WIND ELECTRIC PLANT

摘要

The invention presents the wind electric station which consists of generator 1 that is connected to the wind turbine 2, which operation is controlled. The control system includes microprocessor 3 and cycloconverters 4 and 5, which are controlled from signals from the current frequency transmitter of the generator 6 and the grid 7. The phases of the primary winding of the generator can be switched from star to delta connection and back by the commutation device 8, and the generator operation mode changes from the synchronous at low wind speeds to the double fed induction mode at higher wind speeds, where electrical energy is transferred to the grid from the primary and the secondary winding. At low wind speeds the generator operates as a synchronous generator, its excitation is provided from the grid through the cycloconverter 4, which works as a rectifier, and the primary winding is switched in the star connection. When the wind speed starts to increase the commutation device 8 switches the primary winding of generator in delta connection. If the wind speed is increasing, the cycloconverters 4 and 5 turn the generator into double fed induction generator mode, and electrical energy is generated to the grid both from the primary and secondary winding. This operation mode of the generator provides the opportunity to increase the operation range of the wind speed and also the annual yield of electrical energy.