage dropping, the second power supply is also connected with the power supplies + of capacitors C21 and C22 and an operational amplifier a4 for supplying power to the operational amplifier a 4; the other ends of the capacitors C21, C22 are connected to ground GND.

Referring to fig. 4, the exit switch 6 is identified in the circuit diagram by the symbol Q3; the second thyristor 3-2 is identified in the circuit diagram by the symbol Q2.

Preferably, the exit switch Q3 is IN the form of an input end and an output end, the input end IN is connected with the resistor R21, the output end OUT is connected with the ground GND, when the exit switch Q3 is turned off, the operational amplifier a4 sends an output signal to the control electrode G of the second thyristor Q2 through the resistor R21 via the pin 1, if there is a leakage current exceeding a threshold value, the output signal of the operational amplifier a4 can make the second thyristor Q2 conductive, so as to conduct a power supply circuit of the trip, implement the action of the trip, and trip the leakage breaker. If the exit switch Q3 is closed, the output signal of the operational amplifier a4 is directly short-circuited to the ground after passing through the resistor R21 and the exit switch Q3, and the output signal is pulled down, so that the control electrode G of the second thyristor Q2 is always a low-voltage signal, the second thyristor Q2 cannot be turned on, and indirectly, the leakage protection function of the second driving circuit exits.

The exit switch Q3 may also be set as follows:

referring to fig. 5, optionally, the exit switch Q3 takes the form of an input end and an output end, the input end IN is connected to the resistor R21, the output end OUT is connected to the control electrode G of the second thyristor Q2, when the exit switch Q3 is closed, the operational amplifier a4 sends an output signal to the control electrode G of the second thyristor Q2 through the resistor R21 and the exit switch Q3 via the pin 1, and if there is a leakage current exceeding a threshold value, the output signal of the operational amplifier a4 can turn on the second thyristor Q2, so as to turn on the power supply circuit of the trip, implement the trip operation, and trip the leakage circuit breaker. If the exit switch Q3 is turned off, the output signal of the operational amplifier a4 is disconnected from the gate G of the second thyristor Q2, the second thyristor Q2 cannot be turned on, and the leakage protection function of the second driving circuit is indirectly exited.

Referring to fig. 6, the exit switch Q3 has two output terminals and an input terminal, the input terminal IN is connected to the resistor R21, the first output terminal OUT1 is connected to the gate G of the second thyristor Q2, and the second output terminal OUT2 is connected to the ground GND; when the exit switch Q3 switches on the input terminal IN and the first output terminal OUT1, the operational amplifier a4 sends an output signal to the control electrode G of the second thyristor Q2 after passing through the resistor R21 and the exit switch Q3 through the pin 1, and if there is a leakage current exceeding a threshold value, the output signal of the operational amplifier a4 can switch on the second thyristor Q2, so as to switch on a power supply circuit of the trip, realize the action of the trip, and trip the leakage breaker. If the exit switch Q3 switches on the input terminal IN and the second output terminal OUT2, the output signal of the operational amplifier a4 is disconnected from the gate G of the second thyristor Q2, and at the same time, the output signal is directly shorted to ground, the second thyristor Q2 cannot be switched on, and indirectly, the leakage protection function of the second driving circuit exits.

Through the application scheme of the quit switch, after the leakage protection function of the second drive circuit quits, no matter how large the leakage current is sensed by the leakage current transformer 1, the second drive circuit cannot conduct the power supply circuit 5 of the tripper, and the tripper cannot act, so that emergency power supply under the condition of leakage current can be realized.

Referring to fig. 7, the first thyristor 2-4 is identified by Q1 in the circuit diagram, one end of a coil T1 of the trip device is connected to the live line L, the other end of the coil T1 is connected to a diode, and the other end of the diode is connected to the first thyristor Q1 and the second thyristor Q2; the other end of the first controlled silicon Q1 is connected to the reference ground GND, and the control electrode G of the first controlled silicon Q1 is connected with the resistor R23, the capacitor C and the I/O pin of the CPU of the main processing unit; the other end of the second thyristor Q2 is connected to ground GND, the gate G of the second thyristor Q2, the resistor R22, the capacitor C, and pin 1 of the operational amplifier a 4.

