阅读说明：本技术 断路器及其工作状态检测方法 (Circuit breaker and working state detection method thereof ) 是由 龚峰 曲克峰 于 2019-09-11 设计创作，主要内容包括：公开了一种断路器及其工作状态检测方法,该断路器包括：自检控制模块,根据交流信号同步产生模拟漏电信号并输出至交流电路的零线；感应模块,与交流电路的干线耦合,并根据耦合处磁通量的变化产生触发信号；漏电检测模块,与感应模块相连接以获得触发信号,并根据触发信号产生导通信号；保护模块,分别与交流电路的火线、漏电检测模块和自检控制模块连接,用于根据交流信号产生第一检测信号,以及根据导通信号产生第二检测信号,并将第一检测信号和第二检测信号输出至自检控制模块,自检控制模块根据接收到的第一检测信号和第二检测信号判断断路器的工作状态,由此快速检测该断路器是否能进行漏电保护,整个过程均是上电后自动完成,高效简单。(Disclosed are a circuit breaker and a method for detecting an operating state thereof, the circuit breaker including: the self-checking control module synchronously generates an analog leakage signal according to the alternating current signal and outputs the analog leakage signal to a zero line of the alternating current circuit; the induction module is coupled with a main line of the alternating current circuit and generates a trigger signal according to the change of magnetic flux at the coupling part; the electric leakage detection module is connected with the induction module to obtain a trigger signal and generates a conduction signal according to the trigger signal; the protection module is respectively connected with a live wire of the alternating current circuit, the electric leakage detection module and the self-checking control module, and is used for generating a first detection signal according to the alternating current signal, generating a second detection signal according to the conduction signal, outputting the first detection signal and the second detection signal to the self-checking control module, judging the working state of the circuit breaker according to the received first detection signal and the received second detection signal by the self-checking control module, rapidly detecting whether the circuit breaker can carry out electric leakage protection or not, automatically completing the whole process after being electrified, and being efficient and simple.)

1. A circuit breaker for an alternating current circuit, comprising:

the self-checking control module synchronously generates a simulation leakage signal according to the alternating current signal and outputs the simulation leakage signal to a zero line of the alternating current circuit;

the induction module is coupled with a main line of the alternating current circuit and generates a trigger signal according to the change of magnetic flux at the coupling part;

the electric leakage detection module is connected with the induction module to obtain the trigger signal and generate a conduction signal according to the trigger signal; and

the protection module is respectively connected with the live wire of the alternating current circuit, the electric leakage detection module and the self-checking control module, and is used for generating a first detection signal according to the alternating current signal, generating a second detection signal according to the conduction signal, and outputting the first detection signal and the second detection signal to the self-checking control module,

the self-checking control module judges the working state of the circuit breaker according to the received first detection signal and the second detection signal.

2. The circuit breaker of claim 1, wherein the protection module comprises:

a solenoid connected between the live line of the alternating current circuit and the thyristor for disconnecting or connecting the alternating current circuit; and

and the controlled silicon is connected between the solenoid and the ground, and the control electrode of the controlled silicon is connected to the leakage detection module and used for receiving the conducting signal.

3. The circuit breaker of claim 2, wherein during a positive half cycle of the ac power source, the sensing module generates the trigger signal and outputs the trigger signal to the leakage detection module when a sum of a current vector on a main line of the ac circuit changes a magnetic flux at the coupling, the leakage detection module receives the trigger signal and outputs a conduction signal to a control pole of the thyristor, and the thyristor conducts in accordance with the conduction signal and disconnects the ac circuit via the solenoid.

4. The circuit breaker of claim 2, wherein the protection module further comprises:

a first diode connected in series between the thyristor and the solenoid, a cathode of the first diode being connected to an anode of the thyristor, the first diode being configured to block connection of the thyristor to the solenoid during a negative half-cycle of the AC power source.

5. The circuit breaker of claim 4, wherein the circuit breaker starts fault detection for at least one AC cycle after a preset time of power-up of the AC circuit, and performs fault detection at regular intervals, wherein the fault detection comprises continuous connectivity detection and analog leakage detection.

6. The circuit breaker of claim 5, wherein the connectivity check is performed on the protection module during a positive half-cycle of the AC power source, the AC signal passing through the solenoid to an anode of the thyristor, causing a first node between the thyristor and the first diode to generate the first detection signal,

and the self-checking control module compares the voltage value of the first detection signal with a first threshold voltage and judges whether the circuit breaker breaks down or not according to the comparison.

7. The circuit breaker of claim 6, wherein the circuit breaker further performs the connectivity check for a plurality of ac cycles during a positive half-cycle of the ac power source when the voltage value of the first detection signal is less than the first threshold voltage, and the self-test control module generates an alarm signal when the voltage value of the first detection signal remains less than the first threshold voltage at all times during the connectivity check for the plurality of ac cycles.

8. The circuit breaker of claim 6, wherein the analog leakage detection is performed during a negative half-cycle of the alternating current power supply when a voltage value of the first detection signal is equal to or greater than the first threshold voltage during a positive half-cycle of the alternating current power supply.

9. The circuit breaker of claim 8, wherein the analog leakage detection is performed during a negative half cycle of the ac power source, the self-test control module sends the generated analog leakage signal to the sensing module, and the leakage detection module receives a trigger signal generated by the sensing module and outputs a turn-on signal to the thyristor to turn on the thyristor, so that the first node generates a second detection signal.

10. The circuit breaker of claim 9, wherein the fault detection ends when the self-test control module receives the second detection signal during a negative half-cycle of the ac power source; when the self-checking control module does not receive the second detection signal, the circuit breaker performs the simulated leakage detection in a plurality of alternating current periods, and if the self-checking control module does not receive the second detection signal in a plurality of preset alternating current periods, the self-checking control module generates an alarm signal.

11. The circuit breaker of claim 1, wherein the first detection signal is high and the second detection signal is low.

12. The circuit breaker of claim 10, further comprising:

the rectifier bridge is connected with a trunk line of the alternating current circuit and used for providing power for the self-checking control module and the electric leakage detection module;

the protection resistor is connected between the live wire and the zero line of the alternating current circuit;

a switch for opening or closing the alternating current circuit under the control of the solenoid.

13. The circuit breaker of claim 1, further comprising: and the manual self-checking module is connected between the live wire and the zero line of the alternating current circuit and used for manually detecting the working state of the circuit breaker.

14. The circuit breaker of claim 13, wherein the manual self-test module includes an eighth resistor and a first self-test button connected in series.

15. The circuit breaker of claim 10, wherein the electrical leakage detection module comprises:

the leakage detection chip comprises a plurality of pins and is used for receiving the trigger signal and outputting the conducting signal;

the first resistor is connected with a sixth pin of the leakage detection chip;

the second resistor is connected between the first pin of the leakage detection chip and the induction module;

the first capacitor is connected between the fourth pin and the fifth pin of the leakage detection chip; and

and the second capacitor is connected between the fifth pin and the sixth pin of the leakage detection chip.

16. The circuit breaker of claim 15, wherein the sensing module comprises a sensing coil coupled to a main line of the alternating current circuit, and a third resistor connected between one end of the sensing coil and the second resistor, the third resistor further connected to the second pin of the leakage detection chip, and the other end of the sensing coil connected to the third pin of the leakage detection chip.

