Earth-leakage circuit breaker that prevents malfunction due to noise signals

Abstract

The present invention relates to an earth-leakage circuit breaker that prevents malfunction due to noise signals such that the earth-leakage circuit breaker prevents malfunctioning due to noise signals of the earth-leakage circuit breaker. The earth-leakage circuit breaker that prevents malfunction due to noise signals is implemented by comprising: a filter for maintaining fundamental signals and attenuating harmonic, high frequency and surge pulse noise signals from output signals of a ZCT that detects leakage of a power line current; a differential amplifier for differentially amplifying output signals of the filter; a buffer for stabilizing output signals of the differential amplifier through buffering; an integrator, which integrates the output of the buffer so as to output integrated signals in which the ratio of harmonic, high frequency and surge pulse noise signals is reduced relative to the fundamental signal; a comparison circuit for comparing the output signals of the integrator with a set reference voltage and outputting comparison result signals thereof; a controller for controlling the operation of the integrator and comparison circuit; and a trip driving circuit for driving a trip device according to the output signals of the comparison circuit.

Description

A leakage circuit breaker that prevents malfunction due to noise signals

[0001] The present invention relates to a leakage circuit breaker that prevents malfunction due to noise signals, and more particularly, to a leakage circuit breaker that prevents malfunction due to noise signals (e.g., harmonic waves, high frequencies, surge pulses) of the leakage circuit breaker.

[0002] A leakage circuit breaker is a device that detects leakage current when a power line current leak occurs and operates a trip device to cut off the power, thereby preventing electric shock and fire.

[0003] When a power line current leaks, the signal detected by the leakage circuit breaker has the same frequency as the electrical signal flowing through the power line. This fundamental frequency signal is called the fundamental signal. However, recently, there has been an increasing number of cases in which leakage circuit breakers trip due to the parallel accumulation of capacitive leakage current caused by harmonic signals generated in rectifiers and inverter circuits of electrical and electronic equipment used in large quantities in factories, hospitals, and other places. This causes social damage such as production line stoppages and disruption of emergency medical services. However, since capacitive leakage current does not generate heat, the risk of fire is basically low.

[0004] For reference, the leakage current generated when a person comes into contact with an electric line is a resistive current of the fundamental frequency. Therefore, a leakage circuit breaker that prevents tripping due to harmonic leakage current is necessary. In addition, high-frequency interference signals from high-frequency signal generating devices around the leakage circuit breaker, such as radios, and surge pulse signals that flow into the leakage circuit breaker when a surge current occurs can cause the leakage circuit breaker to trip. In addition to these fundamental signals, signals that cause the leakage circuit breaker to malfunction are called noise signals of the leakage circuit breaker.

[0005] The conventional technology related to the leakage circuit breaker's leakage circuit breaker operation is as shown in Fig. 1.

[0006] The element that detects current leakage in the power line in the leakage circuit breaker is a zero current transformer (ZCT) (20). The filter (30) connected to the output terminal (21) of the ZCT (20) maintains the fundamental wave signal and functions to attenuate harmonic waves, high frequencies, and surge pulse noise signals. Next, the output signal of the filter (30) is amplified by a differential amplifier (40), and the output signal of the differential amplifier (40) is transmitted to a comparator (60) through a buffer (50). The comparator (60) outputs a digital 1 (high) signal when the input signal is greater than a predetermined reference voltage and transmits the digital 1 signal to the trip driving circuit (70). The trip driving circuit (70) drives the trip device (80) according to the output signal of the comparator (60) to perform a blocking operation.

[0007] The key method of the prior art to implement a leakage circuit breaker that selectively responds only to the fundamental signal and not to harmonic, high-frequency, and surge pulse noise signals in these leakage circuit breakers is the filter. However, to sufficiently attenuate harmonic noise signals whose frequency is not significantly higher than the fundamental signal, a filter with a high signal attenuation rate as the frequency increases from the cutoff frequency is essential. At the same time, implementing a filter that effectively removes high-frequency and surge pulse noise signals using analog or digital circuit techniques requires multiple circuit elements and increases circuit complexity. Therefore, implementing a device to prevent malfunction of a leakage circuit breaker into a product raises several negative factors, such as high production costs.

