Page 113 - Hybrid-Renewable Energy Systems in Microgrids

P. 113

An overview of control 6

techniques and technical

challenge for inverters

in micro grid

†
Natarajan Prabaharan*, Amalorpavaraj Rini Ann Jerin**, Ehsan Najafi ,
Kaliannan Palanisamy**
*Madanapalle Institute of Technology and Science, Madanapalle, India;
†
**VIT University, Vellore, India; Qom University of Technology, Qom, Iran

1 Introduction

Modern society has been facing an unsustainable energy due to increasing energy
demand, diminishing of primary energy availability, traditional and aged electrical
transmission and distribution networks [1]. The global warming, limited signifi-
cant amounts of investment, limited energy generation resources, growing energy
dependency emerge that modernization of traditional grid architectures, innovative
solutions, and technologies are inevitable [2,3]. In the recent years, Distributed gen-
eration (DG) of electricity has begun to take attention as a modern solution since it
provides several advantages such as high efficiency and environmental protection,
reduction of transmission and distribution losses, supporting the local power grid and
improving system stability [4–7]. DG plants often integrate with renewable energy
technologies such as photovoltaic (PV) system, wind power, small hydro turbines,
tidal, biogas, etc. Application of individual distributed generators can cause as many
problems as it may solve [6,8]. A better way to realize the emerging potential of DG
is to take a system approach which views generation and associated loads as a sub-
system or a “microgrid”.
The microgrids can be characterized as little, nearby distribution systems including an
arrangement of smaller scale sources, for example, micro-turbines, fuel cells, PV arrays
and wind turbines, storage systems such as flywheels, energy capacitors, and batteries
and controllable and uncontrollable loads [9,10]. It can be associated with utility grid
(grid mode) or operated independently when confined from utility matrix (island mode)
during faults or other outer unsettling disturbances, in this way expanding the nature of
supply, clients can acquire a higher proficiency, less expensive and cleaner energy [7,9].
This capacity of microgrids is one of the key highlights. Furthermore, microgrids may
upgrade local reliability, give bring down speculation cost, diminish emissions, enhance
control quality and decrease the power losses of the distribution network.
Notwithstanding many points of interest of microgrids, there are significant difficul-
ties to interfacing microgrid system to the distribution grid [5,10]. These difficulties can

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