KR101094621B1 - Electronic circuit and signal processing method of auto reset earth leakage breaker - Google Patents

Abstract

The present invention relates to an automatic recovery earth leakage circuit breaker, comprising: an earth leakage detection circuit capable of simultaneously detecting and inspecting an earth leakage before and after the secondary power is shut off; An overcurrent detection circuit capable of real-time inspection of current usage and overcurrent inspection before and after the shutdown of the secondary power; It consists of a central processing unit that identifies the cause of the abnormal power supply after shutting off the secondary power supply and, if the cause is eliminated, attempts to recover.

Description

Electronic circuit and signal processing method of automatic recovery earth leakage breaker {ELECTRONIC CIRCUIT AND SIGNAL PROCESSING METHOD OF AUTO RESET EARTH LEAKAGE BREAKER}

The present invention relates to a ground fault circuit breaker, and more particularly, the cause of the electrical shock which operates the ground fault circuit breaker is read by using the circuit proposed in the present invention, and before the repair, the absence of a ground fault breaker is rechecked if there is no abnormality. The present invention relates to an electronic circuit and a signal processing method of an automatic recovery earth leakage breaker capable of restoring operation.

The earth leakage breaker with automatic recovery function automatically restarts the breaker by re-entering the circuit without manual operation, as specified in the “Safety Standard for Automatic Reclosing Earth Leakage Breaker” announced by the Technical Standards Institute on December 4, 2008. An earth leakage circuit breaker having an automatic reclosing function is provided. When the ground fault circuit breaker trips due to a ground fault in the conventional method, the presence or absence of a ground fault is determined by using a grounding wire to determine whether the ground fault occurs during restoration (for example, refer to Patent Document 1). In general, an earth leakage breaker of less than 30A, which is generally used, has a problem in that it is not easy to actually apply the grounding wire. The voltage of the unstable ground wire installed at the site may be very inaccurate in determining whether there is a short circuit, and when used alone as an outdoor power source, the ground line may be very vulnerable to lightning, which may cause a lot of practical limitations.

In addition, in the case of detecting a short circuit by detecting a short circuit before breaking, there is a disadvantage in that it is indistinguishable from a power interruption due to a momentary and temporary impulse voltage (surge voltage). If the power is temporarily cut off due to the voltage abnormality, it may be necessary to restore the power by determining that a normal short circuit has not occurred, but failing to raise it because it is determined as a continuous short circuit.

Even in case of automatic recovery earth leakage breaker (100) with communication support (RS232, RS485, etc.), if the power is cut off due to tripping of the breaker, the communication is repeatedly cut off at the same time. Functions can be useless. Such a problem of communication failure may occur at any time when the power of the communication repeater is connected to the secondary terminal of the circuit breaker. In order to avoid communication breakdown in the conventional method, it is inconvenient that a separate power source must be connected to the communication repeater so that the communication function can be performed even after the power is cut off. Afterwards, there was a disadvantage that the communication connection can only be maintained for a certain time.

[Patent Document 1] Korean Patent No. 10-0929499

The present invention has been proposed in order to solve the above problems, an object of the present invention is to detect the cause of the breaker of the circuit breaker (or surge voltage), short circuit, overcurrent before blocking and after a short time, such as short circuit and overcurrent It is to provide a circuit and signal processing for the automatic recovery earth leakage breaker (100) to check the input signal state to recover to the initial state by the recovery procedure proposed in the present invention if the problem is solved.

The earth leakage test method has been developed to detect the earth leakage current without the use of ground wire, making it suitable for use in industrial sites.

In addition, the amount of current can be known by real-time communication so that the load (street light, communication repeater, etc.) is abnormal. Until now, the circuit breaker with automatic recovery has no specific means of viewing the amount of current in real time, so there is a limit to maximizing the need for remote control in addition to the automatic recovery. When real-time current monitoring is possible for the remote control of the street lamp, it is possible to determine the lighting of the street lamp as well as the remote control function, which may have the advantage of quickly replacing the bulb of the street lamp.

