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Recent interest in the integration of renewable energy sources (RES) into the power grid has raised concerns in synchronization of the various RES. Grid variables such as voltage, phase angle and frequency should be continuously monitored to guarantee correct operation and synchronization of power converters connected to the power grid. Numerous synchronization methods have been presented over the years to address issues such as unbalanced condition and frequency variation. This paper presents a review of past studies on synchronization methods for grid-connected converters together with their control and modeling techniques. Various estimation techniques for phase angle, frequency and harmonic are discussed and examined. Key challenges for a smart and efficient synchronization are briefly overviewed and possible future works are also recommended. A consolidated review is the particular focus of this paper, as is the provision of information on the best method for synchronizing grid-connected converters. [ABSTRACT FROM AUTHOR]

The occurrence of power swing had been reported to threaten the seamless operation of power system. Several cascaded outages and major blackouts in the world have been traced to mal-operation of distance relays due to power swing occurrences. As such, this paper will present a consolidated review on the power swing phenomenon, covering the causes of power swing, its impact to consumers and generators, as well as its detection and relay blocking schemes to prevent the mal-operation of distance relay. Given the wide arrays of power swing detection techniques and blocking schemes available up to date, particular attention is concentrated at the various power swing detection techniques on high voltage power system. In addition, the effect of modern renewable energy generations to the power swing characteristics is also presented in this paper. [ABSTRACT FROM AUTHOR]

Abstract: Implementations of mini hydro schemes with conventional hydraulic, electrical equipment''s and controllers have proven very expensive and uneconomical. Many developing countries that are in need of rural electrification have encountered economical problem when setting up these mini hydro schemes. To address this problem, alternative options and new designs of these equipment''s have been explored by many researchers around the world. The application of these new designs would reduce the overall cost of mini hydro development and would help in making it a cost effective technology. These new designs will also help developing countries to provide electricity to rural areas or remote regions where interconnection of transmission line from the electrical grid is uneconomical. The new designs can also be an enabling factor in boosting up electricity generation using a renewable energy source. This paper provides survey of all these alternative options and new designs in the controller, hydraulic turbine and generators that have been implemented in different countries of the world. [Copyright &y& Elsevier]

The solar energy generation has grown significantly in the past years. The importance of PV penetration in power system as a major element of renewable energy source has seen it being widely used on a global scale. Despite its promising success, PV penetration presents various issues and its impact on the distribution system has to address for seamless integration in the power system. In this paper, a comprehensive overview on important issues affecting the distribution system as a result of PV penetration is presented. Pertinent issues such as voltage fluctuation, voltage rise, voltage balance, and harmonics and their effect on the system are discussed in details. The islanding issues, which are of critical importance to the stability and integrity of the system, are also thoroughly reviewed. Details on different islanding techniques – remote and local techniques and their advantage and disadvantages are shown. Therefore, this paper can provide useful information and serve as a reference for researchers and utility engineers on issues to be considered with regards to PV penetration. [ABSTRACT FROM AUTHOR]

Solar energy is one of the cleanest forms of energy sources and considered as a green source of energy. Solar energy benefit ranges from low carbon emission, no fossil fuel requirement, long term solar resources, less payback time and other. However like other power generation sources, solar energy has also some Safety, Health and Environmental (SHE) concerns. This paper presents the overview of solar energy technologies and addresses the SHE impact of solar energy technologies to the sustainability of human activities. This paper will also recommend the possible ways to reduce the effect of potential hazards of widespread use of solar energy technologies. [ABSTRACT FROM AUTHOR]

• Proper charging coordination of electric vehicles is essential in achieving an efficient interconnection to the power system avoiding overloading effect. • Electric vehicles are capable of feeding power back to grid during high peak demands reducing the electricity cost and earning profit for consumer. • The incorporation of electric vehicles in the power grid improves the stability of the system as they can behave as energy consumer and energy providers during the low and high load periods respectively. • The optimized solution for battery energy management system is proposed by taking into account the battery degradation cost, which is modelled for real time analysis considering DOD at each time interval. With the growing concerns on the energy depletion and the reduction of CO 2 emission, electric vehicles (EVs) have gained popularity in transport sector due to clean and reliable energy source. However, the charging of EVs has imposed significant load in the electrical distribution system. The stability of power network is disturbed with uncoordinated charging. This work aims to investigate the optimal EV coordination with vehicle to grid (V2G) technology for the cost-benefit analysis. However, the cost of EV battery replacement due to degradation is of paramount concern for the EV users, which constitute the most important ingredient to ensure active participation in V2G energy exchanges. Therefore, battery degradation cost is formulated for real time analysis taking depth of discharge at each time interval. The firefly algorithm has been used to optimize the system cost. The performance of the proposed system is tested on modified 33 bus distribution system in the presence of renewable energy sources (RES). The impact of system cost and energy losses are analysed for different RES penetration, EV capacities and travelling distances. The simulation results show significant reduction in operating cost when RESs are integrated into distribution network. Moreover, V2G technology is beneficial for EV consumers with high penetration of RES. [ABSTRACT FROM AUTHOR]