KR102569278B1 - Removable electric leakage breaking module of PCB for preventing frequency noise malfunction and its device - Google Patents

Abstract

The present invention relates to an earth leakage blocking module and earth leakage breaker for preventing malfunction of frequency noise, which is attachable to and detachable from a PCB.
According to a preferred embodiment of the present invention, a signal processing unit to which a detection signal is input from a zero-phase current transformer (ZCT) or a current sensor; an output driver for receiving an earth leakage detection signal from the signal processing unit and outputting a cutoff signal to a cutoff mechanism to perform a power supply voltage cutoff operation when the input signal is out of the trip level; a circuit protection unit for protecting a circuit from high-frequency noise between the zero-phase current transformer (ZCT) or current sensor and the signal processing unit; Provided is an earth leakage blocking module for preventing malfunction of frequency noise that is detachable to a PCB and an earth leakage breaker using the same.

Description

Removable electric leakage breaking module of PCB for preventing frequency noise malfunction and its device}

The present invention relates to an earth leakage blocking module for preventing malfunction of frequency noise that is detachable from a PCB and an earth leakage breaker using the same.

Unless otherwise indicated herein, material described in this section is not prior art to the claims in this application, and inclusion in this section is not an admission that it is prior art.

In general, an earth leakage breaker is a device that detects leakage current generated from load equipment or lines and blocks main power to protect load devices, lines, and human bodies.

It is a well-known fact that electrical facilities supplied to the load side from household or industrial power lines are obliged to install an earth leakage breaker to cut off the main power within a certain period of time when an earth leakage occurs in order to protect load equipment and lines from disasters caused by leakage current. am.

In other words, an earth leakage breaker is widely used as a device for preventing human accidents or fires by detecting leakage current of various electric wires and devices and cutting off power supplied to the corresponding electric lines and devices when the leakage current is detected.

1 is a conventional leakage current detection circuit configuration. As shown in Figure 1, a general leakage current detection circuit configuration is composed of a power supply unit 10, a signal processing unit 20, an output driving unit 30, and a breaker unit 40.

As shown in FIG. 1, the power supply unit 10 supplies necessary power and voltage to the signal processing unit 20 and the output driving unit 30. The signal input through the signal input to the signal processing unit 20 is a leakage current detection signal, and a zero phase current transformer (ZCT) or current sensor 50 from an AC power (220V, 60Hz) line or a DC power line. ), a current or voltage signal induced by is input.

2 shows an input signal and an output signal in a conventional leakage current detection circuit.

As shown in Figure 2, when this input signal is out of the trip voltage level, the signal processing unit transmits a leakage detection signal to the output driver, and the output driver converts this signal into a trip signal. According to the amount of current required by the cut-off mechanism, a current of several uA to hundreds of mA is output to operate the cut-off mechanism to cut off the power supply voltage.

In the normal state where there is no leakage, the input signal is located inside the trip level, so no trip signal is generated from the output driver in the earth leakage breaker circuit. When the input signal is out of the trip level, a trip signal is generated in the output driver, and the earth leakage breaker proceeds with the breaking operation.

However, in the prior art of such a general earth leakage breaker, the following problems have existed.

(1) It is an increase in cost and defect rate due to the limitation of automation in the manufacturing process of integrated earth leakage blocking module.

That is, with the development of industry and the increase in the supply and utilization of electronic devices, the use of earth leakage breakers has become essential in various environments, and earth leakage breakers of various specifications are being provided to the market accordingly. In such an earth leakage breaker, various types of semiconductors and devices are mounted on a PCB (printed circuit board), and since they are implemented on a single PCB, it is difficult to standardize/automate and secure stable output.

In addition, in the process of inserting leakage-blocking semiconductors and elements into the leakage-blocking PCB, mechanical automatic work using equipment and manual work are mixed, resulting in an increase in the defect rate and difficulty in identifying the cause of the defect, resulting in an increase in production cost.

In addition, the integrated PCB manufacturing method has limitations in the range of use for various purposes, so it has limitations in factory automation / production facility automation and usage.

(2) Occurrence of malfunction due to low-frequency noise.

