JPS6316287Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a synchronous operation device that aims to shorten the time from synchronous parallel operation of synchronous generators to parallel operation.

[Conventional technology]

Conventionally, this type of circuit has been shown in FIG. In the figure, 1 and 1a are three-phase squirrel cage induction motors, 2 and 2a are flywheels, 3 and 3a are synchronous generators, 4 and 4a are automatic voltage regulators, 5 and 5a are voltage setting devices, 6 and 6a are 6
b is a synchronization detection transformer, 7 is a synchronization verification circuit, 8 and 8a are start/stop circuit breakers for induction motors 1 and 1a, 9 and 9a are output circuit breakers for synchronous generators 3 and 3a, and 10 is for load. Circuit breakers 11 and 11a are M-G sets.

Next, the operation will be explained. In Figure 1,
M-G set 1 is set by turning on the start/stop circuit breakers 8 and 8a and starting the induction conductors 1 and 1a.
1 and 11a. Next, the synchronous generators 3 and 3a are caused to generate the voltage set by the automatic voltage regulators 4 and 4a. Now M-G set 11 M-
Consider the case where the G sets 11a are operated in parallel.
First, when the output circuit breaker 9 is manually turned on, the synchronous parallel operation reference is guided to the synchronous verification circuit 7 through the synchronous detection transformer 6. In the synchronous verification circuit 7, the synchronous generator 3
After detecting the voltage phase difference between and 3a and confirming the synchronization point, the output circuit breaker 9a is automatically or manually closed to perform parallel operation. In this conventional parallel operation of synchronous generators, synchronization verification was never performed by making a difference in generator voltage.

[Problem that the invention attempts to solve]

Conventionally, this type of synchronous parallel operation was performed using M-G set 1.
If 1 and 11a have the same capacity, synchronous generators 3 and 3
There is almost no difference in the losses of M-G sets 11 and 11a, which are the elements that generate the frequency difference of a, and the time it takes to reach the synchronization point is
Since this is caused by only a very small increase or decrease in the loss of 1a, it has the disadvantage that it takes several tens of minutes in the worst case to reach the synchronization point.

This invention was made in order to solve the above-mentioned drawbacks of the conventional devices, and the purpose is to obtain a synchronous operation circuit that can shorten the time until synchronous parallel operation.

[Means for solving the problem] The device according to this invention has a voltage regulator that adjusts the output voltage of the synchronous generators to be operated in synchronous parallel operation, and a means that creates a difference in the output voltage of both generators when operated. is provided, and when both generators are operated in parallel in synchronization, the above means is operated to generate a difference in the output voltages of both generators and detect a synchronization point.

[Effect]

In the device according to this invention, when the two synchronous generators are operated in parallel synchronously, the above-mentioned output voltage difference is produced by operating the means for producing a difference between the output voltages of the two generators. Increase the difference in iron loss to shorten the time to reach the synchronization point.

〔Example〕

An embodiment of this invention will be described below with reference to the drawings. Note that reference numerals 1 to 11 in the drawings are the same as those of the prior art and will therefore be omitted. 12 in Figure 2
and 12a are contacts or pushbutton switches (hereinafter referred to as voltage drop switches) provided in sequence to lower the terminal voltage of the synchronous generators 3, 3a. In operation, synchronous generators 3 and 3a
The terminal voltage can be adjusted by adjusting the positions of the voltage setting devices 5 and 5a. 13 and 13a are contacts or pushbutton switches (hereinafter referred to as voltage increase switches) provided to increase the terminal voltages of the synchronous generators 3 and 3a. When the voltage increase switches 13 and 13a are inoperative, the terminal voltages of the synchronous generators 3 and 3a can be adjusted by adjusting the positions of the voltage setting devices 5 and 5a. The voltage drop switches 12, 12a and the voltage increase switches 13, 13a are of a contact type for step-adjusting the voltage for ease of control and ease of starting parallel operation just before the synchronization point.

