JP2012202705A - Leak detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a leak detection device capable of performing a leak block and a leak display at the same time with a simple and low-cost constitution.SOLUTION: The present leak detection device comprises: a zero-phase current transformer 10 through which an AC electric path passes; an integration operation part 20 for integrating output voltages of the zero-phase current transformer 10; a leak detection part 50 for outputting a leak detection signal indicating that leak is occurring in the AC electric path based on operation results performed by the integration operation part 20; an integration part 91 for integrating the output voltages of the zero-phase current transformer 10; and an operation result output part 92 for outputting according to the operation results performed by the integration part 91. The integration operation part 20 and the leak detection part 50 are included in a leak level detection part 80. The operation result output part 92 and the leak detection part 50 are constituted of one module.

Description

  The present invention relates to a leakage detection device. In particular, the present invention relates to a leakage detection device that determines whether or not a leakage has occurred in an AC circuit according to a detection output of a zero-phase current transformer.

  The earth leakage breaker is composed of an annular core (core) made of a magnetic material such as a soft magnetic material that penetrates a plurality of primary conductors constituting an AC circuit, and a toroidal coil wound around the core. A zero-phase current transformer (ZCT) is provided, and it is determined whether or not a leakage has occurred in the plurality of primary conductors according to an output voltage that is a detection output at both ends of the coil of the zero-phase current transformer.

  When a leakage occurs in any of the primary conductors, a difference occurs between the current flowing in the forward direction of the AC circuit and the current flowing in the return direction, and a leakage current based on the difference is generated. Furthermore, since the energization currents of the plurality of primary conductors are unbalanced as a whole, the state of the magnetic flux in the core of the zero-phase current transformer is changed by the magnetic flux generated by the leakage current. Thereby, the induced voltage corresponding to the leakage current is detected at both ends of the coil of the zero-phase current transformer.

  Further, when no leakage occurs in any of the primary conductors, a so-called equilibrium state in which the vector sum of the energization currents of the plurality of primary conductors is zero. In this equilibrium state, magnetic flux exists in the core of the zero-phase current transformer, but these magnetic fluxes cancel each other, and the induced voltage as described above is not detected by the zero-phase current transformer. Therefore, it is possible to determine whether or not a leakage current has occurred in the AC circuit by outputting the output voltage across the coil of the zero-phase current transformer as a detection output.

  As a leakage case in which a leakage current is detected, a normal leakage state and a lightning surge state are considered. Normal leakage refers to leakage in which the current value of the leakage current appears periodically. Lightning surge refers to a leakage in which the current value of the leakage current is relatively large and the current value appears temporarily.

  Of the three types of electric leakage, in the case of normal electric leakage, it is expected that electric leakage will occur for a long time, so it is preferable to immediately cut off the power supply via the AC electric circuit. On the other hand, in the case of a lightning surge, only a short circuit occurs, so it is not preferable to cut off the power supply via the AC circuit for each lightning surge.

  As a conventional earth leakage breaker, an earth leakage breaker capable of preventing unnecessary interruption due to lightning surge is known (for example, see Patent Document 1). This earth leakage circuit breaker is a lightning surge or heavy ground fault (with a relatively large current value of the earth leakage current among normal earth leakages) due to the third comparator having a threshold larger than that of the first comparator for detecting the earth leakage current. The ground fault current due to is distinguished from the leakage current. Furthermore, a 3-wave counter detects whether more than 3 pulses are output from the first comparator during the time gate period created by the monostable multivibrator activated by the output of the third comparator. Distinguish between lightning surge and heavy ground fault. As a result, the cutoff signal is output from the cutoff signal output circuit only in the case of normal leakage including a heavy ground fault.

Japanese Patent Laid-Open No. 10-094161

  By the way, the earth leakage breaker disclosed in Patent Document 1 performs earth leakage interruption, but does not display earth leakage according to an effective value or the like according to the output voltage of the zero-phase current transformer. Therefore, the administrator etc. could not recognize how much electric leakage has occurred. Further, if the leakage break and leakage display are performed simultaneously, it is desirable that the configuration be as simple as possible to reduce the cost.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a leakage detection device capable of simultaneously performing a leakage break and a leakage display with a simple and inexpensive configuration.

  In order to solve the above problems, a zero-phase current transformer through which an AC circuit passes, a first integration calculation unit that integrates an output voltage of the zero-phase current transformer, and a calculation result by the first integration calculation unit A leakage detection unit that outputs a leakage detection signal indicating that a leakage has occurred in the AC circuit, a second integration calculation unit that integrates the output voltage of the zero-phase current transformer, and the first A calculation result output unit that performs output according to the calculation result of the two integral calculation units, and the calculation result output unit and the leakage detection unit are configured as one module.

  In the present invention, the leakage detection unit uses the second integration calculation unit as the first integration calculation unit.

  In the present invention, the second integration calculation unit calculates an average value by averaging the output voltage of the zero-phase current transformer over a longer period than the first integration calculation unit, and calculates the average value. Integrate.

  The present invention further includes a signal comparison unit that outputs a first signal when the calculation result by the first integration calculation unit reaches a predetermined range, and the calculation result output unit includes the second integration value. When the calculation result by the calculation unit reaches outside a predetermined range narrower than the range of the voltage threshold used when determining whether or not the first signal is output by the integral value comparison unit, a warning signal is output.

  Moreover, in this invention, the said calculation result output part changes the output form when outputting the said warning signal according to the calculation result by the said 2nd integral calculation part.

  The present invention further includes a calculation result storage unit that stores calculation result information by the second integration calculation unit for a predetermined time.

  In the present invention, an external terminal unit is provided for outputting information on the calculation result stored in the calculation result storage unit.

  The present invention further includes an information output unit that outputs information on the calculation result stored in the calculation result storage unit to a storage medium.

  Moreover, in this invention, the information transmission part which transmits the information of the calculation result memorize | stored in the said calculation result memory | storage part to an external server is provided.

  Also, in the present invention, when the calculation result by the first integration calculation unit reaches a predetermined range, the integration value comparison unit that outputs the first signal and the output voltage waveform of the zero-phase current transformer are changed. A waveform discriminating unit that detects and counts poles and outputs a second signal when the number of inflection points reaches a predetermined number, and the leakage detector detects the first signal by the integral value comparing unit. When the first signal is output and the second signal is output by the waveform determination unit, the leakage detection signal is output.

