Optimal control of voltage and power in MVDC multi-zonal shipboard power system

Recent advancements in Voltage Source Converters (VSCs) of high-voltage and high-power rating had a significant impact on the development of Multi-Terminal HVDC (MTDC) power transmission systems. The U.S. Navy has proposed Multi-Zonal Medium Voltage DC (MVDC) Shipboard Power System (SPS) architecture for the next generation of their surface combatant. A Multi-Zonal MVDC SPS consists of several VSCs exchanging power through a DC network. Following a system fault or damage, the current flow pattern in the DC distribution grid will change and the DC voltages across the VSCs will assume new values. DC voltage reference or power reference settings of VSCs have to be determined, in advance, which can maintain the DC voltage within desired margins (usually 5% around the nominal value) in steady state, under the pre-fault as well as the post-fault conditions. In this work, the reference settings have been pre-determined by: (1) Development of a sensitivity based algorithm for voltage control of VSCs of the DC system; and (2) Development of an optimal algorithm for voltage and power control of the VSCs. The algorithms have been tested on a simplified representation of the MVDC SPS architecture.