JPS5849045A - System parallel operation control system for synchronous generators - 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 The present invention relates to an improvement in a system performer control system for a synchronous generator in a hydroelectric power plant.

As is well known, hydroelectric power plants have been operated for peak loads due to their short start-up time and excellent coordination, but recently hydropower plants have been constructed in increasingly remote locations. Therefore, as power transmission distances to power demand areas become longer, synchronous generators tend to have larger capacities in order to reduce costs.

In such hydroelectric power plants, in order to secure the power supply for the synchronous generator and the water turbine auxiliary equipment, constantly charging the power transmission line means that the annual operation time is extremely short, such as 600 hours a year. Therefore, power loss due to transmission line loss cannot be ignored. ・My friend, hydroelectric power plants operate synchronous generators by energizing transmission lines only during peak loads.
It is desirable to insert it into the system.

Install a synchronous breaker on the high voltage side, and before operating the synchronous generator and water turbine, first connect the high voltage @ breaker of the main transformer in parallel, and connect the synchronous generator... and water turbine auxiliary equipment via the main transformer. After securing the power source, synchronous generation is started. However, in this case, as mentioned above, the main transformer has also increased in capacity due to the increased capacity of the synchronous generator. The inrush current of the main transformer caused the voltage at the sending end to drop significantly, making the entire system unstable, and in the worst case, there was a risk of a power outage for the entire system.

The present invention provides a system for controlling the parallelization of synchronous generators in the grid, which eliminates power loss in transmission lines and allows the synchronous generators to be safely connected to the grid without destabilizing the grid during peak loads. The purpose is to provide.

To achieve this objective, the present invention provides synchronous circuit breakers on the high voltage side and the low voltage side of the main transformer.

If the high-voltage side synchronous breaker is open and the power source for the synchronous generator and water turbine accessories cannot be received from the power transmission line, secure the power source from another power plant or distribution line and establish the voltage of the synchronous generator. It is characterized in that a high voltage side synchronous breaker is installed in parallel.

The present invention will be explained below with reference to the embodiments shown in the drawings.

FIG. 1 shows a single line diagram of a hydroelectric power plant for explaining the system parallel control system according to the present invention.

In the figure, a synchronous generator 1 is a low-voltage synchronous breaker (CBG)
) 2, Main transformer 3, High voltage side synchronous breaker (CBL)
) 41 to the power transmission line. In order to perform synchronous parallel control of these synchronous circuit breakers 2 and 4, a synchronous parallel control device 5 connects both ends of the low voltage side synchronous circuit breaker 20 via the operating contacts 6m of the relay 6 for high voltage synchronous and low voltage synchronous switching, and the transformers 7 and 8. connected to. At the same time, the return contact 6b% of the relay 6 transformer 9.
10 to both ends of the high voltage side synchronous breaker 40.

The power source for the synchronous generator and water turbine accessories is the station transformer 1.
1. Station breaker (CBH1) Taken out from the midpoint between the low voltage side synchronous breaker 2 and the main transformer 3 via 12. At the same time, it is configured so that it can also be supplied from the distribution line or other power plants via the on-site circuit breaker (CBH2) 13.

In addition, a voltage confirmation relay (VRI) 14 that confirms the supply of voltage from the distribution line or another power plant, and a voltage confirmation relay (VB2) 15 that confirms the existence of a power source for attached equipment are connected via transformers 16 and 17, respectively. connected. Furthermore,
Voltage confirmation relay (VRB) on the low voltage side of main transformer 3
18 are connected via transformer 8.

With this configuration, when stopping the peak load synchronous generator 1, if you want to start power transmission again in a short time after stopping power transmission, simply open the low voltage side synchronous breaker 2 and stop the synchronous generator 1. Then, the high voltage side synchronous breaker 4 is kept closed and on standby.

On the other hand, if power transmission is stopped and there is no need to start power transmission for a while, as described above, in order to eliminate power loss in the transmission line, open the breaker at the other end and open the low-voltage side synchronous breaker 2.
Both of the high cow side futonbunki 4 are placed on standby in an open state.

