JP2007149481A - Electronic circuit breaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily confirm the operation of an overcurrent detection circuit, in an electronic circuit breaker. <P>SOLUTION: The electronic circuit breaker is structured such that a second coil for executing an operation test of the overcurrent detection circuit is arranged in a current transformer in addition to a first coil for overcurrent detection; and, when the operation test of the overcurrent detection circuit is executed, a test current is carried to the second coil to induce electromotive force in the first coil, and the overcurrent detection circuit is operated based on the electromotive force. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electronic circuit breaker that detects an overcurrent of a main circuit by means of a current transformer and an overcurrent detection circuit and cuts off the circuit, and more particularly to a configuration for performing an operation test of the overcurrent detection circuit.

  As a technique described in the literature as a related art related to the present invention, for example, the technique described in JP-A-9-166634 (Patent Document 1) and JP-A-2002-350519 (Patent Document 2) is used. is there. Japanese Patent Laid-Open No. 9-166634 discloses a tripping operation test apparatus that enables an off-line operation test of an electronic circuit breaker without using an external power source such as a commercial power source. After that, the output is converted to a pseudo sine wave by a filter circuit, and this is supplied to the electronic circuit breaker along with the DC power of the battery as an overcurrent or ground fault test signal of the electronic circuit breaker. JP-A-2002-350519 discloses that a test circuit for generating a pseudo tracking current is provided in order to enable an operation test of a circuit breaker against a tracking short circuit, and the test button is turned on as the test circuit. A pulse with a frequency different from the current flowing through the wiring path is output under the control of the MPU and the contact of the instantaneous switching circuit connected to the wiring path It has described a continuously opening and closing was taken out power waveform randomly composed of pulses.

JP-A-9-166634 JP 2002-350519 A

Among the above-mentioned prior arts, the technique described in Japanese Patent Laid-Open No. 9-166634 simply inputs a pseudo sine wave generated by an external circuit of an electronic circuit breaker to the electronic circuit breaker and performs an off-line trip operation test. This is a technique for performing the operation check of the overcurrent detection circuit. The technique described in Japanese Patent Laid-Open No. 2002-350519 performs an operation test of the entire circuit breaker against a tracking short circuit, and is not a technique for confirming the operation of the overcurrent detection circuit. It is also necessary to provide a test circuit that generates a pseudo tracking current.
An object of the present invention is to make it possible to confirm the operation of an overcurrent detection circuit with a simple configuration in an electronic circuit breaker in view of the situation of the prior art.
The objective of this invention is providing the electronic circuit breaker which solved the said subject and improved reliability and usability.

  In order to solve the above problems, in the present invention, a current transformer in an electronic circuit breaker has a first current test for performing an operation test of an overcurrent detection circuit in addition to a first coil for overcurrent detection. When the operation test of the overcurrent detection circuit is performed, a test current is passed through the second coil to induce an electromotive force in the first coil, and the overcurrent detection circuit is based on the electromotive force. Is configured to operate.

  According to the present invention, in an electronic circuit breaker, it is possible to check the operation of the overcurrent detection circuit in a simple configuration and in a mounted state, and the reliability and usability of the entire breaker can be improved.

Embodiments of the present invention will be described below with reference to the drawings.
1 to 4 are explanatory views of an electronic circuit breaker as a first embodiment of the present invention. 1 is an internal configuration diagram of an electronic circuit breaker, FIG. 2 is a configuration diagram of a current transformer used in the electronic circuit breaker of FIG. 1, and FIG. 3 is a current transformer and an overcurrent detection circuit of FIG. FIG. 4 is an external plan view of the electronic circuit breaker of FIG.

  In FIG. 1, 1 is an electronic circuit breaker, 3 is a current transformer that detects an overcurrent of the main circuit by electromagnetic induction, 31 is an annular core that forms an annular magnetic circuit of the current transformer 3, and 32. Is a first coil in the current transformer 3 for detecting the overcurrent of the main circuit, 33 is a second coil for supplying a test current for confirming the operation of the overcurrent detection circuit, An overcurrent detection circuit connected to the first coil 32, 20a and 20b are main circuit conductors forming part of the main circuit, 5 is a movable contact conductor connected to the main circuit conductor 20a side, and 6 is a main circuit conductor. The fixed contact base 7 connected to the circuit conductor 20b side, 7 is a lever for manual operation that rotates the movable contact conductor 5 around the fulcrum and opens and closes the fixed contact base 6, and 8 is when the current of the main circuit is interrupted Arc extinguishing to extinguish an arc generated between the movable contact conductor 5 and the fixed contact base 6 , 9 is a tripping mechanism for opening or closing the movable contact conductor 5 with respect to the fixed contact base 6, 10 is a cover, 21a and 22a are terminals connected to the main circuit conductor 20a side, 21b, Reference numerals 22b denote terminals connected to the main circuit conductor 20b. The main circuit conductor 20a passes through the space in the annular core 31 of the current transformer 3, and the magnetic flux generated by the current flowing in the main circuit conductor 20a is efficiently passed through the core.

