Fault-Tolerant Operation of Micro-Hydro and PV-BSS-based Standalone Microgrid using Predictive Control

This paper presents the fault-tolerant operation of a self-excited induction generator (SEIG) coupled with a micro hydro and solar photovoltaic (PV) based standalone microgrid (SMG). The intermittent nature of these renewable sources is mitigated using a battery storage system (BSS) to ensure an uninterrupted power supply to consumer loads. A three-phase voltage source inverter (VSI) is utilized to integrate the PV–BSS into the SMG. Afixedswitching frequency-based model predictive control (FSF-MPC) is developed for the control of VSI. The control achieves multiple objectives, such as active power injection, regulation of the point of common coupling (PCC) voltage profile, and suppression of load harmonics. Fixed-frequency operation of the VSI is ensured by applying predefined vector combinations with only one state change at any instant. Six fixed vector combinations are assigned to each of the six sectors. The optimal sector is selected based on the minimum cost-function value, which is computed using the duty cycle and the cost-function values of the vectors within that sector. The control is further designed to switch operating modes during faults occurring near the interconnection of the SEIG-based micro-hydro system and the PCC of the SMG. The performance of the proposed control is validated through MATLAB/Simulink simulations under various dynamic operating conditions. In addition, a hardware prototype of the SMG is developed. A dSPACE-based MicroLabBox is used as the controller to verify the real-time performance of the proposed control. Finally, a comparative study with conventional MPC is presented to showcase the merits of the proposed FSF MPC.