JP2001078371A - Commercial-emergency power supply mutual backup system - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To improve the economical burden of power supply equipment without increasing the reliability of the power supply equipment. SOLUTION: Normally, electric power is transmitted from a substation 10 to a power load facility 15 by a commercial power line, and in an emergency, an emergency generator EG installed in the substation is connected to the power load facility by an emergency power line. This is a power distribution system that performs backup power transmission. In such a power distribution system, a commercial side circuit breaker 22 and an emergency side circuit breaker 24 are installed at both ends of a communication high-voltage cable 20 and connected between a commercial power supply and an emergency power supply, so that the The systems can be shared with each other. As a result, the commercial power supply line and the emergency power supply line are each substantially divided into two systems, and mutual backup between the commercial power supply and the emergency power supply is enabled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a commercial power supply system and an emergency power supply system which are connected to each other by a high-voltage cable for communication so that the commercial power supply system and the emergency power supply system can be shared with each other. Alternatively, the present invention relates to a commercial-emergency power supply mutual backup system that enables two-system power transmission. This technique is useful for improving the reliability of the power supply equipment while reducing the economic burden on the power supply equipment.

[0002]

2. Description of the Related Art At a nuclear power plant, various public facilities, factories, and the like, a commercial power supply is received by a high-voltage distribution line from a power company at an in-house substation, and the power is distributed to each power load facility. In addition, an emergency power generator is installed at a substation in the premises as an emergency power supply facility at the time of a power failure. In this way, the power is transmitted from the substation on the commercial power line to each power load facility during normal times, and the emergency power supply circuit installed at the substation on the premises is used to transmit the emergency power line to each power load facility during emergency. A power distribution system for backup power transmission is adopted.

In this case, although depending on the size of the facility, in order to reduce the economic burden on the power supply equipment, power is transmitted from the substation to each power load facility with one line of commercial power, and the substation is connected to the substation. In many cases, power is transmitted from the installed emergency generator to each of the power load facilities with one emergency power supply line.

[0004]

When a commercial power supply has a single line and a power failure occurs, an emergency power generator is operated and power is transmitted to each power load facility through the emergency power supply line. Can be secured. However, for example, when a failure occurs in a high-voltage cable of a commercial power supply line, restoration work may take several days. If it takes a long time to recover or if it takes a long time to take measures, the emergency generator must be continuously operated during that time. However, continuous operation of the emergency generator for a long time requires various measures such as securing fuel and coping with a failure. Therefore, there is a problem in reliability.

An object of the present invention is to provide a power distribution system that is devised so that the economical burden of the power supply equipment does not increase and that the reliability of the power supply equipment can be improved.

[0006]

According to the present invention, power is normally transmitted from a private substation to a power load facility via a commercial power supply line, and in an emergency, the power load is transmitted from an emergency generator installed in the private substation. It is assumed that a power distribution system that backs up power to the facility via an emergency power supply line. According to the present invention, in such a power distribution system, a commercial-side communication breaker and an emergency-side communication breaker are installed at both ends of a communication high-voltage cable and connected between a commercial power supply and an emergency power supply, and the System can be shared with each other. This is a commercial / emergency power supply mutual backup system in which a plurality of commercial power supply lines and emergency power supply lines are substantially provided.

According to the present invention, power is transmitted from a substation to each power load facility by one line of commercial power in a normal state, and is backed up by one emergency power supply from the substation to each power load facility in an emergency. This is effective for improving the reliability of a power distribution system configured to transmit power.

[0008]

FIG. 1 shows a typical configuration example of a commercial-emergency power supply mutual backup system according to the present invention. Here, the commercial power is supplied from the power company to the on-premise substation 1
0 to 2 commercial lines (high-voltage distribution lines 11A, 11
B), and power is received by the extra high power receiving facilities 12A and 12B. In normal times, power is transmitted from the substation 10 on the premises through the commercial distribution board 13 to each power load facility 15 by a commercial high-voltage cable 14 with one line of commercial power. In an emergency, backup power is transmitted from the emergency generator facility 16 installed in the substation 10 to each of the power load facilities 15 via the emergency system high-voltage cable 18 via the emergency switchboard 17 with one emergency power supply line. Is done.