  In the present invention, the waveform discriminating unit starts detecting the inflection point when the output voltage of the zero-phase current transformer is a positive voltage or a negative voltage.

  Further, in the present invention, the first integration calculation unit obtains an effective value of the output voltage of the zero-phase current transformer using integration calculation.

  Also, in the present invention, the first integration calculation unit obtains an average value of the output voltage of the zero-phase current transformer using integration calculation.

  Further, in the present invention, the waveform discriminating unit counts the number of pulses generated by the pulse generating unit, the pulse generating unit generating pulses based on the output voltage waveform of the zero-phase current transformer, and the pulse And a pulse count unit that outputs the second signal when the number reaches a predetermined number.

  In the present invention, the pulse generator generates the pulse when the output voltage of the zero-phase current transformer reaches a predetermined range.

  In the present invention, the pulse generator generates the pulse when the state where the output voltage of the zero-phase current transformer has exceeded a predetermined range continues for a predetermined time or more.

  In the present invention, the pulse generator stops the generation of the pulse when the output voltage of the zero-phase current transformer becomes less than a predetermined voltage after the generation of the pulse is started.

  In the present invention, the pulse generation unit stops the generation of the pulse when a predetermined time has elapsed from the start of the generation of the pulse.

  In the present invention, the pulse generator stops generating the second pulse until a predetermined time has elapsed from the generation of the first pulse.

  In the present invention, the pulse counting unit counts the number of rising edges of the pulses generated by the pulse generating unit, and outputs the second signal when the number reaches a predetermined number.

  In the present invention, the pulse counting unit counts when the pulse width of the pulse generated by the pulse generating unit is equal to or greater than a predetermined width, and when the number reaches a predetermined number, the second signal is output. Output.

  In the present invention, the pulse counting unit counts the number of falling edges of the pulses generated by the pulse generating unit, and outputs the second signal when the number reaches a predetermined number.

  In the present invention, the pulse counting unit stops counting the second pulse until a predetermined time has elapsed from the counting of the first pulse generated by the pulse generating unit.

  In the present invention, the waveform discriminating unit changes a count value counted by the pulse counting unit when a pulse output width based on a pulse generated by the pulse generating unit is a predetermined width or more. Is provided.

  In the present invention, the pulse output width is a time width from the output start point of the pulse generated by the pulse generator to the output end point.

  In the present invention, the pulse output width is a time width from the output start time of the first pulse generated by the pulse generator to the output start time of the second pulse continuous to the first pulse. .

  In the present invention, the pulse output width is a time width from the output end point of the first pulse generated by the pulse generation unit to the output end point of the second pulse continuous to the first pulse. .

  In the present invention, the pulse output width is a time width from the output start time of the first pulse generated by the pulse generator to the output end time of the second pulse.

  The present invention further includes a pulse generation condition changing unit that changes a pulse generation condition by the pulse generation unit based on the count value counted by the pulse counting unit.

  Further, in the present invention, the leakage detection device, wherein the pulse generation condition changing unit changes at least one of a voltage threshold and a time threshold used when determining whether or not the pulse generation unit generates a pulse.

  Further, in the present invention, the pulse generating unit includes a positive pulse that is a pulse based on the positive output voltage of the zero phase current transformer and a pulse that is based on the negative output voltage of the zero phase current transformer. A negative pulse, and the pulse counting unit counts the positive pulse and the negative pulse, and at least one of the number of the positive pulse and the number of the negative pulse is a predetermined number or more. If so, the second signal is output.

  The present invention further includes a signal input unit for inputting a signal output instruction signal for outputting the first signal by the integral value comparison unit or outputting the second signal by the waveform discrimination unit.

  In the present invention, the signal input unit inputs the signal output instruction signal from an external resistor.

  According to the present invention, it is possible to simultaneously perform the earth leakage interruption and the earth leakage display with a simple and inexpensive configuration.

The circuit block diagram which shows the structural example of the leak detection apparatus in the 1st Embodiment of this invention The circuit block diagram which shows the detailed structural example of the waveform discrimination | determination part in the 1st Embodiment of this invention Time chart for explaining a first operation example of the leakage detection device in the first embodiment of the present invention Time chart for explaining a second operation example of the leakage detection device in the first embodiment of the present invention Time chart for explaining a third operation example of the leakage detection device in the first embodiment of the present invention Time chart for explaining a fourth operation example of the leakage detecting device in the first embodiment of the present invention Time chart for explaining a fifth operation example of the leakage detection device in the first embodiment of the present invention The circuit block diagram which shows the detailed structural example of the waveform discrimination | determination part in the 2nd Embodiment of this invention Time chart for explaining an operation example of the leakage detecting device in the second embodiment of the present invention The circuit block diagram which shows the detailed structural example of the waveform discrimination | determination part in the 3rd Embodiment of this invention Time chart for explaining an operation example of the leakage detecting device in the third embodiment of the present invention The circuit block diagram which shows the detailed structural example of the waveform discrimination | determination part in the 4th Embodiment of this invention Time chart for explaining an operation example of the leakage detecting device in the fourth embodiment of the present invention The circuit block diagram which shows the structural example of the leak detection apparatus in the 5th Embodiment of this invention The block diagram which shows the 1st structural example of the leak detection apparatus in the 6th Embodiment of this invention. The block diagram which shows the 2nd structural example of the leak detection apparatus in the 6th Embodiment of this invention. The block diagram which shows the 3rd structural example of the leak detection apparatus in the 6th Embodiment of this invention. The block diagram which shows the 4th structural example of the leak detection apparatus in the 6th Embodiment of this invention. The block diagram which shows the 5th structural example of the leak detection apparatus in the 6th Embodiment of this invention. The block diagram which shows the 6th structural example of the leak detection apparatus in the 6th Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a block diagram showing a configuration example of a leakage detecting apparatus according to the first embodiment of the present invention. A leakage detection device 100 shown in FIG. 1 includes a zero-phase current transformer 10, an integration calculation unit 20, an integration value comparison unit 30, a waveform determination unit 40, and a leakage detection unit 50.

