Start What are resistors used for in wind turbines?
  • Dump resistors (LVRT); Low Voltage Ride Through is the capability of modern wind turbines to operate during disturbances in the grid. Minor disturbances happen often but usually are very short. If the turbine cannot feed (part of) the energy in the grid, the surplus is dumped in a resistor. Regulations differ from country and or energy company. The regulation is fixed in grid codes.

  • Filter resistors: the voltage frequency of the turbine needs to be converted to the same frequency as the grid. For this, semiconductor switches are used. The switching of the semiconductors causes higher harmonics which are bad for the quality of the power. The filter (the resistor is part of the filter) improves the power quality.

  • Charge resistors: They limit the current in an electrical circuit to protect other components from harmful over currents.

  • Discharge resistors: they safely unload the electrical charge in capacitor banks to safe voltage levels when the inverter needs to be serviced or decommissioned.

  • Pitch control: (brake resistors). Sometimes this is done by hydraulics, but electrical brake resistors are needed when it is done.