In such a power distribution system, in the present invention, a commercial communication breaker 22 and an emergency communication breaker 24 are installed at both ends of a communication high-voltage cable 20 so that a commercial power supply and an emergency power supply (specifically, Typically, it is connected between the commercial switchboard 13 and the emergency switchboard 17), which is characteristic. As a result, the commercial system and the emergency system can be shared with each other. With this configuration, as a countermeasure in the event of an abnormality, it is possible to perform power transmission in two commercial systems using an emergency high-voltage cable or two emergency systems using a commercial high-voltage cable.

In the power distribution system shown in FIG. 1, in order to simplify the description, an example is shown in which one emergency generator EG is installed in the substation 10 and power is supplied to five power load facilities. I have. However, when the scale of the facility is large, it is often the case that a plurality of emergency power generators are installed so that each of the emergency power generators can supply power to a corresponding power load facility via a generator bus. In addition, an emergency generator G is separately provided to an especially important power load facility via an emergency generator panel 25.

[0011]

FIG. 2 is a power distribution system diagram showing an embodiment of a commercial / emergency power supply mutual backup system according to the present invention, and FIG. 3 is an explanatory diagram of a power transmission system of a main part thereof.

[0012] The commercial power is sent from the power company to the substation on the premises by two commercial lines (high-voltage distribution lines 11A and 11B of the power company), passes through the commercial distribution board buses 13A and 13B, and the commercial main circuit breakers 30A and 30B, respectively. Is transmitted to one line of the commercial power supply bus 32 via the
Power is transmitted to the corresponding power load facilities (here, a total of nine facilities) by the commercial high-voltage cables 36a to 36i having 34i.

The emergency power supply includes emergency generators G1 to G3 of Nos. 1 to 3 in this case.
0G1 to 40G3 and disconnectors 42G1 to 42G3 are provided to connect the generator buses 44G1 to 44G3 of the 1st to 3rd systems. Each of the No. 1 power load facilities is connected to the No. 1 generator bus 44G1 by emergency high voltage cables 48a to 48c having load breakers 46a to 46c, respectively. Similarly, in the generator bus 44G2 of the No. 2 system,
Each of the No. 2 power load facilities is connected by emergency high voltage cables 48d to 48f having load breakers 46d to 46f, respectively, and the No. 3 generator bus 44G3 has load breakers 46g to 46i, respectively. Each of the No. 3 power load facilities is connected by emergency high voltage cables 48g to 48i. The generator buses are communicated with each other by a bus communication loop 52 having bus communication breakers 50G1 to 50G3 therebetween.

A commercial-emergency connecting line in which a commercial-side communication breaker 22 and an emergency-side communication breaker 24 are installed at both ends of a communication high-voltage cable 20 is connected to a commercial power supply (commercial power bus 3).
2) and the emergency power supply (bus connecting loop 52). As a result, the commercial system and the emergency system can be shared with each other. Therefore, as a countermeasure at the time of occurrence of an abnormality, it is possible to transmit power to two commercial systems using an emergency high-voltage cable or two emergency systems using a commercial high-voltage cable.

As shown in FIG. 2, the emergency power supply includes
For a simulated load test, a simulated load 59 is connected via a simulated load circuit breaker 56, a simulated load disconnector 57, and a circuit breaker 58. Also, in FIG. 2, in order to simplify the drawing,
Although only the c facility is illustrated as the power load facility, it goes without saying that each commercial high-voltage cable and each emergency high-voltage cable are connected to the corresponding power load facility.

As described above, in the emergency power supply of this embodiment,
The generator buses 44G1 to 44G3 are connected by a bus communication loop 52 having bus communication breakers 50G1 to 50G3. Even when a failure occurs in the generator bus or the bus communication circuit breaker, the bus communication loop is connected. Using 52, backup power can be supplied from another emergency generator to a power load facility of a different system.

