KR101611020B1 - Earth leakage circuit breaker - Google Patents

Abstract

It is possible to reduce the average value of the test current, thereby realizing downsizing and thinning of the power supply circuit portion.
An electric leak detecting section 7 for judging the presence or absence of electric leakage of the alternating current on the basis of the secondary output of the image transformer 3 having the alternating current converter 1 as a primary coil, A trip device (6) which is operated by the operation of a switching element based on the output of the electric leakage detecting section, and a switching device A test apparatus 9 for supplying a simulated leakage current to the test coil wound around the video current transformer during a leakage current operation test and a setting section 7g for changing the operation characteristics of the leakage current detection section to the leakage current operation test, .

Description

{EARTH LEAKAGE CIRCUIT BREAKER}

The present invention relates to an earth leakage breaker having a test apparatus for performing a leakage operation test.

In order to periodically test the operation ability of the earth leakage breaker, it is necessary to provide a test apparatus for energizing the detection device with a simulated current.

On the other hand, it is known that the detection apparatus incorporates a low-pass filter in order to prevent harmonic components of the electric path, for example, unnecessary operation due to the switching noise of the inverter For example, see Patent Document 1).

It is also known that a waveform detection function is incorporated in order to prevent unnecessary operation due to surge components, for example, lightning stroke.

For this reason, the conventional testing device of the earth leakage breaker has a configuration in which a current of a pseudo AC signal such as a sinusoidal wave, a rectangular wave, a triangular wave, It is known to conduct current to the current transformer (for example, see Patent Document 2).

Patent Document 1: Japanese Patent Application Laid-Open No. 2007-220381 Patent Document 2: JP-A-2003-219552

As described above, the test apparatus energizes the pseudo alternating current signal to the video current transformer. However, the rated sensitivity current (operation current) of the earth leakage breaker is set to, for example, 30 mA, 100 mA, 500 mA, It becomes a very large current.

For this reason, the power supply circuit needs to cope with this current consumption, and there is a problem that it is difficult to downsize and downsize the power supply circuit.

Further, in order to reduce the test current, there is known a method of winding the electric wire for energizing a plurality of times to the video current transformer. However, in this case, there is a problem that miniaturization and thinning of the video current transformer become difficult.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to obtain an electric leakage circuit breaker capable of reducing the average value of the test current and making the power supply circuit part small and thin.

An electric leakage circuit breaker according to the present invention is a circuit breaker comprising: a video current transformer having a primary coil as an AC current to be subjected to an electrical leak detection; an electrical leak detecting portion for determining the presence or absence of electrical leakage of the AC electrical converter based on a secondary output of the voltage transformer; A trip device that operates based on an output of the electric leak detecting portion when an electric leak occurs, an trip device that operates by an operation of the switching element based on an output of the electric leak detecting portion, A test device for supplying a test leakage current to the test coil wound around the image current transformer for a leakage current operation test during a leakage current operation test, And a setting unit for changing the operating characteristic of the electrical leak detecting unit to the electrical leakage testing time.

The present invention relates to a fault detection circuit for detecting an electric leakage, comprising: a phase current transformer having an AC converter as a primary coil as a primary coil; an electrical leak detecting portion for determining the presence or absence of electrical leakage of the AC converter based on a secondary output of the phase converter; A trip device which is operated by the operation of the switching element based on the output of the electric leak detecting section, and a switching device which is operated normally by closing the alternating current converter and by the operation of the trip device A test apparatus for supplying a test leakage current to the test coil wound around the alternating current transformer, a test coil wound around the current transformer for a short circuit operation test, It is possible to reduce the average value of the test currents This makes it possible to reduce the size and thickness of the power supply circuit, and to reduce the size and thickness of the video transformer.

Fig. 1 is a block diagram showing an example of the internal circuit configuration of the earth leakage breaker according to the first embodiment of the present invention. Fig.
Fig. 2 is an explanatory view for explaining an example of an electrical leak detecting operation of the earth leakage breaker according to the first embodiment of the present invention. Fig.
3 is an explanatory diagram for explaining an example of a leakage test operation of the earth leakage breaker according to the first embodiment of the present invention.
4 is a block diagram showing another example of the internal circuit configuration of the earth leakage breaker according to the second embodiment of the present invention.
5 is an explanatory view for explaining another example of the electrical leak detecting operation of the earth leakage breaker according to the second embodiment of the present invention.
Fig. 6 is an explanatory view for explaining another example of the leakage test operation of the earth leakage breaker in the second embodiment of the present invention. Fig.

