The wind turbine on-grid control device has three modes: soft grid connection, step-down operation, and rectification and inversion. The on-grid control of the wind turbine directly affects whether the wind turbine can transmit electrical energy to the transmission grid and whether the unit is affected by the inrush current when it is connected to the grid.
The anemometer detects the wind speed, and the wind vane detects the wind direction and performs the yaw operation. When the wind speed reaches the power-on value, the pitch system starts to work, and the blades are changed to an appropriate angle according to the wind speed. The speed sensor detects the speed of the fan and the speed of the generator.
When the speed reaches the output power condition, the excitation power supply starts to excite, and the generator starts to output power. When the voltage reaches the on-grid condition, the inverter executes the on-grid operation, enters the booster station, and enters the grid.
Large wind turbines are directly connected to the grid for operation. Therefore, the wind turbines must be installed in one place to form a scale, which is called a wind farm.
There are two different types of wind power generation, namely: stand-alone operation - off-grid and connected to the power system - grid-connected. Off-grid wind power generation is small in scale and can solve the power supply problem in remote areas through energy storage devices such as batteries or in combination with other energy generation technologies (such as wind power/hydropower complementary systems, wind power-diesel unit combined power supply system).
Grid-connected wind power is a large-scale wind farm with a capacity of several megawatts to hundreds of megawatts, consisting of dozens or even hundreds of wind turbines. The grid-connected wind farms can be compensated and supported by the large power grid, and the available wind resources can be more fully developed, which is the main development direction of wind power generation at home and abroad.