Identifying Sensitive Communication Failure Combinations for Wide-Area Damping Controllers

The development of Wide-Area Measurement Systems enabled the use of remote signals in the design of controllers that can improve small-signal stability margins of power systems, called Wide-Area Damping Controllers (WADCs). However, these remote signals are susceptible to failures that can be caused, for example, by malfunctioning in a part of the communication system or even by a direct attack planned specifically to undermine the power system operation. This paper proposes a planning procedure to evaluate remote communication failures on WADCs by removing a set of communication links at a time and evaluating if the dynamic response of the system with the jeopardized WADC is still acceptable in terms of the small-signal stability margin of the system. The procedure which gives the operator two important pieces of information: 1) the number of signals that can be lost in an attack without compromising the op-eration of the system and 2) the most important communication links of the WADC that must have their protection reinforced. The procedure was applied to a modified version of the IEEE Benchmark Brazilian 7-bus Equivalent System, and the critical contingency was found for a situation with 3 communication link losses, validating the effectiveness of the proposed procedure.