Application of capacitors for power factor correction of industrial electrical distribution systems

The author summarizes information for determining the proper circumstances for applying capacitors to improve the operating efficiency of an industrial electrical distribution system. The following topics are discussed; the function of capacitors in an electrical power system; calculations to select the appropriate value of capacitance; selection of the optimal location in the distribution system to connect the capacitors; automatic switching of capacitors to match changes in the power system load, including system variations when capacitor switching is used; economic factors involved to justify the addition of capacitors to an industrial power distribution system; system harmonics and resonance effects in capacitor installations; and requirements of the National Electrical Code (NEC) concerning the characteristics and installation of capacitors