Existing earth leakage blocking circuits are exposed to various switch operations and DC electric devices and various electromagnetic environments, unlike the ZCT, which is a signal generating sensor, or the intrinsic earth leakage signal of a current sensor, so that a noise signal is input and leakage does not occur. Even in this case, a signal exceeding the tripping range is received and an earth leakage blocking signal is transmitted, resulting in malfunction of the earth leakage breaker.

Due to changes in various usage environments of earth leakage circuit breakers, malfunctions due to low-frequency noise of several Hz to tens of Hz have been reported, which greatly deviate from the rated current frequency range of ±0.2 Hz of 50 Hz or 60 Hz, which is the frequency of general AC current lines. .

(3) Malfunction due to low frequency, harmonic and high frequency mixed frequency noise.

Wire noise, which includes various high-frequency electromagnetic waves, distorts the intrinsic earth leakage signal generated from the ZCT or current sensor, damaging the reliability of the earth leakage breaker, and causing damage to various electrical equipment and precision measuring equipment due to malfunction of the earth leakage breaker. Since various low frequency, harmonic and high frequency malfunction signals are input to the earth leakage blocking circuit instead of the intrinsic earth leakage signal from the zero phase transformer (ZCT) or current sensor, the load is continuously transmitted to various elements. Therefore, it becomes a factor that shortens the life of earth leakage breaker.

Figure 3 shows low-frequency, harmonic and high-frequency mixed frequency noise input to the earth leakage blocking circuit measured in actual equipment.

The present invention is intended to be improved in consideration of the above conventional problems, and implements a detachable modular PCB so as to achieve automation and a reduction in defect rate through modularization of the earth leakage breaker PCB, and a device using a low frequency to a zero-phase current transformer approaches. To provide an earth leakage blocking module for preventing malfunction of frequency noise that can be attached to and detached from a PCB and an earth leakage breaker using the same to prevent malfunction in which the leakage current detection output is tripped even when there is no leakage current due to low frequency noise in the input signal. there is

In addition, another object of the present invention is to make it easy to check defects through a test before the detachable earth leakage blocking module is applied to the PCB, so that the defect rate is reduced and it is easy to identify the cause of defects in subsequent work, thereby reducing costs. It is easy to check the defect even when a problem occurs after mounting the earth leakage blocking module, and it is easy to replace and repair by replacing the earth leakage blocking module. there is.

In addition, another object of the present invention is to supply a detachable earth leakage blocking module of a certain quality to the market stably so that standardization of the earth leakage blocking module is possible. An earth leakage blocking module for preventing malfunction of frequency noise that is attachable to and detachable from a PCB and an earth leakage breaker using the same. is to provide

In addition, it is not limited to the technical problems as described above, and it is obvious that other technical problems may be derived from the following description.

According to an embodiment of the present invention, an earth leakage blocking module for preventing frequency noise malfunction detachable from a PCB includes a signal processing unit to which a detection signal is input from a zero-phase current transformer (ZCT) or a current sensor, and the signal processing unit when the input signal is out of a trip level. An output driver that receives an earth leakage detection signal from the processing unit and outputs a blocking signal to the blocking mechanism unit to perform a power supply voltage blocking operation, and between the zero-phase current transformer (ZCT) or current sensor and the signal processing unit, a circuit is protected from high-frequency noise. It is characterized in that it includes a circuit protection unit for protection and a noise removal unit for eliminating malfunctions caused by low frequency, harmonic and high frequency noise.

An earth leakage breaker according to another embodiment of the present invention is characterized in that it includes an earth leakage blocking module for preventing malfunction of frequency noise that is attachable to and detachable from a PCB and a circuit breaker for cutting off power voltage according to the blocking signal.

According to a preferred embodiment of the present invention, the earth leakage blocking module is characterized in that a rectangular concave portion is formed on one side in a horizontal direction so as to span the PCB, and a rectangular or round concave portion is formed at a square corner portion.

According to a preferred embodiment of the present invention, the noise canceling unit receives the output of the circuit protection unit and the leakage detection signal of the zero-phase current transformer (ZCT) or current sensor when the input signal is out of the trip level due to leakage or malfunction frequency noise and pulses A pulse signal detector that converts into a signal, a counter that counts the pulse generated from the pulse signal detector so that it increases by 1 from 0 to N whenever a pulse is input, and an output signal operation is performed after a certain delay time after the pulse signal is input It is characterized by including a delay time generation and output device and a comparator for outputting a signal by comparing whether preset N pulses have been counted during a certain delay time or determining whether a predetermined time has been delayed when N pulses have been counted. .

