JP5433480B2 - Electronic circuit breaker - Google Patents

Description

  The present invention relates to an electronic circuit breaker that protects an electric circuit from an overcurrent.

FIG. 1 shows a structural diagram of an example of an electronic circuit breaker. The electronic circuit breaker comprises a contact portion 11 for interrupting the main circuit, and includes a current detection current transformer 12 for detecting the current of the main circuit. When the predetermined current value is exceeded by the overcurrent tripping control circuit 13 A trip signal is generated assuming that it is an overcurrent, and this trip signal is sent to the overcurrent trip device 14 to cause the tripping operation to trip the mechanism 15 and trip the electronic circuit breaker.

  As shown in Patent Document 1 (Japanese Patent Laid-Open No. 11-096882), a conventional electronic circuit breaker includes a current detection current transformer in each of the three-phase main circuits. Is detected and supplied to an overcurrent trip unit comprising an electronic circuit, and the signal processor detects an overcurrent and causes a trip operation. The arrangement structure of a current detection current transformer of a conventional electronic circuit breaker is shown in FIG. In the conventional electronic circuit breaker, a magnetic core 21 is provided so that this conductor penetrates through each main circuit conductor 24 extending from the three-phase load-side terminals 23 to the power supply side. 22 is wound. A magnetic flux flows in the magnetic core 21 due to the negative overcurrent flowing in each main circuit conductor 24, and a current corresponding to the magnitude of the negative overcurrent flows in the coil 22 due to the magnetic flux, and the negative overcurrent is detected. .

  Each current detection current transformer 21 of the three-phase main circuit is arranged on the same straight line for each phase with respect to the power source-load side direction. That is, the center of the magnetic core 21 and current detection coil 22 of the current detection current transformer 21 and the center of the load side terminal 23 and the main circuit conductor 24 are arranged on the same line.

Japanese Patent Laid-Open No. 11-096882

  In the prior art, the current detection current transformers are arranged on the same straight line with respect to the power source-load direction as described above. However, the current detection current transformer occupies a large space, and these are accommodated. Thus, the lateral dimension of the electronic circuit breaker is determined. For this reason, in order to reduce the size of the electronic circuit breaker, it is essential to reduce the size of the current detection current transformer, that is, the magnetic core and the coil. However, the miniaturization of the magnetic core and coil leads to a decrease in current detection accuracy due to a decrease in magnetic core magnetic flux, and an increase in heat generation due to an increase in detection current due to a decrease in the number of turns in the current transformer coil. Since the cross-sectional area of the main circuit through conductor to be passed through must also be reduced, an increase in electrical resistance leads to an increase in the temperature around the main circuit through conductor and the breaker terminal temperature.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an electronic circuit breaker that is reduced in size and size while maintaining the size and performance of a current detection current transformer in view of the drawbacks of the prior art.

The present invention provides a three-phase main circuit conductor composed of a central phase and both end phases connected between a power supply side terminal and a load side terminal, and a current detection variable for detecting the main circuit current of each phase through the main circuit conductor. An electronic circuit breaker comprising a current collector, a trip control circuit that outputs an overcurrent signal when an overcurrent is detected by the current transformer, and an overcurrent trip device that triggers a trip operation by the trip signal In the vessel
The current detection current transformer of the adjacent phase is shifted along the main circuit conductor in the power source-load side direction and the position is shifted in the phase direction. The current detection current transformers in the both-end phases are arranged so as to be shifted toward the center phase side so as to penetrate the eccentric position .

  Further, in the electronic circuit breaker described above, adjacent phase current detection current transformers are arranged in a staggered manner. In the electronic circuit breaker described above, one of the main circuit conductors of the adjacent phase is formed so as to be displaced toward the adjacent phase at a portion passing through the current detection current transformer. In the electronic circuit breaker described above, one of the adjacent main circuit conductors is formed so as to penetrate the eccentric position of the current detection current transformer.

