Autonomous Power Generating System with Multi-Level Converters

Paper presents a novel topology of autonomous power generating system with a diesel engine and a permanent magnet synchronous generator (DE/PMSG) in configuration with the multi-level converters. The star-connected three-phase back-to-back topology with a five-level diode-clamped rectifier (5LDCR) and a five-level diode-clamped inverter (5LDCI) supplies a three phase output load. The proposed multi-level current mode control technique represented in dq frame and subsequently converted to abc frame provide an effective solution to voltage imbalance problem in a DC link network. The proposed balancing method is applied to "back-to-back" operational mode only. In case of operation from the interfaced battery energy storage (BES), the balancing problem does not exist because individual DC-DC converters (SU/SD) stabilize voltages across four capacitors in the DC link network. Importantly, the gen-set is able to operate with an asymmetrical, a nonlinear and an impact load in three phases and it provides the power factor correction on the generator side