  The zero-phase current transformer 10 includes an annular core (core) made of a magnetic material such as a soft magnetic material that penetrates a plurality of primary conductors that constitute an AC circuit through which a three-phase current flows. And a toroidal coil. When a difference occurs between the current flowing in the forward direction of the AC circuit and the current flowing in the return direction, the zero-phase current transformer 10 generates a leakage current based on the difference. An induced voltage corresponding to the leakage current is generated at both ends of the coil. The zero-phase current transformer 10 outputs this induced voltage to the integration calculation unit 20 and the waveform determination unit 40 as a ZCT output voltage that is an output voltage of the zero-phase current transformer 10. Although not shown, a resistance element is inserted in parallel with the zero-phase current transformer 10 in order to obtain a voltage output from the zero-phase current transformer 10.

  The integration calculation unit 20 is constituted by an integration circuit or the like, integrates the ZCT output voltage, and outputs the integrated voltage (integrated voltage) to the integrated value comparison unit 30 as an output voltage.

  Further, the integral calculation unit 20 may obtain the effective value of the ZCT output voltage using the integral calculation. For example, the square value of the ZCT output voltage is integrated for one period, divided by the time of one period, and the square root of the value is obtained. In this case, the leakage current can be detected with higher accuracy, and the leakage detection performance against distorted waves is improved. Further, the integral calculation unit 20 may obtain an average value of the ZCT output voltage using the integral calculation. For example, the absolute value of the ZCT output voltage is integrated for one period and divided by the time of one period to calculate the absolute value average. The absolute value average value is used for comparison in the integral value comparison unit 30. In this case, the calculation amount can be reduced, and the leakage detection device 100 can be configured at low cost.

  The integral value comparison unit 30 is configured by a comparison circuit or the like, and when the absolute value of the integral value, which is the calculation result by the integral calculation unit 20, is equal to or greater than the absolute value of the integral value determination threshold th1 as a predetermined value, leakage detection is performed. The voltage H is output to the unit 50. On the other hand, when the absolute value of the integrated value is less than the absolute value of the integral value determination threshold th1, the voltage L is output to the leakage detecting unit 50. The fact that the output voltage of the integration value comparison unit 30 is the voltage H corresponds to the integration value comparison unit 30 outputting a predetermined signal (first signal). The voltage H is higher than the voltage L.

  The waveform discriminating unit 40 detects and counts inflection points of the voltage waveform of the ZCT output voltage, and outputs the voltage H to the leakage detection unit 50 when the number of inflection points reaches a predetermined number. On the other hand, when the number of inflection points has not reached the predetermined number, the voltage L is output to the leakage detector 50. The output voltage of the waveform discriminating unit 40 being the voltage H corresponds to the waveform discriminating unit 40 outputting a predetermined signal (second signal). The predetermined number here is, for example, “2”, “3”, and the like. The detailed configuration of the waveform discrimination unit 40 will be described later.

  Further, the waveform discriminating unit 40 may start detecting the above inflection point regardless of whether the ZCT output voltage is a positive voltage or a negative voltage. Thereby, the inflection point can be detected at a high speed, and the AC circuit can be interrupted at a higher speed in the case of a normal leakage.

  The leakage detection unit 50 is configured by an AND circuit or the like, and outputs the voltage H when the output voltage of the integral value comparison unit 30 is the voltage H and the output voltage of the waveform determination unit 40 is the voltage H. The fact that the output voltage of the leakage detection unit 50 is the voltage H corresponds to outputting a leakage detection signal indicating that leakage has occurred in the AC circuit. The leakage detection signal is sent to a tripping coil (not shown) that opens the electric circuit contact as an interruption signal for opening the electric circuit contact of the AC electric circuit (for interrupting the AC electric circuit). As a result, the circuit contact of the AC circuit is opened.

Next, a detailed configuration of the waveform determination unit 40 will be described.
FIG. 2 is a block diagram showing a detailed configuration example of the waveform discriminating unit 40. The waveform determination unit 40 shown in FIG. 2 includes a pulse generation unit 41 and a pulse count unit 42.

  The pulse generation unit 41 is configured by a pulse generation circuit or the like, and generates a pulse based on the ZCT output voltage. Here, a short-time voltage is output as a pulse at a predetermined voltage value (voltage H).

  The pulse count unit 42 includes a pulse counter or the like, counts the number of pulses generated by the pulse generation unit 41, and sets the output voltage to the voltage H when the number of pulses reaches a predetermined number. The signal is output. On the other hand, when the number of pulses does not reach the predetermined number, the output voltage is set to the voltage L, and the second signal is not output.

Next, the operation of the leakage detection device 100 of this embodiment will be described.
FIG. 3 is a time chart for explaining a first operation example of the leakage detecting apparatus 100 of the present embodiment.

  In the example of FIG. 3, it is assumed that the pulse generator 41 generates a pulse when the absolute value of the ZCT output voltage is equal to or greater than the absolute value of the leakage current detection threshold th2. Thereby, without malfunctioning by lightning surge, it operates in the case of a desired leakage current value, and leakage can be detected at higher speed. On the other hand, no pulse is generated when the absolute value of the ZCT output voltage is less than the absolute value of the leakage current detection threshold th2. Further, here, the pulse is counted by the pulse counting unit 42 at the rising edge of the pulse.

  The “leakage current” in FIG. 3 indicates the leakage current generated in the zero-phase current transformer 10 in each case (normal leakage, lightning surge). As shown in FIG. 3, a periodic leakage current is generated in the case of a normal leakage, and a temporary leakage current is generated with a relatively large current value in the case of a lightning surge.

  “ZCT output” in FIG. 3 indicates the output voltage (ZCT output voltage) of the zero-phase current transformer 10 corresponding to the leakage current in each case.

  “Pulse generator output” in FIG. 3 indicates the output voltage of the pulse generator 41 in each case. In the example of FIG. 3, three pulses are generated in the case of normal leakage in the same period, but two pulses are generated in the case of lightning surge, and more pulses are generated in the case of normal leakage. is doing.

  The “counter” in FIG. 3 indicates the count value held by the pulse count unit 42 in each case.