When a single power source is used and the communication equipment is connected to the secondary power source, the power supply can be remotely shut off and the recovery time can be set after the shutdown so that the communication function can be restored after a certain time. There is no need to use a separate earth leakage breaker for telecommunication support equipment, which has the advantage of reducing installation costs.

As described above, it provides a proper electronic circuit configuration and signal processing for a suitable and reliable self-recoverable earth leakage breaker applicable to industrial sites.

In addition, it is possible to check the amount of current used through remote support, and indirectly identify the abnormality of the load at the same time, thereby improving the operational efficiency of the equipment.

1 is a circuit diagram illustrating an earth leakage test circuit of an automatic recovery earth leakage breaker according to an exemplary embodiment of the present invention.
2 is a diagram illustrating an earth leakage test output signal of an automatic recovery earth leakage circuit breaker according to an exemplary embodiment of the present invention.
3 is a circuit diagram showing the load current amount of the automatic recovery circuit breaker according to the embodiment of the present invention.
Figure 4 is a flow chart showing the control step of the central processing unit of the automatic recovery earth leakage breaker in accordance with an embodiment of the present invention
5 is a view showing a remote control of the automatic recovery earth leakage breaker according to an embodiment of the present invention.

(Example)

In order to achieve the above object, the earth leakage test circuit 200 does not need to use a ground wire; An overcurrent inspection circuit 300 for monitoring current in real time; The automatic recovery earth leakage breaker (100) comprising; a central processing unit (70) for real-time monitoring of the surge voltage, short circuit, and overcurrent impact voltage and the like, and the power recovery operation only when the short circuit and short circuit does not occur to provide.

1 is a circuit diagram of an earth leakage test circuit of the present invention, FIG. 2 is an output signal of the earth leakage inspection circuit of FIG. 1, an overcurrent inspection and detection circuit of FIG. 3, FIG. 4 is a flowchart showing a control step of a central processing unit, and FIG. A diagram showing remote control of a recovery earth leakage breaker.

(Earth Leakage Circuit)

As shown in FIG. 1, the ground fault inspection circuit 200 of the present invention includes a power supply control unit 10, a ground fault inspection signal generation unit 20, a ground fault detection unit 30, and an output control unit 40.

The power control unit 10 is a configuration diagram for controlling the power supply so that a single-phase 220V hot line and a neutral line can be alternately supplied using two relays 10a and 10b. In the non-operational state, the relay 1 10a and the relay 2 10b are connected with a contact point 1-3, and conversely, the contact point 2-3 is operated so that a voltage of 220V can be used as a power supply for an electric leakage detection circuit at an intersection. do. This is to use 220V hot line and neutral line as power source for short circuit test.

The power passing through the power control unit 10 is changed by the ground fault inspection signal generator 20 to the ground fault inspection voltage and current value to be supplied to the secondary load. The low voltage generator 20a lowers the high input voltage to a low voltage suitable for the earth leakage test signal. The voltage output to the low voltage generator 20a again limits the voltage between both ends through the zener diodes ZD1 and ZD2 to the zener voltage (40 V in the embodiment of the present invention). The anode terminal of the zener diode ZD1 is connected to the lower line 20b of the voltage output from the power supply controller. Connect to the cathode terminal of the Zener diode to the left terminal of the resistor (R _out ) in the direction of the output terminal, so that the short circuit and overcurrent does not occur during the short circuit test even in the short circuit state of the load 400, and the final output is formed through the diode D1 It serves to protect the current from flowing backward from the load 400.

The ground fault detecting unit 30 finally determines whether the signal output through the amplification and ground fault detection signal generator 30b is present in the central processing apparatus 70.