After the connection, if leakage current exceeding a threshold exists, the output signal of the operational amplifier A4 can enable the second controllable silicon Q2 to be conducted, so that a power supply circuit of the tripper is conducted, the action of the tripper is realized, and the leakage circuit breaker is tripped; similarly, the main processing unit of the first driving circuit outputs a control signal by using an I/O pin of the CPU to control the control electrode G of the first thyristor Q1, so that the first thyristor Q1 is turned on, thereby turning on the power supply circuit of the release, realizing the action of the release, and tripping the residual current circuit breaker. Therefore, the first driving circuit and the second driving circuit can both conduct the power supply circuit 5 of the tripper, and the tripper can act.

Similarly, referring to fig. 7, the control electrode G of the second thyristor Q2 is further connected to the AD sampling pin of the CPU of the main processing unit, so that the main processing unit collects a signal of the control electrode G of the second thyristor Q2 and determines the state of the second driving circuit.

Through the above description of the connection relationship, we can clearly know that:

the first drive circuit is realized in the following way: the leakage current signal that current transformer 1 will sense, after the signal amplification through operational amplifier A3, the AD sampling pin of transmitting CPU, CPU calculates actual leakage current value, and compare with preset current threshold, when actual leakage current value is greater than preset threshold, utilize CPU's IO pin output control signal, control the control utmost point G of first silicon controlled rectifier Q1, make first silicon controlled rectifier switch on, thereby switch on release supply circuit, realize the release action, make the disconnection of leakage circuit breaker, realize the earth leakage protection function.

The second driving circuit is realized in the following mode: the induced leakage current signal is amplified by the leakage current transformer 1 through the operational amplifier A4 and is output to the control electrode G of the second controllable silicon Q2, when the induced leakage current signal of the leakage current transformer 1 reaches a threshold value, the output voltage signal of the operational amplifier A4 reaches the conduction control voltage of the second controllable silicon Q2, so that the second controllable silicon Q2 is conducted, the power supply circuit of the release is conducted, the action of the release is realized, the leakage circuit breaker is disconnected, and the leakage protection function is realized.

Therefore, the first driving circuit and the second driving circuit can realize the function of leakage protection, any one driving circuit has a problem, the leakage protection function cannot be invalid, and the reliability of leakage protection is greatly improved.

From the technical scheme that two driving circuits realize the leakage protection function, the realization of the first driving circuit is mainly realized by a CPU, and the first driving circuit can have better control flexibility as long as a program is made, such as: the protection threshold value of leakage current is adjustable, the driving time of leakage tripping is adjustable, and the like; however, the first driving circuit uses more components than the second driving circuit, and the CPU requires a program to be dominant, which increases the risk that the program will be halted and the leakage trip cannot be realized.

The second driving circuit uses fewer components and does not need to be programmed, so that the risk of failure is relatively low, but the protection threshold of the leakage current is fixed, and the protection threshold of the leakage current is determined as long as the amplification factor of the operational amplifier is determined, and cannot be changed, so that the flexibility is low.

In order to solve the above problem, in the technical solution of the present invention, an exit switch 6 is disposed on the second driving circuit, and the main processing unit performs signal sampling on the control electrode G of the second thyristor Q2 by using the AD sampling pin of the CPU, determines the state of the second driving circuit, and then performs logic control, so as to increase the control flexibility of the electrical leakage breaker.

Referring to fig. 8, the logic control method of the residual current circuit breaker may be implemented by the following steps:

step 1 (100), signal acquisition: and the main processing unit respectively collects the leakage current signal and the signal of the second silicon controlled control electrode through an AD sampling pin of the CPU.

Step 2 (200), signal comparison: the main processing unit compares the two collected signals through a CPU, and enters step 3 when the signal of the second silicon controlled rectifier control electrode is zero and the leakage current signal is not zero; when the two signals are identical, step 4 is entered.

It can be understood that when the leakage current signal is not zero and the signal of the second scr gate is zero, there are two cases, the first case is that the leakage protection function of the second driving circuit is exited, as shown in fig. 4, the exit switch Q3 is closed, and the output signal of the operational amplifier a4 is forced to be grounded, so that the sampling signal is zero; the second case is that the operational amplifier a4 is abnormal and cannot output a signal; in order to better distinguish the two cases, a remote signaling contact point can be arranged on the exit switch, so that the CPU can clearly know the working state of the exit switch to distinguish the two cases.