Embodiment 1

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 of the present invention will be described with reference to Figs. Fig. 1 is a block diagram showing an example of the internal circuit configuration of the earth leakage breaker, Fig. 2 is an explanatory view for explaining an example of an earth leakage detection operation of the earth leakage breaker shown in Fig. 1, Fig. 7 is an explanatory diagram for explaining an example of a leakage test operation of the circuit breaker. Fig.

1, the earth leakage breaker 100 includes an open / close contact 2 for opening / closing an alternating current converter 1, a video current transformer 3 passing through the alternating current transformer 1, A trip coil 6a which is energized through the switching element 8 by the output signal of the earth leakage detector 7 and a trip coil 6a which is energized by the output signal of the earth leakage detector 7 are activated A trip device 6 having a trip mechanism 6b for opening and closing the opening and closing contact 2 when the test switch 10 is turned on and a test switch 10 for outputting a predetermined test signal to the video current transformer A test coil 9 for outputting a control signal to the electric leak detecting portion 7 and a test coil 11 for applying a test signal to the video current transformer 3 and an alternating current A rectifying circuit 4 for converting the output of the rectifying circuit 4 into a DC voltage, And a constant voltage circuit 5 which converts and supplies power to the electric leakage detecting portion 7, the test device 9 and the trip device 6. [

The electric leak detecting section 7 includes an input section 7a for converting the output current of the video current transformer 3 into a voltage signal, a low-pass filter 7a for removing a noise signal having a high frequency superimposed on the output signal from the input section 7a, A level detector 7c connected to the output of the low-pass filter 7b and turned on when the output of the low-pass filter 7b is equal to or higher than a threshold value, and a level detector 7c connected to the output of the level detector 7c, A waveform width detector 7d connected to the output of the waveform width detector 7d and turned on when the ON output of the detector 7c has continued for a predetermined time t1 or longer, A switch 7f for short-circuiting both ends of the low-pass filter 7b based on a control signal from the test apparatus 9; Based on the control signal of the waveform width detector 7d, Detection range setting section (the substrate referred to as "detection range setting unit") is composed of (7g).

The test apparatus 9 includes a test input circuit 9a for detecting that the test switch 10 is pressed and outputting a control signal to the electrical leak detecting section 7 and a test input circuit 9b connected to the output of the test input circuit 9a, And a test signal generating circuit 9b for outputting a test signal to the test coil 11 so that the current transformer 3 is energized.

Hereinafter, the operation of the electrical leak detecting section 7 will be described with reference to Figs. 1 to 3. Fig. When a short circuit occurs and a difference is generated in the current flowing in the alternating current converter 1, an output is generated in the video current transformer 3. The input unit 7a converts the output of the video current transformer 3 into a voltage corresponding to the output. The low-pass filter 7b removes the harmonic components of the voltage of the input section 7a and outputs a signal obtained by extracting the common frequency component. The level detector 7c compares the output of the low-pass filter 7b with a predetermined threshold voltage. The threshold value has a positive side and a negative side. When the output of the low-pass filter 7b becomes equal to or higher than the threshold of both sides, or when the output of the low-pass filter 7b is lower than the threshold of the negative side And outputs it. The waveform width detection unit 7d monitors the output of the level detection unit 7c and outputs the output when the time of output is longer than the predetermined time t1. The trip determination unit 7e counts the number of outputs from the waveform width detection unit 7d and outputs the count to the switching element 8 when the predetermined number of times has been reached. The switching element 8 is turned on by the output thereof and the excitation current flows from the constant voltage circuit 5 to the trip coil 6a through the switching element 8 so that the trip mechanism 6b operates, The contact 2 is opened.

In addition, the tripping section 7e has a function of discriminating between alternating sides from each other in accordance with the characteristics of the earth leakage breaker, and discriminating signals in one direction, for example, positive and negative.

The trip determination unit 7e has a function of resetting the count number when the output of the waveform width detection unit 7d is not within a predetermined period.