[0008] Accordingly, the present invention has been proposed to improve the problem of circuit complexity in order to prevent malfunction of a general leakage circuit breaker due to noise signals (e.g., harmonics, high frequencies, surge pulses) by using a filter with a large signal attenuation rate and to implement a filter that effectively removes harmonics, high frequencies, and surge pulse noise signals as an analog or digital circuit, and the purpose of the present invention is to provide a leakage circuit breaker that prevents malfunction due to noise signals (e.g., harmonics, high frequencies, surge pulses) of the leakage circuit breaker.

[0009] Another object of the present invention is to provide a leakage circuit breaker that prevents malfunction due to noise signals by effectively attenuating harmonic, high frequency, and surge pulse noise signals other than the fundamental signal among the signals output from a zero-phase current transformer (ZCT) of a leakage circuit breaker, thereby preventing malfunction of the leakage circuit breaker due to noise signals.

[0010] In order to achieve the above-mentioned purpose, the "leakage circuit breaker preventing malfunction due to noise signal" according to the present invention,

[0011] ZCT (zero current transformer) that detects leakage of power line current;

[0012] A filter that maintains the fundamental signal from the output signal of the above ZCT and attenuates harmonic, high frequency, and surge pulse noise signals;

[0013] A differential amplifier that differentially amplifies the output signal of the above filter;

[0014] A buffer that stabilizes the output signal of the differential amplifier by buffering it;

[0015] An integrator that integrates the output of the buffer and outputs an integrated signal with the ratio of the harmonic, high frequency, and surge pulse noise signals attenuated in comparison with the fundamental signal;

[0016] A comparison circuit that compares the output signal of the above integrator with a set reference voltage and outputs a signal resulting from the comparison;

[0017] A controller that controls the operation of the above integrator and the above comparison circuit;

[0018] A trip driving circuit that drives a trip device according to the output signal of the above comparison circuit; and

[0019] It is characterized by including a trip device that performs a blocking operation according to the operation of the above trip driving circuit.

[0020]

[0021] Preferably, the controller comprises:

[0022] A fundamental wave period extraction and clock generation circuit that extracts the fundamental wave signal period and generates an operating clock for control;

[0023] An integration start and end time determination circuit that determines the integration start and end times based on the fundamental wave period extraction signal generated by the fundamental wave period extraction and clock generation circuit;

[0024] An integrator control circuit that controls the integration operation of the integrator and initializes the integrator according to the integration start / stop time output from the integration start / stop time determination circuit; and

[0025] It is composed of a comparison circuit control circuit that generates a comparison control signal that controls the comparison operation in conjunction with the above integrator control circuit.

[0026]

[0027] Preferably, the above comparison circuit is

[0028] A switching circuit that controls a comparison operation according to a comparison control signal of the above controller;

[0029] A first comparator that compares the value integrated by the integrator during the first half cycle of the fundamental wave signal with a first reference voltage;

[0030] A second comparator that compares the value integrated by the integrator during the second half cycle of the fundamental signal with a second reference voltage; and

[0031] It is characterized by including a logical combination element that performs a logical combination (OR) of the output of the first comparator and the output of the second comparator.

[0032] According to the present invention, by using a filter and an integrator for noise signal attenuation, the influence of harmonic noise signals can be attenuated more effectively than when using only a filter, the influence of high-frequency noise signals having a frequency much higher than that of the fundamental signal can be eliminated, and the influence of surge pulse noise signals having a very short duration compared to the cycle of the fundamental signal can also be eliminated when a surge pulse occurs, thereby having the effect of preventing an operation error of a leakage circuit breaker.

[0033] In addition, according to the present invention, there is an effect of increasing the reliability of the leakage circuit breaker and reducing the production cost by effectively preventing malfunction of the leakage circuit breaker due to harmonic, high-frequency, and surge pulse noise signals while reducing the complexity of the filter.

[0034] Figure 1 is a circuit diagram of a conventional leakage circuit breaker.

[0035] Figure 2 is a circuit diagram of a leakage circuit breaker that prevents malfunction due to noise signals according to the present invention.

[0036] Fig. 3 is a block diagram of an embodiment of the controller of Fig. 2.