  Further, in the electronic circuit breaker described above, the current detection current transformer is composed of three phases, and the current detection current transformers of both end phases are arranged so as to be shifted to the center phase side. Further, in the electronic circuit breaker described above, the main circuit conductor is composed of three phases, and the main circuit conductors at both ends are arranged so as to be displaced toward the center phase side. .

  In addition, the current detection current transformer is arranged not on the same straight line but offset on the power source-load side without arranging the current detection current transformer. Furthermore, by shifting the current detection current transformers in the phase direction, the current detection current transformers of each phase can be packed in the horizontal width direction, and the current detection current transformers are made dense.

  According to the present invention, the size of the circuit breaker can be reduced without reducing the negative overcurrent detection performance of the main circuit. Further, the temperature rise of the main circuit conductor and the current detection current transformer coil can be suppressed, and furthermore, the current detection current transformer of each phase can be constituted by the same parts, and the parts can be shared.

1 is a longitudinal sectional view of an electronic circuit breaker according to an embodiment of the present invention. It is arrangement | positioning structural drawing of the electric current detection current transformer of this invention Example. It is an arrangement structure diagram of a conventional current detection current transformer.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows the structure of a three-phase electronic circuit breaker as an embodiment. The main circuit system shows the structure of one of the three phases, and FIG. 2 shows a three-phase current detection current transformer. An arrangement structure is shown.

  In FIG. 1, the circuit breaker includes a contact portion 11 for interrupting current of the main circuit conductor 18 connected between the load side terminal 19 and the power source side terminal 20, and an opening / closing mechanism portion 15 for opening and closing the contact portion. And an overcurrent trip device 14 that trips the switching mechanism 15 under conditions such as overcurrent. In the main circuit conductor 18, the current detection current transformer 12 is disposed in the vicinity of the load-side terminal 19. In the current detection current transformer 12, a magnetic core 16 is penetrated by a conductor 18, and a current detection coil 17 is wound around the lower side of the magnetic core 16.

  In FIG. 2, magnetic cores 16, 26, 36 are attached to the main circuit conductors 18, 28, 38 of each phase extending from the load side terminals 19, 29, 39 to the power source side so that the respective phase conductors penetrate. ing. Current detection coils 17, 27, and 37 are wound around the magnetic cores, respectively. When the main circuit conductors 18, 28, and 38 are three-phase R-phase, S-phase, and T-phase, respectively, the R-phase current detection current transformer 12 includes a magnetic core 16 and a current detection coil 17, and an S-phase current The detection current transformer is constituted by a magnetic core 26 and a current detection coil 27, and the T-phase current detection current transformer is constituted by a magnetic core 36 and a current detection coil 37.

  Negative overcurrent of each main circuit conductor is detected by each of the current detection current transformers installed in each phase, and each current detection coil converts the load current into a minute current. The trip device 14 operates upon receiving a signal from the trip control circuit (with built-in trip control board) 13 as the overcurrent signal. Only one set of the trip control circuit 13 and the trip device 14 is provided, and when the current detection coil of any phase detects an overcurrent, the trip operation is performed.

  In this embodiment, as shown in FIG. 2, there is a feature in the arrangement of the current detection current transformer of each phase. The current detection current transformers of adjacent phases are arranged in a shifted position in the power source-load side direction. Specifically, compared to the R-phase current detection current transformers (16, 17) and the T-phase current detection current transformers (36, 37) at both ends, the S-phase current detection current transformer ( 26, 27) are arranged in a staggered manner with their positions shifted along the main circuit conductor (upward in FIG. 2) toward the power supply side.

  With the arrangement described above, the current detection current transformers of adjacent phases can be arranged with their positions shifted in the phase direction. That is, the R-phase and T-phase magnetic cores 16 and 36 of both end phases can be placed close to (shifted from) the S-phase magnetic core 26 of the central phase and the magnetic cores can be partially overlapped. In FIG. 2, the left end of the R-phase magnetic core 16 and the right end of the S-phase magnetic core 26 partially overlap, and the right end of the T-phase magnetic core 36 and the left end of the S-phase magnetic core 26 partially overlap. Yes.