17. The circuit breaker of claim 12, wherein the self-test control module comprises a self-test control chip comprising a plurality of pins, wherein,

the fault pin is used for outputting the analog leakage signal;

the detection pin is used for receiving the first detection signal and the second detection signal;

the alarm pin is used for outputting the alarm signal;

the clock pin is used for receiving an alternating current signal from the alternating current circuit and generating a clock signal to enable the fault pin to start working;

and the power supply pin is used for receiving the voltage signal from the rectifier bridge and supplying power to the self-checking control chip.

18. The circuit breaker of claim 17, wherein the self-test control module further comprises:

a fourth resistor connected between the detection pin and the first node;

the fifth resistor is connected between the power supply pin and the rectifier bridge;

a sixth resistor connected between the clock pin and the live wire of the alternating current circuit;

the seventh resistor is connected between the fault pin and a zero line of the alternating current circuit;

a third capacitor connected between the power supply pin and ground; and

and the second diode is connected in parallel to two ends of the fourth resistor.

19. The circuit breaker of claim 18, wherein the second diode of the self-test control module is turned off during a positive half-cycle of the ac power source, causing the detection pin to detect the second detection signal at the first node during a negative half-cycle of the ac power source during the analog leakage detection.

20. The circuit breaker of claim 17, wherein the detection pin of the self-test control module stops sending the analog leakage signal of the fault pin after receiving the second detection signal, and the analog leakage detection is completed.

21. An operating state detection method of a circuit breaker comprises the following steps:

performing connectivity detection, and generating a first detection signal according to the alternating current signal;

carrying out analog leakage detection, and generating an analog leakage signal in the negative half period of the alternating current signal to cause magnetic flux change;

obtaining a trigger signal generated according to the magnetic flux change, and generating a conducting signal according to the trigger signal;

generating a second detection signal according to the conducting signal; and

and judging the working state of the circuit breaker according to the received first detection signal and the second detection signal.

22. The detection method according to claim 21, further comprising: and starting to perform fault detection of at least one alternating current period after the preset power-on time, wherein the fault detection comprises the continuity detection and the simulation leakage detection which are performed continuously.

23. The detection method of claim 22, wherein performing the connectivity detection, generating the first detection signal from the ac signal comprises:

during a positive half cycle of the alternating current power supply, the alternating current signal passes through a first node to generate the first detection signal;

comparing a voltage value of the first detection signal with a first threshold voltage;

when the voltage value of the first detection signal is greater than or equal to the first threshold voltage, performing the analog leakage detection;

and when the voltage value of the first detection signal is smaller than the first threshold voltage, performing connectivity detection in a plurality of alternating current periods, and when the voltage value of the first detection signal is still smaller than the first threshold voltage in the connectivity detection in the plurality of alternating current periods, generating an alarm signal.

24. The detection method of claim 22, wherein generating a second detection signal based on the turn-on signal, and determining the operating state of the circuit breaker based on the received second detection signal comprises:

generating the trigger signal according to the analog leakage signal in a negative half period of the alternating current power supply;

generating a conducting signal according to the trigger signal;

outputting the conducting signal to enable the first node to generate a second detection signal;

when the second detection signal is received, the fault detection is finished;

and when the second detection signal is not received, carrying out the analog leakage detection of one or more alternating current periods, and if the second detection signal is not received in a plurality of preset alternating current periods, generating an alarm signal.

25. The detection method of claim 24, wherein the analog leakage signal stops sending after receiving the second detection signal, and the analog leakage detection is completed.

26. The detection method according to claim 21, further comprising:

outputting the trigger signal when a current change on a main line of the alternating current circuit generates a magnetic flux change in a positive half cycle of the alternating current power supply;

receiving the trigger signal and outputting a conducting signal;

and disconnecting the alternating current circuit according to the conducting signal.

27. The detection method according to claim 21, wherein the first detection signal is at a high level and the second detection signal is at a low level.

Technical Field

The invention relates to the power electronic related field, in particular to a circuit breaker and a working state detection method thereof.

Background

The appliance leakage protection circuit breaker (ALCI) has the leakage protection function and can effectively prevent the human body from electric shock and fire accidents, thereby being widely applied to household appliances. In addition, the leakage protection circuit breaker of the appliance may have a fault, such as the end of the service life of an internal component, which results in the loss of the leakage protection function, and in this case, if the device is continuously used, a personal electric shock or a fire accident may occur.

Therefore, the conventional ALCI system requires manual labor to test whether the system is working properly. Fig. 1 shows a schematic circuit diagram of a circuit breaker according to the prior art, in which, as shown in fig. 1, an ac circuit is connected between a power supply and a load, an induction coil N1 is coupled to the live line and the neutral line of the ac circuit, the outgoing line of the coil N1 is connected to a leakage protection module 10, the leakage protection module 10 is connected to the control terminal of a thyristor SQ, the anode of the thyristor SQ is connected to a solenoid L, and the cathode is grounded; the solenoid L is connected to a trunk line of the alternating current circuit and controls the opening and the closing of the switches S1 and S2, and the rectifier bridge BD is used for supplying power to the leakage protection module; the trunk line is also connected with a manual detection button BT and a resistor R connected in series with the manual detection button BT. When a circuit is in fault, for example, a factor affecting a main line current appears at a node Q, so that a sum of current vectors between a live line and a zero line of an alternating current circuit is not zero, magnetic flux in an induction coil N1 is changed, an induction potential is induced and sent to the leakage protection module 10, the leakage protection module 10 sends a conduction signal to a control end of a thyristor SQ, the thyristor SQ and a solenoid L are conducted, the solenoid L enables switches S1 and S2 to be disconnected, the alternating current circuit is cut off, and a protection effect is achieved. The manual detection switch BT can be used for manually detecting whether the circuit breaker can work normally.

However, in actual operation, manual testing is often overlooked or forgotten, so that certain key elements in the ALCI system may have the potential of failure, which may cause electric shock safety accidents, and manual testing is inconvenient and needs to be improved.

Disclosure of Invention

In view of the above, an object of the present invention is to provide a circuit breaker suitable for an ac circuit and a detection method thereof, wherein a self-detection control module is provided to send an analog leakage signal and detect a voltage of an anode of a thyristor, so as to determine whether a circuit can normally operate, thereby implementing automatic detection of the circuit.

According to a first aspect of the present invention there is provided a circuit breaker for an ac circuit, comprising:

the self-checking control module synchronously generates a simulation leakage signal according to the alternating current signal and outputs the simulation leakage signal to a zero line of the alternating current circuit;

the induction module is coupled with a main line of the alternating current circuit and generates a trigger signal according to the change of magnetic flux at the coupling part;

the electric leakage detection module is connected with the induction module to obtain the trigger signal and generate a conduction signal according to the trigger signal; and

the protection module is respectively connected with the live wire of the alternating current circuit, the electric leakage detection module and the self-checking control module, and is used for generating a first detection signal according to the alternating current signal, generating a second detection signal according to the conduction signal, and outputting the first detection signal and the second detection signal to the self-checking control module,

the self-checking control module judges the working state of the circuit breaker according to the received first detection signal and the second detection signal.

