Improved Frequency Response Model for Power System with Photovoltaic Generation

With the gradual increase of renewable generation integration, power system with high-penetration photovoltaic(PV) integrated is one of the typical operating scenarios. Large-scale PV entry affects the dynamic frequency characteristics of the power system greatly. Based on the analysis of the insufficiency of the traditional power system frequency response (SFR) model, an improved SFR model of the power system with PV generation is established, considering the effect of PV frequency regulation, equivalent governor delay and frequency regulation deadband. Secondly, the parameter calculation method for the improved SFR model is proposed, in which some parameters are achieved by the weighted average of the information of each unit, and the remaining parameters are identified. Finally, the effect of the improved model and parameter calculation method are verified by simulation cases. Simulation results show that the improved SFR model can reflect the frequency response characteristics of the power system, and its accuracy is better than the traditional SFR model.

I. Introduction

Power system frequency reflects the active power balance of the system, and once the power disturbance occurs, the system frequency will deviate [1]. If the frequency regulation capability of the power system is insufficient, the low-frequency load shedding protection action may be triggered. In severe cases, the system will be disconnected, resulting in large economic losses [2]. With the gradual increase of renewable generation integration, power system with high-penetration PV integrated is one of the typical operating scenarios. Large-scale PV entry greatly affects the dynamic frequency characteristics of the power system [3]. Therefore, it is necessary to study the frequency dynamic response characteristics of power system with PV generation.