JPS62118717A - Detector of single operation of water-wheel generator - 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 an islanding detection device for a water turbine generator, and more particularly to an islanding detection device for a water turbine generator suitable for detecting islanding during a remote shutdown. .

[Technical background of the invention and its problems] A water turbine generator is normally operated while being connected to the electric power system, but if for some reason this connection is cut off and the system is operated independently, this The water turbine generator will be controlled in response to independent operation. If this independent operation of the water turbine generator is not detected accurately, the water turbine governor will not be able to switch properly from load damping to no-load damping, and stable speed governing control of the water turbine generator will not be possible during island operation. .

Furthermore, automatic output control device and automatic reactive power regulator.

Speed governor control devices such as automatic water level regulators and system stabilization devices that control fluctuations in the output of water turbine generators are not excluded during standalone operation, and as a result, the power system is operated with frequencies and voltages that deviate from standard values. Problems such as instability also arise.

However, it is easy to detect this islanding state in the case of islanding due to load shedding within the power plant, but if the power plant is healthy and the other end power plant is shut off, in other words, when the power plant is disconnected at a remote location, This is generally not easy in case of solo operation.

FIG. 4 shows a conventional example for detecting the independent operation state of the water turbine generator during this remote cutoff.

The power station 1 is connected to the other end electric station 3 via a power transmission line 2, and the water turbine generator 11 is connected to a parallel circuit breaker 12 and a main transformer 13. It is connected to the power transmission line 2 via a high voltage side breaker 14.

A detection relay 17 such as an active power relay, a current relay, or a frequency relay is installed via an instrument transformer 15° and an instrument current transformer 16 in the high voltage side circuit of the main transformer 13, and a detection relay 17 such as an active power relay, a current relay, or a frequency relay is installed to cut off the electrical station 3 at the other end. The islanding state was detected based on the shutoff of the device 31. Note that the breaker 18 provided in parallel with the parallel circuit breaker 12 of the power plant 1 is a circuit breaker for the station circuit connected to a load of a non-power source.

However, with this method, the detection relay may be affected due to changes in the output, current, etc. of the water turbine generator during normal operation, or changes in the frequency increase of the water turbine generator when the load is cut off depending on the load condition at that time. 17 was difficult to set, and there was a problem that satisfactory detection results could not be obtained.

In order to eliminate this problem, as shown in FIG. 4, a transfer trip device 4,
5 is provided, a transfer trip transmission line 6 is provided between them, and the cutoff signal of the other end breaker 31 is transferred to the power plant 1.
Detection of isolated operation has been performed.

With this method, islanding can be detected reliably.

A transfer trip transmission line 6 must be installed between the power station 1 and the opposite end electric station 3, which increases the equipment cost.

Further, transfer trip devices 4, 5. Transfer trip transmission line 6
Transfer trip family [4
, 5. The problem is that the equipment cost increases due to the multiplexing of the transfer trip transmission line 6. Furthermore.

In cases where all the contacts of the breaker 31 at the other end are used and it is not possible to send a contact to the transfer trip device, or because there are many equivalent breaker 31 at the other end, the contact of each breaker is
If it cannot be summarized in one place.

There is a problem in that the power plant 1 has to detect the disconnection of the breaker 31 at the opposite end and each disconnection corresponding to the breaker 31 at the opposite end.

[Object of the Invention] The object of the present invention is to provide an islanding detection device for a water turbine generator that eliminates the drawbacks of the above-mentioned conventional system and is capable of detecting islanding at a low cost and more accurately and with high reliability when disconnecting from a remote location. shall be.

[Summary of the Invention] The present invention provides a guide vane position detector for a water turbine governor;
A quantity detector that detects the amount of water turbine generator output or current and a rate of change detector that detects the rate of change of the water turbine generator output or current are installed, and when the position of the guide vane of the water turbine governor is above a specified value, the water turbine generator outputs. Or, if the current is below the specified value and the rate of change when the water turbine generator output or current falls below the specified value is abnormally large, this system accurately detects isolated operation at the time of remote shutoff. be.

[Embodiments of the invention] Hereinafter, the present invention will be described in detail with reference to the drawings.

Figures 1 and 2 are block diagrams of a water turbine generator islanding detection device according to an embodiment of the present invention. In Figure 1, parts that are the same as or equivalent to the conventional configuration diagram Figure 4 are shown. Indicates the same code.

In FIG. 1, reference numeral 20 indicates a water wheel connected coaxially with the water turbine generator 11, 21 indicates a guide vane that changes the amount of water flowing into the water turbine 20 in order to change the output of the water turbine generator 11, and 2
2 is a guide vane position detector for detecting the position of the guide vane 21; 25, 26 is a generator instrument transformer and a generator instrument current transformer for detecting the output of the water turbine generator 11; 23 is a water turbine generator. A water turbine generator output amount detector 24 detects the amount of output of the water turbine generator 11, and a water turbine generator output change detector 24 detects the rate of change in the output of the water turbine generator 11.