According to a preferred embodiment of the present invention, when the output signal from the comparator is transferred, the delay time generator and output unit transfers the output signal of the noise canceling unit to the output driver.

According to a preferred embodiment of the present invention, the circuit protection unit is characterized in that it is composed of one or more capacitors, or a resistor or diode connection circuit is formed and included in the capacitor.

According to the present invention, since the earth leakage blocking module can be attached to and detached from the PCB, there is an effect of achieving automation in the manufacturing process, and low-frequency noise is generated in the input signal, so that it is tripped by the output of the leakage current detection circuit even when there is no earth leakage state. It has the effect of preventing malfunctions.

According to the present invention, it is easy to check defects through a test before the detachable earth leakage blocking module is applied to a PCB, so the defect rate is reduced, and it is easy to identify the cause of defects in subsequent work, thereby reducing costs. Even when a problem occurs after mounting the blocking module, it is easy to check the defect, and replacing and repairing the earth leakage blocking module is easy.

According to the present invention, standardization of earth leakage blocking modules is possible by stably supplying detachable earth leakage blocking modules of constant quality to the market.

The effects of the present invention are not limited to the above effects, and should be understood to include all effects that can be inferred from the detailed description of the present invention or the configuration of the invention described in the claims.

1 is a block diagram of a typical leak current detection circuit in the prior art;
2 is an operating state diagram of an earth leakage circuit in a general earth leakage breaker of the prior art.
3 is a state diagram of low-frequency, harmonic, and high-frequency mixed frequency noise input to an earth leakage blocking circuit measured in actual equipment;
4 is a configuration diagram of an earth leakage blocking module for preventing malfunction of frequency noise detachable from a PCB according to an embodiment of the present invention.
5 is a comparison diagram between a detachable earth leakage blocking module and a conventional earth leakage blocking module according to an embodiment of the present invention.
6 is a front view, a top view, a side view, a bottom view, and a sample perspective view of an earth leakage blocking module for preventing malfunction of frequency noise detachable from a PCB according to an embodiment of the present invention.
7 is a block diagram of a low-frequency noise removal unit of an earth leakage blocking module for preventing malfunction of frequency noise that is attachable to and detachable from a PCB according to an embodiment of the present invention.
8 is a state diagram of operating waveforms of a noise removal unit of an earth leakage blocking module for preventing malfunction of frequency noise that is attachable to and detachable from a PCB according to an embodiment of the present invention.
9 is a state diagram of an operating waveform of a noise canceling unit in a noise-affected state a of an earth leakage blocking module for preventing malfunction of frequency noise detachable from a PCB according to an embodiment of the present invention.
10 is a state diagram of an operation waveform of a noise canceling unit in a noise-affected state b of an earth leakage blocking module for preventing malfunction of frequency noise detachable from a PCB according to an embodiment of the present invention.
11 is a diagram of an output current amplitude change of a signal passing through a circuit protection unit of an earth leakage blocking module for preventing malfunction of frequency noise detachable from a PCB according to an embodiment of the present invention.
12 is a block diagram of high frequency prevention circuits of various circuit protection units of an earth leakage blocking module for preventing malfunction of frequency noise detachable from a PCB according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, referring to the accompanying drawings, an earth leakage blocking module for preventing malfunction of frequency noise detachable from a PCB according to a preferred embodiment and an earth leakage breaker using the same will be described in detail.

For reference, in the drawings below, each component is omitted or schematically illustrated for convenience and clarity, and the size of each component does not reflect the actual size. In addition, like reference numerals refer to like components throughout the specification, and reference numerals for like components in individual drawings will be omitted.

1 to 3 are diagrams of a general leakage current detection circuit configuration, an operating state diagram of the leakage circuit, and a state diagram of low frequency, harmonic and high frequency mixed frequency noise input to the leakage blocking circuit measured in actual equipment according to the prior art.

