Certain conditions are required for the wind turbine to be connected to the grid, mainly when the wind speed reaches the cut-in wind speed, the unit begins to enter the standby state. At this time, the unit begins to wait for the impeller speed to reach the starting state, and then the unit's blades begin to move toward the optimal pitch angle. After the impeller speed reaches the grid connection speed, the unit starts to connect to the grid. Before connecting to the grid, the unit must quickly pass through the tower resonance zone.
There are two different types of wind power generation, namely: independent operation - off-grid type and connected to the power system operation - grid-connected type. 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 systems). Grid-connected wind power generation is a large-scale wind farm, with a capacity of approximately several megawatts to hundreds of megawatts, and is composed of dozens or even hundreds of wind turbines. Grid-connected wind farms can be compensated and supported by the large power grid, and more fully exploit the available wind resources, which is the main development direction of wind power generation at home and abroad. In an increasingly open electricity market environment, the cost of wind power generation will continue to decrease. If the indirect benefits brought by environmental and other factors are taken into account, wind power is also economically very attractive. The reason why grid-connected wind farms have developed rapidly around the world is not only due to their advantages in energy and environmental protection, but also because the wind farms themselves have the following advantages:
(1) Short construction period for wind turbines It and its auxiliary equipment are modular and easy to design and install. The transportation and installation time of a single wind turbine does not exceed three months. The construction period of a 10MW wind farm does not exceed one year, and it can be put into operation after one installation. tower.
(2) The actual land area is small and the requirements for land quality are low. The equipment building area in the wind farm only accounts for about 1% of the wind farm, and the rest of the site can still be used for agriculture, animal husbandry, and fishing.
(3) The operation management has a high degree of automation and can be unattended. On the other hand, wind power generation is limited by its primary energy source - wind energy.