Adaptive Near-Optimal Compensation in Lossy Polyphase Power Systems

This brief provides a formulation and solution for the problem of optimizing power flows in polyphase power systems with significant source (line) impedance. An optimal solution considering significant line impedance has already been obtained in recent works. Unfortunately, it relies on network and load parameters that are not easy to determine during operation. This motivates our interest in a suboptimal, easy to implement solution that relies only on the measurements of the load voltage and current, so as to allow precise control of power delivered to the compensated load as well as the real power flowing out of the compensator, while reducing line losses to within a few percent of the theoretical minimum. Our compensator tracks variations in both network and load conditions, continuously adjusting its current so as to reduce the power dissipated in the line impedance, for both linear and nonlinear loads. Properties of the adaptive compensation procedure are illustrated for an asymmetrical three-phase induction motor supplied with unbalanced nonsinusoidal voltages.