Page 115 - IJEEE-2022-Vol18-ISSUE-1

Received: 15 March 2022 Revised: 20 April 2022 Accepted: 20 April 2022
DOI: 10.37917/ijeee.18.1.13
Vol. 18| Issue 1| June 2022
? Open Access

Iraqi Journal for Electrical and Electronic Engineering

Original Article

Grid-Forming and Grid-Following Based Microgrid
Inverters Control

Ali M. Jasim*, Basil H. Jasim
Electrical Engineering Department, University of Basrah, Basrah, Iraq

Correspondence
*Ali M. Jasim
Electrical Engineering Department,
University of Basrah, Basrah, Iraq
Email: e.alim.j.92@gmail.com

Abstract
Microgrids (M-grids) can be thought of as a small-scale electrical network comprised of a mix of Distributed Generation (DG)

resources, storage devices, and a variety of load species. It provides communities with a stable, secure, and renewable energy

supply in either off-grid (grid-forming) or on-grid (grid-following) mode. In this work, a control strategy of coordinated power
management for a Low Voltage (LV) M-grid with integration of solar Photovoltaic (PV), Battery Energy Storage System
(BESS) and three phase loads operated autonomously or connected to the utility grid has been created and analyzed in the

Matlab Simulink environment. The main goal expressed here is to achieve the following points: (i) grid following, grid forming

modes, and resynchronization mode between them, (ii) Maximum Power Point Tracking (MPPT) from solar PV using fuzzy

logic technique, and active power regulator based boost converter using a Proportional Integral (PI) controller is activated
when a curtailment operation is required, (iii) M-grid imbalance compensation (negative sequence) due to large single-phase

load is activated, and (iv) detection and diagnosis the fault types using Discrete Wavelet Transform (DWT). Under the influence
of irradiance fluctuation on solar plant, the proposed control technique demonstrates how the adopted system works in grid-
following mode (PQ control), grid- formation, and grid resynchronization to seamlessly connect the M-grid with the main

distribution system. In this system, a power curtailment management system is introduced in the event of a significant reduction

in load, allowing the control strategy to be switched from MPPT to PQ control, permitting the BESS to absorb excess power.

Also, in grid-following mode, the BESS's imbalance compensation mechanism helps to reduce the negative sequence voltage

that occurs at the Point of Common Coupling (PCC) bus as a result of an imbalance in the grid's power supply. In addition to
the features described above, this system made use of DWT to detect and diagnose various fault conditions.

KEYWORDS: Microgrid, Grid- Forming Grid- Support Inverter, Distributed Generation, PQ control, Droop Control,

Wavelet Transform, Maximum Power Point tracking.

I. INTRODUCTION meet the load requirement. It should also maintain the

Future power distribution systems are predicted to be appropriate power quality, improve system stability and
more dependable, versatile, and intelligent than those now in power supply availability [4][5]. When M-grid is connected
use. The M-grid idea has been offered as a possible method to the utility grid, it acts as a regulated load or generator,
to meet these goals [1]. With the help of power electronic
devices and renewable energy sources, the concept of M- eliminating the power quality and safety issues that come
grid was introduced. Distributed Generations (DGs) are
energy sources that are used to support power. Diesel with DGs connected directly to the grid [5]. The utility grid
generators, solar cells, fuel cells, and wind turbines are can provide voltage and frequency level control in the M-
common M-grid Renewable Energy Resourced (RERs). To
establish M-grid connection, each RER is frequently paired grid while operating in on-grid mode. However, in off-grid
with power electronic equipment to form DG unit. Through mode, all DG resources should be accountable for power

its quick control action, RER with inverter can reduce balance as well as voltage and frequency level regulation in
oscillation [2]. the M-grid network via active coordinated power

The functionalities of a M-grid system based on the management and power sharing control mechanisms [6].
static transfer switch position are grid-tied mode and The management of M-grid and the usage of renewable
autonomous (islanded) mode [3]. In the event of a power
outage, the M-grid should be operated in islanded mode to energy sources (RESs) in power systems has gained a lot of
attention in recent years as networks progress toward smart

grid operation. This is due to their ability to function in either

grid-connected or islanded mode and ensure vital loads are

supplied with power without interruption in the event of a

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and
reproduction in any medium, provided the original work is properly cited.
© 2022 The Authors. Iraqi Journal for Electrical and Electronic Engineering by College of Engineering, University of Basrah.

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