Design of Robust Higher-Order Repetitive Controller Using Phase Lead Compensator

Mohsin Jamil,Bilal A Khawaja,Muhammad Nasir Khan,Ali Raza,Syed Omer Gilani,Asim Waris

doi:10.1109/access.2020.2973168

Abstract

The performance of conventional repetitive controller (RC) deteriorates under frequency variations and system uncertainties. Due to limited bandwidth, it is also a trivial task to stabilize the conventional RC. This paper proposes a higher-order repetitive controller (HORC) with linear phase lead as a stabilizing compensator and zero-phase tracking error (ZPTE) compensator. The periodic signal generator, used by the HORC, offers relatively high gains in the neighborhood of tuned frequency and its harmonics. Stability conditions for higher-order repetitive (HOR) control system, including the phase lead compensator, are presented. The proposed solution is applied to repetitive current control of a two-level grid-connected inverter. Simulation and experimental results show that the HORC designed using the phase lead compensation is robust to frequency variation in reference/disturbance and system uncertainties.

Highlights

Repetitive controller (RC) offers the best performance over the reference tracking and disturbance rejection for periodic exogenous signals [1]
It is expected that the higher-order repetitive controller (HORC) performs much better under frequency variation as compared to the other two controllers
The designed scheme was applied to the current control of two-level three-phase grid-connected converter

Summary

Introduction

Repetitive controller (RC) offers the best performance over the reference tracking and disturbance rejection for periodic exogenous signals [1]. It is widely exploited in various application areas, e.g., power converters, active filters, multilink robotic manipulators, disk drives, power supplies, where high precision accuracy is required in the equipment [2]–[7]. The source of RC’s high performance is that it offers very high gain at frequencies, which are multiples of the reference/disturbance signal frequency. While on the other hand, HORC controls the issue as mentioned above by supplying comparatively large gain in the neighborhood of the tuned frequency and its multiples. The proposed research work is focused on the design of HORC

Methods

Results

Conclusion