  In the above configuration, when the movable contact conductor 5 and the fixed contact base 6 are turned on (closed), and the current is energized through the main circuit conductors 20a and 20b, the current becomes excessive. In the current transformer 3, an electromotive force corresponding to this is induced in the first coil 32 wound around the core 31. The induced electromotive force is input to the overcurrent detection circuit 4. The overcurrent detection circuit 4 detects the current of the main circuit as an overcurrent based on the electromotive force. The tripping mechanism 9 operates based on the detection result in the overcurrent detection circuit 4 to rotate the movable contact conductor 5 around the fulcrum, and the movable contact conductor 5 is in an off state (open state) with respect to the fixed contact base 6. ) To cut off the main circuit current.

In the above configuration, when a test for confirming the operation of the overcurrent detection circuit 4 is performed, the movable contact conductor 5 is in an off state (open state) with respect to the fixed contact base 6, that is, the main circuit is in an off state (open state). Then, a test current is applied to the second coil 33 of the current transformer 3 from the outside. By applying the test current, an electromotive force corresponding to the change in magnetic flux is also generated in the first coil 32. The electromotive force is input to the overcurrent detection circuit 4, and the overcurrent detection circuit 4 tests whether or not it operates normally based on the electromotive force and confirms the operation.
Hereinafter, the same reference numerals as those in FIG. 1 are used for the components in FIG. 1 used in the description.

FIG. 2 is an external view of the current transformer 3 used in the electronic circuit breaker 1 of FIG.
In FIG. 2, 321 is a coil terminal of the first coil 32, 331 is a coil terminal of the second coil 33, 310a to 310d are core materials constituting the core 31, and 350a to 350d are core materials 310a to 310a, respectively. It is a coupling member that couples two of 310d. The main circuit conductor 20 a is penetrated between the first coil 32 and the second coil 33 in the space of the annular core 31. A current transformer 3 having such a configuration is provided for each main circuit. For example, in a three-phase three-wire main circuit, one current transformer 3 is provided for each line, and an overcurrent is detected for each line. It can be done.

FIG. 3 is a connection diagram between the current transformer 3 and the overcurrent detection circuit 4 of FIG.
In FIG. 3, reference numeral 36 denotes a protection diode for protecting the second coil 33, and reference numeral 332 denotes a coil terminal to which the coil terminal 331 is connected. The overcurrent detection circuit 4 is connected to the coil terminal 321 of the first coil 32, and a test current for confirming the operation of the overcurrent detection circuit 4 is input from the coil terminal 332 to which the coil terminal 331 is connected. . For example, when the rated current is 400 A, the operation can be confirmed by setting the number of turns of the second coil 33 to 4000 turns (T) and the test current value to 0.2 A.

FIG. 4 is an external plan view of the electronic circuit breaker 1 of FIG. The electronic circuit breaker 1 in FIG. 1 has a configuration corresponding to a three-phase three-wire main circuit.
In FIG. 4, 21a, 22a, 23a, 21b, 22b, and 23b are terminals to which the corresponding main circuit conductors are respectively connected. The coil terminal 332 to which the coil terminal 331 of the second coil 33 is connected is provided on the side surface of the electronic circuit breaker 1. A test current for confirming the operation of the overcurrent detection circuit 4 is input from the coil terminal 332.

  According to the first embodiment of the present invention, the electronic circuit breaker 1 can confirm the operation of the overcurrent detection circuit 4 with a simple configuration. Further, even when the electronic circuit breaker 1 is mounted on the main circuit, the operation of the overcurrent detection circuit 4 can be confirmed. For this reason, the reliability and usability of the whole circuit breaker can be improved.

FIG. 5 is an explanatory diagram of a current transformer used in the electronic circuit breaker according to the second embodiment of the present invention. In the second embodiment, a resistor for adjusting the current value of the test current for checking the operation of the overcurrent detection circuit 4 is provided in series with the second coil in the current transformer.
In FIG. 5, reference numeral 37 denotes a resistance for adjusting the current value of the test current. Other symbols are the same as those in FIG. In the configuration of FIG. 5, for example, when the voltage applied to the coil terminal 332 is 100V and the resistance 37 is 500Ω, the test current value is 0.2A. For example, when the rated current of the electronic circuit breaker is 400 A, the operation of the overcurrent detection circuit 4 can be confirmed by setting the number of turns of the second coil 33 to 4000 turns (T). Operations other than the adjustment of the current value of the test current by the resistor 37 are the same as in the case of FIG.

