An Optimal PMU Placement With Reliable Zero Injection Observation

Zero injection (ZI) is an inherent characteristic of a power grid. The effect of ZI (ZI effect) is usually utilized as an auxiliary measurement termed ZI observation for simplification. We discover that the ZI observation can transmit. The reliability of ZI observation becomes weaker, as ZI observation transmits deeper.'' In this paper, a unified phasor measurement unit (PMU) placement model is proposed with considering the reliability of ZI observation. To improve the reliability of ZI observation, the depth of ZI observation is limited, and the ZI utilization rate is minimized. The optimality problem which considers reliable ZI observation is studied, which has not been discussed before. Five working conditions, i.e., base case, N = 1 PMU outage, N = 1 line outage, N = 1 PMU outage, or N = 1 line outage, and the PMU measurement channel limitation are studied. The proposed method is tested on six IEEE test systems, i.e., IEEE 14-, 30-, 39-, 57-, 118-, and 300-bus systems, the Polish 2383-bus test system, and a practical power system in China. Results indicate that the proposed method not only reduces the number of PMUs by employing ZI effect but also ensures the reliability of ZI observation while making full observation of the power system.