Hybrid Measurement Fusion Estimation of Distribution Network Based on Quadratic Constrained Quadratic Estimation

In view of the long-term coexistence of PMU measurement and SCADA measurement in the current power system, this paper analyzes the measurement characteristics of the distribution network. On the basis of the quadratic constraint quadratic estimation model, the Unscented Kalman Filter (UKF) algorithm is introduced to realize the fusion estimation of mixed measurement. The main research contents of this paper are as follows: First, the quadratic constraint estimation model is established, and the hybrid measurement quadratic constraint equation and hybrid measurement equation of PMU and SCADA are proposed; Second, in order to solve the problem of weak robustness of UKF, a Robust Unscented Kalman Filter based on Quadratic Constrained Quadratic Estimation (QCQE-RUKF) is proposed. The Strong Tracking Filter(STF) is introduced to modify the gain matrix in real time to enhance the robustness of the algorithm. Simulation results carried out on the IEEE 30-bus test system show that the QCQE-RUKF can track system status more accurately and reliably than UKF and Extended Kalman Filter (EKF).