In addition, by adjusting the number of wires 30c passing through the image current transformer 30a, the sensitivity of the short circuit may be adjusted, and the number of the wires 30c may be increased to effectively detect a small short circuit current. In other words, Izct (image current transformer output current) is proportional to N (number of passing wires) * I _leakage (leakage current).

On the other hand, Fig. 2 is a ground fault test signal waveform, which can be obtained by controlling the relay 3 (40a) and the relay 4 (40b) by the central processing unit (70). In order to send an earth leakage signal to the left line of the secondary side of the automatic recovery earth leakage breaker 100, the relay 3 40a is turned on and maintained so that the switch is closed, and the relay 4 40b maintains the non-operation state of the switch. Should remain open. By the operation of the relay 3 40a, the ground fault detection signal output from the ground fault inspection signal generator 20 is introduced into the left line of the secondary power supply. Immediately after 200 ms, all the relays are released immediately, and after the relays 40a and 40b maintain 300 ms intervals in the non-operational switch-off state, the relay 3 40a maintains the non-operational state and the relay 4 (4b). Maintains an operating state and introduces the signal output from the ground fault inspection signal generation unit 20 to the right line of the power supply on the secondary side. After 200ms, all the relays are deactivated and wait 12.300s. Set 13 seconds in total. The repetition of the above one cycle is the ground fault test signal waveform shown in FIG. 2. The reason why the secondary power is applied to each of the secondary power sources is that the resistances 80a and 80b due to a short circuit may occur at each of the secondary power lines.

(Earth Leakage Circuit Operation)

Subsequently, a specific earth leakage test operation will be described.

The auto-recovery earth leakage breaker shuts off the power due to any electric shock or short circuit, and sends a short circuit detection signal to the secondary power supply to check the earth leakage condition before recovery.

First, power is supplied from the power controller 10 to the non-operation state of the relays 10a and 10b. That is, the contacts of the relays 10a and 10b maintain 1-3. The applied power generates AC 40V through the ground fault inspection signal generation unit 20. The generated alternating current 40V passes through the ground fault detecting unit 30 and sends the waveform shown in FIG. 2 by the output control unit 40 to the secondary terminal. If the ground fault current generated at the terminal on the secondary side is greater than or equal to a set current threshold value, the ground fault detection unit 30 immediately generates a ground fault detection signal and notifies the connected central processing unit 70. A separate display can be controlled through the central processing unit 70. For example, when a short circuit occurs, the LED lamp (not shown), which is a separate display device, blinks.

In the same manner, the power supply controller 10 operates the relays 10a and 10b to cross the supply of the primary power, and repeats the above-mentioned short circuit test procedure. That is, when the relays 10a and 10b operate, the contact is maintained at 2-3 so that the power line is crossed and the power control unit 10 is supplied.

(Overcurrent test circuit)

As shown in FIG. 3, the overcurrent inspection circuit 300 includes an overcurrent sensing signal generator 50 and an overcurrent sensing unit 60.

The overcurrent detecting unit 60 measures the current passing through the inner diameter of the current transformer 60a through the output of the current transformer 60a.

In addition, by adjusting the number of wires (60c) penetrating the inner diameter of the current transformer (60a) it is possible to adjust the sensitivity of the short-circuit, it is possible to effectively detect a very small short-circuit current by increasing the number of wires. In other words, Ict (output current of the current transformer 60a) is proportional to N (number of through wires) * I (current flowing through a wire).

(Overcurrent test circuit operation)

Subsequently, a specific current test operation will be described.

When the automatic recovery earth leakage breaker 100 is cut off due to any electric shock or short circuit besides an electric short circuit or an over current, a short circuit detection signal is sent to the secondary power supply, and there is no abnormality through a short circuit test before recovery, an over current and a short circuit test. It will try to recover.

