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Item Phase advance compensation of voltage sags using full bridge inverter based DVR(Institute of Electrical and Electronics Engineers Inc., 2018) Remya, V.K.; Parthiban, P.; Nandakumar, A.Voltage sag is considered as the most expensive power quality problem. With the advent of power electronics, custom power devices are introduced to mitigate the sag issues. Among the custom power devices, Dynamic Voltage Restorer (DVR) is the most cost-effective one. The voltage injected in series by the DVR compensates the load profile during sag events. The compensation techniques such as in-phase, energy minimized and phase advance methods determine the way in which the DVR voltage is injected into the grid. By providing a phase advance to the DVR voltage with respect to the supply voltage gives the merit of reduced active power injection and thereby reduces the rating of energy storage. The disadvantages such as increased DVR voltage magnitude, phase shift, load swings and discontinuity of wave shape are associated with this compensation technique. This method is suitable for magnitude sensitive loads. This paper presents simulation results showing the compensation of both sag and swell using phase advance compensation. © 2017 IEEE.Item A comparative study of full-bridge inverter based DVR and SEMI-Z-source inverter based DVR(Institute of Electrical and Electronics Engineers Inc., 2018) Remya, V.K.; Parthiban, P.; Nandakumar, A.There is always a necessity to protect the voltage sensitive industrial systems from Power Quality (PQ) issues to prevent the loss of product quality and revenue. Generally, custom power devices take the responsibility to mitigate these PQ problems, restore the voltage and thus maintain the PQ standards. Dynamic Voltage Restorer (DVR) is one among the custom power devices which offers an economical compensation of load voltage under abnormal supply voltage conditions. The voltage injected in series by the DVR compensates the load profile during PQ events; appropriate voltage injected by the DVR in series with supply protects the load and restores the voltage to pre-defined values. The required injected voltage is generated by the inverter circuit in the DVR system. The most commonly used DVR inverter is the full-bridge inverter which consists of four switches. The Semi-Z-Source (SZS) inverter based DVR which offers same injection capability with only two-switches is compared with the full-bridge inverter. The in-phase compensation technique is employed in both the DVRs for injecting required voltage into the grid. The efficiency, quality of the injected voltage and load voltage are studied. This paper presents simulation results in MATLAB/Simulink environment to validate thecomparison. © 2018 IEEE.Item Dynamic voltage restorer (DVR) –areview(River Publishers editor@jgenng.com, 2018) Remya, V.K.; Parthiban, P.; Ansal, V.; Babu, B.Power quality (PQ) is gaining a great deal of importance as more sensitive loads are introduced into the utility grid. The degradation of product quality, damage of equipment and temporary shutdowns are the general issues associated with PQ problems in industries. Any mal-operation or damage of the industrial sensitive loads results in monetary losses disproportionately higher than the severity of the PQ issues. The evolution of power electronics technology replaced the traditional power quality mitigation methods with the introduction of Custom Power System devices (CUPS). The major power electronic controller based CUPS are DSTATCOM, DVR and UPQC. DVR is a pertinent solution for the economic losses caused by the PQ issues in the industries. Among the CUPS, DVR is the most cost-effective one. In the published literature, only a few papers correspond to the review of DVR technology. In this paper, a systematic review of published literature is conducted and a description is given on the design, standards and challenges in the DVR technology. A detailed survey is conducted on the published literature to address the various aspects and issues in the DVR system. This paper arrangement gives the working principle, structure, various topologies, compensation techniques, voltage sag detection methods and control methods of the DVR under different sections. The section “Challenges faced by the DVR” included in the manuscript can be useful for the researchers beginning their work in the domain of DVR. The simulation results using the sim power system tool of MATLAB/Simulink software are provided for analysis and comparison. © 2018 the Author(s). All rights reserved.Item Single-Phase DVR with Semi-Z-Source Inverter for Power Distribution Network(Springer Verlag, 2018) Remya, V.K.; Parthiban, P.; Ansal, V.; Nandakumar, A.A novel topology of single-phase dynamic voltage restorer (DVR) is proposed to compensate the load voltage during voltage sag and voltage swell events. The semi-Z-source converter is utilised in its inverter operating mode for this proposed topology. The reduction in the number of active switches in the inverter and also in the current conduction path without compromising the output voltage range is the merit of the semi-Z-source inverter-based DVR against the commonly used full-bridge inverter-based DVR. The load voltage contains harmonics within the permissible limits when the compensation is performed by the semi-Z-source inverter-based DVR. The need for the filter circuit is eliminated; hence, the magnitude difference and the phase shift in the inverter output voltage due to the filter circuit are not present in the semi-Z-source inverter-based DVR. The proposed topology is cheap compared to the full-bridge inverter-based DVR topology. The simulations performed in MATLAB/Simulink environment are presented to validate the performance of the proposed topology. A comparison between the semi-Z-source inverter-based DVR and full-bridge inverter-based DVR is presented in this paper. The novel topology of DVR using semi-Z-source inverter is proved to be a better solution to the full-bridge inverter-based DVR. © 2017, King Fahd University of Petroleum & Minerals.