Preferably, the protection module includes:

a solenoid connected between the live line of the alternating current circuit and the thyristor for disconnecting or connecting the alternating current circuit; and

and the controlled silicon is connected between the solenoid and the ground, and the control electrode of the controlled silicon is connected to the leakage detection module and used for receiving the conducting signal.

Preferably, in a positive half cycle of the ac power supply, when a current vector sum change on a main line of the ac circuit causes a magnetic flux change at the coupling, the sensing module generates the trigger signal and outputs the trigger signal to the leakage detection module, the leakage detection module receives the trigger signal and outputs a conduction signal to a control electrode of the thyristor, and the thyristor conducts according to the conduction signal and disconnects the ac circuit through the solenoid.

Preferably, the protection module further comprises:

a first diode connected in series between the thyristor and the solenoid, a cathode of the first diode being connected to an anode of the thyristor, the first diode being configured to block connection of the thyristor to the solenoid during a negative half-cycle of the AC power source.

Preferably, the circuit breaker starts to perform fault detection for at least one ac cycle after the ac circuit is powered on for a preset time, and performs fault detection once every certain time, where the fault detection includes continuous connectivity detection and analog leakage detection.

Preferably, the connectivity check is performed on the protection module during a positive half-cycle of the ac power source, the ac signal passing through the solenoid to the anode of the thyristor, causing a first node between the thyristor and the first diode to generate the first detection signal,

and the self-checking control module compares the voltage value of the first detection signal with a first threshold voltage and judges whether the circuit breaker breaks down or not according to the comparison.

Preferably, the circuit breaker performs the connectivity detection for a plurality of ac cycles when the voltage value of the first detection signal is less than the first threshold voltage during a positive half-cycle of the ac power source, and the self-test control module generates an alarm signal when the voltage value of the first detection signal is still less than the first threshold voltage during the connectivity detection for the plurality of ac cycles.

Preferably, the analog leakage detection is performed during a negative half cycle of the ac power supply when a voltage value of the first detection signal is equal to or greater than the first threshold voltage during a positive half cycle of the ac power supply.

Preferably, the analog leakage detection is performed in a negative half cycle of the ac power supply, the self-checking control module sends the generated analog leakage signal to the sensing module, and the leakage detection module receives a trigger signal generated by the sensing module and outputs a conduction signal to the thyristor to conduct the thyristor, so that the first node generates a second detection signal.

Preferably, in a negative half-cycle of the ac power supply, when the self-test control module receives the second detection signal, the fault detection is ended; when the self-checking control module does not receive the second detection signal, the circuit breaker performs the simulated leakage detection in a plurality of alternating current periods, and if the self-checking control module does not receive the second detection signal in a plurality of preset alternating current periods, the self-checking control module generates an alarm signal.

Preferably, the first detection signal is at a high level, and the second detection signal is at a low level.

Preferably, the circuit breaker further comprises:

the rectifier bridge is connected with a trunk line of the alternating current circuit and used for providing power for the self-checking control module and the electric leakage detection module;

the protection resistor is connected between the live wire and the zero line of the alternating current circuit;

a switch for opening or closing the alternating current circuit under the control of the solenoid.

Preferably, the circuit breaker further comprises: and the manual self-checking module is connected between the live wire and the zero line of the alternating current circuit and used for manually detecting the working state of the circuit breaker.

Preferably, the manual self-test module comprises an eighth resistor and a first self-test button which are connected in series.

Preferably, the electrical leakage detection module includes:

the leakage detection chip comprises a plurality of pins and is used for receiving the trigger signal and outputting the conducting signal;

the first resistor is connected with a sixth pin of the leakage detection chip;

the second resistor is connected between the first pin of the leakage detection chip and the induction module;

the first capacitor is connected between the fourth pin and the fifth pin of the leakage detection chip; and

and the second capacitor is connected between the fifth pin and the sixth pin of the leakage detection chip.

Preferably, the sensing module includes a sensing coil coupled to a main line of the alternating current circuit, and a third resistor connected between one end of the sensing coil and the second resistor, the third resistor is further connected to the second pin of the leakage detection chip, and the other end of the sensing coil is connected to the third pin of the leakage detection chip.

Preferably, the self-test control module comprises a self-test control chip comprising a plurality of pins, wherein,

the fault pin is used for outputting the analog leakage signal;

the detection pin is used for receiving the first detection signal and the second detection signal;

the alarm pin is used for outputting the alarm signal;

the clock pin is used for receiving an alternating current signal from the alternating current circuit and generating a clock signal to enable the fault pin to start working;

and the power supply pin is used for receiving a voltage signal from the rectifier bridge and supplying power to the self-checking control chip.

Preferably, the self-test control module further comprises:

a fourth resistor connected between the detection pin and the first node;

the fifth resistor is connected between the power supply pin and the rectifier bridge;

a sixth resistor connected between the clock pin and the live wire of the alternating current circuit;

the seventh resistor is connected between the fault pin and a zero line of the alternating current circuit;

a third capacitor connected between the power supply pin and ground; and

and the second diode is connected in parallel to two ends of the fourth resistor.

Preferably, the second diode of the self-test control module is turned off in a positive half-cycle of the ac power source, and the second detection signal of the first node is detected by the detection pin in a negative half-cycle of the ac power source during the analog leakage detection.

Preferably, after the detection pin of the self-checking control module receives the second detection signal, the analog leakage signal of the fault pin is stopped from being sent, and the analog leakage detection is completed. According to a second aspect of the present invention, there is provided an operating state detecting method of a circuit breaker, comprising:

performing connectivity detection, and generating a first detection signal according to the alternating current signal;

carrying out analog leakage detection, and generating an analog leakage signal in the negative half period of the alternating current signal to cause magnetic flux change;

obtaining a trigger signal generated according to the magnetic flux change, and generating a conducting signal according to the trigger signal;

generating a second detection signal according to the conducting signal; and

and judging the working state of the circuit breaker according to the received first detection signal and the second detection signal.

Preferably, the detection method further comprises: and starting to perform fault detection of at least one alternating current period after the preset power-on time, wherein the fault detection comprises the continuity detection and the simulation leakage detection which are performed continuously.

Preferably, performing the connectivity test, generating the first test signal from the ac signal comprises:

during a positive half cycle of the alternating current power supply, the alternating current signal passes through a first node to generate the first detection signal;

comparing a voltage value of the first detection signal with a first threshold voltage;

when the voltage value of the first detection signal is greater than or equal to the first threshold voltage, performing the analog leakage detection;

and when the voltage value of the first detection signal is smaller than the first threshold voltage, performing connectivity detection in a plurality of alternating current periods, and when the voltage value of the first detection signal is still smaller than the first threshold voltage in the connectivity detection in the plurality of alternating current periods, generating an alarm signal.

Preferably, generating a second detection signal according to the conduction signal, and determining the operating state of the circuit breaker according to the received second detection signal includes:

generating the trigger signal according to the analog leakage signal in a negative half period of the alternating current power supply;

generating a conducting signal according to the trigger signal;

outputting the conducting signal to enable the first node to generate a second detection signal;

when the second detection signal is received, the fault detection is finished;

and when the second detection signal is not received, carrying out the analog leakage detection of one or more alternating current periods, and if the second detection signal is not received in a plurality of preset alternating current periods, generating an alarm signal.

Preferably, after receiving the second detection signal, the analog leakage signal stops sending, and the analog leakage detection is completed.

