This paper investigates the performance of a seven-level Packed U Cell (PUC7) inverter-based transformerless Dynamic Voltage Restorer (DVR) topology under short-time voltage variations (voltage sags and swells). Unlike existing multilevel inverter (MLI)-based DVR solutions, proposed structure requires only one DC source (suitable for PV-based systems), capacitor, six switching devices to genera...

This paper presents a study of a D-STATCOM (Distribution Static Compensator) used for mitigating voltage sag. The basic idea of the voltage sag mitigation, using a D-STATCOM is to dynamically inject a current of desired amplitude, frequency and phase into the grid line. The proposed method extracts the active and reactive parts of the positiveand negative-sequence component for generating refer...

The booming electronics itself carries an impact on power quality. Superconducting Magnetic Energy Storage (SMES) is proposed to enhance power quality in three-phase systems under various loads. This paper aimed to compensate the voltage sags under various faults in the grid systems. The SMES is selected as an energy storage unit to improve the capability of voltage sag compensation. Optimized ...

This paper presents a novel approach for fault detection and identification in order to estimate voltage sag during a fault. One of the best approaches for voltage sag estimation is instantaneous voltage estimation. The approach uses traditional state estimation where redundant measurements are available. The proposed method is used to estimate voltage sag performance during a fault. At the fau...

Dynamic voltage restorer (DVR) is a protecting device for sensitive loads which compensates grid fluctuations. Although using fault current limiting devices (FCL) method of and electrical networks against short circuits. In recent years, some methods have been proposed to combine these two reduce the cost converters use benefits each simultaneously. A new topology control DVR an FCL presented i...

Power quality is considered as one of the most important issue in power distribution systems. Voltage sag is considered as one of the most common power quality problems. It may cause sensitive equipment to malfunction and process interruption. In this work a method of optimal network reconfiguration is proposed to mitigate voltage sag problem in power distribution networks. It is applied to a d...

The dynamic voltage restorer (DVR) is one of the modern devices used in transmission systems to protect power flow against sudden changes in voltage amplitude. The proposed algorithm is applied to some disturbances in load voltage caused by induction motors starting, and a three-phase short circuit fault. Also, the capability of the proposed DVR has been tested to limit the downstream fault cur...

This paper discusses the design and development of Dynamic Voltage Restorer (DVR) controller for voltage unbalanced compensation using d-q-o transformation technique. The controller in d-q-o coordinates has better performance than conventional controllers. The controlled variables in d-q-o coordinates are then inversely transformed to the original voltages which produced reference voltages to a...