A Reduced Switch AC-AC Converter with the Application of D-STATCOM and Induction Motor Drive

In this paper, a reduced switch AC-DC-AC converter is used as a distribution static compensator (DSTATCOM) and induction motor drive. The AC-DC-AC nine switch converter (NSC) is a reduced switch topology of conventional 12-switch back to back converter. With a 25% reduced switch count, NSC has lower losses when operated at constant frequency mode compared to twelve switch converter (TSC). The idea is to operate NSC input terminal as an active front-end rectifier to mimic synchronous generator (SG) operation. The induction motor is connected at the output of the NSC for irrigation application where no speed regulation is required. In distribution generation (DG), a large capacitor bank is used to deliver required reactive power. This may lead to over-voltage at the point of common coupling (PCC) when the load is turned off. To manage reactive power transfer at PCC, a control scheme is developed for NSC such that it can absorb or deliver reactive power with induction motor drive. Similar to SG, V-curve and inverted V-curve is plotted. The simulation and hardware results prove the feasibility of the proposed system.