JP2005124342A - Two-line load power supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a two-line load power supply device reducing power loss in power generated by a private electric generator and supplying power to the other load system. <P>SOLUTION: When the power generated by the private electric generator 14 becomes larger than the load power of either load group 10 supplied with the power, a linkage circuit breaker 9 that connects together the load-side ends of the load-side circuit breakers 5 and 8 in two lines 1 and 2 is closed. Further, the power supply-side circuit breaker 7 and the load-side circuit breaker 8 in the other line 2 are opened. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a two-line load power supply apparatus in which two lines supply power to different loads.

JP-A-8-19180

  In recent years, offices such as factories have installed regular private power generation facilities to supply power to loads and to receive power supply from power companies. Regular private power generation equipment is mainly used to absorb peak power with large load fluctuations.

  On the other hand, power is supplied from two power lines from a power company in order to stabilize power supply. Receiving power supply by two lines is described in Patent Document 1 described above. In Patent Document 1, two lines are switched and used for normal use and backup, but recently, the two lines supply power to different loads (two load groups).

  One line is configured by connecting circuit breakers (power circuit breaker and load circuit breaker) to the power supply system side (power supply side) and the load side of the transformer, respectively. At the time of maintenance and inspection of the transformer on one line, power is supplied to the two load groups from the other line. For this purpose, a link breaker that connects the load side ends of the load side breakers of both lines is provided.

  When the linkage breaker is normally closed, the transformers of both lines are connected in parallel, and the impedance is reduced. Should a ground fault occur in the load system in this state, an excessive current that cannot be interrupted by the circuit breaker will flow and damage the equipment. In order to prevent this, the linkage breaker is always open except during the maintenance and inspection of the transformer.

  Two load groups (load systems) fed respectively from two lines have one system with large load fluctuations and the other system with relatively small load fluctuations. Power is supplied by connecting a regular private power generation facility to a load system with large load fluctuations.

  In the prior art, a regular private power generation facility supplies power to one load system having a large load fluctuation. The cost of a regular private power generation facility is lower than the purchased power from the power system when the amount of generated power increases. For this reason, it is desired that the regular private power generation facility be operated with large generated power. The generated power of the regular private power generation facility may be larger than the load power of one load system having a large load fluctuation. Surplus power larger than the load power of one load system is fed to the other load system via two lines. However, since power is supplied to the other load system via two transformers, there is a problem that power loss becomes large.

  An object of the present invention is to provide a two-line load power supply apparatus that can reduce power loss of power generated by a private power generation facility and supply power to the other load system.

  A feature of the present invention is that when the generated power of the private power generation facility becomes larger than the load power of one of the load systems being fed, the linked circuit breaker that connects the load side ends of the two load side circuit breakers is closed. The power circuit breaker and the load circuit breaker of the other line are opened.

  In other words, the present invention feeds surplus power from the private power generation facility to the other load system via the linkage breaker with little power loss.

  In the present invention, surplus power of the private power generation facility is supplied to the other load system via the parallel circuit breaker, so that power loss can be reduced and power can be supplied to the other load system.

  In the first and second lines, a power supply circuit breaker and a load circuit breaker are connected to the power supply side and load side of the transformer, respectively. The load-side ends of the load-side circuit breakers of both lines are connected by a linked circuit breaker that is normally open. The first load group having a large load fluctuation is supplied with power from the first line, and the second load group is supplied with power from the second line. A regular private power generation facility is connected to the first load group. When the private power generated by the private power generation facility becomes larger than the load power of the first load group, the linked circuit breaker is closed and the power supply circuit breaker and the load circuit breaker of the second line are opened.

  FIG. 1 shows an embodiment of the present invention.

  In FIG. 1, power from the power system is fed via two lines 1 and 2. Line 1 is called the first line and line 2 is called the second line. In the first line 1, a power circuit breaker 4 and a load circuit breaker 5 are connected to the power supply side and the load side of the transformer 3, respectively. In the second line 2, a power source circuit breaker 7 and a load side circuit breaker 8 are connected to the power source side and the load side of the transformer 6, respectively. Although the system circuit breaker etc. are provided in the electric power system side of the power supply side circuit breakers 4 and 7, illustration is abbreviate | omitted.

  The load-side ends of the load-side circuit breakers 5 and 8 of both lines 1 and 2 are connected by a linked circuit breaker 9 that is normally open. A first load group 10 having a large load fluctuation is connected to the first line 1 via a load circuit breaker 11, and a second load group 12 having a small load fluctuation is connected to the second line 2 via a load circuit breaker 13. Is done. In addition, the 1st load group 10 and the 2nd load group 12 are comprised from several load.

  A regular private power generation facility 14 is connected to the first load group 10 via a main circuit breaker 15. The private power generation facility 14 includes a prime mover (diesel engine) and a generator. The output voltage and output current of the private power generation facility 14 are detected by the transformer 16 and the current transformer 17 and added to the generated power detection device 18. The generated power detection device 18 detects private power generation. The load voltage and load current of the first load group 10 are detected by the transformer 19 and the current transformer 20 and added to the load power detection device 21. The load power detection device 21 detects the load power of the first load group 10.

  The self-generated power detected by the generated power detection device 18 and the load power of the first load group 10 detected by the load power detection device 21 are input to the comparison device 22. The comparison device 22 adds a circuit breaker operation signal to the circuit breaker control device 23 when the self-generated power becomes larger than the set power by the load power of the first load group. When the circuit breaker control device 23 receives the circuit breaker operation signal from the comparison device 22, the circuit breaker control device 23 closes the linkage circuit breaker 9 and opens the power-side circuit breaker 7 and the load side circuit breaker 8 of the second line 2.