4 is a configuration diagram of an earth leakage blocking module for preventing malfunction of frequency noise detachable from a PCB according to an embodiment of the present invention. 5 is a comparison view of a detachable earth leakage blocking module and a conventional earth leakage blocking module, FIG. 6 is a front view, a top view, a side view, a bottom view, and a sample perspective view of the earth leakage blocking module of the present invention, and FIG. 7 is a sample perspective view of the earth leakage blocking module of the present invention Figure 8 is a block diagram of the low-frequency noise canceling unit, Figure 8 is a state diagram of the operating waveform of the noise canceling unit of the earth leakage blocking module of the present invention, Figure 9 is a state diagram of the operating waveform of the noise canceling unit in the noise effect state a of the earth leakage blocking module of the present invention 10 is a state diagram of the operation waveform of the noise canceling unit in the noise-affected state b of the earth leakage blocking module, and FIG. 11 is a diagram of the output current amplitude change of a signal passing through the circuit protection unit of the earth leakage blocking module of the present invention. It shows a block diagram of a high frequency prevention circuit of various circuit protection units of the invention.

Referring to an embodiment of the present invention with reference to FIG. 4, the earth leakage blocking module 200 for preventing frequency noise malfunction detachable from a PCB is configured to receive a detection signal from a zero-phase current transformer (ZCT, 400) or a current sensor 400. The signal processing unit 220 and, when the input signal is out of the trip level, receives the leakage detection signal from the signal processing unit 220 and outputs a blocking signal to the circuit breaker unit 300 to perform a power supply voltage blocking operation. A circuit protection unit 240 for protecting the circuit from high-frequency noise between the driver 230, the zero-phase current transformer (ZCT, 400) or the current sensor 400 and the signal processing unit 220, and low-frequency, harmonic and It is characterized in that it includes a noise removal unit 250 for removing malfunction due to high-frequency noise.

4a and 4b are schematic diagrams of an earth leakage blocking circuit to which an earth leakage blocking module for preventing frequency noise erroneous operation detachable from a PCB of the present invention is applied.

As shown in Figure 4, the present invention is basic consisting of a signal generator 400, a signal processor 220, and an output driver 230 of a zero-phase current transformer (ZCT) or current sensor, like a conventional leakage current detection circuit. It is configured by adding a circuit protection unit 240 to protect the circuit from high-frequency noise and a noise removal unit 250 to eliminate malfunctions caused by low-frequency, harmonic, and high-frequency noise.

According to a preferred feature of the present invention, the earth leakage blocking module 200 forms a rectangular concave portion (A) open on one side in the horizontal direction so as to span the PCB, and has right-angle or round-shaped groove portions (B, C) at square corners. can be formed.

As shown in Fig. 6, Fig. 6a is a plan view and a bottom view of the detachable earth leakage blocking module in the form of a board, and Fig. 6b shows a left side view and a right side view of the detachable earth leakage blocking module. it did

In addition, FIG. 6C shows a front view of the detachable earth leakage blocking module, where the earth leakage blocking module 200 forms a rectangular concave portion A opened on one side in the horizontal direction so that it can be accurately mounted on a PCB (printed circuit board). In addition, right-angled or round grooves may be formed at both ends (B) of the square corner portion to prevent double fallout and bonding between accurate module patterns, and at both ends (C) of another square corner portion for testing. A right-angled or round groove may be formed to allow circuit wires to pass through.

According to a preferred feature of the present invention, the noise canceling unit 250 controls the output of the circuit protection unit 240 and the zero-phase current transformer (ZCT, 400) or A pulse signal detector 251 that receives the leakage detection signal of the current sensor 400 and converts it into a pulse signal, and counts the pulse generated from the pulse signal detector 251 to increase by 1 from 0 to N each time it is input. The counter 252 and the delay time generator and outputter 253, which perform an output signal operation after a predetermined delay time after the pulse signal is input, compare whether preset N pulses have been counted during a predetermined delay time or N It may include a comparator 254 that outputs a signal by determining whether a predetermined time has been delayed when pulses are counted.

7 shows a configuration block diagram of the low-frequency noise canceling unit 250 of the present invention. As shown in FIG. 7, the low-frequency noise removal unit 250 attenuates the signal generated under the influence of low-frequency noise, and only when it is a normal earth leakage blocking signal that generates a leakage current of 50 Hz or 60 Hz ± 0.2 Hz, which is the rated current frequency of a general AC current line. A high signal is output to the output driver 230 to operate the cut-off switch of the cut-off mechanism 300 .

