A PMU-augmented stability power limit assessment for reliable arming of special protection systems

This paper studies the application of phasor measurement unit (PMU) data for security-enhanced arming of special protection systems. A PMU-based hybrid method is proposed to assess transient stability limits of a multi-machine system in advance of network contingencies. The method is based on the single machine equivalent (SIME) technique, which combines time-domain algorithms with the direct method of equal-area criterion, to determine stability power limits on major transmission lines. In addition, based on the real-time network condition obtained by synchrophasor measurements, a strategy is proposed to effectively determine whether an arming signal should be issued for the next probable contingency. The effectiveness of the PMU-based automatic arming method is evaluated and discussed through simulation studies conducted in the real-time digital simulator (RTDS) and MATLAB software environment.