Nowadays, automatic network connection is adopted for network connection. When the grid connection device detects that it can automatically connect to the grid, it will automatically connect to the grid and then simply close the circuit breaker. I don't know how your power plant is connected to the grid! If there is no response when the circuit breaker is closed after the device connected to the network detects the signal that it can be connected to the network, check whether the circuit breaker is normal, whether the knife switch is normal, whether the low voltage side and the high voltage side of the main output transformer are open circuits, etc.
The problem is:
1. Before connection to the network, changes in the opening of the guide vanes will affect the speed of the unit, that is, the frequency, because at this time only the water flow affects the mechanical power of the vanes guidelines. HASAs the guide vanes open wider, the rotational speed also increases, and then the frequency increases.
2. After being connected to the network, the power conversion of the turbine is the mechanical power of the water flow on the guide vane. Once one side of the generator is connected to the grid, there is electromagnetic. the power, which is the load. After being connected to the network, the mechanical power is converted into electromagnetic power, so when the water flow increases (the opening of the guide vane increases), the load will increase the electromagnetic power after the network; Connection equals mechanical power:
For example, now the water turbine produces electricity. After the machine was connected to the grid, it received a charge of 10,000 KW. Suddenly the network connection switch was unplugged. the opening of the guide vane was not adjusted in time, theturbine would definitely be overspeeding, because at that time the electromagnetic power was 0.
I don't know how to put it that way. Can you understand?