  In addition, the main circuit conductor of the phase shifted in position is formed so as to be displaced toward the adjacent phase in accordance with the shift of the position of the current detection current transformer of the adjacent phase in the phase direction. The S-phase main circuit conductor 18 is processed and formed so that the shape thereof is displaced toward the S-phase side of the adjacent phase at a portion that penetrates the magnetic core 16. The T-phase main circuit conductor 38 is processed and formed so that its shape is displaced toward the S-phase side of the adjacent phase at a portion that penetrates the magnetic core 36. The processed conductor is formed so that the cross-sectional area does not change, and the passing current capacity is not reduced.

  If the main circuit conductors 18 and 38 are greatly displaced in the adjacent S-phase direction, the insulation distance between the conductors may be shortened and the insulation performance may be deteriorated. Therefore, in this embodiment, the main circuit conductors 18 and 38 in which the displacement is formed pass through the eccentric positions of the magnetic cores 16 and 36, respectively, so that the displacement does not increase.

  In this embodiment, as shown in FIG. 2, the arrangement of the current detection current transformer of each phase is changed in the lateral direction so that the current detection current transformer of each phase is shifted in the power source-load side direction and the phase direction so as not to interfere. The current sensing current transformer can be packed. This makes it possible to reduce the overall width of the circuit breaker while maintaining the specifications of the current detection current transformer.

  Further, in this embodiment, the main circuit conductors 18 and 38 and the current detection current transformer are removed from the center positions of the main circuit conductors 18 and 38 and the current detection current transformer with respect to the R and T phases of the circuit breaker. The cross-sectional area of the main circuit conductor and the insulation distance between the phases can be secured by avoiding the interference of the fluid cores 16 and 38.

  With the arrangement structure of the current detection current transformer and the shape of the main circuit conductor described above, it is possible to reduce the size of the circuit breaker in the width direction while maintaining the size of the current detection current transformer. Therefore, if you do not change the size and dimensions of the circuit breaker, you can ensure the thickness margin of the circuit breaker case, without changing the cross-sectional area of the main circuit conductor, the current detection current transformer coil specifications, The temperature rise of each component can be suppressed.

  DESCRIPTION OF SYMBOLS 11 ... Contact part, 12 ... Current detection current transformer, 13 ... Trip control circuit, 14 ... Overcurrent trip device, 15 ... Opening / closing mechanism part, 16, 26, 36 ... Magnetic core, 17, 27, 37 ... Current Detection coil, 16, 17, 26, 27, 36, 37 ... Current detection current transformer, 18, 28, 38 ... Main circuit conductor, 19, 29, 39 ... Load side terminal, 20 ... Power supply side terminal, 16/17 , 36..., Current detection current transformers at both ends, 26, 27... Current detection current transformers at the center phase, 18, 38... Main circuit conductors at both ends, 28.

Claims (4)

A three-phase main circuit conductor composed of a central phase and both end phases connected between the power supply side terminal and the load side terminal, a current detection current transformer for detecting the main circuit current of each phase through the main circuit conductor; In an electronic circuit breaker comprising a trip control circuit that outputs an overcurrent signal when an overcurrent is detected by the current transformer, and an overcurrent trip device that causes a trip operation by the trip signal,
The current detection current transformer of the adjacent phase is shifted along the main circuit conductor in the power source-load side direction and the position is shifted in the phase direction. An electronic circuit breaker characterized in that the current detection current transformers at both ends of the phase are shifted to the center phase side so as to penetrate the eccentric position . 2. The electronic circuit breaker according to claim 1, wherein current detection current transformers of adjacent phases are arranged in a staggered manner . 3. The electronic circuit breaker according to claim 1, wherein one of the main circuit conductors of the adjacent phase is formed to be displaced toward the adjacent phase at a portion penetrating the current detection current transformer. Electronic circuit breaker. 4. The electronic circuit breaker according to claim 3, wherein the main circuit conductors at both ends are arranged so as to be displaced toward the center phase .

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