Fuzzy Mathematics-Based Outer-Loop Control Method for Converter-Connected Distributed Generation and Storage Devices in Micro-Grids

Lorena Castro,Maximiliano Bueno-López,Juan Mora-Flórez

doi:10.3390/computation9120134

Lorena Castro, Maximiliano Bueno-López + Show 1 more

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https://doi.org/10.3390/computation9120134

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Abstract

The modern changes in electric systems present new issues for control strategies. When power converters and distributed energy resources are included in the micro-grid, its model is more complex than the simplified representations used, sometimes losing essential data. This paper proposes a unified fuzzy mathematics-based control method applied to the outer loop of a voltage source converter (VSC) in both grid-connected and islanded modes to avoid using simplified models in complex micro-grids and handle the uncertain and non-stationary behaviour of nonlinear systems. The proposed control method is straightforwardly designed without simplifying the controlled system. This paper explains the design of a fuzzy mathematics-based control method applied to the outer-loop of a VSC, a crucial device for integrating renewable sources and storage devices in a micro-grid. Simulation results validated the novel control strategy, demonstrating its capabilities for real field applications.

Highlights

IntroductionMicro-grids improve the reliability of electrical systems, supplying power to connected or islanded networks incorporating distributed generation, and these contribute to reducing pollution and integrating renewable energy resources [1]
This paper aims to present the possibility of using an fuzzy-logic control (FLC) to control different micro-grid variables, such as voltage, frequency, active power, and reactive power [12]
When the fuzzy logic-based control method is applied, the converter has higher oscillations, but the establishment time is similar to the proportional-integral approach (PI)-based control method proposed in [24]

Summary

Introduction

Micro-grids improve the reliability of electrical systems, supplying power to connected or islanded networks incorporating distributed generation, and these contribute to reducing pollution and integrating renewable energy resources [1]. There are many technical challenges regarding the integration of micro-grids into conventional distribution systems [2], including power flow control between the grid and the power converter [3], power management [4], voltage and frequency stability in grid-islanded mode [5,6,7], fault detection, and power quality, among others [8,9]. This paper aims to present the possibility of using an FLC to control different micro-grid variables, such as voltage, frequency, active power, and reactive power [12]. This paper contributes to demonstrating the capabilities of artificial intelligence in the control modules of converters in micro-grids

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