[0037] Fig. 4 is an exemplary circuit diagram of the comparison circuit of Fig. 2.

[0038] Figure 5 is a waveform diagram of the fundamental and harmonic signals.

[0039] Figure 6 is a waveform that shows the first half of the fundamental signal combined with a high-frequency signal.

[0040] Figure 7 is an example of the waveform of a surge pulse signal.

[0041] Figure 8 is an example of a waveform in which a surge pulse occurs in the first half of the fundamental wave signal.

[0042] Hereinafter, a leakage circuit breaker that prevents malfunction due to noise signals according to a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0043] The terms and words used in the present invention described below should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical idea of ​​the present invention based on the principle that the inventor can appropriately define the concept of the term in order to explain his or her own invention in the best way.

[0044] Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are only preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0045] FIG. 2 is a circuit diagram of a leakage circuit breaker that prevents malfunction due to noise signals according to a preferred embodiment of the present invention, and components having the same function and operation as those of the prior art FIG. 1 are given the same reference numerals.

[0046] A leakage circuit breaker that prevents malfunction due to noise signals according to the present invention may include a ZCT (20), a filter (30), a differential amplifier (40), a buffer (50), an integrator (90), a comparison circuit (110), a trip driving circuit (70), a trip device (80), and a controller (100).

[0047] ZCT (zero current transformer) (20) detects leakage of power line current.

[0048] The above-described current transformer (20) has a structure in which a winding is wound around a ring-shaped magnetic core. The input line (10) and the output line (11) of the power line are connected to an electrical load by penetrating the inside of the ZCT (20) ring. When a leakage current occurs, the sum of the currents of the input line (10) and the output line (11) does not become zero, and an EMF (electro motive force) voltage signal is generated at the output terminal (21) of the ZCT (20) according to Ampere's law and Faraday's law. The current flowing through the power line is a sine wave with a fundamental frequency of 60 Hz or 50 Hz. Therefore, the fundamental frequency of the ZCT (20) output signal due to the leakage current of the electric line is the same as the fundamental frequency of the power line. This signal is called a fundamental signal.

[0049] The filter (30) maintains the fundamental wave signal from the output signal (21) of the ZCT (20) and attenuates harmonic, high frequency, and surge pulse noise signals.

[0050] The output signal of ZCT (20) contains harmonic, high frequency, and surge pulse noise signals mixed in addition to the fundamental signal. In order to implement a leakage circuit breaker that selectively responds only to the fundamental signal, the filter (30) maintains the fundamental signal among the output signals of ZCT (20) and functions to attenuate harmonic, high frequency, and surge pulse noise signals.

[0051] The differential amplifier (40) differentially amplifies and outputs the output signal of the filter (30), and the buffer (50) buffers and stabilizes the output signal of the differential amplifier (40) and then transmits it to the integrator (90).

[0052] The integrator (90) integrates the output of the buffer (50) and outputs an integrated signal with the ratio of the harmonic, high frequency, and surge pulse noise signals attenuated in comparison with the fundamental signal to the comparison circuit (110).

[0053] Here, the integrator (90) plays a role in attenuating the influence of harmonic, high-frequency, and surge pulse noise signals on the fundamental signal. Hereinafter, the attenuation function of the integrator (90) for harmonic, high-frequency, and surge pulse noise signals will be explained separately for each signal.

[0054] The equation representing the fundamental wave signal output from the buffer (50) is as shown in [Mathematical Equation 1] below.

[0055]

[0056] Here, the subscript 0 indicates that the parameter is related to the fundamental signal. It is based on the starting point of the fundamental signal. In other words, the phase of the fundamental signal. Set to 0 and expand the formula. is the frequency of the fundamental signal, which is the same as the frequency of the power line. If the frequency of the power line is 60 Hz, The period of the fundamental signal is expressed by [Mathematical Formula 2] below.

[0057]

[0058] Here = If 60Hz is 16.7 ms. Through the integrator (90), the fundamental wave signal is converted to the first half cycle (t = 0 ~ 0.5) of the fundamental wave signal. ) The integrated value is as shown in [Mathematical Formula 3] below.

