Modelling and Control Strategy for Hybrid PV and Central Receiver CSP in Power System Restoration

This paper proposes the dynamic modelling and the coordinating control strategy of the thermal energy storage (TES) based photovoltaic and concentrating solar power (PV/CSP) hybrid power system which is employed in the initial stage of power system restoration. Firstly, a coordinating control strategy of the hybrid system is established in consideration of the dynamic balance of system power and power quality problems during the restoration. Secondly, a CSP station with TES system and the dynamic control system is investigated to diminish system active power fluctuations from illumination changes. And the initial storage capacity of the TES is reasonably evaluated to complete the severest system restoration. Finally, the PV system with STATCOM is designed for the stability of voltage and frequency at the point of PV/CSP integration. In Matlab/Simulink, a model is built in to simulate the transient process of PV/CSP self-start, no-load transformer and transmission line charging, and the start-up of the long-distance auxiliary machine. Result shows that the proposed methods can effectively decrease the voltage and frequency fluctuations and achieve the purpose of smoothing power system restoration.

I. Introduction

The expansion of power system brings challenges to the restoration process after the blackout. The vulnerability of power system structure and the complexity of restoration strategy further increase the possibility of restoration failure. Therefore, in order to minimize the accident losses in the power outage, the study on the power system restoration at initial stage is of great significance [1]. Photovoltaic (PV) and concentrated solar power (CSP) station, which are two types of technology with rapid integration in power system and self-starting capability, have great potential for the application in the power system restoration [2].