Preferably, the detection method further comprises:

outputting the trigger signal when a current change on a main line of the alternating current circuit generates a magnetic flux change in a positive half cycle of the alternating current power supply;

receiving the trigger signal and outputting a conducting signal;

and disconnecting the alternating current circuit according to the conducting signal.

Preferably, the first detection signal is at a high level, and the second detection signal is at a low level.

This circuit breaker adopts the first detected signal that protection module produced according to alternating current circuit's alternating current signal to and adopt and provide simulation leakage signal by self-checking control module, make the work of leakage detection module, open protection module, and judge the operating condition of circuit breaker jointly according to the second detected signal that protection module produced, can detect this circuit breaker and whether can carry out normal earth leakage protection, whole process is automatic completion after the electricity is gone up, need not the manual work, both the efficiency has been improved, also can protect user's personal safety.

The circuit breaker starts to perform fault detection in at least one alternating current period after being electrified for a preset time, and when the fault detection is performed, the connectivity detection is performed on the protection module in the positive half period of the alternating current power supply, so that the protection circuit can give an alarm in time when the fault occurs; carry out the simulation electric leakage detection alone in alternating current power supply's negative half internal, whether detection electric leakage detection module and protection module can play the earth leakage protection effect when the electric leakage takes place for the circuit, carry out two kinds of detections in turn in alternating current power supply's positive and negative half internal, can produce alarm signal when the circuit breaker breaks down, the suggestion user changes the circuit breaker, in time ensures safety.

The simulated leakage signal generated by the self-checking control module can ensure that the circuit breaker simulation circuit can perform protection work when leakage occurs, but the normal protection function of the circuit breaker when the circuit really breaks down can not be influenced, and the power supply can be timely cut off through the protection module when the circuit leaks electricity.

The circuit breaker judges whether the circuit breaker can normally work or not by detecting the voltage of the anode of the controlled silicon, the circuit breaker plays a role in protecting a circuit, the method is simple and efficient, the detection result is visual, and the judgment can be rapidly carried out.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent from the following description of the embodiments of the present invention with reference to the accompanying drawings.

Fig. 1 shows a schematic circuit diagram of a circuit breaker according to the prior art.

Fig. 2 shows a schematic block diagram of a circuit breaker according to an embodiment of the invention.

Fig. 3a and 3b show a schematic block diagram and a schematic circuit diagram, respectively, of a circuit breaker according to a further embodiment of the present invention.

Fig. 4 shows a detailed schematic circuit diagram of the circuit breaker of fig. 3a and 3 b.

Fig. 5 shows an operation waveform diagram of the circuit breaker according to the embodiment of the invention when the circuit breaker is normal in function when analog leakage detection is performed.

Fig. 6 is a waveform diagram illustrating an operation of a circuit breaker when the circuit breaker fails in performing analog leakage detection according to an embodiment of the present invention.

Fig. 7a and 7b are waveform diagrams illustrating the operation of the circuit breaker according to the embodiment of the invention when the thyristor is short-circuited and the solenoid is open-circuited during the connectivity detection.

Detailed Description

Various embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Like elements in the various figures are denoted by the same or similar reference numerals. For purposes of clarity, the various features in the drawings are not necessarily drawn to scale.

Fig. 2 shows a schematic block diagram of a circuit breaker according to an embodiment of the invention. The circuit breaker comprises an induction module 101, a self-test control module 102, an electric leakage detection module 103 and a protection module 104. As shown in fig. 2, the live line L and the neutral line N in the main line of the ac circuit are connected to the power supply terminal and the load terminal, and the on/off of the ac circuit is controlled by the switches S1 and S2.

The self-test control module 102 is connected to the live line L to obtain an ac signal, and synchronously generates an analog leakage signal Vleak according to the ac signal, and outputs the analog leakage signal Vleak to a node Q2 of a zero line N of the ac circuit, so as to cause a magnetic flux change at a coupling position of the sensing module 101 and a main line of the ac circuit.

The sensing module 101 is coupled to the main line of the ac circuit, and is configured to convert the magnetic flux change at the coupling into a trigger signal Vtri, and output the trigger signal Vtri to the leakage detection module 103, where the sum of the current vectors on the main line of the ac circuit is not zero, which causes the magnetic flux change, and the sensing module 101 generates the trigger signal Vtri according to the magnetic flux change.

The leakage detecting module 103 is connected to the sensing module 101 to obtain a trigger signal Vtri generated by the sensing module 101 according to the change of the magnetic flux, and generate a conducting signal Vcon according to the trigger signal Vtri, and output the conducting signal Vcon to the protection module 104.

The protection module 104 is connected between the live wire of the ac circuit and the leakage detection module 103, and is configured to generate a first detection signal VS1 according to an ac signal from the ac circuit, and generate a second detection signal VS2 according to a conduction signal Vcon from the leakage detection module 103, where the protection module 104 is electrically connected to the self-test control module 102, and the self-test control module 102 determines a working state of the circuit breaker according to the received first detection signal VS1 and the received second detection signal VS 2.

The circuit breaker starts to perform fault detection of at least one alternating current period after the alternating current circuit is electrified for a preset time, wherein the fault detection comprises connectivity detection and simulation leakage detection which are continuously performed in positive and negative half periods of an alternating current power supply. Preferably, during the positive half cycle of the ac power, the protection module 104 generates a first detection signal VS1 according to the ac signal from the ac circuit, and the self-test control module 102 receives the first detection signal VS1 and determines whether the protection module 104 can work normally; in a negative half cycle of the alternating current power supply, the self-test control module 102 outputs a simulated leakage signal Vleak to the sensing module 101, the sensing module 101 generates a trigger signal Vtri according to magnetic flux change caused by the simulated leakage signal Vleak, the leakage detection module 103 generates a conduction signal Vcon according to the trigger signal Vtri and outputs the conduction signal Vcon to the protection module 104, the protection module 104 generates a second detection signal VS2 according to the conduction signal Vcon from the leakage detection module 103, and the self-test control module 102 receives the second detection signal VS2 and judges whether the leakage detection module 103 and the protection module 104 can work normally.

Preferably, when the self-test control module 102 does not operate, if the current on the live wire or the neutral wire at the node Q2 changes, so that the sum of the current vectors on the main line of the ac circuit also changes, the magnetic flux in the sensing module 101 also changes, the sensing module 101 generates the trigger signal Vtri, and outputs the trigger signal Vtri to the leakage detection module 103, the leakage detection module 103 receives the trigger signal Vtri and outputs the conducting signal Vcon to the protection module 104, and the protection module 104 receives the conducting signal Vcon, and turns off the switches S1 and S2 accordingly, thereby disconnecting the ac circuit.

Fig. 3a and 3b show a schematic block diagram and a schematic circuit diagram, respectively, of a circuit breaker according to a further embodiment of the present invention. The circuit breaker is an optimized solution of fig. 2, and as in the embodiment of fig. 2, the circuit breaker includes an induction module 110, a self-test control module 120, an electric leakage detection module 130, a protection module 140, and further includes a rectifier bridge 150 and a manual self-test module 160.