Next, the operation will be explained with reference to FIG. Let us consider a case where the synchronous generators 3 and 3a are operated in parallel after the M-G sets 11 and 11a have been started in the same way as the conventional device. Now assume that the synchronous generator 3 is operated in parallel with the synchronous generator 3a. The process is the same as the conventional one until the synchronous generators 3 and 3a generate the voltage set by the automatic voltage regulators 4 and 4a and the output breaker 9 is closed, but when the synchronous verification circuit 7 is put into operation, the synchronous generator Since the voltage phase difference between voltages 3 and 3a moves very slowly, it may take a considerable amount of time to reach the synchronization point. Therefore, in the device according to this invention, the output voltages of the synchronous generators 3 and 3a are controlled to be different from each other so that the synchronization point is reached early. In other words, the iron loss of the synchronous generator is
As shown in the curve shown in the figure, it depends on the generator voltage, so by making a difference between the voltages of the two generators, the difference in iron loss between the two generators will increase, the frequency difference between them will be expanded, and the phase difference will increase. The rate of change will increase and the synchronization point will be reached earlier. Specifically, either the voltage drop switch 12 or 12a or the voltage increase switch 13 or 13a is selected and closed so that the phase difference detected by the synchronization verification circuit 7 reaches a smaller direction in a shorter time. .
That is, if the phase difference is now progressing toward the synchronization point in the forward direction with respect to the 180° point as a reference, the voltage drop switch 12 is closed, and if it is progressing toward the synchronization point in the delay direction, the voltage drop is closed. By closing the switch 12a, the frequency difference between the synchronous generators 3 and 3a is expanded, and the rate of change of the phase difference is increased, so that the time required to reach the synchronization point, that is, the parallel point, can be shortened. Furthermore, if the voltage increase switch 13a is also closed when the voltage drop switch 12 is closed, it is possible to further increase the rate of change in the phase difference between the synchronous generators 3 and 3a. The voltage drop switch or the voltage increase switch, or both of them, which are closed as described above, are automatically or manually opened near the synchronization point, and the terminal voltages of the synchronous generators 3 and 3a are adjusted in advance by the automatic voltage regulator 4. , 4a, and then the synchronous generators 3a are operated in parallel.

Further, in the above embodiment, an MG set of the same capacity that takes the longest time to synchronize has been described, but the same effects as in the above embodiment can be obtained with MG sets of different capacities.

According to an embodiment of the invention, the conventional device can be used as is, and only a voltage drop switch and/or a voltage increase switch can be added to the sequence. As mentioned above, if the voltage increase switch 13a is also closed when the voltage decrease switch 12 is closed, the time until the synchronization point can be further shortened. Synchronous generator 3 when closed
Of course, it is necessary to suppress the voltage at the terminal a in advance so that it does not become extremely overvoltage.

[Effect of idea]

As described above, according to the present invention, the voltage regulator is provided with a means for creating a difference in the output voltages of the generators to be operated in synchronous parallel operation, and when the synchronous parallel operation is started, this means is operated to generate the above output voltage. As a result, the difference in iron loss between the two generators increases, the frequency difference between them increases, and the ratio of the phase difference increases, reaching the synchronization point early and synchronizing. Parallel operation can be started early.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an M-G set including a conventional synchronous verification circuit, Fig. 2 is a block diagram showing a synchronous verification circuit according to an embodiment of this invention, and Fig. 3 is an iron loss due to generator voltage. This is a curve showing the size of . In the figure, 3 and 3a are synchronous generators, 4 and 4a are automatic voltage regulators, 12 and 12a are voltage drop switches, and 13 and 13a are voltage increase switches. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Scope of utility model registration request] first and second voltage regulators that respectively adjust the output voltages of the first and second synchronous generators to be operated in synchronous parallel; and the first voltage regulator or the second voltage regulator.
means for causing a difference in output voltage between the first and second synchronous generators when operated, the voltage regulator being provided in the voltage regulator or both of the voltage regulators; A synchronous operation device for synchronous generators, characterized in that when operating in parallel, a voltage difference is generated between the two synchronous generators by operating the means to detect a synchronization point.