Next, the operation of the test apparatus 9 of the present embodiment will be described. The test input circuit 9a determines that the test switch 10 is closed and outputs it. The output of the test input circuit 9a is connected to the waveform width detection section 7d, thereby changing the predetermined time t1 to t2 (t1 >> t2). The output of the test input circuit 9a is also connected to the LPF bypass section 7f to close the switch connected in parallel to the LPF to bypass the output of the input section 7a.

In addition, the output of the test input circuit 9a is connected to the trip judging unit 7e, and switches to a function of discriminating a signal in one direction at the time of the test operation.

The test signal generating circuit 9b outputs a pulse signal of a predetermined period and a predetermined pulse width (? T2) by the output of the test input circuit 9a. The signal of the test signal generating circuit 9b is converted into a pulse current and applied to the test coil 11, and the video current transformer 3 generates a pulse output according to the signal.

The input unit 7a converts the output of the video current transformer 3 into a pulse voltage corresponding to the pulse output. Here, since the low-pass filter 7b is bypassed by the LPF bypass unit 7f, the signal of the input unit 7a is inputted to the level detection unit 7c while remaining the original waveform. The level detector 7c compares the threshold value with the threshold value and outputs the same. The waveform width detection section 7d outputs the waveform width detection section 7d when the output of the level detection section 7c has continued for a predetermined time t2 or longer. Thereafter, the test operation, that is, the operation ability of the earth leakage breaker is tested by opening and closing the open / close contact 2 in the same manner as described above.

×A)가 된다. 이 파고치(

×A)의 크기를 가지고, 주기 T, 펄스폭 t2인 펄스 전류를 테스트 코일(11)에 흘렸을 경우, 그 실효치는 (

×A×

)가 되어, 전력 용량은 큰 폭으로 저감된다. According to the present embodiment, since the pseudo signal to be supplied to the video current transformer 3 is a pulse waveform (pulse-like simulated leakage current), the average value of the signal is reduced to a large extent compared with a sinusoidal wave, a square wave, The capacitance can be reduced, and the power supply circuit section (the video current transformer 3, the test coil 11, etc.) can be downsized and thinned. For example, in order to obtain the sinusoidal output of FIG. 2 (b), if the effective value of the sinusoidal current flowing to the test coil 11 is A, the crest value (wave height value)

X A). This Pagochi (

× A), and the pulse current having the period T and the pulse width t2 is passed through the test coil 11, the effective value thereof is (

× A ×

), And the power capacity is greatly reduced.

In addition, since the ON duty of the pulse waveform can be shortened by shortening the detection time of the pulse width detection, the peak value of the pseudo signal can be increased without increasing the average value of the signal. Therefore, it is possible to reduce the number of test coils of the video current transformer, thereby making it possible to reduce the size and thickness of the video current transformer.

Embodiment 2 Fig.

A second embodiment of the present invention will be described with reference to Figs. 4 to 6. Fig. Fig. 4 is a block diagram showing another example of the internal circuit configuration of the earth leakage breaker, Fig. 5 is an explanatory view for explaining an example of the earth leakage detection operation of the earth leakage breaker shown in Fig. 4, Fig. 21 is an explanatory view for explaining an example of a leakage test operation of the earth leakage breaker; Fig.

In the present embodiment, the leakage detection section 7 of the first embodiment is provided with a short pulse detection section (referred to as a test pulse determination section) 17h in place of the switch 7f and the detection width setting section 7g, The detection unit 17 is used.

The electric leak detecting section 17 includes an input section 17a for converting an output current of the video current transformer 3 into a voltage signal, a low-pass filter 17a for removing a noise signal having a high frequency superimposed on an output signal from the input section 17a, A level detector 17c connected to the output of the low-pass filter 17b and turned on when the output of the low-pass filter 17b is equal to or higher than a threshold value, and a level detector 17c connected to the output of the level detector 17c, A waveform width detector 17d connected to the output of the waveform width detector 17d and turned on when the ON output of the detector 17c has continued for a predetermined time t1 or longer, A test pulse judging section 17e which is connected to the output of the input section 17a and operates only when the control signal from the test apparatus 9 is on and drives the switching element 8, (17h).

