AIS-Based Coordinated and Adaptive Control of Generator Excitation Systems for an Electric Ship

An artificial immune system (AIS)-based control of generator excitation systems for the U.S. Navy's electric ship is presented in this paper to solve power quality problems caused by high-energy loads such as direct energy weapons. The coordinated development of the AIS controllers mainly consists of two parts-innate immunity (optimal) and adaptive immunity. The parameters of the controllers for the former, to provide optimal performance, are determined simultaneously using particle swarm optimization. For dramatic changes in the ship's power system, adaptive control based on the immune system feedback law is developed. The feedback law adapts the controllers' parameters only during transient disturbances. After the disturbance, the controllers' parameters are restored to their innate values. A ship's real-time power system and the proposed AIS control of all excitation systems have been implemented on a real-time digital simulator and a digital signal processor, respectively. Results from the hardware-in-the-loop studies show that the AIS controllers can provide effective control of all generators' terminal voltages during pulsed loads, restoring and stabilizing them quickly.