In the present invention, when the input signal is out of the trip level due to a leakage or malfunction frequency noise, the pulse signal detector (251, detector) detects the output of the circuit protection unit 240 and the current leakage of the zero-phase current transformer (ZCT, 400) or current sensor (400) It receives the detection signal and receives the signal generated from the signal input terminal as input and converts it into a pulse signal. Each time a pulse generated from the pulse signal detector 251 is input, the counter 252 counts the number from 0 to N by 1.

At this time, the delay time generator and output unit 253 performs an operation of outputting high after a certain delay time has elapsed. In this way, the comparator 254 compares the signal generated from the counter 252 and the delay time generator and output unit 253.

The comparator 254 compares whether preset N pulses have been counted for a certain delay time or determines whether a predetermined time has been delayed when N pulses have been counted, and outputs a high signal.

If the pulse signal is caused by noise, the noise canceling unit 250 initializes all operations, restarts the time delay operation, and counts the pulses.

According to a preferred feature of the present invention, when the output signal from the comparator 254 is transferred, the delay time generator and output unit 253 transfers the output signal of the noise canceling unit 250 to the output driver 250.

As shown in the block diagram of the low frequency noise canceling unit of the leakage current detection circuit in FIG. 7, when a high signal is output from the comparator 254, a delay time is generated and the output unit 253 outputs the output signal of the noise canceling unit 250. It is transmitted to the driving unit 230.

8 shows the operation of the noise canceling unit 250 as a waveform.

As shown in FIG. 8, when a short circuit occurs, the input signal vibrates as a signal with an amplitude much larger than (+) and (-) trip levels and an AC power frequency (60 Hz). When the delay time generator 253 becomes a high signal after a certain delay time, if N pulses are counted, it is determined that a short circuit has occurred and the output of the noise canceling unit 250 is converted into a high signal, and in other cases, the output is Do not convert to high signal.

9 shows an operating waveform of the noise canceling unit 250 in the leakage current detection circuit for preventing malfunction of low-frequency noise in a noise-affected state a.

As shown in FIG. 9, low-frequency noise is loaded on the input signal and it deviates from the (+) trip level, and thus a pulse signal is generated.

In this case, in the noise canceling unit 250, since the preset N value (here N = 4) is not counted until the delay time operation is completed, the delay time generator 253 first finishes the time delay operation, and the counter ( 252) and delay time generator 253 are initialized. In this way, the noise canceling unit 250 can remove the malfunction of the high frequency noise through the counter 252 and the delay time operation.

10 shows an operating waveform of the noise canceling unit 250 in the noise-affected state b.

As shown in FIG. 10, since the low frequency + high frequency noise carried on the input signal continuously deviate from the trip level, the output of the counter 254 is counted to the set value N in a short time. Each time, the comparator 254 initializes the counter 252 and the delay time generator 253 because the delay time generator 253 did not complete the time delay operation. In this way, since the noise canceling unit 250 only repeats the initialization operation of the counter 252 and the delay time generator 253 and does not generate an output signal, it is possible to eliminate malfunctions for low frequency + high frequency noise.

According to a preferred feature of the present invention, the circuit protection unit 240 may be composed of one or more capacitors, or may include a resistor or diode connection circuit to the capacitor.

FIG. 11 shows the result of noise attenuation with the circuit protection circuit applied between the zero-phase current transformer 400 and the noise removal unit 250, and the input amplitude of each frequency band is the signal that has passed through the circuit protection unit 240. The output current amplitude change is shown.

In addition, FIG. 12 shows an example of a circuit configuration method for preventing circuit damage caused by various high frequencies applied to the circuit protection unit 240 of the present invention.

In the circuit configuration of FIG. 12, the reactance of a capacitor for high-frequency alternating current and pulsating current acts like a variable resistance when the capacitor functions to store and discharge electric charge, and interacts with the AC power source. it is caused In a circuit connected to an AC power supply with a frequency of , the reactance of the capacitor follows the equation:

where f is the frequency and C is the capacitance value. Accordingly, as the frequency increases, the reactance value of the capacitor decreases, and the high-current noise signal generated in the high-frequency region flows through the circuit protection part of low reactance resistance, and the effect affecting the internal device is eliminated to protect the device and various high-voltage noise signals. It is possible to attenuate the malfunction signal by frequency.

