Full-Order Terminal Sliding-Mode Control of Brushless Doubly Fed Induction Generator for Ship Microgrids

William Cai,Wei Xu,Minghao Zhou,Dong Wang,Yi Liu,Hongyu Su

doi:10.3390/en14217302

Abstract

This paper proposes a full-order terminal sliding-mode (FOTSM) control scheme for brushless doubly fed induction generator (BDFIG)-based islanded microgrids. To deal with mismatched uncertainties in the BDFIG system, virtual control technique-based full-order sliding-mode control is applied to stabilize the amplitude and frequency of terminal voltage. In the current loops, two full-order terminal sliding-mode controllers are designed to make sure that the current tracking errors can reach their equilibrium points in finite time. It is demonstrated by the comprehensive simulations that the proposed method can significantly improve the tracking accuracy, the rapidness, and the robustness to the uncertainties of the BDFIG control system and can enhance the output voltage quality. Furthermore, an experimental study of the proposed control method for BDFIG-based islanded microgrids would be another important future work.

Highlights

The controller design for the brushless doubly fed induction generator (BDFIG)-based microgrid is somewhat difficult to develop for the following two main reasons: (1) the mathematical model of the BDFIG is a class of highly nonlinear multi-input-multi-output (MIMO) systems with unavoidable uncertainties and lots of degrees of freedom; (2) the parameters of the power winding (PW), the control winding (CW), and the rotor vary with current frequency, motor temperature, and magnetic saturation effect
By introducing the ideal of both the full-order terminal sliding-mode (FOTSM) control algorithm and the virtual control technique, this paper proposes a novel FOTSM-based control method to stabilize the amplitude and frequency of terminal voltage under the parameter perturbation and electrical load vary
In order to demonstrate the effectiveness of the proposed method, PI controllers, linear sliding mode (LSM), and FOTSM controllers are designed for performance comparison

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. The controller design for the BDFIG-based microgrid is somewhat difficult to develop for the following two main reasons: (1) the mathematical model of the BDFIG is a class of highly nonlinear multi-input-multi-output (MIMO) systems with unavoidable uncertainties and lots of degrees of freedom; (2) the parameters of the PW, the CW, and the rotor vary with current frequency, motor temperature, and magnetic saturation effect. Due to the low sensitivity to parameter perturbations and the strong robustness to external disturbance, the sliding mode control (SMC) is proposed for the IM [27,28], the DFIG [29], and the BDFIGs [30]. By introducing the ideal of both the full-order terminal sliding-mode (FOTSM) control algorithm and the virtual control technique, this paper proposes a novel FOTSM-based control method to stabilize the amplitude and frequency of terminal voltage under the parameter perturbation and electrical load vary.

Dynamic Model of the BDFIG

Outer Loop Subsystem

Inner Loop Subsystem

Full-Order Terminal Sliding-Mode Controller Design

Simulations

Start-Up Response

Load Adding Response

Voltage Change Response

Findings

Discussion

Conclusions