  “Counter output” in FIG. 3 indicates the output voltage of the pulse count unit 42 in each case. In the example of FIG. 3, when the third pulse is generated, the output voltage of the pulse count unit 42 is the voltage H.

  “Integration calculation output” in FIG. 3 indicates the output voltage of the integration calculation unit 20 in each case.

  “Integral value comparison output” in FIG. 3 indicates the output voltage of the integral value comparison unit 30 in each case.

  The “leakage detection signal output” in FIG. 3 indicates the output voltage of the leakage detection unit 50 in each case.

  According to such a first operation example, it is possible to quickly identify a normal electric leakage and a lightning surge.

  FIG. 4 is a time chart for explaining a second operation example of the leakage detecting apparatus 100 of the present embodiment.

  In the example of FIG. 4, it is assumed that the pulse generator 41 generates a pulse when a state where the absolute value of the ZCT output voltage is equal to or greater than the absolute value of the leakage current detection threshold th2 continues for a predetermined time or longer. On the other hand, when the absolute value of the ZCT output voltage is less than the absolute value of the leakage current detection threshold th2, or the state where the absolute value of the ZCT output voltage is greater than or equal to the absolute value of the leakage current detection threshold th2 does not continue for a predetermined time or longer. If this happens, no pulse is generated.

  As shown in FIG. 4, since the continuation of the predetermined time is considered together with the voltage value of the ZCT output voltage, the “pulse generator output” is output at a timing delayed by a predetermined time as compared with FIG. Accordingly, the timing of “counter”, “counter output”, and “leakage detection signal output” is also delayed. Thereby, without malfunctioning by lightning surge, it operates in the case of a desired leakage current value, and leakage can be detected at higher speed. Furthermore, it is strong against noise and the robustness is improved.

  In FIG. 4, “integral calculation output”, “integral value comparison output”, and “leakage detection signal output” are not shown.

  FIG. 5 is a time chart for explaining a third operation example of the leakage detecting apparatus 100.

  In the example of FIG. 5, it is assumed that the pulse generation unit 41 stops the generation of the pulse when the absolute value of the ZCT output voltage becomes less than the absolute value of the pulse stop determination threshold th3 after the start of the generation of the pulse. Yes. On the other hand, if the absolute value of the ZCT output voltage is greater than or equal to the absolute value of the pulse generation determination threshold th3, pulse generation is continued.

  As shown in FIG. 5, the pulse generation is stopped when the “pulse generation unit output” is less than the absolute value of the pulse stop determination threshold th3 within a predetermined range. Therefore, one pulse is generated until the absolute value of the leakage current detection threshold th3 becomes equal to or greater than the absolute value of the pulse stop determination threshold t3. Further, here, the pulse is counted by the pulse counting unit 42 at the fall of the pulse. Therefore, the timing of “counter”, “counter output”, and “leakage detection signal output” is delayed as compared with the case of counting at the rising edge of the pulse.

  In FIG. 5, “integral calculation output”, “integral value comparison output”, and “leakage detection signal output” are not shown.

  In addition, here, the case where the voltage is taken into consideration for stopping the pulse is shown, but time may be taken into consideration instead of the voltage. For example, the pulse generator 41 may stop the pulse when a predetermined time has elapsed from the start of the pulse generation.

  FIG. 6 is a time chart for explaining a fourth operation example of the leakage detecting apparatus 100 of the present embodiment.

  In the example of FIG. 6, it is assumed that the pulse generation unit 41 does not generate the next pulse for a predetermined time after the generation of the pulse in the normal leakage. That is, it is assumed that the pulse generator 41 stops generating the second pulse until a predetermined time has elapsed from the generation of the first pulse. Of course, this can also be applied to lightning surges.

  In the example of FIG. 6, in the lightning surge, the pulse generator 41 generates the first pulse and the second pulse without passing the predetermined time, but the pulse count unit 42 counts from the first pulse count. It is assumed that the counting of the second pulse is stopped until a predetermined time is obtained. Of course, it is also possible to apply this in normal electric leakage.

  In the example of FIG. 6, in normal leakage, the generation timing for one pulse is included in the output mask period as a predetermined time. In this case, the second pulse to be generated by the pulse generator 41 overlaps with the output mask period, and therefore occurs after the end of the output mask period. Therefore, the count value of the pulse count is counted with a delay of one pulse.

  In the example of FIG. 6, in the lightning surge, the count mask period as a predetermined time includes the count timing for one pulse. In this case, since the second pulse to be counted by the pulse counting unit 42 overlaps the count mask period, it is counted after the end of the count mask period. Therefore, the count value of the pulse count is counted with a delay of one pulse. Therefore, since the timing of the “counter” is delayed, the timings of the “counter output” and “leakage detection signal output” are also delayed accordingly.

  In FIG. 6, “integral calculation output”, “integral value comparison output”, and “leakage detection signal output” are not shown.

  Thus, by providing the mask period for a predetermined time, it is possible to accurately generate pulses or perform pulse counting. In particular, erroneous detection of lightning surge can be prevented, and malfunction of the leakage detection device 100 can be prevented.

  FIG. 7 is a time chart for explaining a fifth operation example of the leakage detecting apparatus 100 of the present embodiment.

  In the example of FIG. 7, it is assumed that the pulse counting unit 42 performs counting when the pulse width (time width) of the pulse generated by the pulse generating unit 41 is equal to or greater than a predetermined width. On the other hand, when the pulse width of the pulse is less than the predetermined width, it is not counted as a pulse.

  Further, here, the pulse is counted by the pulse counting unit 42 at the fall of the pulse. Therefore, the timing of “counter”, “counter output”, and “leakage detection signal output” is delayed as compared with the case of counting at the rising edge of the pulse.

  In FIG. 7, “integral calculation output”, “integral value comparison output”, and “leakage detection signal output” are not shown.

(Second Embodiment)
The leakage detection device 100 according to the second embodiment includes a waveform determination unit 40B instead of the waveform determination unit 40 described in the first embodiment. In addition, about the leak detection apparatus 100 of this embodiment, about the structure similar to the leak detection apparatus 100 shown in 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  FIG. 8 is a block diagram showing a configuration example of the waveform discriminating unit 40B in the second embodiment of the present invention. The waveform discriminating unit 40B shown in FIG. 8 includes a count value changing unit 43 in addition to the pulse generating unit 41 and the pulse counting unit 42.

