Polynomial Observer-Based Controller Synthesis and Fault-Tolerant Control for Tracking Optimal Power of Wind Energy Conversion Systems

Van-Phong Vu,Dinh-Nhon Truong,Van-Dung Do,Ton Duc Do,Nguyen Vu Quynh,Phuc Duc-Hong Bui,Van-Thuyen Ngo,Vu The Mai

doi:10.1109/access.2020.3016433

Abstract

This article proposes a new approach to design a fault-tolerant control (FTC) scheme for tracking the optimal power of wind energy conversion systems (WECSs). In this article, the considered fault will not only impact on actuator but also sensors. As the fault severely affects the performance of WECSs, the FTC are required to be worked accurately and effectively. The polynomial observer, as a part of the proposed FTC system, is synthesized to estimate the aerodynamic torque, electromagnetic torque, and fault simultaneously without using sensors to measure. The information of these parameters is sent back to the LQR (Linear Quadratic Regular) controller of WECSs. Both fault and aerodynamic torque in this study are unnecessary to fulfil any constraint. It should be noted that WECSs is reconstructed to a new form based on the descriptor technique, then the observer will design for this new form instead of the original system. Based on Lyapunov methodology and with the aid of SOS (Sum-Of-Square) technique, the conditions for polynomial observer design are derived in the main theorems. Finally, the simulation results have proved the effectiveness and merit of the proposed FTC method.

Highlights

Wind energy has been increasingly utilized for electric power generation as one of promising renewable energy resources to replace fossil-fuel energies
The information of these parameters is feed-backed to the controller which is constructed on the basis of the LQR technique for fault-tolerant control (FTC) and tracking the optimal power point of wind energy conversion systems (WECSs)
In this article, we proposed a new approach to design a polynomial observer for estimating both the unknown states and faults

Summary

INTRODUCTION

Wind energy has been increasingly utilized for electric power generation as one of promising renewable energy resources to replace fossil-fuel energies. Ii) With the influence of faults in both sensor and actuator, the previous methods in [19]–[25] are not able to apply for this case To overcome this challenge, the WECSs is modified to the polynomial system framework, and the descriptor technique is employed to reconstruct the WECS models to a new form. Iii) A polynomial disturbance observer is synthesized for WECSs to estimate aerodynamic torque, electromagnetic torque, and fault simultaneously without using sensors The information of these parameters is feed-backed to the controller which is constructed on the basis of the LQR technique for FTC and tracking the optimal power point of WECSs. iv) The aerodynamic torque and fault in this article are arbitrary and unnecessary to satisfy any constraint that is mandatory in [8]–[12]. Assumption 1: 1) ω and id are available. 2) iq is not known, i.e., Te is unknown either. 3) Wind speed v and aerodynamic torque Ta are unknown

PROBLEM STATEMENT

POLYNOMIAL OBSERVER SYNTHESIS

RESULTS AND DISCUSSION

CONCLUSION