Therefore, when the synchronous generator 1 is stopped and a main engine operation command is input, as shown in the 7tif-chart in FIG. When the confirmation relay 14 is activated, that is, when power can be received from the distribution line or another power plant, the in-house circuit breaker 13 is closed to secure power for the simultaneous generator and the attached equipment of the water turbine. As a result, when the voltage confirmation relay 15 operates and the power supply for the attached equipment is secured, the high-voltage synchronous/low-voltage synchronous switching relay 6t is set to the reset state and the main engine, that is, the synchronous generator and the water turbine are started. Next, when the main engine rotational speed reaches 80% of the rated value, the low-voltage side synchronous breaker 2 is closed, and the excitation control of the synchronous generator 1 is started.Thus, the voltage of the synchronous generator 1 is started, When that voltage is established, the synchronous parallel control device 5 utilizes the voltage input via the contact 6b, which is closed by the return of the synchronous switching relay 6.
Synchronously connect the high voltage side synchronous breaker Hiro.

On the other hand, when the main engine operation command is input, if the voltage check relay 14 is inoperative, that is, it is not possible to receive power from the distribution line or another power plant, it is checked whether the voltage check relay 11 is operating.

As a result, when the voltage check relay 18 is inoperative, that is, the high voltage side synchronous circuit breaker 4 is also open and power source for the attached devices cannot be obtained, the synchronous generation machine 1 is given up on joining the system.

However, if the voltage confirmation relay 18 is activated and the high-voltage side synchronous breaker 4 is closed and it is possible to take out the power for the attached equipment, then the station circuit breaker 12 is closed and the power for the attached equipment is secured, and then the n synchronous switching is performed. Relay 6t-operate. Thereafter, as described above, the main engine is started, and when the main engine rotational speed reaches 80% of the rated value, the synchronous generator 1 is immediately excited, and when the synchronous generator l voltage is established, the synchronous parallel control device 5 is operated to synchronously close the low voltage side synchronous circuit breaker 2.

In this way, when the power source for the synchronous generator and the attached equipment of the water turbine can be secured from the distribution line or another power plant, synchronous parallel connection of the high voltage side synchronous circuit breaker 4, that is, high voltage synchronous parallel connection control is performed.

On the other hand, if the power source for the auxiliary equipment cannot be obtained from the distribution line or other power plant, but can be obtained via the main transformer 3,
Performs synchronous parallel entry of the low voltage side synchronous circuit breaker 2, that is, low voltage synchronous parallel entry control.

This makes it possible to prevent the excitation inrush power of the main transformer 3, and to enable synchronous parallel connection of the synchronous generators without destabilizing the system.

In the above example, when a synchronous generator is connected to the system, the hydroelectric power station in question first determines whether it is possible to receive power from the distribution line or another power station, and if it is not possible to receive power from the main transformer. I explained that it is necessary to judge whether the power supply for the attached device can be taken out from the power transmission line because the power supply for the attached device is energized, but first it is determined whether the power supply for the attached device can be taken out from the power transmission line. However, when the power cannot be extracted, it may be determined whether or not it is possible to receive power from the distribution line or another power plant.

As described above, according to the present invention, synchronous circuit breakers are provided on the high-voltage side and low-voltage side of the main transformer, while power source for the synchronous generator and accessories of the water turbine can also be obtained from distribution lines and other power plants. When the power source for the above-mentioned attached equipment cannot be obtained from the power transmission line, it is obtained from the distribution line or another power plant and the synchronous generator is connected synchronously, thereby eliminating power loss in the power transmission line. At the same time, it becomes possible to stably connect a synchronous generator to the grid without generating an excitation inrush current during peak load.

[Brief explanation of the drawing]

FIG. 1 is a single heave diagram of a hydroelectric power plant according to one embodiment of the present invention, and FIG. 2 is a flowchart for explaining its operation. l...Synchronous generator, 2...Low voltage side synchronous breaker, 3...
... 9.10, 16.17... Transformer, 11... Station transformer, 12.13... Station circuit breaker, 14, 15.
18...Voltage confirmation relay.

Claims (1)

[Claims] In system parallel control method 2 of a synchronous generator, in which the synchronous generator is synchronously connected to the grid via the main transformer, a synchronous circuit breaker is provided on the high voltage side and the low voltage side of the main transformer, while the synchronous generator and the water turbine are The configuration is such that the power source for the accessory equipment can be obtained from the distribution line and other power plants, and when the synchronous generator is started, the high-voltage side synchronous breaker is opened and the power source for the accessory equipment is obtained from the power transmission line. When the synchronous generator cannot be used, the synchronous generator is started using the power from the distribution line and another power plant, and after the low voltage side synchronous breaker is closed, the high voltage side synchronous circuit breaker is used to synchronize the generator. Systematic entertainer control method of -