FIG. 2 shows a configuration diagram of a circuit for detecting independent operation of the water turbine generator 11 in combination with FIG. 1.

24T is a time-limited return relay, and 27 is an auxiliary relay.

Further, 12a is an auxiliary a contact of the parallel circuit breaker 12, and 24
a is the output a contact of the water turbine generator output change detector 24, 22
a is the output a contact of the guide vane position detector 22, 23b
is the output contact of the water turbine generator output amount detector 23, 24Ta
27a is the a contact of the time-limited return relay 24T, and the a contact of the auxiliary relay 27.

The islanding detection device of this embodiment is configured as described above,
When the parallel circuit breaker 12 and the high pressure side circuit breaker 14 are in parallel to the human system, the opening degree of the guide vane 21 is controlled by an automatic output control device, an automatic water level regulator, etc., and the output of the water turbine generator is controlled. Ru.

FIG. 3 shows the relationship between the water turbine generator output and the guide vane opening degree over time in this embodiment.

As shown in Figure 3, during normal operation before remote shutoff, the guide vane opening and the turbine generator output have a certain relationship, and the guide vane opening and the turbine generator output are controlled. Therefore, the auxiliary relay 27 does not operate.

In this state, if the other end breaker 31 of the other end electric station 3 shuts off or the high voltage side breaker 14 shuts off,
As shown at point A, the water turbine generator output changes rapidly towards zero,
The guide vane opens as the rotation speed of the water turbine generator increases, and the guide vane closes after a certain period of time under the control of the water turbine governor. Therefore, on the condition that the parallel breaker auxiliary a contact 12a is closed, the guide vane position detector output a contact 22a is closed until it becomes below the specified value, and the water turbine generator output amount detector output contact 23b is closed as specified. water turbine generator output change detector output a contact 24a closes, time-limited return relay 24T operates, and time-limited return relay a contact 24Ta closes, auxiliary relay 27 operates, and its auxiliary relay a contact An independent operation signal is output from 27a. This signal causes the speed governor to be switched from load damping to no-load damping, and to exclude adjustment devices such as an automatic output control device, automatic reactive power adjustment device, automatic water level adjustment device, and system stabilization device.

In this embodiment, the guide vane 2 of the water turbine governor is
1 position is detected by the guide vane position detector 22. The water turbine generator output is monitored and controlled by the water turbine generator output amount detector 23 and the water turbine generator output change rate detector 24, respectively, and when the water turbine generator output suddenly decreases due to a remote cutoff, etc., the water turbine governor time is controlled. Since isolated operation is detected based on the characteristic that the guide vane 21 closes, it is possible to accurately detect a remote cutoff.

[Effects of the Invention] As described above, according to the present invention, it is possible to easily and inexpensively use equipment normally installed in a power plant without installing expensive equipment such as a transfer trip device or a transfer trip transmission line. Moreover, an isolated operation detection device for a water turbine generator can be obtained which can reliably detect isolated operation of the generator at the time of remote shutoff.

[Brief explanation of drawings]

FIGS. 1 and 2 are block diagrams of a water turbine generator islanding detection device according to an embodiment of the present invention. FIG. 1 is a device connection block diagram, and FIG. FIG. 3 is a diagram showing the relationship between the output of a water turbine generator and a guide vane, and FIG. 4 is a diagram showing the configuration of a conventional islanding detection circuit for a water turbine generator. DESCRIPTION OF SYMBOLS 1... Power plant, 2... Power transmission line, 3... Other end power plant, 4, 5... Transfer trip device, 6... Transfer trip transmission line, 11... Water turbine generator, 12...Parallel breaker, 13...Main transformer, 14...High voltage side breaker. 15...Instrument transformer, 16...Instrument current transformer. 17...Detection relay, 18... Breaker, 20.
... Water turbine, 21... Guide vane, 22... Guide vane position detector, 23... Water turbine generator output amount detector, 24... Water turbine generator output change detector, 25... Water turbine Generator instrument transformer, 26... Water turbine generator instrument current transformer. 27... Auxiliary relay, 31... Opposite end breaker. (7317) Agent: Patent Attorney Noriyuki Chika (
8105) King Hongbun Figure 1 Figure 2 1 minute Words Figure 3

Claims (1)

[Claims] An islanding detection device for a water turbine generator operated in parallel with a system includes a guide vane position detector that detects the position of a guide vane of a water turbine governor, and a water turbine generator output that detects the output or current amount of the water turbine generator. A power detector and a water turbine generator output change rate detector for detecting the rate of change of the water turbine generator output or current are provided, and when the position of the guide vane is above a specified value, the water turbine generator output or current is below the specified value. , and the islanding of the water turbine generator is detected by detecting that the rate of change when the output or current of the water turbine generator becomes equal to or less than a specified value is abnormally large. Detection device.