As shown in fig. 3a and 3b, the live line L and the neutral line N in the main line of the ac circuit are connected to the power supply terminal and the load terminal, and the on/off of the main line of the ac circuit is controlled by the switches S1 and S2. The self-test control module 120 is connected with the live wire L to obtain an alternating current signal, and the self-test control module 120 synchronously generates an analog leakage signal Vleak according to the alternating current signal and outputs the analog leakage signal Vleak to the sensing module 110; the sensing module 110 is coupled to the main line of the ac circuit for generating a trigger signal Vtri according to the change of the magnetic flux; the leakage detecting module 130 is connected to the sensing module 110 to obtain a trigger signal Vtri, and generates a conducting signal Vcon according to the trigger signal Vtri; the protection module 140 is connected between the live line L and the leakage detection module 130, and is configured to generate a first detection signal VS1 according to an ac signal of an ac circuit, and generate a second detection signal VS2 according to a conduction signal Vcon, and the self-test control module 120 determines the operating state of the circuit breaker according to the received first detection signal VS1 and the received second detection signal VS 2.

The input end of the rectifier bridge 150 is connected to the main line of the ac circuit, and is used to provide power for the self-checking control module 120 and the leakage detection module 130, one end of the input end of the rectifier bridge 150 is connected to the neutral line N, and the other end corresponding to the neutral line N is connected to the live line L, while one of the two output ends of the rectifier bridge 150 is grounded, and the other output end supplies power to the self-checking control module 120 and the leakage detection module 130, respectively, and provides a voltage signal.

The manual self-checking module 160 is connected between the live line L and the zero line N of the main line of the ac circuit, has a first end connected to the live line L in the main line of the ac circuit, and has a second end connected to the zero line N in the main line of the ac circuit, and is used for manually detecting the operating state of the circuit breaker. For example, the manual self-test module 160 includes a resistor R8 and a self-test button B1 connected in series, and the self-test button B1 may manually test the operating state of the circuit breaker.

The circuit breaker of this embodiment still includes: and the protection resistor RV is connected between the live wire L and the zero line N and plays a role in protection. Switches S1 and S2 are connected in series to the live line L and the neutral line N, respectively, for disconnecting or connecting an ac circuit.

Further, the sensing module 110 includes a sensing coil SC1 coupled to the main line of the ac circuit, and a resistor R3 connected between one end of the sensing coil SC1 and the leakage detecting module 130, and the other end of the sensing coil SC1 is also connected to the leakage detecting module 130. The sensing coil SC1 may sense the sum of current vectors on the main line of the ac circuit, for example, when a factor affecting the current on the main line of the ac circuit appears at the node Q2, so that the sum of current vectors between the live line L and the neutral line N of the ac circuit is not zero, a change of magnetic flux may be generated in the coil SC1, and the sensing module 110 generates the trigger signal Vtri according to the change of magnetic flux, and outputs the trigger signal Vtri to the leakage detecting module 130 through the resistor R3.

The protection module 140 includes a solenoid SQL and a thyristor SQ1, the solenoid SQL is connected between the live line L of the ac circuit and the thyristor SQ1, and is used to turn off or on the ac circuit by controlling the opening or closing of the switches S1 and S2; the thyristor SQ1 is connected between the solenoid SQL and ground, the anode of the thyristor SQ1 is connected to one end of the solenoid SQL, the other end of the solenoid SQL is connected to the hot line L, the cathode of the thyristor SQ1 is grounded, and the control electrode is connected to the leakage detecting module 130 for receiving the conducting signal Vcon for conducting. The protection module 140 further includes a diode D1 connected in series between the thyristor SQ1 and the solenoid SQL, the cathode of the diode D1 being connected to the anode of the thyristor SQ1, the diode D1 being adapted to block the connection of the thyristor SQ1 to the solenoid SQL during the negative half-cycle of the ac power supply. Taking a point between the anode of the thyristor SQ1 and the cathode of the diode D1 as a node Q1, the self-test control module 120 detects the first detection signal VS1 and the second detection signal VS2 from the node Q1.

The operating condition of the circuit breaker of this embodiment is consistent with the description of fig. 2, and the circuit breaker starts to perform fault detection of at least one ac cycle after the ac circuit is powered on for a preset time, and performs fault detection once every certain time, tests whether the circuit breaker can normally operate, and plays a role in circuit protection. The fault detection includes a connectivity detection and an analog leakage detection performed continuously in the positive and negative half-cycles of the ac power source.

During fault detection, in the positive half cycle of the ac power supply, the connectivity of the protection module 140 is detected, the ac signal first reaches the anode of the thyristor SQ1 through the solenoid SQL and the diode D1, so that a voltage is generated at the node Q1 as the first detection signal VS1, the self-test control module 120 receives the first detection signal VS1 at the node Q1, compares the voltage value of the first detection signal VS1 with the threshold voltage Vth1, and detects the connectivity between the solenoid SQL and the thyristor SQ 1. When the voltage value of the first detection signal VS1 is less than the threshold voltage Vth1, it indicates that the solenoid SQL may fail, and to avoid false alarm, connectivity detection is performed in the next several ac cycles, for example, connectivity detection is repeated for multiple times (e.g., 3 times or more, where the number of detections is determined according to actual needs), and if the voltage value of the first detection signal VS1 is less than the threshold voltage Vth1 in each connectivity detection, it is determined that the circuit breaker has failed and cannot perform leakage protection any more, the self-test control module 120 generates an alarm signal to prompt a user to replace the circuit breaker; if the voltage value of the first detection signal VS1 reaches or exceeds the threshold voltage Vth1, the solenoid SQL is normally connected to the thyristor SQ1, and then the analog leakage detection is performed during the negative half-cycle of the ac power. During the positive half cycle of the ac power, the self-test control module 120 only receives the first test signal VS1, but does not emit the analog leakage signal Vleak.

In a negative half cycle of the ac power supply, performing analog leakage detection, wherein the self-test control module 120 outputs an analog leakage signal Vleak to the sensing module 110, and actually, the self-test control module 120 outputs the analog leakage signal Vleak to the node Q2, so that a magnetic flux change is generated in the sensing coil SC1, the sensing module 110 generates a trigger signal Vtri according to the magnetic flux change, the leakage detection module 130 receives the trigger signal Vtri generated by the sensing module 110, and outputs a conducting signal Vcon to a control end of the thyristor SQ1 of the protection module 140, so as to conduct the thyristor SQ1, and generate a low voltage at the node Q1 as a second detection signal VS 2; the self-test control module 120 connected to the node Q1 receives the second detection signal VS2 and determines whether the leakage detection module 130 and the protection module 140 can work normally. When the self-test control module 120 receives the second detection signal VS2, it indicates that the circuit breaker can perform normal earth leakage protection, and the fault detection is finished.

When the self-test control module 120 does not detect the second detection signal VS2, it indicates that the thyristor SQ1 is not turned on, and a fault may occur inside the circuit breaker, so that verification is performed again, the circuit breaker performs fault detection for a plurality of (e.g., 3 or more, where the number of detection times is determined according to actual needs) continuous ac cycles, and repeats analog leakage detection for a plurality of times, if the self-test control module 120 does not receive the second detection signal VS2 in a plurality of preset ac cycles, it is determined that the circuit breaker has a fault, and leakage protection cannot be performed any more, at this time, the self-test control module 120 generates an alarm signal to prompt a user to replace the circuit breaker. Preferably, the second detection signal VS2 is low, for example, during the first negative half cycle of the ac power source starting after the preset time of power up, the self-test control module 120 does not detect low level at the node Q1, then performs fault detection for the second ac cycle, if low level is detected at the node Q1, then the fault detection is finished, if low level is not detected at the node Q1, then performs fault detection for one to multiple ac cycles, repeats the above steps until low level is not detected when fault detection for a preset number (for example, 4 th) ac cycles is performed, and then the self-test control module 120 generates an alarm signal in the next ac cycle.

