JP2001068346A - Controller of transformer in electric power plant power supply facility - Google Patents

Abstract

PROBLEM TO BE SOLVED: To save a consumed power amount and prolong a lifetime of cooling facilities by a method wherein release signals of a generator switch and a field system circuit-breaker are inputted to a controller of the cooling facilities of a transformer in an electric power plant power supply facilities, and a cooling means of a major transformer is stopped by this controller. SOLUTION: A controller 20 supplies power from a generator 1 to a power system via a major transformer 3 in a state such that a generator switch 6 and a field system circuit-breaker 15 are closed. When the generator 1 is stopped in this state, the generator 1 is stopped according to a stop command to the generator 1 and a release command to the generator switch 6 and the field system circuit-breaker 15 from the controller 20, also the generator switch 6 and the field system circuit-breaker 15 are released, and a stop command is outputted also to an induced motor 18A to stop the induced motor 18A. Accordingly, an oil is circulated for natural cooling between the major transformer 3 and a cooling facility 12. In the generator power supply facility, a consumed power amount of the cooling facility is saved in proportion to non- operation of the induced motor 18A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling system control system for a main transformer in a power plant in a power plant, and particularly to a low pressure synchronous system as an oil-conducting air-cooling or oil-supplying air-cooling transformer and a generator synchronous system. The present invention relates to a control device for a transformer in a power plant power supply facility.

[0002]

2. Description of the Related Art As a method of synchronizing a generator and an electric power system in a power generation plant, a method of synchronizing and merging with a main circuit breaker on a high voltage side of a main transformer (high-voltage synchronous system) is known.
And a method of synchronizing with a generator load switch installed between the generator and the main transformer (low voltage side of the main transformer) (low-voltage synchronous system).

[0003] In the high-pressure synchronous method generally used in nuclear power plants, the generator 1 and the main transformer 2 and the in-house transformer 4 cannot be electrically separated as shown in FIG. The power supply to the place when the machine 1) is started and stopped is separately performed by a starting transformer 5 connected to a power system. Therefore, the duty of the main transformer 2 in the high-voltage synchronous system is only to increase the power generated by the generator 1 to the power system voltage and to transmit the power, and the cooling equipment 12 of the main transformer 2 is linked with the operation of the generator 1. There was no problem with driving. 3 is a main circuit breaker.

[0004] On the other hand, many of the next nuclear plants to be constructed in the future are planning to use a low-pressure synchronous system. In the low-voltage synchronous system, a generator load switch 6 is installed between the generator 1 and the secondary side of the main transformer 2 and between the in-plant transformer 4 as shown in FIG. 6 is a system in which the generator 1 and the power system are synchronously incorporated. Further, the generator 1 and the main transformer 2 are connected by the generator load switch 6.
In addition, since it becomes possible to electrically isolate the in-house transformer 3, when starting / stopping the coolant (when starting / stopping the generator)
By opening the load switch 6 for the generator, it becomes possible to receive the power inside the plant from the power system via the main transformer 2, and the start-up transformer 5, which is an essential equipment in the high-voltage synchronous system, Can be streamlined. In addition, Japanese Patent Application Laid-Open No. 58-148635 and Japanese Patent Application Laid-Open
No. 137735 can be mentioned.

[0005]

For this reason, the main transformer 2 of the plant adopting the low-voltage synchronous system not only transmits the electric power of the generator 1 to the power system but also starts the generator and performs regular inspection of the plant. When the generator is stopped, it is also responsible for supplying power from the power system to the in-house power system. When the plant is stopped, the amount of power required by the power system in the office is about several percent of the capacity of the main transformer, but when the cooling equipment of the main transformer 2 is operated, the power consumption increases,
The life of cooling equipment such as pumps and motor fans is shortened.

SUMMARY OF THE INVENTION An object of the present invention is to stop the operation of the cooling system of the main transformer when the plant is stopped, thereby saving power consumption and extending the life of the cooling system. To provide a control device for the vessel.

[0007]

To achieve the above object, a primary side of a main transformer is connected to a power system, and a secondary side of the main transformer and a generator are connected via a generator load switch. Connected in series, branch-connected each of the excitation power transformer and the in-house transformer from the secondary side of the main transformer and the load switch for generator, and set the magnetic field to the secondary side of the excitation power transformer. In a power plant power supply connected to a generator field winding via a circuit breaker, the open signal between the generator load switch and the field circuit breaker is used to control the transformer cooling equipment in the power plant power supply. Input to the device,
The control device stops the cooling means of the main transformer.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is an overall schematic diagram of a nuclear power plant employing a low-pressure synchronous system. In FIG. 1, the steam generated in the core of the nuclear reactor 8 is guided to a high-pressure turbine 10 and a low-pressure turbine 11 via a steam regulating valve 9 and a main steam pipe, and drives a generator 1 connected thereto to generate electric power. I do. The generator load switch 6 synchronizes the generator 1 to the electric power system at a low voltage by closing operation, boosts the electric power by the main transformer 2 and transmits the electric power to the electric power system, and also loads the internal load, for example, the power receiving via the internal transformer 4. Power is supplied to the circuit breaker 4A.