[0059]

[0060] Here, k is a constant multiplied by the integral value of the signal according to the circuit structure of the integrator (90).

[0061] The same integrator (90) is used to generate a sinusoidal signal with amplitude A, frequency f, and phase θ for the first half cycle of the reference wave (t = 0 ~ 0.5 ) The integrated value is as shown in [Mathematical Formula 4] below.

[0062]

[0063] The method of attenuating harmonic signals using this integrator (90) is as follows.

[0064] The harmonic signal frequency is am. is the phase of the harmonic signal based on the starting point of the fundamental signal. The subscript n denotes the nth harmonic signal. In order to analyze only the effect of the integrator (90) on the harmonic signal, it is assumed that the amplitudes of the fundamental signal and the harmonic signal input to the integrator (90) are equal to A.

[0065] If we substitute this into [Mathematical Formula 4] above, we get the following result.

[0066]

[0067] When the signal is an odd harmonic signal, that is, n = 2m+1 (m≥1), is substituted into [Mathematical Equation 5], the result is as follows.

[0068]

[0069] That is, by using the integrated value of the signal over the first half cycle of the fundamental signal using an integrator (90), the influence of the odd (2m+1) harmonic signal is reduced to less than 1 / (2m+1) compared to the fundamental signal.

[0070] Figure 5 shows the 3rd and 5th harmonic signals along with the fundamental signal during the first half of the fundamental signal. For the sake of intuitive simplicity, the case where the harmonic signals have the same phase as the fundamental signal is shown. The half-cycle of the fundamental signal ( ) is the period of the odd harmonic signal ( ) is m+0.5 times, it can be seen that the harmonic signal's own half-cycle contributes to the integral value. In the case where the phases of the fundamental signal and the harmonic signal are different, the integral value of the harmonic signal is as in [Mathematical Formula 7] below. It decreases as much as that.

[0071] When the signal is an even harmonic signal, that is, n = 2m (m≥1), is substituted into [Mathematical Equation 5], the result is as follows.

[0072]

[0073] That is, by using the integrated signal obtained by integrating the signal over the first half cycle of the fundamental signal using the integrator (90), the influence of the even-numbered (2m) harmonic signal is completely eliminated. Of course, signals generated from rectifiers of electrical and electronic equipment generally have mirror symmetry within the half cycle of the power line sinusoidal signal. In the Fourier series of such signals, the even-numbered harmonic components become zero. However, even if an even-numbered harmonic signal component is generated in some equipment, the influence can be completely eliminated by using the integrator (90) according to the present invention.

[0074] The second half of the fundamental signal (t = 0.5 ~ ) The results of integration during the above [Equation 3], [Equation 6], and [Equation 7] only change signs. Therefore, all logical developments and results are the same as in the first half cycle.

[0075] To summarize, when a signal mixed with a fundamental signal and a harmonic signal is input to an integrator (90), if the signal is integrated over a half cycle of the fundamental signal and the result is used, the influence of the odd harmonic signal is reduced to less than the value divided by the multiple of the harmonic signal, and the influence of the even harmonic signal is completely eliminated.

[0076] Therefore, by combining and using the filter and integrator described above according to the present invention, the influence of harmonic noise signals can be prevented more effectively than when using a filter alone.

[0077] Next, the attenuation function for the harmonic signal of the integrator (90) is explained as follows.

[0078] The frequency of the high-frequency signal output from the buffer (50) is much higher than the frequency of the fundamental signal. For example, the frequency of a radio signal that causes interference with a leakage current circuit breaker and causes malfunction is approximately 100 MHz. This is much higher than the frequency of the leakage current fundamental signal, which is 60 Hz.

[0079]

[0080] Here, the subscript H indicates that it is a parameter related to high-frequency signals. T H is the period of the high-frequency signal. In order to analyze only the effect of the integrator (90) on the fundamental signal and harmonic signal, it is assumed that the amplitudes of the fundamental signal and the high-frequency signal input to the integrator (90) are equal to A.

[0081] If this is substituted into [Mathematical Equation 4] above, it is as shown in [Mathematical Equation 9] below.

[0082]

[0083] Here is the phase of a high-frequency signal relative to the starting point of the fundamental signal.

