Advanced Repetitive Controller to Improve the Voltage Characteristics of Distributed Generation with Nonlinear Loads

Abstract

This paper presents an enhanced control strategy which consists of a proportional-integral controller and a repetitive controller (RC) for improving the voltage performance of distributed generation (DG) under nonlinear load conditions. The proposed voltage controller is able to maintain a sinusoidal voltage at the point of common coupling (PCC) of the DG regardless of the harmonic voltage drop in the system impedance due to nonlinear load currents. In addition, by employing the delay time of the RC at one-sixth of the fundamental period, the proposed RC can overcome the slow response drawback of the traditional PI-RC. The proposed control strategy is analyzed and the design of the RC is presented in detail. The feasibility of the proposed control strategy is verified through simulation and experimental results.

An Enhanced Harmonic Voltage Compensator for General Loads in Stand-alone Distributed Generation Systems

“…1. In order to supply a high quality output voltage ( L v ) at the PCC, many control efforts have been developed [5]- [15]. For the case of balanced linear loads, a proportional-integral (PI) controller in the synchronous reference frame is sufficient to produce a sinusoidal output voltage at the PCC [5]- [7].…”

“…However, the PI controller is unable to maintain a sinusoidal DG output voltage when unbalanced and/or nonlinear loads are connected to the PCC due to its limitation of the control bandwidth. In order to overcome this issue, several advanced control methods have been proposed such as PI controllers in [8], [9], predictive control [10], [11], adaptive control [12], multiple resonant controllers [13], [14], and repetitive control [15].…”

Low Cost and High Performance UPQC with Four-Switch Three-Phase Inverters

“…But the hysteresis control cannot assure a good performance of the load voltage due to the variation of the switching frequency. To overcome this drawback and to effectively compensate a large number of harmonic components, this paper adopts the repetitive control technique to regulate the voltage harmonics [26].…”

“…Similar to the shunt APF control, the modulation signals for two phase legs Sr a and Sr b of the series APF are also adjusted as Detail on design procedure of the RC for harmonic compensator is described clearly in [26].…”

Application of a C-Type Filter Based LCFL Output Filter to Shunt Active Power Filters

“…Voltage source converters (VSCs) have been widely used in many application fields, such as distributed generations [1]- [3], microgrids [4], shunt active power filters (SAPFs) [5]- [7], adjustable speed drivers (ASDs) [8], uninterruptible power supplies (UPS) [9], etc. The proper implementation of close-loop current control schemes and pulse-width modulation (PWM) strategies in a VSC can insure good current output performance within its control bandwidth.…”