The ticket-type exciting device between the generator load switch 6 and the main transformer 2 includes an exciting power transformer 13, a thyristor rectifier 14, a field circuit breaker 15, a generator field winding 15A, and the like. Is done. In order to convert a part of the generator output from the branch circuit into an AC voltage equivalent to the DC voltage required by the field circuit, the exciting device lowers the voltage with the exciting power transformer 13 and the secondary side of the exciting power transformer 13. The output of the (low voltage side) is converted from AC to DC by the thyristor rectifier 14 and the field current necessary for maintaining the generated voltage is supplied to the generator 1. When the generator 1 is started, an initial excitation current is supplied to the generator from the in-house DC power supply via the initial excitation device.

When the plant is stopped, the generator load switch 6
Is open, and the generator 1, the main transformer 2, and the in-house transformer 4 are electrically separated. Power in the plant is supplied from the power system via the main transformer 2 and the plant transformer 4. In this case, the electric power passing through the main transformer 2 is only the in-house electric power,
This is about several percent of the capacity of the main transformer 2, for example, about 5%.

At the time of starting the fuel, the steam generated from the reactor 8 is guided to the high-pressure turbine 10 and the low-pressure turbine 11 via the steam regulating valve 9 and the main steam pipe, and the generator 1 mechanically connected to the high-pressure turbine 10 and the low-pressure turbine 11. Drive and start power generation.
The electric power generated from the generator 1 is synchronized with the generator 1 and the electric power system due to the closing operation of the generator load switch 6, and
After being raised to the voltage of the power system via the main transformer 2, the power is transmitted by the power system, while a part of the power is supplied to the power system via the power transformer 4. At this time, the electric power passing through the main transformer 2 is equivalent to the electric power generated by the generator 1, which is almost the rated capacity. The configuration of the main transformer 2 will be described with reference to FIG.

In general, there are various types of cooling of the transformer, such as self-cooling, air cooling, and water cooling, depending on the capacity and application. Further, a transformer employing a wind-cooling or water-cooling system generally has a self-cooling capacity of several% to several tens% of the capacity of the transformer. The capacity of the main transformer 2 of the nuclear power plant is 1000 MVA to 20
It is a 00MVA class and employs an oil-guiding air cooling system as a cooling system. FIG. 2 shows a schematic configuration diagram of the oil guiding air cooling system.

In the oil-guiding air cooling system, an oil conduit 17A communicates between a main transformer main body 16 and a cooling facility (unit cooler) 12 as shown in FIG. This is a method in which the horn 17 is driven to circulate oil between the main transformer main body 16 and the cooling facility 12 to cool the iron core and the windings in the main transformer main body 16 and have a high cooling efficiency. The oil is cooled by the cool air when the fan 18 is rotated by driving the induction motor 18A of the cooling facility 12. A separator 19 for separating the main transformer main body 16 and the cooling facility (unit cooler) 12 is attached to a part of the oil conduit 17A.

The separation device 19 is connected to a control device 20 as shown in FIG. The control device 20 is connected to the generator 1, the generator load switch 6, the field circuit breaker 15, and the cooling facility (unit cooler) 12. The operation of the control device 20 will be described with reference to FIG.

In the state shown in FIG. 1, when the generator load switch 6 and the field breaker 15 are closed, the electric power from the generator 1 is transmitted to the electric power system via the main transformer 3. When the generator 1 is stopped in this state, the controller 1
Command, generator load switch 6 and field breaker 15
, The generator 1 is stopped, the generator load switch 6 and the field breaker 15 are opened (that is, the AND condition is satisfied), and a stop command is also issued to the induction motor 18A. Then, the induction motor 18 also stops. Therefore, the oil circulates naturally between the main transformer 3 and the cooling facility 12. In this case, the electric power passing through the main transformer 2 is only the in-house power, and the self-capacity of the main transformer 2 can sufficiently cope with it. As a result, in the power plant equipment of the present invention, the power consumption of the cooling equipment is reduced by the amount that the induction motor 18A does not operate.

