Several issues have been reported with the expansion of the electric power grid and the increasing use of intermittent power sources, such as the need for expensive transmission lines and the issue of cascading blackouts, which can adversely affect critical infrastructures. Microgrids (MG) has been widely accepted as a viable solution to improve grid reliability and resiliency, ensuring continuous power supply to loads. However, to ensure the effective operation of the Distributed Energy Resources (DER), Microgrids need to have Energy Management and Control Systems (EMCS). Therefore, considerable research has been conducted to achieve smooth profiles in grid parameters during operation at optimum running cost. This paper aims to provide a review of EMCS techniques that have evolved in recent years. Firstly, the fundamentals of microgrids are discussed for a general overview of the field. Then, a critical literature review is undertaken for the various methods applied for EM optimization in microgrid applications. Multiple factors have been explored in the objective functions throughout this review, including MG daily operational costs, energy storage degradation, revenue through trading with the grid or other parties, and Greenhouse Gas (GHG) emissions. A review of control systems has been conducted next by categorizing them based on the different applications in MGs for stable operation. This paper also focuses on IEEE standards related to MG operation and control to facilitate other researchers to build upon a standardized set of rules and to enhance the interoperability of the diverse EMCS techniques.

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High temperature that reaches to 50 °C in summer, high humidity, and dust storms are considered as the main characteristics of the climate of many countries around the world such as those in the Gulf States, Asia, and Africa. According to the latest studies, air conditioning (A/C) systems in the residential areas used around 65% of the generated energy. This paper is aimed at presenting a new residential thermal model that can be used to estimate the energy consumption of A/C units used to achieve comfort in houses. The results of the newly developed residential thermal model will be compared with exiting residential thermal models using simscape in matlab program and data measurements. Different physical properties of the house that affect the heat gains through the house envelop at different weather conditions, and the internal heat gains are taken into account in this study. Hourly, daily, monthly, and annually energy consumption and coefficient of performance (COP) are calculated, based on actual hourly outdoor temperature measurements and indoor generation heat for the year 2017, using the three thermal models and compared with the pertinent actual measurements. The total measured energy consumption for nine months' work in 2017 was 14488.09 kWh, and the total energy consumption predicted by the simulation for the simple model, intermediate model, and comprehensive model were 8438.40 kWh, 12656.10 kWh, and 13900.61 kWh, respectively, with deviations of 41.75%, 12.65%, and 4.05%, respectively, from the actual measurements.

In-depth understanding of the pollution problems such as dry bands and the polymeric aging process requires better determination of electric field strength and its distribution over the polymeric surface. To determine the electric field distribution over the insulator surface, this research proposes utilizing a novel approach model based on nonlinear electrical characteristics derived from experimental results for polluted polymer insulators. A case study was carried out for a typical 11 kV polymeric insulator to underline the merits of this new modeling approach. The developments of the proposed pollution model and the subsequent computational works are described in detail. The study is divided into two main stages; laboratory measurements and computer simulations. In the first stage, layer conductance tests were carried out to develop nonlinear field-dependent conductivity for the pollution modeling. In the second part, equipotential and electric field distributions along the leakage were computed using the finite element method (FEM). Comparative field studies showed that the simulation using the proposed dynamic pollution model results in more detailed and realistic field profiles around insulators. This may be useful to predict the formation of dry bands and the initiation of electrical discharges on the polymeric surface.

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