In order to check the over-current and short-circuit state after the interruption, the overcurrent test low voltage generator 50a of the overcurrent detection signal generator 50 outputs an alternating current of 40 V, and then operates two relays 50b and 50c to the outside. Make output The upper power supply line (see FIG. 3) of the signal output from the overcurrent detection signal generator 50 passes through the inner diameter of the current transformer 60a and is connected to the left line of the secondary power supply terminal. The remaining lower (see Figure 3) output line is connected to the right side of the secondary power supply. The current measured depends on the resistance of the secondary load 400. The voltage output through the current transformer 60a is converted into a current value that is actually flowing in the current measurement and overcurrent detection determination circuit 60b and is transmitted to the central processing unit 70 in real time. In the central processing unit, it is possible to set the value of the current in the current measurement and overcurrent detection discrimination circuit 60b to determine whether the overcurrent, the load is connected, and whether it is at an appropriate level. For example, if the measured current value is more than the overcurrent set value, it is overcurrent. If the load is less than the minimum use set value, the load is not connected. If it is used in an appropriate range, it can be determined as a normal state.

(Automatic Recovery Circuit Breaker (100) Automatic Recovery Process)

4 is a flowchart illustrating a control step of the central processing unit 70 of the automatic recovery earth leakage breaker 100 according to the embodiment of the present invention.

When the power is not cut off, the load is normally operated by the power supply, and the central processing unit 70 uses the leakage detection unit 30 and the overcurrent detection unit 60 to monitor the secondary power state in real time. Will be monitored.

When the power is cut off (S100), the cause of operation is determined according to the signals transmitted from the ground fault detecting unit 30 and the overcurrent detecting unit 60, and when it is determined that the power is cut off by the overcurrent (S110), no recovery attempt is performed. In addition, the LED lamp (not shown), which is a separate display device, blinks and informs the user that the LED has fallen due to overcurrent.

If the cause of the interruption is not the overcurrent, it is determined whether or not the electric leakage has fallen more than the set number of electric leaks (four times in the embodiment) within 30 minutes of the predetermined time. If the power is cut off for more than 4 consecutive times of leakage, LED lamp (not shown), which is a separate display device, is blinked and the user is notified of continuous leakage.

If it is determined that the current is not a continuous short circuit, the ground fault detection circuit 200 determines whether a short circuit occurs in the secondary line (S130), and in turn, the overcurrent test circuit 300 checks the overcurrent. (S140). If a short circuit or an overcurrent is detected (S150), the test is repeated within a predetermined time (1 hour in the present invention) (S160). If the short-circuit or overcurrent is not resolved even when the test is performed within the test time, the test is terminated and the LED lamp (not shown), which is a separate display device, blinks to notify the user that the test time is exceeded.

When the short-circuit and overcurrent phenomena are eliminated within the set inspection time (S150), the power is restored (S170).

The cause of the power cut off and the number of recovery attempts are stored in the memory in the CPU 70 so that the user can see it at any time.

(Communication function)

In adding the communication function according to the present invention, a function of automatic recovery after a certain time after the addition is added. As shown in FIG. 5, the communication repeater 500 that enables remote control is connected to the secondary side of the automatic recovery earth leakage breaker 100 so that even after the communication is cut off at the same time as the interruption command of the breaker in the remote server 600, It is restored so that the communication is not permanently disconnected.

As shown in FIG. 3 through communication, the current value obtained through the current sensing unit 60 can be obtained in real time, so that the amount of current used can be grasped. If there is no current consumption in the state that power is not cut off, it can be used as a means to determine the abnormality of the load.

Although described with respect to the preferred embodiment of the present invention as described above, those of ordinary skill in the art, the present invention without departing from the spirit of the invention defined in the appended claims It can be carried out in a variety of variations. For example, by providing a display device in addition to the LED lamp in the automatic recovery circuit breaker according to the present invention it can be more effective to inform the user of various situations (circuit, short circuit, etc.). In addition, if a short circuit or current reference value detected by the user is detected, a monitoring signal may be separately created using a comparator.

