Adaptive limited lookahead controller for minimizing power losses in flexible active compensators

Abstract

A Scalable Limited Lookahead Controller is proposed for coordinating multiple Shunt Switching Compensators (SSCs) to serve flexible compensation objectives while minimizing the power losses. A strategy utilizing Current Physical Component (CPC) theory with Recursive Discrete Fourier Transformation is used to orthogonally decompose the SSC reference currents into active, reactive, unbalanced and harmonic current components. These components then are associated with scaling coefficients which define the percentage of each desired component within the SSC compensated current, and therefore, providing flexibility and controllability for different compensation objectives. The proposed limited lookahead controller uses the system model and the current plant measurements to forecast the future states and then search for the values of the scaling coefficients to minimize the energy loss in SSCs, satisfying all the constraints. This scheme provides fast, accurate, and real time computation of the reference current coefficients, while maintaining a small latency. Our approach is applicable for systems such as shipboard distribution systems that requires flexible energy management with high degree of robustness avoiding single points of failure. MATLAB/Simulink simulation results of a three SSCs system are presented and discussed.