Autonomous power generating system with generic n-level back-to-back converters

Paper presents novel topology of autonomous power generating system with diesel engine and permanent magnet synchronous generator (DE/PMSG) in configuration with multilevel converters. The star-connected three-phase back-to-back topology with generic n-level diode-clamped rectifier (MLDCR) and inverter (MLDCI) supplies three phase output load. The proposed multi-level current mode control techniques represented in synchronous frames and subsequently converted to stationary frames provide effective solution to voltage imbalance problem in n-level DC link network. The 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 (n-1) capacitors in the DC link network. Importantly, the gen-set is able to operate with asymmetrical, non-linear and impact loads in three phases and it provides the power factor correction on the generator side.