10: power control unit 20: earth leakage test signal generator
30: leakage detection unit 40: output control unit
50: overcurrent detection signal generator 60: overcurrent detection unit
70: central processing unit 80: earth leakage resistance
100: automatic recovery earth leakage breaker 200: earth leakage inspection circuit
300: overcurrent test circuit 400: load
500: communication repeater 600: remote server

Claims (9)

In the automatic recovery earth leakage circuit breaker that cuts off the power according to the cause of the short circuit, short circuit, and other electric shock, and automatically recovers when there is no abnormality through the short circuit and short circuit test,
A short circuit detecting circuit capable of real-time monitoring of a short circuit of the secondary power before the secondary power is cut off, and a short circuit test after the power is cut off;
An overcurrent detection circuit which monitors the current consumption of the load in real time before the secondary power is cut off and performs an overcurrent inspection test after the power is cut off; And
A central processing unit for generating a control signal to determine the cause of operation of the automatic recovery earth leakage breaker according to the signals transmitted from the sensing circuits and to recover the automatic recovery earth leakage breaker;
The ground fault detection circuit for inspecting the ground fault after the power is cut off, includes: a power control unit controlling the power line to be changed by receiving power;
An earth leakage test signal generation unit configured to receive a power output from the power control unit and output a lowered voltage for an earth leakage test;
A ground fault detecting unit for receiving a signal from the ground fault inspection signal generation unit and passing the signal to an inner diameter of the current transformer to determine the amount of the ground fault current; And
And an output control unit which receives a signal from the ground fault detecting unit and selects and outputs a terminal to be inspected.
delete The method according to claim 1,
The ground fault detection unit allows a ground fault monitoring by passing the secondary power line before the secondary side power cut to the inner diameter of the video current transformer, and when the ground fault inspection is performed after the secondary side power cut, the signal line output from the ground fault inspection signal generator is output to the image current transformer. Automatic recovery earth leakage circuit breaker, characterized in that configured to adjust the leakage current sensitivity by passing through the inner diameter of several times. The method according to claim 1,
The output control unit is a self-recovery earth leakage circuit breaker, characterized in that consisting of a relay for selectively controlling the terminal, the electrical separation between the lines. The method according to claim 1,
The overcurrent detection circuit includes an overcurrent detection signal generator; And
An auto-recovery earth leakage circuit breaker including an overcurrent detection unit that measures the current used for the load in real time before the power is cut off, and determines an overcurrent and a short circuit condition after the power is cut off. The method according to claim 5,
The overcurrent detector passes one of the secondary power lines through the inner diameter of the current transformer before shutting off to monitor the amount of current used in the load, and the signal line output from the overcurrent detection signal generator during the overcurrent inspection after the secondary power is cut off. Auto-recovery earth leakage circuit breaker, characterized in that for adjusting the current sensitivity by passing one of the lines through the inner diameter of the current transformer multiple times. The method according to claim 1,
The CPU may determine whether the load state is overcurrent, no load, and proper state according to the current value setting range, and generate a signal so that the state of the load may be distinguished using a display device and a buzzer. Automatic recovery earth leakage breaker. The communication repeater of claim 1, further comprising a communication repeater connected to the secondary side to recover after a certain period of time even if the communication is cut off at the same time as the blocking command of the breaker at the remote server so that the communication is not permanently disconnected. Automatic recovery earth leakage breaker. In the method of determining the power recovery after the power is cut off,
A first step of determining the cause of the electric shock before the interruption;
A second step of generating a warning signal without attempting to recover when it is determined that the cause of interruption is an overcurrent or a short circuit;
A third step of performing a short circuit test when it is determined in step 2 that the current is not an overcurrent or a short circuit;
A fourth step of checking whether there is an overcurrent or a short circuit; And
A self-recovery earth leakage circuit breaker comprising five steps of periodically checking the test inspection of the third and fourth stages within the time set by the user, and recovering the power if it is determined that there is no short circuit, overcurrent, and short circuit within the time. .

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