After power-on, the power supply supplies power to the circuit breaker and subsequent loads through a trunk line of the alternating current line, after power-on preset time, for example, 1s or 2s, fault detection is started, continuous connectivity detection and simulation leakage detection are alternately performed in a fixed positive half period and a fixed negative half period of one or more alternating current power supplies, and after the leakage protection function of the circuit breaker is detected to be normal, the fault detection is finished. After the load works for a period of time, for example, 11.25min, the circuit breaker enters alternative connectivity detection and simulated leakage detection, and personal safety of a user is protected all the time. And after the normal power supply is carried out for 11.25min, the fault detection is carried out, and the like. If one ac cycle is, for example, 20ms, when the self-test control module 120 does not detect the second detection signal VS2 in the first ac cycle, the self-test control module continuously performs a plurality of (for example, 3) preset analog leakage detections for the ac cycles, and when a plurality of (for example, a total of 4) analog leakage detections for the ac cycles have passed, the self-test control module does not detect the second detection signal VS2, the self-test control module performs an alarm after 80ms (corresponding to 4 ac cycles) of fault detection, and the alarm may be implemented in an LED blinking manner or a buzzer beeping manner.

The method starts to carry out connectivity detection and simulation leakage detection after the preset time of power-on, only detects whether the leakage protection function of the circuit breaker is normally carried out, does not influence the normal work of the circuit breaker, and does not influence the leakage protection function of the circuit breaker when the leakage condition occurs. Further, in any ac cycle of the ac power supply, when the sum of the current vectors on the ac main line changes, magnetic flux changes at the coupling position of the main line and the sensing coil SC1, the sensing module 110 generates the trigger signal Vtri, which is output to the leakage detection module 130, the leakage detection module 130 receives the trigger signal Vtri and outputs the conducting signal Vcon to the control electrode of the thyristor SQ1 of the protection module 140, during the positive half cycle of the ac circuit, the diode D1 is conducted, so that the thyristor SQ1 is connected to the solenoid SQL, which generates electromagnetic force under the action of current, turns off the switches S1 and S2, and disconnects the ac circuit, thereby avoiding accidents caused by leakage and injury.

Fig. 4 shows a detailed schematic circuit diagram of the circuit breaker of fig. 3a and 3 b. The circuit breaker is a circuit structure instantiated by the block diagram of fig. 3. The circuit breaker includes an induction module 110, a self-test control module 120, an electric leakage detection module 130, a protection module 140, a rectifier bridge 150, and a manual self-test module 160.

With reference to fig. 3a and 3b, the self-test control module 120 of the present embodiment includes a self-test control chip IC1 and a plurality of resistors and capacitors, and the leakage detection module 130 includes a leakage detection chip IC2 and a plurality of resistors and capacitors.

The self-test control chip IC1 includes a plurality of pins, shown as 6 pins, wherein the fault pin 1 is connected to the node Q2 through a resistor R7 connected in series for outputting an analog leakage signal Vleak to the node Q2; the detection pin 4 is connected to the node Q1 through a diode D2 and a resistor R4 connected in parallel, and is used for receiving a first detection signal VS1 and a second detection signal VS 2; the clock pin 2 is connected to the live wire L of the ac circuit through a resistor R6, and is configured to receive an ac signal from the live wire L and start timing, and after a preset time, start fault detection. After the predicted time is timed, for example, 1 or 2s, the clock pin 2 receives an alternating current signal from a live wire and processes the alternating current signal in the self-test control chip IC1 to obtain a clock signal, and the falling edge of the clock signal enables the fault pin 1 to start working and send out an analog leakage signal Vleak; the power supply pin 3 is connected to a non-grounded output end of the rectifier bridge 150 through a resistor R5, and is used for receiving a voltage signal from the rectifier bridge 150 and supplying power to the self-test control chip IC 1; the alarm pin 5 is used for outputting an alarm signal when the circuit breaker breaks down; the ground pin 6 is used for grounding, and the power pin 3 and the ground pin 6 are connected through a capacitor C3.

The leakage detecting chip IC2 includes a plurality of pins, which are shown as 6 pins, pin 1 and pin 2 are used for receiving the trigger signal Vtri, and pin 4 is connected to the gate of the thyristor SQ1 and is used for outputting the turn-on signal Vcon; the pin 1 and the pin 2 are both connected with a resistor R3 of the sensing module 110, a resistor R2 is also connected in series between the pin 1 and the resistor R3, and the pin 3 is directly connected with one end of the sensing coil SC1 without the resistor R3; pin 5 is connected to ground and the cathode of thyristor SQ 1; pin 6 is connected to rectifier bridge 150 through resistor R1, and the live line L of the ac circuit supplies power to the leakage detecting chip IC2 through pin 6. The capacitor C1 is connected between the pin 4 and the pin 5 of the leak detection chip IC2, and the capacitor C2 is connected between the pin 5 and the pin 6 of the leak detection chip IC 2.

Further, the circuit breaker continuously performs connectivity detection and simulated leakage detection in at least one alternating current period after the preset power-on time. During the fault detection, the connectivity detection is performed on the protection module 140 in the positive half cycle of the ac power source, the ac signal reaches the anode of the thyristor SQ1 and the node Q1 through the solenoid SQL and the diode D1, and is simultaneously connected to the detection pin 4 of the self-checking control chip IC1, a voltage is generated at the node Q1, which is the first detection signal VS1, due to the forward conduction and reverse blocking functions of the diode D2 of the self-checking control chip IC1, the diode D2 is turned off in the positive half cycle of the ac power source, the conduction voltage drop of the diode D1 is small, the voltage at the node Q1 is similar to the power source voltage, when the actual voltage at the node Q1 detected by the detection pin 4, i.e. the voltage of the first detection signal VS1 does not reach the preset threshold voltage Vth1, e.g. 60V, it is considered that the solenoid SQL and the thyristor 1 may not be connected, and in the following several ac cycles, the connectivity detection is performed to prevent false alarm SQ, for example, the connectivity test is repeated for a plurality of times (for example, 3 times or more, where the number of tests is determined according to actual needs), and if the voltage value of the first test signal VS1 is smaller than the threshold voltage Vth1 in each connectivity test, it is determined that a fault is detected, and an alarm signal is generated at the alarm pin 5 of the self-test control chip IC 1. When the detection pin 4 detects that the voltage value of the first detection signal VS1 at the node Q1 is equal to or greater than the threshold voltage Vth1, the solenoid SQL connection is considered normal, and the analog leakage detection is performed. The voltage value of the first detection signal VS1 is greater than a threshold voltage, for example, a high level or a pulse.

