Performance comparison of conventional STATCOM and STATCOM with energy storage in a low voltage induction motor application

This paper presents a performance comparison between a conventional STATCOM and a STATCOM with an integrated energy storage (ESTATCOM), within a low voltage stone crusher application. The systems are compared in terms of supply grid current rating mitigation capabilities, line voltage regulation and voltage flicker compensation characteristics. In addition, the required current ratings for the compensator inverter bridges, as well as the system total energy consumptions are studied. The functionality and power losses of the ESTATCOM have been studied with a small-scale laboratory test setup and the full-scale systems by computer simulations with Matlab Simulink software. According to the research results the ESTATCOM shows best performance within line voltage regulation, voltage flicker compensation, and supply current mitigation properties. In addition the ESTATCOM inverter bridge could be rated significantly smaller than the one of the conventional STATCOM. Load compensation increases the system energy consumptions when the supply grid is strong, but when the supply grid is weak the ESTATCOM consumes slightly less energy than the other studied cases. Overall, load compensation becomes most beneficial within weak supply grids with the STATCOM devices studied.