JPS6082026A - Device for protecting generating plant - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a protection device for a power plant that trips a variable circuit breaker when a malfunction of a generator circuit breaker is detected.

[Prior art]

Conventionally, so-called unit systems have been employed in thermal power plants, nuclear power plants, and the like.

FIG. 1 is a diagram showing the main circuit system of such a power plant. The generator 2 driven by the steam turbine IK is
The phase separation bus 3 connects directly to the main transformer 4 for boosting the voltage generated by the generator, and the phase separation bus 3 is connected to the in-house transformer 5 by multi-branched buses in the middle of the phase separation bus 3. It composes a unit system that brings together the following.

Note that the generator 2 is supplied with field current from its field winding 2aK exciter 6 via a field breaker 7.

In this case, the main transformer disconnector 8 is installed on the high voltage side of the main transformer 4, that is, connected to the high voltage bus 9 of the main transformer 4. Also,
A starting transformer 1o, which supplies staining force to the main circuit system when starting up the power plant, is also connected to the high-voltage bus 9 via an electromotive circuit breaker 11.

However, in recent years, with the intention of omitting the starting transformer 1o, a phase-separated bus 3 between the generator 2 and the main transformer 4 has been introduced as shown in FIG.
A circuit in which a generator breaker (or load switch) 12 is installed in the 0 circuit is considered.

In the case of the circuit shown in Fig. 2, it is necessary to protect the steam turbine 1 and open the generator breaker 12 when an internal accident occurs in the generator 2, but it is necessary to remove the fault point when the generator breaker 12 is not operating. There was a drawback that it was not possible.

[Summary of the invention]

This invention was made in order to eliminate the above-mentioned drawbacks, and includes a generator breaker non-operation detection circuit. The object of the present invention is to provide a protection device that eliminates failure points.

[Embodiments of the invention]

FIG. 3 is a diagram showing an embodiment of the present invention, and shows a circuit diagram of a generator protection device which is the central part of the present invention. Block A shown on the left side is a means for detecting the cause of tripping the generator 2, such as a motorization detection relay 67G for steam turbine protection and a field loss relay 40G for detecting an internal fault in the generator. Protective relays and other conditions (conditions from trip cause detectors) 12.13 are shown.

Such a means A is connected to each input terminal of an OR gate 14.15, the output terminals of which are connected to the locking gates 86T, 86GIC, and their outputs are connected to the OR gate 16.

The block B shown on the right side of FIG.
connected to the output end of the

The tripped means B include the steam turbine 1, the field circuit breaker 7, the generator circuit breaker 1-2, and the transformer circuit breaker 8. It is connected to the lockout relays 86T and 86Gld, the steam turpinto field circuit breaker 7, the generator circuit breaker 12, and other devices, and is also connected to each input terminal of the AND gate 17 together with the closing signal of the generator circuit breaker 8. The output terminal of the AND gate 17 is connected to the regenerative circuit breaker 8 via a timer 18.

In the circuit configuration shown in FIG. 3, if an accident occurs in which one component constituting the means A, for example, the generator field loss relay 40G operates, the lockout relay 86G operates through the OR gate 15. As a result, the steam turpint field circuit breaker 7 and the generator circuit breaker 12 are immediately tripped to remove the fault current.

However, if the generator breaker 12 is inoperable at this time, that is, if the lockout relay condition is satisfied and the generator breaker 12 does not open even after a certain period of time, the timer 18 is activated to shut off the generator through the AND gate 17. Trip the device 8.

As a result, it is possible to remove the fault current even when the generator circuit breaker 12 is not operating.

In the above embodiment, the operation of the lockout relay 86G and the closing contact of the generator circuit breaker 12 are
Although the timer 18 is operated via the generator circuit breaker 12, a fault current continuation detection relay may be provided in place of the closing contact of the generator circuit breaker 12.

The same applies to the case where 86T is opened in the event of a steam turbine accident when a generator load switch is installed at the generator circuit breaker 120s.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to remove a fault point even when the generator circuit breaker is not operating, and a highly reliable protection system can be obtained.

[Brief explanation of the drawing]

1 and 2 are diagrams showing the main circuit system of a thermal power plant or a nuclear power plant, and FIG. 3 is a circuit diagram showing an embodiment of the protection device according to the present invention. DESCRIPTION OF SYMBOLS 1... Steam turbine, 2... Generator, 3... Phase separation bus, 4... Main transformer, 5... Station transformer, 6-
... Exciter, 7... Field circuit breaker, 8... Raw transformer circuit breaker, 9... High voltage bus, 10... Starting transformer, 11...
- Ecstatic circuit breaker, 12... Generator circuit breaker, 14, 15.
16...or gate, 17...and gate, 18
... Timer, 67G... Steam turbine motorization detection relay, 40G... Generator field loss relay, 86T
...Steam turbine protection port pull-out relay, 86G.
... Generator internal accident lockout relay. In addition, in the figures, the same reference numerals indicate the same parts. Attorney Masuo Oiwa Figure 1 Procedural Amendment (spontaneous) to the Commissioner of the Japan Patent Office 1, Indication of the case: Japanese Patent Application No. 188158/1982 2, Title of the invention: Power plant protection device 3, To Hitoshi Katayama, representative of the person making the amendment Section 5. Drawing to be corrected 6. Contents of correction The drawing shown in Fig. 8 is corrected as shown in the attached sheet. 7. One or more documents containing the revised catalog of attached documents in Figure 8

Claims (1)

[Claims] generator circuit breakers connected in series in the circuit connecting the generator to the main transformer, through which the field current is supplied;
In a protection device for a power plant equipped with a main transformer and a transformer circuit breaker, a trip command is sent to the generator circuit breaker and field circuit breaker in the event of an accident in the prime mover that drives the generator or an internal accident in the generator. A power plant equipped with a logic circuit that takes the logical product of a condition indicating that the generator breaker is not tripped and a condition indicating that the generator breaker does not trip, and a generator breaker failure detection circuit that outputs an output after a predetermined time period from the output of this logic circuit. protection device.