Referring to fig. 9, one end of a remote signaling contact 6-3 is connected to an AD sampling pin of a CPU of a main processing unit and a resistor R48, the other end of the resistor R48 is connected to VDD3.3, and the other end of the remote signaling contact 6-3 is connected to a ground GND; under the condition that the exit switch is closed, the remote signaling contact is kept in an open state under the action of the spring 6-2, a signal acquired by an AD sampling pin of the CPU is equivalent to a voltage signal of 3.3V, when a moving contact swing arm 6-1 of the exit switch 6 is opened along the direction shown by an arrow, the exit switch can be opened, and meanwhile, the remote signaling contact is closed by utilizing the displacement of the opening of the moving contact swing arm 6-1, so that the signal acquired by the AD sampling pin of the CPU is equivalent to a voltage signal of 0V; by such signal change, the on and off states of the exit switch 6 can be accurately determined, and thus whether the earth leakage protection function exits or not can be accurately determined.

In the comparison process, if the leakage protection function of the second driving circuit exits and the leakage signal value acquired by the first driving circuit is greater than the preset threshold value, the emergency power supply under the condition of needing leakage is considered, the signal value is used as the basic value of leakage protection, and the protection threshold value is determined again.

Step 3 (300), re-determining the protection threshold: and the main processing unit takes the current collected leakage current signal value as a basic value or takes 0 as the leakage current basic value to re-determine the protection threshold value.

Specifically, as described in step 2, when it is determined that emergency power supply is required under the condition of leakage current, the CPU uses the leakage current value as a basic value, and if leakage current is superimposed on the basic value and the superimposed amount of leakage current exceeds a predetermined protection threshold, the first driving circuit is used to open the leakage circuit breaker to perform leakage protection. For example, when emergency power supply is required under the condition of leakage current of 50mA, the protection threshold value is determined to be 80mA, and when leakage current is generated and the superposition sum is greater than 80mA, the first driving circuit is used for disconnecting the leakage circuit breaker to play a role of leakage protection.

If after a period of time, the leakage current of 50mA disappears, and the leakage protection function of the second driving circuit is still in an exit state, the exit switch is considered to be a human factor, the exit switch is forgotten to reset, so that the second driving circuit cannot work, at the moment, the protection threshold value can be determined to be 30mA again, when the leakage current is generated and the amplitude is greater than 30mA, the first driving circuit is directly utilized to disconnect the leakage breaker, the leakage protection effect is achieved, meanwhile, the information is sent to a user through the communication unit, and the exit switch is timely reset.

Of course, for the second case described in step 2, the protection threshold is directly determined to be 30mA, and when a leakage current occurs and the amplitude is greater than 30mA, the first driving circuit is directly used to open the leakage breaker, so as to perform the leakage protection function.

And step 4, (400), continuing to collect: and the main processing unit continues to acquire the leakage current signal through the AD sampling pin of the CPU, and when the leakage current signal is increased and the increment exceeds the threshold value, the step 5 is carried out.

For the condition that the two sampling signals are consistent, no matter the second driving circuit can not drive the second silicon controlled rectifier to be conducted, the CPU outputs a control signal to the control electrode of the first silicon controlled rectifier by using the I/O pin, and the first silicon controlled rectifier is conducted, so that the leakage tripping protection function is realized.

And step 5 (500), controlling and outputting: the main processing unit sends a control signal to the first controlled silicon through an I/O pin of the CPU, so that the first controlled silicon is conducted, and the conduction of a power supply circuit of the release is realized.

Through the description of the control method, the control flexibility can be seen, and the problem that the leakage protection function cannot be reset in time after exiting can be solved; the second condition described in step 2 can be further expanded, and by comparing the leakage current signal with the signal of the second thyristor control electrode, the self-checking judgment of the abnormality of part of the circuits can be further performed. And the abnormal information is sent through the communication unit 7, so that a user is informed that the leakage circuit breaker is abnormal and replaced as soon as possible, and the use safety is ensured.

In the present invention, the circuit uses the zero line as a reference ground.

Finally, it should be noted that the above-mentioned embodiments are only preferred embodiments of the present invention, so as to better explain the principle and practical application of the present invention, thereby enabling those skilled in the art to better understand the present invention, and not to limit the scope of the present invention. Under the inventive concept of the present invention, the equivalent structural changes made by the contents of the present specification and the attached drawings, or the direct/indirect application to other related technical fields, are all included in the scope of the present invention.