  In this configuration, the power supply side circuit breaker 4 and the load side circuit breaker 5 of the first line are closed, and the main circuit breaker 15 is closed to move the power system and the private power generation facility 14 to the first load group 10. Supply power. The first load group 10 is supplied with the grid power and the private power generated by the private power generation facility 14 via the first line 1. Similarly, the power supply side circuit breaker 7 and the load side circuit breaker 8 of the second line are closed to supply power to the second load group 12. The second load group 12 is fed with system power via the second line 2. In this state, the linkage breaker 9 is open. The main circuit configuration of the two-line load power supply apparatus is as shown in FIG.

  Thus, in a state where power is supplied to the first load group 10 and the second load group 12, the private power generation power of the private power generation equipment 14 is detected by the generated power detection device 18, and the load power of the first load group 10 is the load. It is detected by the power detection device 21. The self-generated power detected by the generated power detection device 18 and the load power of the first load group 10 detected by the load power detection device 21 are input to the comparison device 22. The comparison device 22 applies a circuit breaker operation signal to the circuit breaker control device 23 when the self-generated power becomes larger than the set power by the load power of the first load group.

  When the circuit breaker control device 23 receives the circuit breaker operation signal from the comparison device 22, the circuit breaker control device 23 closes the linkage circuit breaker 9 and opens the power-side circuit breaker 7 and the load side circuit breaker 8 of the second line 2. The main circuit configuration of the two-line load power supply apparatus is as shown in FIG. The second load group 12 is supplied with the grid power and the private power generated by the private power generation facility 14 via the first line 1. That is, surplus power of the load power fed to the first load group 10 among the privately generated power generated by the private power generation facility 14 is fed to the second load group 12 via the linkage breaker 9.

  The comparison device 22 does not output a circuit breaker operation signal when the private power generated by the private power generation facility 14 is smaller than the load power of the first load group. The comparison device 22 generates a circuit breaker operation signal when the self-generated power is larger than a set value by the load power of the first load group, and extinguishes the circuit breaker operation signal when the self-generated power becomes smaller than the load power of the first load group. Has hysteresis characteristics. This is to prevent frequent switching of the circuit breaker.

  When the circuit breaker operation signal of the comparison device 22 disappears, the circuit breaker control device 23 opens the linked circuit breaker 9 and closes the power supply circuit breaker 7 and the load circuit breaker 8 of the second line 2. The main circuit configuration of the two-line load power supply apparatus is as shown in FIG. The second load group 12 is fed with system power via the second line 2.

  Here, the maintenance inspection of the transformer 3 of the first line 1 is performed as shown in FIG. The first load group 10 is fed with system power and private power generated by the private power generation facility 14 via the second line 2. Further, the maintenance and inspection of the transformer 6 of the second line 2 is performed as shown in FIG. 5 for the main circuit configuration of the two-line load power supply apparatus. The second load group 12 is fed with system power via the first line 1.

  In this way, load feeding is performed by two lines. When the self-generated power becomes larger than the load power of one load system to which power is being fed, the linked circuit breaker is closed, and the power circuit breaker on the other line The load-side circuit breaker is opened to supply surplus power from the private power generation facility to the other load system via the linked circuit breaker with low power loss. Therefore, surplus power of the private power generation facility is supplied to the other load system via the parallel circuit breaker, so that power loss can be reduced and power can be supplied to the other load system.

It is a block diagram which shows one Example of this invention. It is a main circuit block diagram for demonstrating this invention. It is a main circuit block diagram for demonstrating this invention. It is a main circuit block diagram for demonstrating this invention. It is a main circuit block diagram for demonstrating this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1, 2 ... Line 3, 6 ... Transformer 4, 7 ... Power supply side circuit breaker 5, 8 ... Load side circuit breaker, 9 ... Linkage circuit breaker 10, 12, ... Load group, 11, 13 ... Load interruption 14 ... Private power generation equipment, 15 ... Main circuit breaker, 16, 19 ... Transformer, 17, 20 ... Current transformer, 18 ... Generated power detection device, 21 ... Load power detection device, 22 ... Comparison device, 23 ... Circuit breaker control device.

Claims (2)

  A first line in which a circuit breaker is connected to each of the power supply side and the load side of the transformer; a second line in which a circuit breaker is connected to each of the power supply side and the load side of the transformer; A link breaker for connecting the load side ends of both load circuit breakers of two lines, a first load group fed from the first line, a second load group fed from the second line, A private power generation facility that feeds power to one load group; load power detection means that detects load power fed to the first load group; self-generated power detection means that detects power generated by the private power generation facility; And a circuit breaker control means for closing the linked circuit breaker when the generated power becomes larger than the load power of the first load group, and opening the power circuit breaker and the load circuit breaker of the second line. A two-line load power feeder characterized by the above.   A first line in which a circuit breaker is connected to each of the power supply side and the load side of the transformer; a second line in which a circuit breaker is connected to each of the power supply side and the load side of the transformer; A linked circuit breaker that is normally open to connect the load-side ends of both load circuit breakers of two lines, a first load group with a large load fluctuation that is normally fed from the first line, and A second load group that is fed from two lines, a regular private power generation facility that feeds power to the first load group, load power detection means that detects load power fed to the first load group, and the private power generation facility A self-generated power detecting means for detecting the generated power of the second circuit, and closing the linked circuit breaker when the self-generated power becomes larger than a set value by the load power of the first load group, and the power supply side circuit breaker of the second line And circuit breaker control means for opening the load side circuit breaker. 2 line load power supply device according to claim Rukoto.

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