Dynamic State Estimation of Synchronous Generator based Distributed Energy Resource in Autonomous Microgrid

The reliability and security of microgrid vastly depends on the fast control actions. Synchronous generator based Distributed Energy Resources (DER) are mostly commissioned in microgrid because of low cost and easy to control. When the microgrid toggle from grid connected mode to islanded mode, the control of DER is crucial to support the critical loads without compromising on reliability. A robust dynamic state estimator (DSE) can be employed to get an access to internal states of the generator for control. With the advent of //PMU into the distribution system made DSE possible. Due to the uncertainty of renewable energy resources and loads, DSE plays a vital role in monitoring and control applications. The real time monitoring of internal states of synchronous generator based DER is achieved by using kalman filter variants have been implemented in DSE. In this paper linearized variant and non-linear variants of kalman filter such as extended kalman filter (EKF), Unscented Kalman Filter (UKF), Square-root Unscented Kalman filter (SRUKF) and Robust Unscented kalman filter (RUKF) respectively have been implemented and tested for DSE. SRUKF and RUKF gives best estimates to the states with less absolute error when compared to other techniques. Computation time of RUKF is way less than SRUKF, hence RUKF is better alternative to SRUKF for real time DSE in microgrids.