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This paper introduces a novel hybrid AC/DC microgrid design based on distribution FACTS devices. The objective of this design is to enhance the microgrid operation performance such as stabilize the buses voltage, reduce the feeder losses, improve the power factor and mitigate the harmonic distortion using the distribution FACTS devices. In the proposed design of microgrid which includes PV, fuel cell, battery, micro gas turbine, wind turbine, and diesel engine within microgrid, Switched Filter Compensator (SFC) is presented as AC-side D-FACTS device and Green Plug Filter Compensator (GPFC) is introduced as DC-side D-FACTS devices. Optimization search method based particle swarm optimization (PSO) is developed to optimize the control gains of D-FACTS controllers to achieve an effective integration of distributed energy resources technologies within MGs and to achieve higher microgrid performance. The results shown are generated from MATLAB simulation of the presented microgrid, where comparisons of with and without FACTS modules are presented in grid connected and islanding operation modes. Results show superiority and improved performance using the presented distribution FACTS. [ABSTRACT FROM AUTHOR]

Microgrids are small scale energy grids that can provide adequate energy supply to cover regional demand by integrating renewable energy generation and storage technologies. This paper develops a high performance dynamic model of a microgrid system comprising a wind turbine, a PV, a fuel cell, a micro gas turbine generator, an energy storage, electric loads with variable load profile and flexible AC transmission system (FACTS) devices. The FACTS devices based on static VAR compensators have been employed as a supervisory controller. Key performance indicators such as microgrid power losses, buses voltage deviations, buses power factor, buses voltage total harmonic distortion and voltage-frequency deviation are used to evaluate the performance of this microgrid in grid-connected and islanding modes. The results obtained from the Matlab/Simulink environment show that the proposed microgrid design with SVC has the ability to meet its special requirements such as bus voltages stabilization, reduction of feeder losses, power factor enhancement and mitigation of total harmonic distortion using SVC in grid-connected and islanding modes. [ABSTRACT FROM AUTHOR]

Abstract: Identification and classification of voltage and current disturbances in power systems is an important task in power system monitoring and protection. This paper presents a new approach for power system disturbances identification and classification. The concept of linear Kalman filter together with discrete wavelet transform (DWT) is used to extract two parameters; the amplitude and the slope from the captured voltage or current waveform. DWT is used to help Kalman filter to give a good performance; the captured distorted waveform is passed through the DWT to determine the noise inside it and the covariance of this noise is fed together with the captured voltage waveform to the Kalman filter. The two parameters are the inputs to fuzzy-expert system that uses some rules on these inputs to identify the class to which the waveform belongs. To prove the ability of the new approach for classifying power system disturbances, detailed digital simulation and experimental results involving various types of power quality events are presented. The results depict that the proposed technique has the ability to accurately identify and classify PQ disturbances. [Copyright &y& Elsevier]