After the connectivity detection is passed, analog leakage detection is performed in the negative half cycle of the ac power supply, the clock pin 2 of the self-detection control chip IC1 processes the ac signal from the live wire L of the ac circuit to obtain a clock signal, when the clock signal is at the falling edge, the fault pin 1 sends the generated analog leakage signal Vleak to the node Q2, due to the characteristic of the diode D1, the diode D1 is turned off in the negative half cycle of the ac power supply, the thyristor SQ1 is not conducted with the solenoid SQL, but is connected to the detection pin 4 through the node Q1, at this time, the power pin 3 inside the self-detection control chip IC1 is electrically connected to the detection pin 4, the power pin 3 supplies power to the detection pin 4, the voltages of the two are close, for example, 5V, and can equivalently, the two pins are connected through a resistor. The sensing coil SC1 generates a trigger signal Vtri accordingly, pin 1 of the leakage detecting chip IC2 receives the trigger signal Vtri, and outputs a conducting signal Vcon from pin 4 to the gate of the thyristor SQ1 to conduct the thyristor SQ1, and pin 4 is preferably a SCR pin; after the thyristor SQ1 is turned on, when SQ1 is turned on, the diode D2 pulls down the voltage of the node Q1, so that the node Q1 generates a second detection signal VS2, at this time, the detection pin 4 is used for receiving the second detection signal VS2, at this time, the electrical connection between the detection pin 4 and the power pin 3 is disconnected, and the power pin 3 still supplies power to the whole self-test control chip IC 1; when the detection pin 4 of the self-detection control chip IC1 receives the second detection signal VS2, the analog leakage signal Vleak of the fault pin 1 stops sending, and one-time analog leakage detection is completed. Preferably, the second detection signal VS2 is low, and the voltage at the node Q1 detected by the detection pin 4 changes from high to low from the positive half cycle to the negative half cycle of the ac power. If the detection pin 4 of the self-checking control chip IC1 does not receive the second detection signal VS2 with a low level in the negative half-cycle of the ac power, the circuit breaker will repeat the analog leakage detection for multiple ac cycles, and if the detection pin 4 of the self-checking control module 120 does not receive the second detection signal VS2 with a low level in a preset multiple ac cycles, the self-checking control module 120 generates an alarm signal. For example, the analog leakage detection may be performed for four ac cycles, and if the second detection signal VS2 is not detected for four times, the circuit breaker is considered to be in a fault, and when the 4 th cycle is ended and the 5 th ac cycle is started, the alarm pin 5 of the self-test control chip IC1 generates an alarm signal.

This circuit breaker adopts self-checking control module to provide simulation leakage signal, makes the work of electric leakage detection module, opens protection module to through the anodal voltage of the silicon controlled rectifier that detects protection module, judge whether the circuit breaker can normally work, can detect whether this circuit breaker can carry out normal earth leakage protection, play the guard action to the circuit, whole process all is automatic completion after the electricity is gone up, need not the manual work, both improved efficiency, also can protect user's personal safety.

The circuit breaker starts to perform fault detection in at least one alternating current period after being electrified for a preset time, and when the fault detection is performed, the connectivity detection is performed on the protection module in the positive half period of the alternating current power supply, so that the protection circuit can give an alarm in time when the fault occurs; carry out the simulation electric leakage detection alone in alternating current power supply's negative half internal, whether detection electric leakage detection module and protection module can play the earth leakage protection effect when breaking down, carry out two kinds of detections in turn in alternating current power supply's positive and negative half internal, can produce alarm signal when the circuit breaker breaks down, the suggestion user changes the circuit breaker, in time ensures safety. And the normal protection function of the circuit breaker when the circuit really breaks down is not influenced, and the power supply can be cut off in time through the protection module when the circuit leaks electricity.

Fig. 5 shows an operation waveform diagram of the circuit breaker according to the embodiment of the invention when the circuit breaker is normal in function when analog leakage detection is performed. Fig. 5 is a signal waveform diagram of each pin of the circuit breaker described in the embodiment of fig. 4 at the time of fault detection, and in conjunction with fig. 4 and fig. 5, the clock pin 2 of the self-test control chip IC1 is connected to the live line L of the ac circuit through the resistor R6, so that the ac signal of the live line L of the ac circuit is received and processed into the clock signal CLK, so that the clock signal CLK is generated synchronously with the ac circuit, the clock signal CLK is a square wave signal with a high level of about 6V, the period of the clock signal CLK represents the ac period of the ac circuit, and the ac power source is, for example, 110V/60Hz or 220V/50 Hz. After the circuit breaker is powered on for a preset time, the circuit breaker performs fault detection, and the falling edge of the clock signal CLK transmitted by the clock pin 2 enables the fault pin 1 to send an analog leakage signal Vleak to the node Q2 (as indicated by time t1 in the figure), so as to start analog leakage detection. When the fault pin 1 does not generate the analog leakage signal Vleak, the fault pin is equivalent to a high-impedance state when the voltage of the zero line is greater than 0, and the fault pin is clamped near 0V when the voltage of the zero line is less than 0V.

As shown in fig. 5, the time period t0-t1 is the positive half cycle of the ac power, the connectivity detection is performed, the ac signal reaches the anode of the thyristor SQ1 through the solenoid SQL and the diode D1, the anode voltage of the thyristor SQ1 is high, for example, 150V, and the high level is detected by the detection pin 4;

at time t1, the negative half cycle of the ac power supply is entered, and the analog leakage detection is started, and the present embodiment mainly describes the voltage change of the signal received or generated by each pin during the analog leakage detection. At the falling edge of the clock signal CLK, the fault pin 1 sends an analog leakage signal Vleak to the node Q2; in the negative half cycle of the alternating current power supply, the diode D1 is cut off, the voltage of the anode of the thyristor SQ1 drops, the voltage detected by the detection pin 4 drops, however, the detection pin 4 is connected with the power supply pin 3 in the self-checking control chip IC1, the detection voltage of the detection pin 4 is basically the same as the voltage of the power supply pin 3, so the detected voltage drops by a small section and rises, the anode of the thyristor SQ1 is connected to the detection pin 4 through the node Q1, the diode D2 and the resistor R4, and the voltage of the node Q1 is about 0.7V lower than the voltage of the detection pin 4 (the forward conduction voltage of the diode D2).

Before the time t2, the analog leakage signal Vleak pulls down the voltage of the normal zero line N, the induction coil SC1 generates a trigger signal Vtri according to the analog leakage signal Vleak, the alternating current amplitude of the trigger signal Vtri is about 5mV, and at this time, the detection voltage of the detection pin 4 is firstly reduced by a small section and then increased; at time t2, pin 1 of the leakage detection chip IC2 receives the trigger signal Vtri, and outputs a conduction signal Vcon to the gate of the thyristor SQ1 through pin 4(SCR pin), where the conduction signal Vcon is a short pulse of about 700mv, the gate of the thyristor SQ1 receives the conduction signal Vcon and conducts, the detection pin 4 is disconnected from the internal electrical connection of the power supply pin 3, the detection pin 4 detects the voltage of the node Q1, and at this time, the detection pin 4 receives the second detection signal VS2 at the node Q1, and since the diode D2 is turned on, the node Q1 pulls down the voltage of the detection pin 4 through the diode D2, so that the voltage received by the detection pin 4 drops to a low level. Therefore, the circuit breaker can perform normal leakage protection, the voltage of the alarm pin 5 is at a low level, so that fault detection is finished, the fault pin 1 stops sending the analog leakage signal Vleak, the influence of the analog leakage signal Vleak on the voltage of the zero line L disappears, the zero line L returns to an original high level (about 150V), the trigger signal Vtri also returns to an original potential, and fault detection is finished.

the time period t0-t1 is the positive half cycle of the ac power source, the time period t1-t3 is the negative half cycle of the ac power source, e.g., 16.67ms, and the negative half cycle of the ac power source is about 8.33 ms.

