Trends in power system wide area protection

The conceptual definition of wide area protection, emergency control and power system optimization is described in this paper. The structure for a wide area protection system must be designed according to the available technology of the user. Enhancement of the system using smart control appears to have a big potential. The introduction of the phasor measurement unit (PMU) has greatly improved the observability of the power system dynamics. The automatic control can be either preventive, or corrective action. During normal operation, the focus is on economic optimization of system operation. During more challenging network conditions, the focus of control shifts towards stability consideration. The ultimate objective is keeping much as possible of the network intact and generators connected to the grid. The wide area protection systems are made against large disturbances, designed to improve power system reliability and/or to increase the transmission capacity. It is also able to communicate with traditional SCADA systems to improve functions like DSM, DA, EMS and SE.