[0084] From the above [Mathematical Formula 3] and [Mathematical Formula 9], the absolute value of the ratio of the high-frequency signal to the fundamental signal becomes very small, and when expressed as a formula, it is as shown in [Mathematical Formula 10] below.

[0085]

[0086] Figure 6 depicts the first half of a fundamental signal along with a high-frequency signal. The integral of the high-frequency signal, which has a much higher frequency than the fundamental signal, cancels out with each short, repeated cycle, and the resulting integral will be less than or equal to the integral of the high-frequency signal's own half-cycle.

[0087] The second half of the fundamental signal (t = 0.5 ~ ) The same logic applies.

[0088] To summarize, if an integrated signal is used by integrating the signal over a half cycle of the fundamental signal using an integrator (90), the influence of the high-frequency signal can be ignored compared to the fundamental signal.

[0089] Next, the attenuation function of the integrator (90) for a surge pulse signal having a very short duration compared to the period of the fundamental signal is described as follows.

[0090] Surge pulse signal duration T P is usually about several tens of μs. Figure 7 shows T P A typical example of a surge pulse signal Sp(t) with a duration of 20 μs is shown. The first zero crossing point T of the oscillating and decaying surge pulse signal ZC A rectangular pulse Rp(t) with the same pulse width is also shown. The integral value of Sp(t) that oscillates at a zero crossing is the pulse width T. ZC It is obvious that the integral value of Rp(t) becomes smaller than that of .

[0091] Fig. 8 illustrates the occurrence of a surge pulse signal at an arbitrary point in time within the first half cycle of the fundamental signal together with the fundamental signal. In order to analyze only the effect of the integrator (90) on the fundamental signal and the surge pulse signal, it is assumed that the amplitudes of the fundamental signal and the surge pulse signal input to the integrator (90) are equal to A. Since the duration of the surge pulse signal is very short, it can be seen that the value obtained by integrating the surge pulse signal over the half cycle of the fundamental signal will be much smaller than the value obtained by integrating the fundamental signal over the same section.

[0092] The limit of the integral value for the surge pulse signal Sp(t) is expressed as a formula as in [Mathematical Formula 11].

[0093]

[0094] From the above [Mathematical Expression 3] and [Mathematical Expression 11], the absolute value of the ratio of the integral values ​​of the surge pulse signal and the fundamental signal satisfies the following.

[0095]

[0096] For example, if Tzc is 5 μs, T0 is 16.7 ms, so the ratio becomes 1 / 1000 by [Mathematical Formula 12]. The second half of the fundamental signal (t = 0.5 ~ ) It is self-evident that the same logic holds true for this.

[0097] To summarize, if an integrated signal is used by integrating the signal over a half cycle of the fundamental signal using an integrator (90) for the surge pulse signal, its influence can be ignored compared to the fundamental signal.

[0098] In addition, the controller (100) controls the start and end of integration of the integrator (90) and the comparison operation of the comparison circuit (110).

[0099] The above controller (100) controls the integration operation of the integrator (90) and the comparison operation of the comparison circuit (110) connected to the integrator (90).

[0100] The configuration of the controller (100) is as shown in Fig. 3.

[0101] The fundamental signal period extraction and clock generation circuit (103) has the function of extracting the period T0 of the fundamental signal and generating a clock for control accordingly. In one embodiment, the period of the fundamental signal can be extracted from a power line.

[0102] The integration start and end time determination circuit (104) determines the integration start and end time of the integrator (90) based on the fundamental wave period extraction signal generated by the fundamental wave period extraction and clock generation circuit (103). The integration start point of the integrator (90) is determined by considering the signal delay of the ZCT (20), filter (30), differential amplifier (40), and buffer (50). The integration end time is determined so that the integration period becomes 0.5T0, which is half of the fundamental wave signal period.

[0103] The integrator control circuit (105) generates integration operation control signals of the integrator (90) according to the integration start and end points determined by the integrator start and end point determination circuit (104) and drives the start and end of integration of the integrator (90) through the control signal line (101). The integrator (90) integrates a signal output from the buffer (50) according to the signal of the controller (100). In addition, the integrator control circuit (105) has a function of initializing the integrator (90) after the operation of the comparison circuit (110) by the integration signal output from the integrator (90) is completed.

