Electromagnetic Core Analysis of a DFIG State-Feedback Power Controller

A L L F Murari,J A T Altuna,K A C Chirapo,A J Sguarezi Filho,A Pelizari

doi:10.1590/2179-10742019v18i31497

Abstract

The energy demand by modern society grows every day that allied with sustainable development requires the use of alternative sources in the new energy matrix. In this context, the wind energy as source by using a doubly-fed induction generator stands out due to its operational savings but still faces some conflicts in its power control. This paper proposes a state feedback plus integral controller for rotor current control. In order to verify the controller operation, an electromagnetic finite element analysis simulation of the interior of the machine was carried out, assuring the non-saturation of the core, which would lead to a control instability and it can increase the machine losses. For this, a machine modeling was presented into state equations in order to establish a power control diagram. The results of electromagnetic simulation and the experimental bench results when united ensure the correct functioning of the proposed system and the satisfactory efficiency of the controller. In this way, it can be concluded that the use of this control technique in counterpart with the conventional PI increases the response time of the system without affecting the electromagnetic dynamics of the generator.

Highlights

The doubly-fed induction generator (DFIG) is a machine consolidated in wind energy systems due to concern about CO2 emissions
This paper proposes a state feedback controller using a additional integral mesh current control for a DFIG at variable speed wind profile
A variable speed DC motor coupled to the DFIG axis was used to transmit a torque equivalent to that generated by the blades of a wind turbine

Summary

INTRODUCTION

The doubly-fed induction generator (DFIG) is a machine consolidated in wind energy systems due to concern about CO2 emissions. The power control algorithm calculates the proportional and integral gains to perform one complex voltage vector that provides the voltage to be applied to the rotor side converter using pole placement This proposed controller employs (field oriented control) decouples the stator currents, so that, the active and reactive powers should reach their desired reference values by means of properly setting the rotor currents. The result obtain in the experimental setup endorse the performance of the controller

MACHINE MODEL AND ROTOR CURRENT VECTOR CONTROL

Stator Power Control

Considerations about the machine saturation in the control design

FINITE ELEMENT SIMULATION

EXPERIMENTAL RESULTS

CONCLUSION