(Two-system power transmission of commercial power supply) When a failure occurs in the commercial high-voltage cables 36a to 36i or the load breakers 34a to 34i, the commercial and emergency communication breakers 22, 24 are manually turned on. Emergency high-voltage cable 20
This is a backup system for transmitting commercial power using the system. The following safety measures (interlock conditions) are adopted to avoid collision between different types of power supply (commercial power supply and emergency power supply). The condition that the communication breakers 22 and 24 can be turned on is that the generator breakers 40G1 to 40G3 are cut off and that there is no voltage on the receiving side (each generator bus 44G1 to 44G3). The closing of the communication breakers 22 and 24 is a manual operation in consideration of safety. Communication breaker 22, due to power failure (loss of voltage) of commercial power supply
24 automatically shuts off.

(Two-system power transmission of emergency power supply) In the event of a total power failure in the premises, all emergency power generators are automatically started to start power transmission, and the commercial and emergency communication breakers 22, 24 are automatically turned on. Emergency power to the commercial power bus 32,
The load breaker 34a (the power supply in the substation) is automatically turned on. When a failure occurs in the emergency system high-voltage cables 48a to 48i or the load circuit breakers 46a to 46i, the emergency power generator G is used by using the commercial system high-voltage cables 36a to 36i.
This is a backup system for transmitting an emergency power supply from 1 to G3. The following safety measures (interlock conditions) are adopted to avoid collision between different types of power supply (commercial power supply and emergency power supply). When the commercial main circuit breakers 30A, 30B are cut off, the communication circuit breakers 22, 24 are automatically turned on. When there is no voltage on the receiving side (commercial power supply bus 32), the communication breakers 22, 24 are automatically turned on. When the commercial power returns, the communication breakers 22 and 24 are automatically cut off.

(Embodiment of power transmission system of two commercial systems) Assuming the following events, the operation and countermeasures in that case will be described below. FIG. 4 shows a failure point (X mark) and a backup route (thick broken line). 1. Expected event c Commercial high-voltage cable 36c during transmission of commercial power to facility
Is short circuited (ground fault) and the load breaker 34c
Automatically shuts down. Facility c is a facility that supplies backup power from the emergency generator G1 of the substation in the premises. Therefore, the emergency generator G1 automatically starts due to a power failure (power failure), the corresponding emergency circuit breaker 40G1 is automatically turned on, and the emergency power is transmitted. Since it takes a long time (several days) to recover from the failure of the commercial high-voltage cable 36c, the emergency generator G1 is operated continuously in the related art. In order to operate the emergency generator continuously for a long time (several days), various measures such as securing fuel and coping with a failure are required. Therefore, the power transmission by the emergency generator is stopped, and commercial power is supplied to facility c using the commercial-emergency communication line (commercial-side communication circuit breaker 22, communication high-voltage cable 20, emergency-side communication circuit breaker 24). Transmit power.

