Design and Control of a Photovoltaic Energy and SMES Hybrid System With Current-Source Grid Inverter

This paper proposes a novel photovoltaic (PV) energy and superconducting magnetic energy system (SMES) hybrid system based on the current-source grid inverter (CSGI). The key is to integrate the SMES coil into the dc link of CSGI for PV energy and battery systems. Thus, the SMES and PV energy system can share the CSGI, and the hybrid system offers more straight forward control on the grid side. The battery is added to the system for increase of storage capacity and effective operation under quenching condition. The dc choppers are applied to exchange the power between the PV, battery, and SMES. The battery-side dc converter and the PV-side boost converters are utilized to deliver their power to the voltage bus of dc choppers. The dc choke is proposed to take place of the SMES coil while quenching condition occurs. The control schemes for the proposed hybrid system for both normal SMES and quenching conditions are presented. The operation of the hybrid system under faulty grid conditions is also given. The simulation is developed to verify the validity of the proposed system and control schemes.