Unlike the conventional power generating technology, like thermal or hydro plants, which uses synchronous type of generating machine, the generator used in wind power plants is usually asynchronous type or induction machine. Induction machine works in the same principle as a power transformer. Most of the electric motors around the world are induction machine.
The process of induction in an induction machine, or even in a power transformer, consumes reactive power. Induction machine, whether it operates as a motor or generator, consumes reactive power from the power supply where it is connected. In a wind farm, each generating unit absorbs or consumes reactive power from the grid. To compensate or provide the reactive power requirement of the wind farm, a power capacitor, which generates reactive power, is installed.
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