  The count value changing unit 43 is configured by a control circuit or the like, detects a pulse output width based on the pulse generated by the pulse generating unit 41, and counts the pulse when the pulse output width is equal to or greater than a predetermined width or less than a predetermined width. The count value by the unit 42 is changed. In this case, for example, the count value is increased by one.

Here, the “pulse output width” is as follows (see FIG. 9 described later).
(A) Time width T1 from the output start time (rising time) of the pulse P1 to the output end time (falling time)
(B) Time width T2 from the output start time of the pulse P1 as the first pulse to the output start time of the pulse P2 as the second pulse continuous with the first pulse
(C) Time width T3 from the end of output of pulse P1 to the end of output of pulse P2
(D) Time width T4 from the output start time of the pulse P1 to the output end time of the pulse P2.

  FIG. 9 is a time chart for explaining an operation example of the leakage detection device 100 of the present embodiment.

  In the example of FIG. 9, the counter value is increased by 1 when the pulse output width is equal to or greater than the time width T3. Thereby, the timing which changes a count value can be flexibly set. Therefore, by setting any one of the time widths T1 to T4 to the pulse output width, malfunction can be prevented without delaying the operation time of the leakage detection device 100.

  In FIG. 9, “integral calculation output”, “integral value comparison output”, and “leakage detection signal output” are not shown.

(Third embodiment)
The leakage detection device 100 according to the third embodiment includes a waveform determination unit 40C instead of the waveform determination unit 40 described in the first embodiment. In addition, about the leak detection apparatus 100 of this embodiment, about the structure similar to the leak detection apparatus 100 shown in 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  FIG. 10 is a block diagram showing a configuration example of the waveform discriminating unit 40C in the third embodiment of the present invention. 10 includes a pulse generation condition change unit 44 in addition to the pulse generation unit 41 and the pulse count unit 42. The waveform determination unit 40C illustrated in FIG.

  The pulse generation condition change unit 44 is configured by a control circuit or the like, and changes the pulse generation condition by the pulse generation unit 41 based on the count value counted by the pulse count unit 42. The pulse generation conditions include a voltage threshold and a time threshold used when the pulse generator 41 determines whether or not to generate a pulse. The pulse generation condition changing unit 44, for example, at least the voltage threshold (for example, “leakage current detection threshold th2” described in the first embodiment) and the time threshold (for example, “predetermined time” described in the first embodiment). Change one.

  FIG. 11 is a time chart for explaining an operation example of the leakage detection device 100 of the present embodiment.

  In the example of FIG. 11, the pulse generation condition changing unit 44 changes the time threshold value at the time of pulse generation determination at the time when the counter output becomes “2”. That is, the time threshold value of the pulse generator 41 at the time of 2 counts is changed to instantaneous detection. As a result, malfunction of leakage detecting device 100 due to lightning surge or the like can be prevented, and the AC circuit can be interrupted at a higher speed in the case of normal leakage.

  In FIG. 11, “integral calculation output”, “integral value comparison output”, and “leakage detection signal output” are not shown.

(Fourth embodiment)
The leakage detection device 100 according to the fourth embodiment includes a waveform determination unit 40D instead of the waveform determination unit 40 described in the first embodiment. In addition, about the leak detection apparatus 100 of this embodiment, about the structure similar to the leak detection apparatus 100 shown in 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  FIG. 12 is a block diagram showing a configuration example of the waveform discriminating unit 40D in the fourth embodiment of the present invention. The waveform discriminating unit 40D shown in FIG. 12 includes a positive pulse generating unit 41A, a negative pulse generating unit 41B, a positive pulse counting unit 42A, and a negative pulse counting unit 42B.

  The positive-side pulse generator 41A generates a positive-side pulse that is a pulse based on the positive-side ZCT output voltage. The negative-side pulse generator 41B generates a negative-side pulse that is a pulse based on the negative-side ZCT output voltage. The conditions for generating a positive pulse or a negative pulse from the ZCT output voltage are the same as described above.

  The positive pulse counting unit 42A counts the positive pulse, and when the count number is equal to or larger than a predetermined number, the output voltage is set to the voltage H and the second signal is output. The negative-side pulse counting unit 42B counts negative-side pulses, and when the count number is a predetermined number or more, the output voltage is set to the voltage H and the second signal is output. Therefore, the second signal is output when at least one of the number of positive side pulses and the number of negative side pulses is a predetermined number or more. The conditions for counting the positive side pulse or the negative side pulse are the same as those described above.

  FIG. 13 is a time chart for explaining an operation example of the leakage detecting apparatus 100 of the present embodiment.

  “Positive side pulse generation unit output” in FIG. 13 indicates the output voltage of the positive side pulse generation unit 41A in each case. In the example of FIG. 13, in the case of normal leakage in the same period, two positive pulses are generated, but in the case of lightning surge, one positive pulse is generated, and normal leakage is more common. The pulse is generated.

  The “positive counter” in FIG. 13 indicates the count value held by the positive pulse counting unit 42A in each case.

  “Negative pulse generator output” in FIG. 13 indicates the output voltage of the negative pulse generator 41B in each case. In the example of FIG. 13, two positive pulses are generated in the case of normal leakage during the same period, but two negative pulses are also generated in the case of lightning surge.

  The “negative counter” in FIG. 13 indicates the count value held by the negative pulse count unit 42B in each case.

  “Counter output” in FIG. 13 indicates an output in consideration of the positive counter and the negative counter. In the example of FIG. 13, when at least one of the positive side pulse counting unit 42A and the negative side pulse counting unit 42B counts at least one of the positive side pulse and the negative side pulse two or more waves, the output voltage of the counter output is the voltage H It becomes. Therefore, in the example of FIG. 13, the counter output becomes the voltage H only in the case of normal leakage.

  In FIG. 13, “integral calculation output”, “integral value comparison output”, and “leakage detection signal output” are not shown.

  Thus, half-wave leakage can be easily detected by performing pulse generation and pulse count while distinguishing the positive side and the negative side of the ZCT output voltage.

