Optimal PMU allocation for high-sensitivity wide-area backup protection scheme of transmission lines

In spite of the outstanding benefits provided via phasor measurement units (PMUs) to smart grids in the field of wide area protection, they increase the cost of the infrastructure. Based on PMU location and system topology, subsets of buses and lines are formed representing backup protection zones (BPZs). This paper introduces a proposed criterion to overcome the shortage in formulating the BPZs. Also, this paper presents a proposed framework to define the optimal PMU locations regarding wide area BPZs. The framework is expressed as a multi-objective function, which aims to enhance the system observability, increase the number of transmission lines belonging to BPZs and increase the BPZ threshold sensitivity. The genetic algorithm technique (GA) is used to obtain the optimal locations of PMUs for different cases. The effectiveness of the proposed framework is evaluated by investigating the 14-bus IEEE standard system for different cases of fault location, type and resistance. Furthermore, the 39-bus system is considered for some cases as a larger system. The results show the possibility of enhancing the sensitivity of the BPZs of the system regarding optimal PMU locations.