Design, analysis, and implementation of proportional-resonant filters for shunt compensation

Abstract

Summary Recent technological advances in power electronics has led to a substantial increase in nonlinear loads. This has led to deterioration in quality of power in distribution networks and sparked interest in power quality issues and its solutions. This paper discusses the issue of harmonics, which is a power quality problem: their estimation and subsequent control and mitigation using a shunt compensator. The control of shunt compensator using proportional-resonant (PR) controllers has been designed and implemented. Literature review presents a wide range of control techniques and proportional-integral (PI) controllers are the simplest and most commonly used in industries. Recently introduced PR controllers have been presented as an alternative to PI controllers. These controllers are believed to overcome the shortcomings of the conventional PI controller, which include the presence of steady-state errors and the need for transformation in three-phase systems using the synchronous dq frame. The added advantages of PR controllers include the possibility of implementation for simultaneous detection and extraction of harmonic components without requiring excessive computational efforts. This paper highlights the application of PR controller for harmonic estimation and their reduction in the utility grid using shunt compensator. Closed loop control using PR controllers as filters has been demonstrated using simulation as well as experimental results. Extensive results are presented for different loading conditions, and they demonstrate the application of PR controllers in grid-interfaced converter for power quality improvement.