Modeling and Simulation of Single Phase Grid Voltage Phase-Locked Method Based on Unscented Transformation Kalman Filter

In order to meet the requirements of new energy power connected to grid, it is crucial to obtain the grid synchronization information as the control signal. The method of single phase grid voltage phase locked loop is studied in this paper. And the method of unscented transformation Kalman filter is used to obtain the synchronization information of grid. Based on the analysis of basic principles of unscented transformation Kalman filter, the transformation of UT transform was introduced to replace the nonlinear function. And according to the expected grid synchronization information, state space model of voltage signal is derived to improve the estimation precision of the state variables. Finally, the simulation results of different fault states are carried out to verify the effectiveness of the proposed method on tracking the synchronization information.