(Fifth embodiment)
FIG. 14 is a block diagram showing a configuration example of a leakage detection apparatus E according to the fifth embodiment of the present invention. The leakage detection device 100E includes a zero-phase current transformer 10, an integration calculation unit 20, an integration value comparison unit 30, a waveform determination unit 40, a leakage detection unit 50E, and a plurality of logic calculation units as integrated circuits. Here, the first logic operation unit 60 and the second logic operation unit 70 are exemplified as the plurality of logic circuit units, but the present invention is not limited to this. Instead of the waveform discriminating unit 40, the waveform discriminating units 40B to 40D described above may be used. About the leak detection apparatus 100E of this embodiment, about the structure similar to the leak detection apparatus 100 shown in the 1st-4th embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The first logic operation unit 60 and the second logic operation unit 70 cause the output voltage of the integral value comparison unit 30 to be the voltage H (that is, output the first signal) or the output voltage of the waveform determination unit 40 to be the voltage It has a function as a signal input unit for inputting a signal output instruction signal for setting H (that is, outputting the second signal). Therefore, the plurality of algorithms described in the first to fourth embodiments can be changed by these circuit units.

  The first logic operation unit 60 is configured by an OR circuit or the like, and outputs a voltage H when at least one of the output voltage of the integral value comparison unit 30 and the output voltage of the external circuit unit is the voltage H.

  The second logic operation unit 70 is configured by an OR circuit or the like, and outputs a voltage H when at least one of the output voltage of the waveform determination unit 40 and the output voltage of the external circuit unit is the voltage H.

  In addition, as an external circuit unit of the first logic operation unit 60 and the second logic operation unit 70, a low-capacity chip resistor can be considered. This chip resistor is connected to the input pins of the first logic operation unit 60 and the second logic operation unit 70. Thereby, a circuit including an external circuit part can be configured at low cost. As described above, the signal output instruction signal may be input from the external resistor.

  The leakage detection unit 50E is configured by an AND circuit or the like. When the output voltage of the first logic operation unit 60 is the voltage H and the output voltage of the second logic operation unit 70 is the voltage H, the leakage detection unit 50E Output. The fact that the output voltage of the leakage detection unit 50E is the voltage H corresponds to outputting a leakage detection signal indicating that a leakage has occurred in the AC circuit. The leakage detection signal is sent to a tripping coil (not shown) that opens the electric circuit contact as an interruption signal for opening the electric circuit contact of the AC electric circuit (for interrupting the AC electric circuit). As a result, the circuit contact of the AC circuit is opened.

  According to such a leakage detection device 100E of the present embodiment, if the output voltage of the external circuit unit connected to the first logic operation unit 60 is the voltage H, the first to fourth embodiments. Since the output voltage of the integrated value comparing unit 30 is always equivalent to the voltage H, the function of the integrated value comparing unit 30 can be disabled. Similarly, if the output voltage of the external circuit unit connected to the second logic operation unit 70 is a voltage H, the waveform discriminating unit 40 or the like (40, 40B to 40D) of the first to fourth embodiments. Since the output voltage of any one of the above is equivalent to the voltage H always, the function of the waveform discriminating unit 40 and the like can be invalidated. That is, one of the functions can be disabled using the external circuit unit.

  Further, here, it has been described that a part of the function of the leakage detection device 100E is invalidated using the first logic operation unit 60 and the second logic operation unit 70, but these circuit units may not be used. . For example, in order to change each threshold value such as at least one voltage threshold value or time threshold value of the integration calculation unit 20, the integration value comparison unit 30, or the waveform determination unit 40, or to change the count value from an external device (not shown). The change signal may be input. For example, when changing each threshold value, the measurement voltage and the measurement time may be changed to values that always exceed the threshold value. For example, the count value may be changed to a value that always exceeds the count threshold. Even with such a configuration, a part of the function of the leakage detection device 100E can be similarly disabled.

(Sixth embodiment)
FIG. 15 is a block diagram illustrating a configuration example of a leakage detecting apparatus 100F according to the sixth embodiment of the present invention. The leakage detection device 100F of the present embodiment has a function as the leakage detection devices 100 and 100E excluding the zero-phase current transformer 10 and the zero-phase current transformer 10 described in the first to fifth embodiments. It has the 2nd system which integrates a system (leakage level detection part 80), and the output voltage (ZCT output voltage) of zero phase current transformer 10, and outputs according to an integration result. That is, the first system realizes a function related to leakage break, and the second system realizes a function for notifying the user of the amount of leakage (leakage current value).

  The leakage level detection unit 80 as the first system includes the integration calculation unit 20, the integration value comparison unit 30, the waveform determination unit 40, the leakage detection unit 50, and the like as described above. Among these, the leakage level detection unit 80 includes at least the integration calculation unit 20 and the leakage detection unit 50. The leakage detection unit 50 outputs a leakage detection signal based on the calculation result by the integration calculation unit 20.

The second system includes an integration unit 91 and an operation result output unit 92.
The integration unit 91 integrates the ZCT output voltage and has the same configuration as the integration calculation unit 20 described above. The calculation result output unit 92 performs output according to the calculation result (integration value) by the integration unit 91. The calculation result output unit 92 outputs various types of information using, for example, a display or a speaker (not shown). Here, as the calculation result, for example, the effective value (effective value calculation result) of the ZCT output voltage using the integral calculation as described above, or the average value (average value calculation result) of the ZCT output voltage using the integral calculation. Is output.

  Here, each component of the first system and the second system is configured in one integrated circuit (one module). Therefore, cost reduction can be aimed at by comprising the earth-leakage detection apparatus 100F with the same package in this way. That is, it is possible to carry out the earth leakage interruption and the earth leakage display at the same time with a simple and inexpensive configuration.

  Also, as shown in FIG. 16, an integration unit 91 may be used as the integration calculation unit 20 described in the first embodiment. That is, the leakage level detection unit 80 may not include the integration calculation unit 20, and the integration value comparison unit 30 may input the output of the integration unit 91. In this way, the cost can be reduced by using a common configuration for integration. In addition, since the hardware such as the integration circuit is shared, it does not depend on the difference due to hardware or the calculation method for integral calculation, so the level detection value for leakage detection and the display for displaying the leakage degree Since there is no error between the values, it can be adjusted so that there is no contradiction between the two.