Fig. 6 is a waveform diagram illustrating an operation of a circuit breaker when the circuit breaker fails in performing analog leakage detection according to an embodiment of the present invention.

Fig. 6 is a signal waveform diagram of each pin when the circuit breaker described in the embodiment of fig. 4 still performs fault detection when an internal part module has a fault, where the internal fault of the circuit breaker does not include the case where the solenoid SQL is open and the thyristor SQ1 is short, that is, the connectivity detection of the positive half cycle is not affected, and the case where the thyristor SQ1 is short and the solenoid SQL is open will be described in fig. 7a and 7 b. In conjunction with fig. 4 and 5, the fault detection is started at time t0, and the connectivity detection is performed during the time period t0-t1, and the waveform diagrams of the signals are the same as those in fig. 5. This embodiment mainly describes voltage changes of signals of each pin when a breaker failure is found in the analog leakage detection.

At the time t1, the negative half cycle of the alternating current power supply is entered, the analog leakage detection is started, the diode D1 is cut off, the voltage of the anode of the controlled silicon SQ1 is reduced, the voltage of the node Q1 detected by the detection pin 4 is reduced, and the fault pin 1 sends an analog leakage signal Vleak to the node Q2 at the falling edge of the clock signal CLK; the detection pin 4 is connected to the power supply pin 3 inside the self-test control chip IC1, and the voltage is similar, so that a voltage waveform that changes from high to low and then rises appears.

The analog leakage signal Vleak generated by the fault pin 1 is related to the voltage of the zero line, and is a voltage signal obtained by conversion, that is, a voltage waveform obtained by subtracting a voltage waveform obtained by pulling down the voltage of the zero line from a normal voltage waveform of the zero line, that is, a waveform of the analog leakage signal Vleak shown in fig. 6.

In a time period from t1 to t2, if the sensing module 110 functions normally, the sensing coil SC1 generates a trigger signal Vtri according to the analog leakage signal Vleak, and pin 1 of the leakage detection chip IC2 receives the trigger signal Vtri, but since other parts of the circuit breaker have faults (for example, the leakage detection chip IC2 has faults), the leakage detection chip IC2 cannot output a conduction signal Vcon to the control electrode of the thyristor SQ1, and the level of the SCR pin is still low level, at this time, since the thyristor SQ1 is not conducted, the voltage detected by the detection pin 4 is not changed, and the voltage of the detection pin 4 is always high level; at the moment, the circuit breaker is ready for fault detection in the next alternating current period to verify whether the circuit breaker really has faults or not, so that the detection is continued, and at the moment of t2, the circuit breaker starts to enter the positive half period of the alternating current power supply, and the analog leakage signal Vleak cannot be generated;

in a time period from t1 to t2, if the sensing module 110 fails, the sensing coil SC1 cannot generate the trigger signal Vtri according to the analog leakage signal Vleak, and the trigger signal Vtri is always 0, so that the leakage detection chip IC2 cannot output the conduction signal Vcon to the control electrode of the thyristor SQ1, and the conduction signal Vcon of the SCR pin is always 0, which is consistent with the above description; the circuit breaker is now ready for the next ac cycle of fault detection to verify whether the circuit breaker has indeed failed.

Therefore, no matter which part of the circuit breaker fails, as long as the detection pin 4 does not detect the low-level second detection signal VS2 at the node Q1 after the thyristor SQ1 is turned on in the analog leakage detection stage, it is considered that the circuit breaker may fail, and multiple cycles of analog leakage detection are required again to determine whether the circuit breaker really fails, so that after time t2, whether the sensing module 110 normally operates has no influence on the voltage values of other pins.

At time t2, starting a new fault detection of the ac cycle, during the time period t2-t4, the trigger signal Vtri varies in the form of a half-wave of a sine wave, and the rest of the signal coincides with the waveform during the time period t0-t 2;

fault detection of a third alternating current cycle and a fourth alternating current cycle is carried out in a time period t4-t6 and a time period t6-t8 respectively, and the waveform change of each signal in the time period t4-t6 and the time period t6-t8 is consistent with the waveform change in the time period t2-t 4;

at time t8, the fault detection of the 4 th ac cycle is finished, and in the 4 analog fault detection stages, the second detection signal VS2 with low voltage is not detected at the detection pin 4, so that the circuit breaker is deemed to be actually faulty and the fault detection is finished. At this time, the alarm pin 5 outputs an alarm signal, the alarm signal is, for example, a square wave signal with a high level of 5V, and the alarm signal is, for example, expressed in a form of flashing of an LED lamp or in a form of buzzer buzzing; but is not shown in the form of a square wave signal because of the short time period represented in the figure.

Fig. 7a and 7b are waveform diagrams illustrating the operation of the circuit breaker according to the embodiment of the invention when the thyristor is short-circuited and the solenoid is open-circuited during the connectivity detection.

As shown in fig. 7a, connectivity detection is started at time t0, if a thyristor SQ1 is short-circuited, the anode voltage of a thyristor SQ1 is always 0, the thyristor SQ1 cannot be turned on, the voltage detected by a detection pin 4 is always 0, and the detection pin 4 does not detect a first detection signal VS1 of a high level, so that it is considered that the circuit breaker may have a fault, and at this time, connectivity detection of a plurality of ac cycles is required, so that once connectivity detection is performed again from time t2, after the four ac cycles of connectivity detection are performed at time t0-t2, t2-t4, t4-t6, and t6-t8, the detection pin 4 does not detect the first detection signal VS1 of a high level, and it is considered that the circuit breaker has actually failed, so that an alarm signal is generated at time t8 at the alarm pin 5. The alarm signal is, for example, a square wave signal, which is displayed in the form of a buzzer or in the form of flashing of an LED lamp, and the high level of the square wave signal is, for example, 5V, and the square wave signal is not shown in the figure because of the short time.

As shown in fig. 7b, when the connectivity detection is started at time t0 and the solenoid SQL is opened, the anode voltage of the thyristor SQ1 is 0 and the voltage detected at the detection pin 4 is 0, and it is determined that the circuit breaker may fail; at time t1, when the negative half cycle of the ac power supply is entered, the voltage at node Q1 is detected at pin 4, and the voltage at pin 4 is high due to the presence of pin 3.

At the time t2, the positive half cycle of the alternating current power supply is entered again, and then the connectivity detection of other alternating current cycles is carried out to prevent false alarm, wherein the time periods of t2-t4, t4-t6 and t6-t8 are shown in the figure; the connectivity detection is carried out for three repeated alternating current cycles at t2-t4, t4-t6 and t6-t8, and all voltages detected by the detection pins 4 are 0 in the three alternating current cycles to confirm that the circuit breaker has a fault, so that an alarm signal in the form of a square wave is generated at t 8.

Embodiments of the invention are described above, and these embodiments do not set forth any exhaustive details or limit the invention to the specific embodiments described. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. The scope of the invention should be determined from the following claims.