Analysis of Control Strategies Based on Virtual Inertia for the Improvement of Frequency Stability in an Islanded Grid with Wind Generators and Battery Energy Storage Systems

Iván Pazmiño,Sergio Martinez,Danny Ochoa

doi:10.3390/en14030698

Abstract

Rising levels of non-synchronous generation in power systems are leading to increasing difficulties in primary frequency control. In response, there has been much research effort aimed at providing individual electronic interfaced generators with different frequency response capabilities. There is now a growing research interest in analyzing the interactions among different power system elements that include these features. This paper explores how the implementation of control strategies based on the concept of virtual inertia can help to improve frequency stability. More specifically, the work is focused on islanded systems with high share of wind generation interacting with battery energy storage systems. The paper presents a methodology for modeling a power system with virtual primary frequency control, as an aid to power system planning and operation. The methodology and its implementation are illustrated with a real case study.

Highlights

In the last two decades, electric power systems have experienced very significant changes in their operational requirements, mainly due to a growing share of non-conventional renewable energy in the electricity generation mix, along with the operation of grids with a higher degree of complexity [1,2,3]
If an increasing share of electricity generation based on non-conventional renewable energy resources is added to this type of power systems, one of the consequences is a significant reduction of the equivalent inertia of the system [8]
Given that the objective of this study is based on the application of virtual inertia, a brief presentation of the concept and its application in a variable speed wind turbine will be given

Summary

Introduction

In the last two decades, electric power systems have experienced very significant changes in their operational requirements, mainly due to a growing share of non-conventional renewable energy in the electricity generation mix, along with the operation of grids with a higher degree of complexity [1,2,3]. From the point of view of the power system, this is seen as a lack of inertial response To address this issue, previous works have outlined the design and implementation of additional control schemes that provide certain complementary regulation capabilities to certain renewable generators (e.g., photovoltaic [9,10], wind [11,12], hybrid of both [3,13]) and battery energy storage systems [14,15], with the aim of modifying the active power injected into the network in response to variations in frequency, similar to how conventional synchronous generators do; the use of the term “virtual inertia”. Very interesting review papers addressing inertia and frequency control strategies can be found in [8,16,17]

Objectives

Methods

Results