Further, the life of the induction motor 18A can be extended as much as the operation of the induction motor 18A is not performed, so that the life of the cooling equipment can be extended. In addition, the electric power in the station is detected by the current transformer 4B, input to the control device 20, and the detected value is constantly monitored by the control device 20. When the drive of the cooling equipment 12 becomes a necessary value, the induction motor is necessary only. 18A
To drive. In this case, if the induction motor 18A is frequency-controlled, since all the induction motors 18A are operating at a low speed, it is possible to quickly start up and quickly reach the maximum load for an urgent load.

Further, in accordance with a command for separating the main transformer main body 16 and the cooling facility (unit cooler) 12 from the control device 20 to the separating device 19, a valve (not shown) of the separating device 19 is closed, and the main transformer main body is separated. Prevents oil from leaking from 16 and separate cooling equipment (unit cooler)
12 is maintained and inspected.

FIG. 3 is a block diagram showing a cooling system 12 for the main transformer 3, a separating device 19, and a control device 20 for controlling the generator 1.
The operation logic diagram of FIG.

The operating conditions of the cooling facility (unit cooler) 12 are that the main transformer 3 is closed, the load switch 6 for the generator is closed, and the cooling facility (unit cooler) 1 is closed.
2 and the cooling device (unit cooler) 12 is in the automatic operation mode, etc., and the cooling condition (unit cooler) is satisfied. 12) The 12 operating conditions are satisfied. If at least one of the AND conditions 23 is not satisfied, the operating condition of the cooling facility (unit cooler) 12 is not satisfied.

The operating conditions of the separation device 19 are that the generator load switch 6 is closed, that the field circuit breaker 15 is open, that the separation device 19 activation command is issued, and the like. Are satisfied, the separation operation condition of the separation device 19 is satisfied. If at least one of the AND conditions 22 is not satisfied, the separation condition of the separation device 19 is not satisfied.

The conditions for turning on the generator load switch 6 are as follows: the control device 20 confirms that the main transformer 3 and the cooling facility 12 are connected, and the turning on of the generator load switch 6 When the AND condition 24 such as the condition is satisfied, the closing condition of the generator load switch 6 is satisfied. A
If at least one of the ND conditions 24 is not satisfied, the closing condition of the generator load switch 6 is not satisfied.

[0023]

As described above, according to the present invention, the induction motor of the cooling facility can be stopped according to the open condition of the load switch for the generator and the field breaker. As a result, in the power plant power supply equipment of the present invention, the power consumption of the cooling equipment can be saved and the life of the cooling equipment can be prolonged by the amount that the induction motor does not operate. In addition, by separating these accessories from the main transformer, maintenance of these accessories can be performed even while the main transformer is operating.
Inspection becomes possible.

[Brief description of the drawings]

FIG. 1 is a power system diagram of a power plant power supply equipment according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a transformer used in FIG.

FIG. 3 is a diagram showing operation logic of the control device used in FIG. 1;

FIG. 4 is a power system diagram of a power plant power supply system employing a conventional high-voltage synchronous system.

FIG. 5 is a power system diagram of a power supply facility of a power plant employing a conventional low-voltage synchronous system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Generator, 2 ... Main transformer, 3 ... Main circuit breaker, 4 ... In-house transformer, 6 ... Generator load switch, 12 ... Cooling equipment, 13
... Exciting power supply transformer, 14 ... Thyristor rectifier, 15 ... Field circuit breaker, 16 ... Main transformer main body, 18 ... Cooling fan, 1
8A: induction motor, 19: equipment separating device, 20: control device.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masashi Sugiyama 3-1-1, Sachimachi, Hitachi-shi, Ibaraki Pref. Hitachi, Ltd. Hitachi Works, Ltd. (72) Koji Nishi 3-2-2 Sachimachi, Hitachi-shi, Ibaraki No. 1 Hitachi Engineering Co., Ltd. F-term (reference) 5E050 CA04 CB04 CB05

Claims (4)

[Claims] A generator is connected to a power system via a generator load switch and a main transformer, and an exciting power supply transformer is connected between a secondary side of the main transformer and the generator load switch. In a power plant power plant equipped with a branch transformer and a field circuit breaker connected to the secondary side of the exciting power supply transformer and a cooling means in the main transformer, a load switch for the generator is connected. A control device for a transformer in a power plant power plant, comprising: a control device for stopping a cooling means in accordance with an AND condition for opening a field circuit breaker. 2. The control device for a transformer in a power plant according to claim 1, wherein a plurality of motor fans constituting the cooling means are connected to the control device. 3. A control device monitors the power detected by the current transformer detecting the power flowing through the in-house transformer, and if the main transformer requires power to be cooled, cooling means for the required power. The control device for a transformer in a power plant power supply facility according to claim 1, wherein the main transformer is cooled at (1). 4. The transformer according to claim 1, wherein an equipment separating device is provided between the main transformer and the cooling means, and the control of the equipment separating device is performed by a control device. Control device.