Distributed control for paralleled PWM inverters in the DC Zonal Distribution System

Abstract

The modular DC Zonal Electrical Distribution System (DC ZEDS) offers many advantages over traditional radial shipboard electrical distribution. The advantages of DC ZEDS will be exploited in the next class of surface combatants. Part of the development research for DC ZEDS includes the design of autonomous DC-to-AC inverter modules having robust load sharing capability. This thesis will focus on these DC-to-AC inverters. Paralleled inverters in the DC ZEDS must be flexible and modular. The optimum flexibility is achieved when an electrical system can automatically reconfigure after the number of operating inverters changes. A distributed control system for paralleled inverters is investigated to achieve this flexibility and increase the system's battle damage survivability. Modularity of the system design allows for simplified testing and a reduction in cost through bulk purchasing. Unique distributive control methods are developed in this thesis that will allow isolated inverters in separate watertight compartments to coordinate their actions without interconnections between the units.