The application of capacitors to electric power systems can be used for 1) the control of power flow, 2) the improvement of stability, 3) voltage profile management, 4) power factor correction and 5) loss minimization. The application of capacitors for loss minimization has been of interest to distribution engineers for several years, and as such a variety of techniques and procedures have been devised. This paper presents a review of techniques and procedures, of capacitor application for loss minimization, spanning t k m decades. The proreduses determine the location, size and quantity of capacitors to be allocated to distribution primary feeders subject to a variety of constraints, most importantly minimization of losses.
L Introduction to Capacitor ApplicationDesired objectives for applying capacitors in electric power system, include 1) power flow control, 29 improvement of stability, 3) power factor correction, 4) voltage profile management and 5) loss minimization. These objectives are achieved by either 1) shunt application or 2) series application. The method used depends on the desired outcome. The capacitor is a source of reactive power. Applying shunt capacitors to primary distribution feeders provides an alternate source of reactive power to reduce the level of reactive power provided by the supply.
IL 12R Loss Components1% feeder losses can be separated into hvo components based on the hvo components of current along the feeder as 1) the in-phase or energy component of current, due to the real component and 2) the out of phase component of the current, due to the reactive component. The real power loss in a line section is given by : P = ( 1 1 ' R = I~~R + I,?R where P = powerloss 1 1 , /I( = current magnitude (1) R = resistance lR,I = real, reactive current components Reducing the inductive reactive portion of the line loading, would reduce the reactive losses. With a bghly inductive load we want to reduce the level of inductive load current. This is done by h e addition of shunt capacitors.Work on applying shunt capacitors for loss reduction spans three decades and varies greatly in content. The main challenge is to select and place the appropriate number and size of capacitors to achieye a desired outcome. that include loss reduction. voltage regulation. as well as power flow control. The following gives an oyeniew of work in the field.
