PMU based generator parameter identification to improve the system planning and operation

Abstract

To ensure the system stability, generator owners are required to provide their generator models and parameters to ISO/RTO for system analysis. In addition to field testing, there is increasing demand of online approach for parameter identification. The approach of Phasor Measurement Unit (PMU) based generator unit's parameter identification is a new emerging technology to satisfy these requirements. However, for large and complex electrical systems, the estimation of generator parameters based on PMU measurements remains a very challenge task. This paper proposed a systematic identification process to provide solution for the parameter identification problems. Three crucial steps are introduced in the proposed process. Firstly, hybrid dynamic simulation is implemented to obtain the dynamic equivalent circuit of the external system to reduce the computational time. Secondly, trajectory sensitivities and parameter correlation analysis is used to determine key parameters to further improve the computational efficiency. Finally, a minimum variance calibration strategy is proposed to derive the parameters of generator. A sample system is used to illustrate the effectiveness of the proposed approach.