The test pulse judging section 17h is connected to the level detecting section 17h1 which is turned on when the output of the input section 17a is equal to or higher than the threshold value and the level detecting section 17h2 which is connected to the output of the level detecting section 17h1, A trip judging section 17h3 connected to the output of the waveform width detecting section 17h2 and driving the switching element 8 in accordance with the output of the waveform width detecting section 17h2, . Other configurations are the same as those in the first embodiment, and a description thereof will be omitted.

Hereinafter, the operation of the electrical leak detecting section 17 will be described with reference to Figs. 4 to 6. Fig. When a short circuit occurs and a difference occurs in the current flowing in the alternating current converter 1, an output is generated in the video current transformer 3. The input unit 17a converts the output of the video transformer 3 into a voltage corresponding to the output. The low-pass filter 17b removes the harmonic components of the voltage of the input section 17a and outputs a signal obtained by extracting a commercial frequency component. The level detector 17c compares the output of the low-pass filter 17b with a predetermined threshold voltage. When the output of the low-pass filter 17b is greater than or equal to the threshold value on both sides, or when the output of the low-pass filter 17b is below the threshold value on the negative side, the threshold value is output on both sides.

The waveform width detection unit 17d monitors the output of the level detection unit 17c and outputs the output when the output time has continued for a predetermined time t1 or longer. The trip determination unit 17e counts the number of times of output from the waveform width detection unit 17d and outputs the count to the switching element 8 when the predetermined number of times is reached. (Fig. 5). The switching element 8 is turned on by the output thereof, and the exciting current flows from the constant voltage circuit 5 to the trip coil 6a via the switching element 8 so that the trip mechanism 6b operates, The open / close contact 2 is opened.

Next, the operation of the test apparatus 9 of the present embodiment will be described. The test input circuit 9a determines that the test switch 10 is closed and outputs it. The output of the test input circuit 9a is connected to the test pulse judgment unit 17h. When the output of the test input circuit 9a is turned on, the test pulse judgment unit 17h operates.

Further, the trip judging unit 17h3 has a function of discriminating a signal in one direction.

The test signal generating circuit 9b outputs a pulse signal of a predetermined period and a predetermined pulse width (? T2) by the output of the test input circuit 9a. The signal of the test signal generating circuit 9b is converted into a pulse current and applied to the test coil 11, and the video current transformer 3 generates a pulse output according to the signal.

Next, the operation of the test pulse judging section 17h of the present embodiment will be described. When the test switch 10 is closed, the test input circuit 9a turns on the output of the test input circuit 9a, and the test pulse judgment unit 17h operates. The level detecting section 17h1 compares the output of the input section 17a with a predetermined threshold voltage. The threshold value has both sides and the sound side. When the output of the input section 17a becomes equal to or more than the threshold value of both sides, or when the output of the input section 17a becomes equal to or less than the threshold value of the sound side, the threshold value is output.

The waveform width detection unit 17h2 monitors the output of the level detection unit 17h1 and outputs the output when the time of the output has continued for a predetermined time t2 (t1 >> t2) or longer. The trip determination unit 17h3 counts the number of times of output from the waveform width detection unit 17h2 and outputs the count to the switching element 8 when the predetermined number of times is reached. (Fig. 5). The switching element 8 is turned on by its output, and the tripping mechanism 6b operates by energizing the trip coil 6a through the switching element 8 from the constant voltage circuit 5, The contact 2 is opened.

According to the second embodiment, since the pseudo signal to be supplied to the video current transformer 3 is a pulse waveform (pulse-like simulated leakage current), the average value of the signal is reduced to a large extent as compared with a sine wave, a square wave, The power capacity is also reduced, and the power supply circuit portion (the video current transformer 3, the test coil 11, etc.) can be downsized and thinned.

In addition, since the ON duty of the pulse waveform can be shortened by shortening the detection time of the pulse width detection, the peak value of the pseudo signal can be increased without increasing the average value of the signal. Therefore, it is possible to reduce the number of test coils of the video current transformer, thereby making it possible to reduce the size and thickness of the video current transformer.

The above-described Embodiment 1 and Embodiment 2 described above have the following features 1 to 4 when they are changed in perspective.