2. Operation procedure Check the "OFF" display of the commercial load circuit breaker 36c of the facility c, and pull out to the disconnection position. Manual shutdown of emergency generator a. Preventive measures for backup of emergency generators: Remove auxiliary relay of power failure signal of facility c to prevent backup of emergency generators G1 to G3. (When two or more emergency generators are installed and backup power is supplied) b. Emergency generator manual stop measures: The operating emergency generator G1 is switched from automatic to manual and manually stopped. Transmission of commercial power to emergency generator bus a. The switch of the commercial communication breaker 22 is switched from automatic to manual, and the commercial communication breaker 22 is manually turned on. (However, the condition is that the generator breakers 40G1 to 40G3 are cut off.) B. The emergency side circuit breaker 24 is manually turned on. When the emergency side communication circuit breaker 24 is manually turned on, commercial power is transmitted to the emergency generator bus 44G3. c. After the commercial power is transmitted to the emergency generator bus 44G3, the switching switch of the commercial side circuit breaker 22 is switched from manual to automatic. (This is because power cannot be transmitted from the emergency power generators G1 to G3 during a commercial power failure unless the switching switch of the commercial-side contact breaker 22 is set to automatic.) The commercial power supply uses an emergency high-voltage cable. Power transmission a. In order to transmit power to the facility c connected to the first generator bus 44G1, the bus connection circuit breaker 50G3 is manually switched from automatic to manual. No. 1 generator bus 44G1
Is supplied with commercial power. b. The switch of the emergency system load breaker 46c of facility c where the commercial power supply is stopped is switched from automatic to manual, and the load breaker 46c for facility c is manually turned on. Commercial power is transmitted to facility c using the emergency system high-voltage cable 48c. c. Check the voltmeter and circuit breaker on the emergency power receiving board at facility c. Preparatory measures for restoration of commercial power a. It is confirmed that the restoration of the commercial high-voltage cable 36c at the facility c has been completed. b. Confirm that the commercial load circuit breaker 34c of facility c is "off" and insert it to the connection position. Power recovery operation of commercial power supply a. Notify facility c of commercial power restoration. b. The commercial load breaker 34c is turned on. Power-off measures for commercial-emergency lines a. Take measures to stop the supply of commercial power. b. The switching switch of the commercial side circuit breaker 22 is switched from automatic to manual. c. The commercial communication breaker 22 is manually shut off. d. The switching switch of the commercial side circuit breaker 22 is switched from manual to automatic. e. Check that the emergency-side communication circuit breaker 24 is automatically shut off. c. Shutdown of emergency load breakers in facility a. No. 1 generator bus 44G1 and No. 3 generator bus 44G3
, The bus communication circuit breaker 50G3 automatically shuts off. b. The emergency load breaker 46c for facility c is manually shut off. c. Switch the switching switch for facility c from manual to automatic. Auxiliary relay measures for emergency generator c. Auxiliary relay for power failure signal at facility will be installed, and emergency generator will be in standby state (normal) for backup power supply.

3. Power failure response When commercial power is interrupted while commercial power is being transmitted to the emergency system a. The commercial-side and emergency-side communication circuit breakers 22 and 24 automatically shut off due to the voltage loss of the generator bus 44G3 and the commercial-emergency communication line. b. The emergency side communication circuit breaker 24 automatically shuts off due to the voltage loss of the generator bus 44G3 of the No. 3 system. When the third generator G3 is automatically activated and the generator voltage is established, the emergency side communication breaker 24 and the busbar communication breakers 50G2, 50G3 are turned off.
The generator breaker 40G3 is automatically turned on under the conditions of (1) and power is transmitted to the No. 3 facility. c. No. 2 generator bus 44G2 and No. 3 generator bus 44G3
, The bus communication circuit breaker 50G2 automatically shuts off. The second generator G2 is automatically started, and when the generator voltage is established, the generator breaker 40G2 is automatically turned on under the condition that the bus connection circuit breakers 50G1 and 50G2 are turned off, and the power is transmitted to the second facility. d. No. 1 generator bus 44G1 and No. 3 generator bus 44G3
, The bus communication circuit breaker 50G3 automatically shuts off. The first generator G1 is automatically activated, and when the generator voltage is established, the bus communication circuit breaker 50G1 is automatically turned on under the condition that the bus communication circuit breakers 50G1 and 50G3 are turned off, and power is transmitted to the No. 1 facility.

(Embodiment of Emergency Two-System Power Transmission System) Assuming the following event, the operation and countermeasures in that case will be described below. FIG. 5 shows a failure point (X mark) and a backup route (thick broken line). 1. Assumed event At the time of a total power outage on the premises, the emergency high-voltage cable 48c was short-circuited (ground fault) while emergency power was being transmitted to facility c, and the emergency load breaker 46c at the premises substation was automatically shut off. Since it takes a long time (several days) to recover the failure of the premises cable, the facility c is in a completely blackout state. c. In the event of a total power outage in the premises, the commercial and emergency contact breakers 22 and 24 are automatically turned on from the emergency generators G1 to G3, and power is transmitted to the commercial power bus 32.

