Dynamic Control of a Current-Source Inverter/ Double-Wound Synchronous Machine System for AC Power Supply

A novel dc-to-ac conversion system consisting of a load commutated current-source inverter, a double-wound synchronous machine, a position sensor, and a control circuit is being used increasingly as an ac power source in dc electric railway coaches. A detailed transient analysis of this dc-to-ac conversion system is presented and a new dynamic control strategy is proposed. It is shown that the proposed control not only stabilizes the output frequency and voltage of the system over a wide range of variations in the dc input voltage and/or the output load, but also secures safe commutation of thyristors in the inverter during transients.