[0028] The present invention is characterized in that, in a case where a short circuit occurs in the alternating current converter, it is determined whether or not there is a short circuit in the alternating current converter based on the secondary output of the voltage transformer, A trip device which is operated by the operation of the switching element based on the output of the electric leak detecting section, and a switching device which is operated normally by closing the alternating current converter and by the operation of the trip device A test apparatus for supplying a test leakage current to the test coil wound around the alternating current transformer, a test coil wound around the current transformer for a short circuit operation test, And a setting unit for changing the power supply voltage.

[0029] In a second aspect of the present invention, the testing apparatus supplies the test coil with a pulse-shaped simulated current leakage current as the simulated current leakage current, and the setting section sets the operating characteristics of the current- It is an earth leakage breaker that changes to operate according to the leakage current.

A third aspect of the present invention is directed to a method for detecting a short circuit in an AC electric vehicle, comprising the steps of: detecting a short circuit in the AC converter based on a secondary output of the rectifier; A trip device which is operated by the operation of the switching element based on the output of the electric leak detecting section, and a switching device which is operated normally by closing the alternating current converter and by the operation of the trip device A test apparatus for supplying a pulsed current as a simulated leakage current for a leakage current operation test in a leakage current operation test on a test coil wound around the alternating current transformer, Operating according to a secondary output of the video current transformer based on the current to operate the switching element (Test pulse judging section) for judging whether or not a fault has occurred.

A fourth aspect of the present invention is to provide a method of controlling an alternating current (AC) in an alternating current (AC) converter, comprising the steps of: A switching device connected in series with the trip device to operate the trip device in accordance with the conduction of the switching device (switching element, switching device, And a test circuit (test apparatus) for supplying a simulated leakage current to a test coil wound around the video current transformer by an ON operation of the test switch, wherein the ON duty of the simulated leakage current is determined by the ON duty of the test switch When the ON operation of the electric leak detecting circuit is not ON, When ON operation of the location, a circuit breaker in which the short circuit detecting circuit changes a detectable detection sensitivity of the simulated leakage current.

Further, the present invention can be appropriately modified, omited, and the like within the scope of the invention.

In the drawings, the same reference numerals denote the same or substantially equal parts.

2: open / close contact, 3: video current transformer,
6: Trip device, 7: Leakage detection part,
7g: setting section (detection width setting section), 8: switching element,
9: test device, 10: test switch,
11: Test coil, 100: Earth leakage breaker.

Claims (3)

A current transformer having a primary coil as an alternating current path of an electric leak detecting object,
An electric leak detecting section for judging whether or not there is a short circuit of the alternating current converter according to whether the waveform width of the pulse-shaped signal to which the secondary output of the video current transformer is converted is equal to or greater than a predetermined value t1,
A switching element that operates based on an output of the electric leak detecting portion when a short circuit occurs in the AC converter,
A tripping device operated by the operation of the switching element based on the output of the electric leakage detecting portion,
An open / close contact for closing the alternating current converter at normal time and opening the alternating current transformer by the operation of the trip device,
A test circuit for supplying a pulse current simulated leakage current to the damping test coil by turning ON the test switch,
And a setting unit for changing an operation characteristic of the electric leakage detecting unit to the electric leakage operation test time,
When the test switch is turned on and a pulse-like simulated leakage current is supplied to the test coil, the predetermined value is changed to t2 smaller than t1 by the setting unit, and based on the changed predetermined value t2, Is operated. A current transformer having a primary coil as an alternating current converter for detecting an electric leakage,
An electric leak detecting section for judging whether or not there is a short circuit of the alternating current converter according to whether the waveform width of the pulse-shaped signal to which the secondary output of the video current transformer is converted is equal to or greater than a predetermined value t1,
A switching element that operates based on an output of the electric leak detecting portion when a short circuit occurs in the AC converter,
A tripping device operated by the operation of the switching element based on the output of the electric leakage detecting portion,
Closing contact that closes the AC converter and opens the AC converter by the operation of the trip device,
A test circuit for supplying a pulse-like simulated leakage current to the test coil wound on the video current transformer by ON operation of the test switch, and
And a test pulse determination unit operating according to a secondary output of the video current transformer based on the pulse current supplied to the test coil to operate the switching element,
When the test switch is turned on and a pulse-like simulated leakage current is supplied to the test coil, the predetermined value is changed to t2 smaller than t1, and the test pulse judging section operates on the basis of the changed predetermined value t2 Features an earth leakage breaker. delete

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