[0104] The comparison circuit control circuit (106) functions to generate a comparison control signal that controls the comparison operation of the comparison circuit (110) in conjunction with the integrator control circuit (105). After the integration of the integrator (90) is completed, the operation of the comparison circuit (110) is controlled through the control signal line (102).

[0105] The above comparison circuit (110) compares the output signal of the integrator (90) with a predetermined reference voltage according to the comparison control signal generated from the comparison circuit control circuit (106), and outputs the comparison result signal to the trip driving circuit (70).

[0106] The configuration of the above comparison circuit (110) is as shown in Fig. 4.

[0107] The switching circuit (113) controls the comparison operation according to the control signal output from the controller (100) through the control signal line (102). That is, the switching circuit (113) is connected to the output signal line (91) of the integrator (90) and transmits the integration signal to the first and second comparators (114, 115). The first comparator (C1) (114) compares the value of the positive signal integrated during the first half cycle (0 to 0.5T0) of the fundamental signal with the reference voltage V1 (116) and outputs a digital 1 (high) signal when the integration signal value is large. The second comparator (C2) (115) compares the value of the negative signal integrated during the second half cycle (0.5T0 to T0) of the fundamental signal with the reference voltage V2 (117) and outputs a digital 1 (high) signal when the integration signal value is small. The outputs of the first comparator (114) and the second comparator (115) are logically combined through an OR gate (118), and the resulting signal is output to the trip driving circuit (70) through the signal line (111). When the integrator (90) is initialized in the controller (100), the switching circuit (113) of the comparison circuit (110) is connected to the ground (112). A series of operations consisting of the start of integration of the integrator (90), integration of a half cycle (0.5T0) of the fundamental wave, integration end, comparison operation on of the comparison circuit (110), comparison of the integration signal with the reference voltages, comparison operation off of the comparison circuit (110), and initialization of the integrator (90) are repeated.

[0108] Power line current leakage can occur at any point during the fundamental signal's cycle. However, by utilizing the integrator (90) operation described above and the associated comparator circuit (110) operation, the presence or absence of leakage current can be detected through two consecutive operations. That is, leakage can be detected within the fundamental signal's cycle T0 (16.7 ms for 60 Hz power).

[0109] The output of the above comparison circuit (110) is transmitted to the trip driving circuit (70) through the signal line (111), and the trip driving circuit (70) drives the trip device (80) according to the signal to perform a blocking operation. Since the trip driving circuit (70) and the trip device (80) are the same as those of a conventional leakage circuit breaker, a detailed description thereof will be omitted in the present invention.

[0110] According to the present invention described above, by using a filter and an integrator for noise signal attenuation, the influence of harmonic noise signals, high-frequency noise signals, and surge pulse noise signals can be more effectively removed than when using only a filter, thereby more effectively preventing operation errors of a leakage circuit breaker.

[0111] In addition, according to the present invention, the reliability of the leakage circuit breaker can be increased and the production cost can be reduced by reducing the complexity of the filter while effectively preventing malfunction of the leakage circuit breaker due to harmonic, high frequency, and surge pulse noise signals.

[0112] Although the invention made by the present inventor has been specifically described according to the above embodiments, it is obvious to a person having ordinary skill in the art that the present invention is not limited to the above embodiments and can be modified in various ways without departing from the spirit thereof.

[0113] The present invention is applied to a technology for preventing malfunction of a leakage circuit breaker.

[0114] *Explanation of symbols

[0115] 20: ZCT, 30: Filter, 40: Differential Amplifier, 50: Buffer, 70: Trip Drive Circuit,

[0116] 80: trip device, 90: integrator, 100: controller,

[0117] 103: Fundamental wave period extraction and clock generation circuit, 104: Integral start and end time determination circuit,

[0118] 105: Integrator control circuit, 106: Comparator control circuit, 110: Comparator circuit,

