JPS63154025A - Synchronous parallel running apparatus for 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 [Industrial Field of Application] The present invention relates to a synchronous addition device for a generator used when a generator is added to a power system.

[Conventional technology]

FIG. 2 is a block diagram showing a conventional synchronous coupling device for a generator, and FIG. 3 is a connection diagram of this synchronous coupling device for a generator.

In Fig. 3, 1 is the system bus, 2 is the circuit breaker that closes when synchronous connection is made, the 3Fi generator pressure regulator, and 4 is the system bus 1.
5 is the voltage transformer for the system bus instrument, 6 is the voltage transformer for the generator instrument, 7 is the synchronous coupling device, 8 is the automatic voltage regulator (AVR), and 9 is the generator to be coupled to the system. Speed regulator, 10 is breaker closing circuit, 11 is system side bus voltage, 1
．． 2Fi generator voltage.

In FIG. 82, 13 is a voltage adjustment circuit, 14 is a rotation speed adjustment circuit, and 15 is a synchronization detection circuit. The system side bus voltage 11 and the generator voltage 12 are sent to the synchronous coupling device 7 via the voltage transformers 5 and 6, respectively. And voltage adjustment circuit 13
compares the respective voltage values of the grid side bus voltage 11 and the generator voltage 12, and if the latter is smaller than the former, outputs a voltage increase command 16 to the automatic voltage regulator 8, and if the latter is larger than the former. If so, a voltage drop command 17 is output.

Similarly, the rotation speed adjustment circuit 14 compares the respective frequencies of the system side bus voltage 11 and the generator voltage 12, and outputs a rotation speed increase command 18 or a rotation speed decrease command 19. In this way, the voltage 9 frequency of the generator voltage 12 is controlled to match that of the system side bus voltage 11, and furthermore, when the synchronization detection circuit 15 detects that the phases of the two match,
The synchronization detection circuit 15 outputs a synchronization closing command 20 to the breaker closing circuit 10. According to this, υ, breaker closing circuit 10
The breaker 2 is turned on, and the synchronous addition of the generator 40 is completed.

[Problem that the invention seeks to solve]

Since the conventional synchronous coupling device for a generator is constructed as described above, it has the following problems. In other words, the generator voltage is controlled to match the grid-side bus voltage, so if the grid-side bus voltage rises to a voltage higher than the generator's rating, the generator will follow suit. There is a risk of overexcitation. In this case, no particular problem will occur if the generator is equipped with an automatic overexcitation protection device, but if it is not, continuous monitoring must be continued to ensure that the generator does not become overexcited during work. It disappears.

This invention has been made with the aim of solving the above-mentioned problems, and regardless of the presence or absence of an automatic overexcitation protection device, it reliably prevents overvoltage of the generator at the time of synchronization, thereby saving the operator's safety. The object of the present invention is to obtain a synchronous coupling device for a generator that can eliminate the need for monitoring.

[Means for solving the invention]

The synchronous coupling device for a generator according to the present invention is provided with a voltage upper limiter circuit, and when the detected value of the generator voltage exceeds a preset upper limit value, the voltage from the voltage regulator circuit to the automatic voltage regulator is This is to restrict the ascending command.

[Effect]

The voltage upper limiter circuit in this invention restricts the voltage increase command from the voltage adjustment circuit when the detected value of the generator voltage exceeds the set upper limit value, so this upper limit value is set at or near the generator rating. By setting this, overvoltage of the generator can be prevented.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, 21 is a voltage upper limiter circuit, 22 is a voltage converter that detects the generator voltage 12 and converts it into a low level signal, and 23 is a signal related to the generator voltage 12 output from the voltage converter 22. A monitor switch 24 compares with a preset upper limit value (the rated value of the generator 4 or a normal operation value), and 24 is a voltage increase command signal 16 from the voltage adjustment circuit 13 and an output signal from the monitor switch 23. This is an AND circuit that takes the AND of .

Next, the operation will be explained. The voltage adjustment circuit 13 compares the received grid-side bus voltage 11 and the generator voltage 12, and if the latter is smaller, outputs a voltage increase command 16 to the AND circuit 24. On the other hand, as long as the voltage is above ξ vine circuit 2
The No. 1 monitor switch 23 compares the signal related to the generator voltage 12 sent via the voltage converter 22 with an upper limit value, and if the signal is less than the upper limit value, it issues an output signal to the AND circuit. As a result, the AND condition of the AND circuit 24 is satisfied, and a voltage increase command 25 is output to the automatic voltage regulator 8.

When the generator voltage 12 increases with the increase in the grid side bus voltage 11 and the value of the signal input to the monitor switch 23 exceeds the upper limit value, the monitor switch 23 outputs a signal to the AND circuit 24. does not generate an output signal. Therefore, the AND condition of the AND circuit 24 is not satisfied and the voltage increase command 25 is not issued, so that generation of overvoltage in the generator 4 can be reliably prevented.

Although the above embodiment has been described assuming that the voltage upper limiter circuit 21 is housed inside the box body of the synchronous insertion device 7, the present invention is not limited to this. The same effect as in the above embodiment can be obtained by connecting a voltage relay for a synchronous joining device to the voltage relay and using this voltage upper limit signal.

Ma7'? In Fig. 3, it is assumed that the generator 4 has a relatively large capacity, as can be seen from the use of the generator transformer 3JfI, but of course the capacity is not limited. , it may also be that of Xiaoyonglong.

〔Effect of the invention〕

As described above, according to the present invention, a voltage upper limiter circuit is provided, and when the detected value of the generator voltage exceeds a preset upper limit value, a voltage increase command is issued from the voltage regulation circuit to the automatic voltage regulator. Since it is configured to be restrained, it is possible to reliably prevent overvoltage of the generator at the time of synchronization, and there is an effect that monitoring by a worker can be made unnecessary.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a generator synchronous coupling device according to an embodiment of the present invention, FIG. 2 is a block diagram showing the configuration of a conventional generator synchronous coupling device, and FIG. 3 is a block diagram showing the configuration of a conventional generator synchronous coupling device. It is a connection diagram showing a connection state. 1 is the system bus, 2 is the breaker, 4 is the generator, T is the synchronous addition device, 8 is the automatic voltage regulator, 11 is the system side bus voltage,
12 is the generator voltage, 13 is the voltage adjustment circuit, 16 and 25
Reference numeral 17 indicates a voltage increase command, 17 indicates a voltage decrease command, and 21 indicates a voltage upper limit IJ transmitter circuit. In the drawings, the same reference numerals indicate the same or equivalent parts. Patent applicant Mitsubishi Electric Corporation (2 others) - 7: masxst 8: @ dynamic voltage adjustment Aoi 11 1 source side bus 4L 12: generator pressure 13; Voltage increase command 17: Voltage decrease command 21: ti, leg-claw limiter rotation f each Fig. 2

Claims (1)

[Claims] Equipped with a voltage adjustment circuit that outputs a voltage increase command or voltage decrease command to an automatic voltage regulator based on a comparison between the generator voltage and the system side bus voltage when the generator is synchronously connected to the system side bus. The synchronous coupling device for a generator includes a voltage upper limit limiter circuit that detects the generator voltage and restricts a voltage increase command from the voltage adjustment circuit when the detected value exceeds a preset upper limit value. A synchronous coupling device for a generator, characterized by the following.