  The calculation result output unit 92 may output an average value (average value) of the integration values calculated by the integration unit 91. Further, the integral value comparison unit 30 may compare the average value (average value) calculated by the integral calculation unit 20 with a predetermined value (integration value determination threshold th1). The average value is, for example, a time average. At this time, it is preferable that the period when the calculation result output unit 92 averages is longer than the period when the integral value comparison unit 30 averages. Alternatively, the integration unit 91 may average the ZCT output voltage over a longer period than the integration calculation unit 20 to calculate an average value of the ZCT output voltage, and integrate the average value to obtain an integration value. As a result, an integrated value (corresponding to a leakage current value) or the like can be accurately output without being affected by fluctuations in the ZCT output voltage due to noise such as surge voltage.

  In addition, although demonstrated as an average value here, you may use an effective value instead of an average value.

  Further, the calculation result output unit 92 has an absolute value of the calculation result (integrated value) by the integration unit 91 larger than the absolute value smaller than the absolute value of the leakage current detection threshold th2 for leakage detection in the leakage level detection unit 80. In this case, a warning signal (alarm) may be output. The warning signal here may be a warning based on audio information or a warning based on display information. In other words, if the calculation result by the integration unit 91 reaches outside the predetermined range narrower than the voltage range used when determining whether or not the first signal is output by the integration value comparison unit 30, a warning signal may be output. Good. Thereby, the user can recognize the state of the electric leakage in advance before detecting the electric leakage to the extent that the AC electric circuit is interrupted.

  Further, the calculation result output unit 92 may change the output form when outputting the warning signal according to the calculation result by the integration unit 91. In this case, for example, the LED is turned on when the absolute value of the calculation result by the integrating unit 92 exceeds 50% of the absolute value of the leakage current detection threshold th2, and exceeds 80% of the absolute value of the leakage current detection threshold th2. In some cases, it is possible to output an alarm sound. Thereby, it is possible to accurately notify the urgency (level) until the electric leakage is interrupted, and it is possible to avoid a situation where the electric leakage is suddenly interrupted.

  As illustrated in FIG. 17, the leakage detection device 100 </ b> F may include a calculation result storage unit 93 that stores a calculation result of the integration unit 91. The calculation result storage unit 93 stores, for example, calculation result information for a predetermined time (for example, for one week). At this time, the information may be overwritten and rewritten after a predetermined time has elapsed. The calculation result information includes an integrated value (effective value, average value) of the ZCT output voltage. Thereby, it becomes easy to identify the cause of the interruption by storing the calculation result for a certain time until the electric leakage interruption.

  Further, as shown in FIG. 18, the leakage detection device 100 </ b> F includes an external terminal unit 94 for outputting calculation result information by the integration unit 91 and calculation result information by the calculation result storage unit 93 via an external terminal. You may prepare. The external terminal unit 94 is, for example, a USB (Universal Serial Bus) terminal. By providing the external terminal unit 94, information on the calculation result can be easily output, and the cause of the interruption can be easily identified.

  Further, as shown in FIG. 19, the leakage detection device 100 </ b> F may include an information output unit 95 that outputs information on the calculation result by the integration unit 91 and information on the calculation result by the calculation result storage unit 93 to the storage medium. The storage medium is, for example, a USB memory or an SD card. Thereby, for example, by outputting a calculation result for a certain period of time until the electric leakage is interrupted to the storage medium, data can be easily carried and the cause of the interruption can be easily identified.

  As illustrated in FIG. 20, the leakage detection device 100 </ b> F may include an information transmission unit 96 that transmits information on the calculation result by the integration unit 91 and information on the calculation result by the calculation result storage unit 93 to an external server. As a result, for example, by outputting a calculation result for a certain period of time until the electric leakage interruption to the external server, the electric leakage situation can be easily grasped even at a remote center or the like, and the cause of the electric interruption can be easily identified.

100, 100E, 100F Earth leakage detection device 10 Zero phase current transformer (ZCT)
20 Integral calculation unit (an example of a first integral calculation unit)
30 Integral Value Comparison Unit 40 Waveform Discrimination Unit 41 Pulse Generation Unit 41A Positive Side Pulse Generation Unit 41B Negative Side Pulse Generation Unit 42 Pulse Count Unit 42A Positive Side Pulse Count Unit 42B Negative Side Pulse Count Unit 43 Count Value Change Unit 44 Pulse Generation Conditions Change unit 50 Leakage detection unit 60 First logic operation unit 70 Second logic operation unit 80 Leakage level detection unit 91 Integration unit (an example of a second integration operation unit)
92 operation result output unit 93 operation result storage unit 94 external terminal unit 95 information output unit 96 information transmission unit th1 integral value determination threshold th2 leakage current detection threshold th3 pulse stop determination threshold

Claims (33)