[0119] 113: Switching circuit, 114, 115: First and second comparators,

[0120] 118: OR gate

Claims

1. ZCT (zero current transformer) that detects leakage of power line current; A filter that maintains the fundamental signal from the output signal of the above ZCT and attenuates harmonic, high frequency, and surge pulse noise signals; A differential amplifier that differentially amplifies the output signal of the above filter; A buffer that stabilizes by buffering the output signal of the above differential amplifier; An integrator that integrates the output of the above buffer and outputs an integrated signal with the ratio of harmonic, high-frequency, and surge pulse noise signals attenuated compared to the fundamental signal; A comparison circuit that compares the output signal of the above integrator with a set reference voltage and outputs a signal resulting from the comparison; A controller for controlling the operation of the above integrator and the above comparison circuit; A trip driving circuit that drives a trip device according to the output signal of the above comparison circuit; and A leakage circuit breaker preventing malfunction due to noise signals, characterized by including a trip device that performs a blocking operation according to the operation of the above trip driving circuit.

2. In claim 1, the integrator, A leakage circuit breaker that prevents malfunction due to noise signals, characterized by integrating a signal over a certain period of time and using the integral signal obtained through the integration result to attenuate the influence of harmonics, high frequency, and surge pulse signals compared to the fundamental signal.

3. In claim 1, the controller, A fundamental wave period extraction and clock generation circuit that extracts the fundamental wave signal period and generates an operating clock for control; An integration start and end time determination circuit that determines the start and end points of integration based on the fundamental wave period extraction signal generated by the fundamental wave period extraction and clock generation circuit; An integrator control circuit that controls the integration operation of the integrator and initializes the integrator according to the integration start / stop time output from the integration start / stop time determination circuit; and A leakage circuit breaker preventing malfunction due to noise signals, characterized by including a comparison circuit control circuit that generates a comparison control signal that controls a comparison operation in conjunction with the above-mentioned integrator control circuit.

4. In claim 1, the comparison circuit, A switching circuit that controls a comparison operation according to a comparison control signal of the above controller; A first comparator for comparing the value integrated by the integrator during the first half cycle of the fundamental signal with a first reference voltage; A second comparator for comparing the value integrated by the integrator during the second half cycle of the fundamental signal with a second reference voltage; and A leakage circuit breaker preventing malfunction due to noise signals, characterized by including a logical combination element that performs logical OR on the output of the first comparator and the output of the second comparator.

5. In claim 1, the integrator, A leakage circuit breaker for preventing malfunction due to noise signals, characterized in that the influence of odd-numbered harmonic signals among the harmonic signals is attenuated to less than the odd-numbered multiple of the harmonic signal by using the integrated signal obtained by integrating the signal over a half cycle of the fundamental signal in comparison with the fundamental signal.

6. In claim 1, the integrator, A leakage circuit breaker preventing malfunction due to noise signals, characterized in that the influence of even-numbered harmonic signals among the harmonic signals is removed by using the integrated signal obtained by integrating the signal over a half cycle of the fundamental signal.

7. In claim 1, the integrator, A leakage circuit breaker for preventing malfunction due to noise signals, characterized in that the influence of the high-frequency signal is attenuated in proportion to the frequency ratio of the fundamental signal frequency and the high-frequency signal by using the integrated signal obtained by integrating the signal over a half cycle of the fundamental signal compared to the fundamental signal.

8. In claim 1, the integrator, A leakage circuit breaker for preventing malfunction due to a noise signal, characterized in that the influence of the surge pulse signal is attenuated in proportion to the duration of the surge pulse signal and the period ratio of the fundamental signal by using the integrated signal obtained by integrating the signal over a half cycle of the fundamental signal compared to the fundamental signal.

9. A leakage circuit breaker for preventing malfunction due to a noise signal, characterized in that in claim 1, the influence of the odd-numbered harmonic signal among the harmonic signals compared to the fundamental signal is first attenuated by the filter, and secondarily attenuated by the integrator.

10. In claim 1, the controller, A leakage circuit breaker preventing malfunction due to noise signals, characterized in that the circuit breaker controls to integrate an input signal of the integrator for half a period of the fundamental signal, turns on the comparison circuit, controls to transmit the integration signal of the integrator to the comparison circuit, turns off the comparison circuit after the operation of the comparison circuit, and initializes the integrator, and repeats the series of processes at least twice, so that even if leakage occurs at any point in time, the leakage is detected within one period of the fundamental signal.

Images