Compensation of Voltage Sags and Swells Using Dynamic Voltage Restorer Based on Bi-Directional H-Bridge AC/AC Converter Yu-KChen , Xian-Zhi Qiu , Yung-Chun Wu , and Chau-Chung Song Citation: Chen, Y.-K.; Qiu, X.-Z.; Wu, Y.-C.; Song, C.-C. Compensation of Voltage Sags and Swells Using Dynamic Voltage Restorer Based on Bi-Directional H-Bridge AC/AC Converter. Academic Editors: Chang-Hua Lin and Jahangir Hossain Received: Published: 30 August 2021 Department of Aeronautical Engineering, National Formosa University, Hu-Wei 632, Taiwan

 

Abstract: In this paper, the compensation of voltage sags and swells using a dynamic voltage restorer (DVR) based on a bi-directional AC/AC converter is presented for stabilizing single-phase AC line voltage. The H-bridge AC/AC converter with bi-directional switches and without bulk capacitor is adopted as the power topology of the proposed system. The proposed novel topology of DVR is adopted to compensate both voltage sag and swell conditions. Additionally, the power factor is closed to unity because a bulk capacitor is not required. The inner and outer loop control is proposed to improve the response with gain scaling; gain control is adopted to reduce the overshoot. Finally, a 2 kVA prototype has been implemented to verify the performance and accuracy of the control method for the DVR system. The peak efficiency of the system is up to 94%, and it can compensate 50% voltage swells and 25% voltage sags.

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A Study of Control Technique in Stationary Reference Frame for Improving the Disturbance Rejection Performance in Parallel Operation of Multi-Modular UPS--Hyo-Jun Ryu-- Department of Automotive Engineering (Automotive-Computer Convergence) Graduate School of Hanyang University

 A Study of Control Technique in Stationary Reference Frame for Improving the Disturbance Rejection Performance in Parallel Operation of Multi-Modular UPS--Hyo-Jun Ryu-- Department of Automotive Engineering (Automotive-Computer Convergence) Graduate School of Hanyang University

ABSTRACT

 This paper proposes a control technique for improving the disturbance rejection performance of a voltage controller during the parallel operation of multi modular UPS. In a single operation of the modular UPS, it is possible to improve disturbance rejection performance by conducting the feed-forward compensation for the load current, which is the disturbance of the voltage controller. However, a circulating current may occur when the modular UPS operates in parallel with the feed-forward control compensates for the load current. As a result, load sharing between UPS modules becomes uneven, and in severe cases, the parallel operation may not be possible. In this paper, the circulating current impedance model according to the load current feed-forward compensation gain explains the circulating current occurrence during the modular UPS parallel operation. In addition, a control technique, which is the feed-forward compensation for a portion of the load current considering a decrease of circulating current impedance, is proposed. However, the load current feed-forward compensation technique that considers circulating current impedance deteriorates disturbance rejection performance compared to a single operation of modular UPS, which is possible to apply for the load current feedforward compensation regardless of circulating current impedance. Therefore, this paper proposes another feed-forward compensation technique with a 2-DOF voltage controller structure to improve the reduced disturbance rejection performance. This technique ensures the cascade control performance of the structure of the voltagecurrent controller by maintaining the voltage controller's reference tracking performance and improving the disturbance rejection performance of the voltage controller. The effectiveness of the proposed feed-forward compensation technique is demonstrated by experimental results obtained through the operation of the fourparallel connected the 500 W modular double conversion UPS.

Battery Management System—Balancing Modularization Based on a Single Switched Capacitor and Bi-Directional DC/DC Converter with the Auxiliary Battery---Mohamed DAOWD-

Battery Management System—Balancing Modularization Based on a Single Switched Capacitor and Bi-Directional DC/DC Converter with the Auxiliary Battery Mohamed Daowd *, Mailier Antoine, Noshin Omar, Philippe Lataire, Peter Van Den Bossche and Joeri Van Mierlo Department of Electrical Engineering and Energy Technology 

 Abstract:

 Lithium-based batteries are considered as the most advanced batteries technology, which can be designed for high energy or high power storage systems. However, the battery cells are never fully identical due to the fabrication process, surrounding environment factors and differences between the cells tend to grow if no measures are taken. In order to have a high performance battery system, the battery cells should be continuously balanced for maintain the variation between the cells as small as possible. Without an appropriate balancing system, the individual cell voltages will differ over time and battery system capacity will decrease quickly. These issues will limit the electric range of the electric vehicle (EV) and some cells will undergo higher stress, whereby the cycle life of these cells will be shorter. Quite a lot of cell balancing/equalization topologies have been previously proposed. These balancing topologies can be categorized into passive and active balancing. Active topologies are categorized according to the active element used for storing the energy such as capacitor and/or inductive component as well as controlling switches or converters. This paper proposes an intelligent battery management system (BMS) including a battery pack charging and discharging control with a battery pack thermal management system. The BMS user input/output interfacing. The battery balancing system is based on battery pack modularization architecture. The proposed modularized balancing system has different equalization systems that operate inside and outside the modules. Innovative single switched capacitor (SSC) control strategy is proposed to balance between the battery cells in the module (inside module balancing, IMB). Novel utilization of isolated bidirectional DC/DC converter (IBC) is proposed to balance between the modules with the aid of the EV auxiliary battery (AB). Finally an experimental step-up has been implemented for the validation of the proposed balancing system.

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https://www.academia.edu/23460584/Battery_Management_System_Balancing_Modularization_Based_on_a_Single_Switched_Capacitor_and_Bi_Directional_DC_DC_Converter_with_the_Auxiliary_Battery

Design and Analysis of Maintenance Free Lead Acid Battery System Used in UPS-Pratik Roy University of Windsor

  Design and Analysis of Maintenance Free Lead Acid Battery System Used in UPS Pratik Roy, Student Member, IEEE, Varun Kumar Vats, Student Member, IEEE and Pronay Kumar Chakrobarty, Student Member, IEEE 

 Abstract—Voltage interruption can be happened by several reasons like blackout, brownout, noise, spike etc. Those incidents have consequential effect on computer’s hardware such as data losses, burning of sensitive equipment etc. So, UPS broadly called an uninterruptible power supply device is used in computer to provide a backup power source which will maintain the consistency in voltage and flow of electricity which in turn will provide consistent power input. Batteries are used as energy storage device in UPS which store electric energy during charging state and discharge that electric energy during any kind of interruption to provide backup as additional power source for the computer. So, the most important integral part of UPS is the battery pack which is used as energy storage device in UPS. Main goal of this paper is to design the suitable battery pack for UPS so that it can give maximum backup range to the computer within a certain economical range or cost limit. Also, another goal is to analyze the electrical and thermal parameters of the designed battery pack and cell and suggest better solutions to make the wet battery cell maintenance free (no need of addition of water).

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 https://www.academia.edu/37317680/Design_and_Analysis_of_Maintenance_Free_Lead_Acid_Battery_System_Used_in_UPS

A High Gain Single Switch DC-DC Converter with Double Voltage Booster Switched Inductors Nagaraju Addagatla, Rajender Boini-Advances in Science and Technology Research Journal 2023, 17(2), 1–11

 A High Gain Single Switch DC-DC Converter with Double Voltage Booster Switched InductorsNagaraju Addagatla1, Rajender Boini1*1 Department of EEE, Chaitanya (Deemed to be University) Warangal, Telangana, India* Corresponding author’s email:nagaraju.addagatla@gmail.com 

 ABSTRACT

The research for novel power conversion topologies and the development of cutting-edge power component tech-nologies are driven by the demand for renewable and much more efficient electricity generation, delivery, and con-version. Simulation and analysis high voltage gain DC-DC converter with double voltage booster switched induc-tor are analyzed in this paper. Multilevel boost converter topologies recently reintroduced, are gaining popularity as a solution for industrial and transportation power systems because they enable the use of innovative, efficient, but relatively low voltage low-voltage devices at greater voltage and power levels. there is only one power switch on the converter that is planned here, three diodes, two capacitors, and two inductors to achieve ultra-high gain with better efficiency. High voltage gain, minimal switch stress, and the ability to lessen input-current ripple and capacitor voltage ripple are all benefits of the topology. When it switches complementary, the capacitors’ ripple is reduced, which lowers the size requirement for the capacitors. A 12V, 500 watts prototype was analyzed, simulated and designed. at a duty cycle of 0.75 it is achieved high DC-DC gain i.e 19 and efficiency 93%. The practicality of the converter will be demonstrated by the close agreement between the analysis and simulation findings. 

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http://www.astrj.com/pdf-161447-89064filename=A%20High%20Gain%20Single%20Switch.pdf