Claims (9)

1. A residual current circuit breaker is characterized by comprising a leakage current transformer, a first driving circuit, a second driving circuit, a release and a release power supply circuit; the first driving circuit and the second driving circuit are used for conducting a power supply circuit of the release; the first drive circuit includes: the device comprises a sampling circuit, a main processing unit, a first power supply and a first controllable silicon; the second driving circuit comprises an amplifying circuit and a second silicon controlled rectifier; the control electrode of the first silicon controlled rectifier, a first power supply and a sampling circuit are connected with the main processing unit, the sampling circuit is further connected with the output end of the leakage current transformer, and the first power supply is further connected with a live wire L and a zero line N at the upper end of a breaking point of the leakage current breaker; the input end of the amplifying circuit is connected with the output end of the leakage current transformer, and the output end of the amplifying circuit is connected with the control electrode of the second controllable silicon; the first silicon controlled rectifier and the second silicon controlled rectifier are connected in series in a power supply circuit of the release, and the first silicon controlled rectifier and the second silicon controlled rectifier are in parallel connection; and the release power supply circuit is connected with a live wire L and a zero line N at the lower end of a breaking point of the electric leakage circuit breaker.

2. The residual current circuit breaker according to claim 1, wherein the second driving circuit further comprises an exit switch, an input terminal of the exit switch is connected to the output terminal of the amplifying circuit, and an output terminal of the exit switch is connected to a reference ground of the circuit, or to a control electrode of the second thyristor, or to both the control electrode of the second thyristor and the reference ground of the circuit, so as to short-circuit the output signal of the amplifying circuit to ground, or disconnect the output terminal of the amplifying circuit from the control electrode of the second thyristor and simultaneously short-circuit the output signal of the amplifying circuit to ground.

3. A residual current circuit breaker as claimed in claim 2, characterized in that the exit switch has an input and an output, the input of the exit switch being connected to the output of the amplifying circuit and the output of the exit switch being connected to the reference ground of the circuit.

4. A residual current circuit breaker as claimed in claim 2, characterized in that the withdrawable switch has an input and an output, the input of the withdrawable switch being connected to the output of the amplifying circuit, the output of the withdrawable switch being connected to the control electrode of the second thyristor.

5. A residual current circuit breaker as claimed in claim 2, characterized in that the withdrawable switch has an input and two outputs, the input of the withdrawable switch being connected to the output of the amplifying circuit, the withdrawable switch having a first output connected to the control pole of the second thyristor and a second output connected to the reference ground of the circuit.

6. The residual current circuit breaker according to claim 2, wherein the exit switch is provided with a remote signaling contact, and the remote signaling contact is connected to the main processing unit for the main processing unit to acquire the breaking state of the exit switch.

7. A residual current circuit breaker according to claim 1, characterized in that the control electrode of the second thyristor is further connected to the main processing unit for the main processing unit to collect the signal of the control electrode of the second thyristor.

8. A residual current circuit breaker according to claim 1, characterized in that said second driving circuit further comprises a second power supply, said second power supply being connected to the live line L at the upper end of the breaking point of the residual current circuit breaker for supplying power to the amplifying circuit.

9. A method for controlling an earth leakage breaker according to any of claims 1-8, characterized in that it comprises the following steps:

step 1, signal acquisition: the main processing unit respectively collects a leakage current signal and a signal of a second silicon controlled control electrode through an AD sampling pin of the CPU;

step 2, signal comparison: the main processing unit compares the two collected signals through a CPU, and enters step 3 when the signal of the second silicon controlled rectifier control electrode is zero and the leakage current signal is not zero; when the two signals are consistent, entering step 4;

step 3, re-determining the protection threshold: the main processing unit takes the current collected leakage current signal value as a basic value, or takes 0 as the leakage current basic value, and the protection threshold value is determined again;

and 4, continuously acquiring: the main processing unit continues to collect the leakage current signal through the AD sampling pin of the CPU, and when the leakage current signal is increased and the increment exceeds the threshold value, the step 5 is carried out;

and step 5, controlling output: the main processing unit sends a control signal to the first controlled silicon through an I/O pin of the CPU, so that the first controlled silicon is conducted, and the conduction of a power supply circuit of the release is realized.

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