In order to prevent long term voltage instability and induced cascading events, a load shedding strategy based on the sensitivity of relay operation margin to load powers is discussed and proposed in this paper. The operation margin of critical impedance backup relay is defined to identify the runtime emergent states of related system component. Based on sensitivity analysis between the relay operation margin and power system state variables, an optimal load shedding strategy is applied to adjust the emergent states timely before the unwanted relay operation. Load dynamics is also taken into account to compensate load shedding amount calculation. And the multi-agent technology is applied for the whole strategy implementation. A test system is built in real time digital simulator (RTDS) and has demonstrated the effectiveness of the proposed strategy.
Proceedings of the 2012 Ieee International Conference on Power Systems (powercon): Powercon 2012, 2012
Voltage instability; Load shedding; Sensitivity analysis; Relay operation margin; Multi agent; RTDS
2012 IEEE International Conference on Power System Technology (POWERCON), 2012