The Effect of Optimal PMU Placement in Power System State Estimation Considering the Seasonal Load Curve

State estimation is one of the essential processes in controlling and monitoring a power system. State estimation with conventional and low precision measurements is now replaced by fast and direct measurements provided by Phasor Measurement Units (PMUs). However, the high cost of PMU requires engineers to place these meters optimally. In this article, depending on the desired observability depth and considering the conventional measurements, various methods for combining PMU measurements to increase the accuracy in power system state estimation have been investigated. The key idea of this method is to maintain full observability of the system and reduce the installation costs of the meter. Also, the results of two scenarios using MATLAB software on IEEE standard systems, 14 and 30 buses, have been investigated regarding PMU placement and its effect on the estimation error. A seasonal load profile is considered to measure the accuracy of the state estimation and make the simulation more realistic. The simulation results show that the effect of the optimal placement of the phasor measurement unit, even in the state of incomplete observability of the power system, has increased the accuracy and speed of the estimation.