A DSTATCOM controller tuned by Particle Swarm Optimization for an Electric Ship Power System

In an all-electric ship power system, the power quality problems mainly arise due to the pulsed loads, which cause the degradation of the overall system performance. The paper proposes the application of DSTATCOM to improve these power quality problems of an electric ship. DSTATCOM is a shunt compensation device, which regulates the bus voltage by injecting reactive power during the pulsed load operations. The control strategy of DSTATCOM plays an important role to meet the objectives. The paper proposes a controller design strategy which is based on particle swarm optimization (PSO). PSO, an algorithm that falls into swarm intelligence family, is very effective in solving non-linear optimization problems. Here, the optimal parameters of a controller are found using PSO. To evaluate the performance of the proposed controller, a simplified model of a ship power system is developed in MATLAB/SIMULINK environment, which comprises of a 36 MW generator, 10 MW propulsion motor and pulsed loads of different values of real and reactive power. The effectiveness of the DSTATCOM and the PSO based controller are examined on the test system for pulsed loads of 100, 200 and 500 millisecond durations and also for a pulse train of 100 millisecond interval.