Multiple space vector control for self-commutated power converters

This paper proposes the multiple space vector control strategy for self-commutated converters. The strategy makes it possible to realize a significant reduction in power losses with lowest possible switching frequency in steady state, continuous operation with high speed tracking of commands in the transient state and flexible controls with the utilization of degrees of freedom in the assignment of voltage vectors to the converters. High efficiency of the strategy is confirmed by experiments in which two pulse switching mode and the speed of response in 5(ms) with one side model of the converter terminals of self-commutated HVDC ( High Voltage Direct Current ). The continuous operation is verified by simulations in a one-line ground fault. Another simulation based on the unbalanced dc voltages shows the balance control of dc voltages to be effective in HVDC transmission with self-commutated converters connected in series on the ac and the dc sides.