A simplified microgrid voltage and frequency response characteristic modelling method based on system identification

摘要

A novel modelling method is proposed in this paper for modelling the point of common coupling (PCC) voltage and frequency response (VFR) of the microgrid (MG) via system identification techniques. The proposed modelling method uses the voltage and frequency data sampled at PCC to identify the VFR model without knowing the features of MG, such as the MG's topology, the models of the distributed generators (DGs) and loads connected to it. Compared with the commonly used mechanism modelling method, the proposed method greatly simplifies the process of modelling MG. The obtained identified VFR model can mimic the characteristics of the voltage and frequency response at the PCC with simple structure and low order, which can significantly reduce the computational cost. Based on the simplified model, a new guide for parameters tuning of secondary voltage and frequency controllers in the MG system is presented. The proposed modelling method has been validated on a MG experimental platform, and the obtained VFR model has been applied to the design of the secondary voltage and frequency controllers. The designed results also have been validated on the experimental platform, and the experimental results show the optimized secondary controllers have favorable stability and dynamic performance.