Comparative Analysis of Fuzzy Logic and PI Controller Based Electronic Load Controller for Self-Excited Induction Generator

Eshani Mishra,Sachin Tiwari

doi:10.1155/2017/5620830

Abstract

Rural areas suffer from limited grid connectivity. Small hydroplants can provide electricity at a cheap cost with low environmental impact in these regions. Self-excited induction generators are widely used in hydroplants since they operate on a standalone basis because of the connection of capacitor bank that provides reactive power at no load. However, SEIGs suffer from poor voltage and frequency regulation. Thus, an electronic load controller (ELC) is connected across SEIG to regulate voltage and frequency. Generally, the control scheme for an ELC circuit is based on the conventional proportional integral control, which is easy to implement and performs well under linear load conditions. However, PI controllers handle nonlinearity poorly. This paper presents a fuzzy logic control (FLC) based control scheme for ELC in a constant power generation system (SEIG). The control scheme is designed and simulated in MATLAB under both linear and nonlinear load conditions. A comparison of both the controllers is conducted which highlights the superiority of the fuzzy logic control scheme.

Highlights

The growing focus towards sustainable and efficient power generation has led to development of alternative sources like renewable energy
This paper presents a control scheme based on fuzzy logic control (FLC) method which implements hysteresis current control method for Pulse Width Modulation (PWM) generation scheme for the pulses given to the Current-Controlled Voltage Source Inverter (CC-VSI)
The graph of DC link voltage (Vdc) for both fuzzy logic controller and proportional integral (PI) controller under linear and nonlinear load conditions is analyzed for their comparison

Summary

Introduction

The growing focus towards sustainable and efficient power generation has led to development of alternative sources like renewable energy. In a hydropower station which is a constant power source, an electronic load controller is connected across the SEIG for its voltage and frequency regulation. PI based controllers are simple to implement and less complex [8] but suffer from several drawbacks They cannot handle nonlinearity in the system and require accurate mathematical models to function. These drawbacks are overcome by fuzzy logic based ELC for the SEIG system. Fuzzy logic controller (FLC) is a viable choice when accurate mathematical calculations are impossible and load conditions are nonlinear. The proposed fuzzy logic based ELC is compared with the conventional PI based controller for SEIG system under linear and nonlinear load conditions. Advances in Electrical Engineering ia ila a Constant power prime mover c ib b ic SEIG

System Configuration

Control Schemes

Control Algorithm

Results and Discussion

Conclusions