scholarly journals Load sharing methods for inverter-based systems in islanded microgrids: A review

2017 ◽  
Vol 30 (2) ◽  
pp. 145-160
Author(s):  
Augustine Egwebe ◽  
Meghdad Fazeli ◽  
Petar Igic ◽  
Paul Holland

This paper explores and discusses various design considerations for inverter-based systems. Different load sharing techniques are presented for the integration of renewable energy sources within islanded microgrids. In off-grid connection, renewable energy sources are often configured to share power based on their rated capacity. This paper explores both conventional and dynamic load sharing interaction between distributed generation units, both in an inductive (high voltage) and resistive (low voltage) networks. Load sharing based on the proper design of virtual impedance is also reviewed.

2018 ◽  
Vol 5 (2) ◽  
pp. 299
Author(s):  
Gede Endrawadi ◽  
I Wayan Sukerayasa ◽  
Wayan Gede Ariastina

The power plant with renewable energy sources is needed to reduce the pollution. One of this kind is in Bali, that is PLTSa (Garbage Power Plant) Suwung. However, PLTSa Suwung is no longer operating for now. PLTSa Suwung is connected with Serangan feeder, this connection named Distributed Generation. When PLTSa Suwung doesn’t operate, it will affect the Serangan feeder’s voltage profile. The change of voltage profile will be analyzed with EDSA Technical 2000 Service Pack 3.5 software. The research will give five scenarios with different electrical power supply from each scenario. The gap of the voltage profile between scenario 1 (100% power supply from PLTSa) and scenario 5 (0% power suplly from PLTSa) is 0,0079% for medium voltage bus and 0,0062% for low voltage bus. This small gap shows that the connected PLTSa Suwung doesn’t give effect to voltage profile of Serangan feeder.


Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2151
Author(s):  
Feras Alasali ◽  
Husam Foudeh ◽  
Esraa Mousa Ali ◽  
Khaled Nusair ◽  
William Holderbaum

More and more households are using renewable energy sources, and this will continue as the world moves towards a clean energy future and new patterns in demands for electricity. This creates significant novel challenges for Distribution Network Operators (DNOs) such as volatile net demand behavior and predicting Low Voltage (LV) demand. There is a lack of understanding of modern LV networks’ demand and renewable energy sources behavior. This article starts with an investigation into the unique characteristics of householder demand behavior in Jordan, connected to Photovoltaics (PV) systems. Previous studies have focused mostly on forecasting LV level demand without considering renewable energy sources, disaggregation demand and the weather conditions at the LV level. In this study, we provide detailed LV demand analysis and a variety of forecasting methods in terms of a probabilistic, new optimization learning algorithm called the Golden Ratio Optimization Method (GROM) for an Artificial Neural Network (ANN) model for rolling and point forecasting. Short-term forecasting models have been designed and developed to generate future scenarios for different disaggregation demand levels from households, small cities, net demands and PV system output. The results show that the volatile behavior of LV networks connected to the PV system creates substantial forecasting challenges. The mean absolute percentage error (MAPE) for the ANN-GROM model improved by 41.2% for household demand forecast compared to the traditional ANN model.


Author(s):  
Bisma Imtiaz ◽  
Imran Zafar ◽  
Cui Yuanhui

Due to the rapid increase in energy demand with depleting conventional sources, the world’s interest is moving towards renewable energy sources. Microgrid provides easy and reliable integration of distributed generation (DG) units based on renewable energy sources to the grid. The DG’s are usually integrated to microgrid through inverters. For a reliable operation of microgrid, it must have to operate in grid connected as well as isolated mode. Due to sudden mode change, performance of the DG inverter system will be compromised. Design and simulation of an optimized microgrid model in MATLAB/Simulink is presented in this work. The goal of the designed model is to integrate the inverter-interfaced DG’s to the microgrid in an efficient manner. The IEEE 13 bus test feeder has been converted to a microgrid by integration of DG’s including diesel engine generator, photovoltaic (PV) block and battery. The main feature of the designed MG model is its optimization in both operated modes to ensure the high reliability. For reliable interconnection of designed MG model to the power grid, a control scheme for DG inverter system based on PI controllers and DQ-PLL (phase-locked loop) has been designed. This designed scheme provides constant voltage in isolated mode and constant currents in grid connected mode. For power quality improvement, the regulation of harmonic current insertion has been performed using LCL filter. The performance of the designed MG model has been evaluated from the simulation results in MATLAB/ Simulink.


2015 ◽  
Vol 38 (1) ◽  
pp. 9-13
Author(s):  
H.A. Khattab ◽  
M.F Awad-alla ◽  
S.M Allam ◽  
S.M farrag

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