The typical resistor for power system is the neutral grounding resistor. It performs neutral grounding in main transformers and generators, and restrains fault currents caused by grounding accidents to power lines, so as to protect equipment against damage in power plants and transformer stations and to prevent induction faults to communication lines running along power lines.
The transformer excitation plunge electric current restraint resistor and the resistor for higher harmonic removal filters that are installed in large number are used with the purpose to improve the quality of electric power.