Coordination of a distribution level continuously controlled compensation device with existing substation equipment for long term VAr management

The implementation of a continuously-controlled reactive compensation device, such as an SVC or a “static condenser” (STATCON), in a distribution-level substation provides opportunities to improve power quality and reliability due to the speed of response of such a device. Further benefits can be gained by coordinating the reactive compensation device and its related controls with other substation voltage control equipment, such as load tap changing (LTC) transformers and mechanically-switched capacitors. The results presented in this paper illustrate the impact that a ±12 MVAr STATCON can have on a 150 MW, 12.5 kV load bus, in the Commonwealth Edison power system. Three control concepts for various levels of integration of the substation STATCON, LTCs, and mechanically-switched capacitors are presented. With broader application of SVCs and STATCONs at distribution substations, various other control strategies may also evolve