2. Operation procedure Transmit emergency power from commercial high voltage cable a. The operation switch of the load breaker 34c on the commercial side of the facility c is switched from a distant place to the site, and is manually turned on. b. An emergency power supply is transmitted from facility high voltage cable 36c to facility c. c. Check the voltmeter and circuit breaker on the commercial power receiving board at facility c. d. The operation switch of the commercial load circuit breaker 34c of facility c,
Switch away from the site.

3. When the commercial power is restored, the commercial side and emergency communication breakers 22 and 24 are automatically shut off, and the emergency generators G1 to G3 are automatically stopped. Commercial power is automatically transmitted to facility c.

[0025]

As described above, according to the present invention, a commercial communication breaker and an emergency communication breaker are installed at both ends of a communication high-voltage cable and connected between a commercial power supply and an emergency power supply. And the emergency system can be shared with each other.
Since the system is a commercial-emergency power supply mutual backup system, the following remarkable effects are obtained. A commercial two-line power transmission system using an emergency high-voltage cable can be performed, and the reliability of power supply is improved. The installation of power supply facilities is rationalized, and two commercial systems can be achieved with the minimum necessary cost. Emergency generator fuel will be secured and measures to be taken in case of failure will be reduced. The reliability of power supply is improved by transmitting power from two systems of an emergency power supply to which a commercial high-voltage cable is applied. It can also be used for high-voltage cable maintenance and replacement work.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a commercial-emergency power supply mutual backup system according to the present invention.

FIG. 2 is a power distribution system diagram showing one embodiment of the present invention.

FIG. 3 is an explanatory diagram of a power transmission system of the main part.

FIG. 4 is an explanatory diagram of a commercial two-system power transmission system.

FIG. 5 is an explanatory diagram of an emergency two-system power transmission system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Substation 11A, 11B High-voltage distribution line of electric power company 12A, 12B Extra high-power receiving equipment 13 Commercial distribution board 13A, 13B Commercial distribution board bus 14 Commercial high-voltage cable 15 Electric load equipment 16 Emergency generator equipment 17 Emergency distribution board 18 Emergency High-voltage cable 20 High-voltage cable for communication 22 Commercial circuit breaker 24 Emergency circuit breaker

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Toyomi Yamada 4002 Narita-cho, Oarai-machi, Higashiibaraki-gun, Ibaraki Pref. DD13 GG13 SS01 SS05 SS08 TT01 5H590 CA21 CE02

Claims (2)

[Claims] 1. Normally, power is transmitted from a substation on a premises to a power load facility via a commercial power line, and in an emergency, an emergency generator installed at the substation on the premises is backed up to the power load facility via an emergency power line. In a power distribution system to transmit power, install a commercial side circuit breaker and an emergency side circuit breaker at both ends of the communication high voltage cable, connect them between the commercial power supply and the emergency power supply, and connect the commercial system and the emergency system to each other. A commercial / emergency power supply mutual backup system, characterized in that the system can be shared so that a plurality of systems are practically used. 2. Normally, power is transmitted from a substation at a substation via a commercial high-voltage cable to each power load facility via a commercial distribution board with one line of commercial power, and an emergency generator installed at the substation in an emergency is used. A power distribution system in which a single emergency power line is used as a backup power supply to each of the above-mentioned power load facilities via an emergency high-voltage cable via an emergency power distribution board, and a commercial-side communication breaker and an emergency-side communication cut-off at both ends of the communication high-voltage cable A commercial two-line system using an emergency system high-voltage cable or a commercial system high-voltage cable by installing a device and connecting it between the commercial power supply and the emergency power supply so that the commercial system and the emergency system can be shared with each other. A commercial-emergency power supply mutual backup system, characterized in that it enables power transmission of two emergency systems using the system.