  According to the second embodiment of the present invention, the operation of the overcurrent detection circuit 4 can be confirmed with a simple configuration in the electronic circuit breaker. In addition, even when the electronic circuit breaker is mounted on the main circuit, the operation of the overcurrent detection circuit 4 can be confirmed. For this reason, the reliability and usability of the whole circuit breaker can be improved. In particular, in the second embodiment, since the current value of the test current can be adjusted by the resistor 37, the degree of freedom in selecting the test current generation source connected to the coil terminal 332 is increased, and the usability is further improved. It becomes possible to plan.

FIG. 6 is an explanatory diagram of an electronic circuit breaker as a third embodiment of the present invention. (A) is explanatory drawing of the current transformer used for the electronic circuit breaker of a 3rd Example, (b) is an external appearance top view of the electronic circuit breaker of the 3rd Example.
In the third embodiment, a resistor for adjusting the current value of the test current for confirming the operation of the overcurrent detection circuit 4 is provided in series with the second coil, as in the second embodiment. And a power supply as a test current supply source and a switch for turning on and off the supply of the test current.

  In FIG. 6, 1 ′ is an electronic circuit breaker as a third embodiment of the present invention, 38 is a power supply for supplying a test current, and 39 is for turning on / off the supply of the test current from the power supply 38. The switch 39 a is a button part of the switch 39. Other reference numerals are the same as those in the second embodiment shown in FIG. In such a configuration, when an operation test of the overcurrent detection circuit 4 is performed, the button 39a of the switch 39 is pressed, the switch 39 is turned on, and a test current having a current value adjusted by the resistor 37 is supplied from the power source 38. The second coil 33 is supplied and energized. By applying the test current, an electromotive force is generated (induced) in the first coil 32, and the electromotive force is input to the overcurrent detection circuit 4. Based on the electromotive force, the overcurrent detection circuit 4 tests whether or not it operates normally, and confirms the operation.

  Also according to the third embodiment of the present invention, the operation of the overcurrent detection circuit 4 can be confirmed with a simple configuration in the electronic circuit breaker 1 ′. Further, even when the electronic circuit breaker 1 ′ is mounted on the main circuit, the operation of the overcurrent detection circuit 4 can be confirmed. For this reason, the reliability and usability of the whole circuit breaker can be improved. In particular, in the third embodiment, the power supply 38 and the switch are built in, and the operation check of the overcurrent detection circuit 4 can be performed by a one-touch operation of pressing the button unit 39a, thereby further improving the usability. Is possible.

It is an internal block diagram of the electronic circuit breaker as a 1st Example of this invention. It is a block diagram of the current transformer in the electronic circuit breaker of FIG. It is a figure which shows the connection state of the current transformer of FIG. 2, and an overcurrent detection circuit. It is an external appearance top view of the electronic circuit breaker of FIG. It is explanatory drawing of the current transformer used for the electronic circuit breaker of the 2nd Example of this invention. It is explanatory drawing of the electronic circuit breaker as a 3rd Example of this invention.

Explanation of symbols

1, 1 '... electronic circuit breaker,
3. Current transformer,
4 ... Overcurrent detection circuit,
5 ... movable contact conductor,
6 ... fixed contact stand,
7 ... Lever,
8 ... Arc extinguishing part,
9 ... tripping mechanism,
10 ... cover,
20a, 20b ... main circuit conductors,
21a, 22a, 23a, 21b, 22b, 23b ... terminals,
31 ... Core,
32 ... first coil,
33 ... second coil,
36 ... Protective diode,
37 ... resistance,
38 ... Power supply,
39 ... switch,
39a ... button part,
310a-310d ... Core material,
321, 331 ... Coil terminal,
332 ... Coil terminal,
350a-350d ... coupling member.

Claims (3)

An electronic circuit breaker that detects the overcurrent of the main circuit by means of a current transformer and an overcurrent detection circuit and interrupts the circuit,
The current transformer includes a first coil and a second coil on an annular core,
When an overcurrent flows in the main circuit, the overcurrent is detected by the first coil, and when an operation test of the overcurrent detection circuit is performed, a test current is passed through the second coil to An electronic circuit breaker configured to induce an electromotive force in a first coil and operate the overcurrent detection circuit based on the electromotive force.   The electronic circuit breaker according to claim 1, wherein the current transformer has a configuration in which a resistor is connected in series to the second coil. An electronic circuit breaker that detects the overcurrent of the main circuit by means of a current transformer and an overcurrent detection circuit and interrupts the circuit,
A current transformer comprising a first coil for detecting an overcurrent of a main circuit and a second coil for performing an operation test of the overcurrent detection circuit on an annular core;
A power supply for supplying a test current for performing the operation test to the second coil;
A switch for turning on and off the supply of the test current;
When the operation test of the overcurrent detection circuit is performed, the switch is turned on, a test current is passed through the second coil, an electromotive force is induced in the first coil, and the electromotive force is An electronic circuit breaker characterized in that the overcurrent detection circuit is operated based on the above.

Images