Voltage control practices and tools used for system voltage control of PJM

PJM has developed a pilot program of on-line (real time) voltage control in which a system wide Optimal Voltage Control (OVC) demonstration system has been implemented and run on-line parallel with PJM existing system at PJM control center since Jan. 2010. The pilot program was for nine months. The OVC system consists of Data I/O Management, Control Strategy Calculation, Operation Log Management and Control Process Dispatch. It is interfaced with PJM EMS system, automatically receives real-time snapshot from PJM EMS periodically, and calculates optimal voltage schedules for each generator, LTC and switchable shunt in the PJM system. The practices, experiences and results of the pilot program are presented in this panel paper. Significant potential benefits can be achieved with OVC techniques in both aspects of security and economy: (1) average reduction of transmission system loss is about 1.19%, which means energy savings of more than 220 million kWh/year and monetary savings of more than $17 million/year; (2) Average increase of system VAR reserve is about 1.08%; (3) Improvement on system security for pre-contingency and post-contingency is significant, including improvement on these security indices in voltage limits violations, and voltage stability limits violations.