In addition, as the attenuation of the waveform returned to the current sensor and the zero-phase current transformer 400 sensor of the noise signal in the high frequency region progresses, the amplitude of the current passing through the circuit protection unit 240 is attenuated, so that the current passing through the circuit protection unit 240 It can be confirmed that the amount of residual current or noise current affecting various elements is attenuated.

In most real malfunction environments, high-frequency noise is generated in a very short period of time without succession, so even if the capacitor connected to the 1st-block is destroyed, it can be protected again in the 2nd-block, and if this is extended to the N-block, subsequent devices Various loads input to can be removed, and a diode can be added to prevent its reverse current.

According to another embodiment of the present invention, the earth leakage breaker of the present invention may include an earth leakage blocking module 200 detachable from the PCB for preventing malfunction of frequency noise and a circuit breaker 300 for blocking power voltage according to the blocking signal. there is.

As shown in FIG. 4A, the earth leakage blocking module 200 for preventing frequency noise malfunction detachable from the PCB of the present invention includes a power supply unit 100, a blocking mechanism unit 300, and a zero-phase current transformer (ZCT, 400) or a current The sensor 400 may be circuit-connected as shown in FIG. 4a to form an earth leakage breaker detachable from a PCB for preventing malfunction of frequency noise.

Although the preferred embodiments of the present invention have been described with reference to the accompanying drawings, the embodiments described in this specification and the configurations shown in the drawings are only the most preferred embodiments of the present invention and represent all the technical ideas of the present invention. Since it is not, it should be understood that there may be various equivalents and modifications that can replace them at the time of this application. Therefore, the embodiments described above should be understood as illustrative and not restrictive in all respects, and the scope of the present invention is indicated by the claims to be described later rather than the detailed description, and the meaning and scope of the claims and their All changes or modified forms derived from equivalent concepts should be construed as being included in the scope of the present invention.

10: power supply unit, 20: signal processing unit, 30: output driving unit, 40: breaker unit, 50: zero-phase current transformer (ZCT) or current sensor,
100: power supply unit, 200: detachable earth leakage blocking module, 220: signal processing unit, 230: output driving unit, 240: circuit protection unit, 250: low frequency noise removal unit, 251: pulse signal detector unit, 252: counter, 253: delay time generation and output, 254: comparator,
300: breaker unit, 400: zero-phase current transformer (ZCT) or current sensor

Claims (6)

a signal processing unit to which a detection signal is input from a zero-phase current transformer (ZCT) or a current sensor;
an output driver for receiving an earth leakage detection signal from the signal processing unit and outputting a cutoff signal to a cutoff mechanism to perform a power supply voltage cutoff operation when the input signal is out of the trip level;
a circuit protection unit for protecting a circuit from high-frequency noise between the zero-phase current transformer (ZCT) or current sensor and the signal processing unit;
a noise canceling unit for removing malfunctions caused by low frequencies;
Rectangular grooves formed on the bottom so as to be vertically coupled to the PCB and vertically supported; and
one or more rectangular or round grooves formed at corners;
including,
The noise canceling unit,
a pulse signal detector that converts the output of the circuit protection unit and the leakage detection signal of the ZCT or current sensor into a pulse signal when the input signal is out of the trip level due to leakage or malfunction frequency noise;
a counter that counts the pulse generated from the pulse signal detector so as to increase by 1 from 0 to N each time the pulse is input;
a delay time generator and output unit that performs an output signal operation after a predetermined delay time has elapsed since the pulse signal is input; and
A comparator that outputs a signal by comparing whether preset N pulses have been counted for a certain delay time or determining whether a predetermined time has been delayed when N pulses have been counted:
including,
When an output signal is transmitted from the comparator, the delay time generator and the output unit transfer the output signal of the noise removal unit to the output driver.
delete delete delete According to claim 1,
The earth leakage blocking module for preventing malfunction of frequency noise detachable to a PCB, characterized in that the circuit protection unit configures one or more capacitors or configures and includes a circuit connecting a resistor or a diode to the capacitor.
An earth leakage breaker characterized by comprising a circuit breaker for preventing malfunction of frequency noise, attachable to or detachable from the PCB of claim 1 or claim 5, and a circuit breaker for cutting off the power supply voltage according to the blocking signal.