Advanced Energy Technologies
Ghazanfar Shahgholian
Abstract
Distributed flexible ac transmission system (D-FACTS) is a light-weight version of FACTS, which it is easily allocated and costs less than flexible ac transmission system (FACTS) devices. They have potential benefits to improve the system stability and improvement in power quality in microgrid (MG). ...
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Distributed flexible ac transmission system (D-FACTS) is a light-weight version of FACTS, which it is easily allocated and costs less than flexible ac transmission system (FACTS) devices. They have potential benefits to improve the system stability and improvement in power quality in microgrid (MG). The integration of distributed energy sources, loads, electrical energy storage devices, and electronic power devices, as well as the operation of microgrids in connected or island-connected modes has expanded their use. It is a small main grid that can generate electricity when disconnected from the main network. In addition, microgrids reduce the high investment costs required to upgrade the network. The application of DFACTS devices for improving the microgrid operation has been investigated by some researches. This paper provides a review of impact and role of various DFACTS devices in the function of microgrids, which has been reported in recent years in various pieces of the literature. DFACTS devices with their properties are described. Finally, a useful reference and framework for the study is provided for future expansion of DFACTS devices so as to improve the performance of the microgrid.
Renewable Energy Resources and Technologies
Babak Keyvani; Bahador Fani; Hamed Karimi; Majid Moazzami; Ghazanfar Shahgholian
Abstract
Conventional droop control method has been widely adopted for power sharing between Distributed Generators (DGs) in microgrids. However, the mismatched feeder impedance of the Voltage-Sourced Inverters (VSI) may generate reactive power sharing error during islanding operation of a microgrid. In this ...
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Conventional droop control method has been widely adopted for power sharing between Distributed Generators (DGs) in microgrids. However, the mismatched feeder impedance of the Voltage-Sourced Inverters (VSI) may generate reactive power sharing error during islanding operation of a microgrid. In this paper, an improved droop control method is suggested to improve the reactive power sharing accuracy. In the proposed method, the slope correction of the droop characteristics is performed in such a way that the reactive power sharing error is reduced. In this method, the errors of reactive power sharing are detected by applying a clear signal to the microgrids and, then, by adding a new term to the P-ω and correcting the slope of Q-E, the reactive power sharing is done. In this way, the proposed method can successfully improve the reactive power sharing accuracy even at different X/R ratios. Another feature of this method is its high operation speed compared to the other methods of droop feature correction. The simulation results for a prototype microgrid point to the efficiency and flexibility of the proposed method.