A zero-phase current transformer through which the AC circuit passes,
A first integration operation unit for integrating the output voltage of the zero-phase current transformer;
A leakage detection unit that outputs a leakage detection signal indicating that leakage has occurred in the AC circuit, based on a calculation result by the first integration calculation unit;
A second integration operation unit for integrating the output voltage of the zero-phase current transformer;
A calculation result output unit that performs output according to a calculation result by the second integral calculation unit;
With
The leakage detection device in which the calculation result output unit and the leakage detection unit are configured by one module. The leakage detection device according to claim 1,
The leakage detection unit is a leakage detection apparatus using the second integration calculation unit as the first integration calculation unit. The leakage detection device according to claim 1 or 2,
The second integration calculation unit is a leakage detection device that averages output voltages of the zero-phase current transformers for a longer period than the first integration calculation unit, calculates an average value, and integrates the average value. The leakage detection device according to any one of claims 1 to 3, further comprising:
A signal comparison unit that outputs a first signal when a calculation result by the first integration calculation unit reaches a predetermined range;
The calculation result output unit is outside a predetermined range in which a calculation result by the second integration calculation unit is smaller than a voltage threshold range used when determining whether or not the first signal is output by the integration value comparison unit. A leakage detection device that outputs a warning signal when it reaches. The leakage detection device according to claim 4,
The calculation result output unit is a leakage detection device that changes an output form when outputting the warning signal according to a calculation result by the second integration calculation unit. The leakage detection device according to any one of claims 1 to 5, further comprising:
An electric leakage detection apparatus comprising a calculation result storage unit that stores information on a calculation result by the second integration calculation unit for a predetermined time. The leakage detection device according to claim 6, further comprising:
An electrical leakage detection device comprising an external terminal unit for outputting information on a calculation result stored in the calculation result storage unit. The leakage detection device according to claim 6, further comprising:
An electric leakage detection apparatus comprising an information output unit that outputs information on a calculation result stored in the calculation result storage unit to a storage medium. The leakage detection device according to claim 6, further comprising:
An electrical leakage detection apparatus comprising an information transmission unit that transmits information on a calculation result stored in the calculation result storage unit to an external server. The leakage detection device according to any one of claims 1 to 9, further comprising:
An integration value comparison unit that outputs a first signal when a calculation result of the first integration calculation unit reaches a predetermined range;
Detecting and counting inflection points of the output voltage waveform of the zero phase current transformer, and outputting a second signal when the number of inflection points reaches a predetermined number;
With
The leakage detection device outputs the leakage detection signal when the first signal is output by the integral value comparison unit and the second signal is output by the waveform determination unit. The leakage detection device according to claim 10,
The said waveform discrimination | determination part is a leak detection apparatus which starts the detection of the said inflection point, when the output voltage of the said zero phase current transformer is a positive voltage or a negative voltage. The leakage detection device according to claim 10 or 11,
The first integral calculation unit is a leakage detection device that calculates an effective value of an output voltage of the zero-phase current transformer using an integral calculation. The leakage detection device according to claim 10 or 11,
The first integration calculation unit is a leakage detection device that calculates an average value of the output voltage of the zero-phase current transformer using integration calculation. The leakage detection device according to any one of claims 10 to 13,
The waveform discrimination unit
A pulse generator for generating a pulse based on the output voltage waveform of the zero-phase current transformer;
A pulse count unit that counts the number of pulses generated by the pulse generation unit, and outputs the second signal when the number of pulses reaches a predetermined number;
A leakage detection device comprising: The leakage detection device according to claim 1,
The pulse generation unit is a leakage detecting device that generates the pulse when the output voltage of the zero-phase current transformer reaches a predetermined range. The leakage detection device according to claim 15,
The pulse generation unit is a leakage detection device that generates the pulse when a state in which the output voltage of the zero-phase current transformer has exceeded a predetermined range continues for a predetermined time or more. The leakage detection device according to any one of claims 14 to 16,
The pulse generation unit is a leakage detecting device that stops generation of the pulse when the output voltage of the zero-phase current transformer becomes less than a predetermined voltage after generation of the pulse is started. The leakage detection device according to any one of claims 14 to 16,
The pulse generation unit is an electrical leakage detection device that stops generation of the pulse when a predetermined time has elapsed from the start of generation of the pulse. The leakage detection device according to any one of claims 14 to 18, comprising:
The pulse generation unit is a leakage detecting device that stops generating the second pulse until a predetermined time has elapsed from the generation of the first pulse. The leakage detection device according to any one of claims 14 to 19,
The pulse count unit counts the number of rising edges of the pulses generated by the pulse generator, and outputs the second signal when the number reaches a predetermined number. The leakage detection device according to any one of claims 14 to 19,
The pulse count unit counts when the pulse width of the pulse generated by the pulse generator is a predetermined width or more, and outputs the second signal when the number reaches a predetermined number. The leakage detection device according to any one of claims 14 to 19,
The leakage detecting device that counts the number of falling pulses generated by the pulse generator and outputs the second signal when the number reaches a predetermined number. The leakage detection device according to any one of claims 14 to 22,
The leak detection device, wherein the pulse counting unit stops counting the second pulse until a predetermined time has elapsed from the counting of the first pulse generated by the pulse generating unit. The leakage detection device according to any one of claims 14 to 23, wherein:
The leakage detecting device includes a count value changing unit that changes the count value counted by the pulse counting unit when the pulse output width based on the pulse generated by the pulse generating unit is equal to or greater than a predetermined width. The electric leakage detection device according to claim 24,
The leak detection device, wherein the pulse output width is a time width from an output start time to an output end time of a pulse generated by the pulse generator. The electric leakage detection device according to claim 24,
The leakage detection device, wherein the pulse output width is a time width from an output start time of a first pulse generated by the pulse generator to an output start time of a second pulse that is continuous with the first pulse. The electric leakage detection device according to claim 24,
The leakage detection device, wherein the pulse output width is a time width from an output end point of the first pulse generated by the pulse generation unit to an output end point of a second pulse continuous with the first pulse. The electric leakage detection device according to claim 24,
The leakage detection device, wherein the pulse output width is a time width from an output start point of the first pulse generated by the pulse generator to an output end point of the second pulse. The leakage detection device according to any one of claims 14 to 28, further comprising:
An electric leakage detection apparatus comprising: a pulse generation condition changing unit that changes a pulse generation condition by the pulse generation unit based on a count value counted by the pulse count unit. The leakage detection device according to claim 29, wherein
The pulse generation condition changing unit is a leakage detecting device that changes at least one of a voltage threshold and a time threshold used when determining whether or not the pulse generating unit generates a pulse. The leakage detection device according to any one of claims 14 to 30, comprising:
The pulse generation unit, a positive pulse that is a pulse based on the positive output voltage of the zero-phase current transformer, a negative pulse that is a pulse based on the negative output voltage of the zero-phase current transformer, Occur and
The pulse counting unit counts the positive pulse and the negative pulse, and when at least one of the number of the positive pulse and the number of the negative pulse is a predetermined number or more, the second signal is The leakage detection device that outputs. The leakage detection device according to any one of claims 14 to 31, further comprising:
A leakage detecting device comprising a signal input unit for inputting a signal output instruction signal for outputting the first signal by the integral value comparing unit or outputting the second signal by a waveform discriminating unit. The electric leakage detection device according to claim 32, comprising:
The signal input unit is a leakage detection device for inputting the signal output instruction signal from an external resistor.

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