The International Journal of Engineering and Science (IJES) || Volume || 7 || Issue || 6 Ver. II || Pages || PP 83-93 || 2018 || ISSN (e): 2319 – 1813 ISSN (p): 23-19 – 1805 DOI:10.9790/1813-0706028393 www.theijes.com Page 83 Multiple Control of Unidirectional Ac-Dc Step-Up Converters for Improving Power Quality Saiyad Tausif R.B. Ali, Dr.Rakesh G.Shriwastava M-tech Scholar (Power Electronics and Power System), Suersh Deshmukh College of Engineering and Technology, Selukate, Wardha 442001(Maharashtra) INDIA Ph.D(Electrical). Associate Professor Department of Electrical Engineering, Datta Meghe Institute of Engineering, Technology & Research Salod(Hirapur),Wardha 442001(Maharashtra) INDIA Corresponding Author: Saiyad Tausif R.B. Ali --------------------------------------------------------ABSTRACT----------------------------------------------------------- The ineluctability of solid state ac-dc step-up converters to raise power quality in terms of power factor correction (PFC), diminished total harmonic distortion at input ac mains and absolutely regulated dc output have motivated the control methods based on power electronics based compensators and other static controllers, such as FACTS technologies. Utmost power factor correction circuits present in the industrial market exploit unidirectional ac-dc step-up converter topologies, this is an around no-cost solution for compensating harmonic current and reactive power in residential application. By using unidirectional ac-dc step-up converter harmonic current and reactive power compensation is at beforehand investigated. But the amount of reactive power injected from an individual converter to the grid should be bounded due to input current distortion. This paper propose additionally to quantify the input current distortion by the unidirectional ac-dc step-up converter used for supplying not only active power to the load but also reactive power. KEYWORDS - Active power filter(APF), harmonic current compensation(HCC), power factor correction(PFC), reactive power compensation(RPC), unidirectional ac-dc step-up converter. --------------------------------------------------------------------------------------------------------------------------------------- Date of Submission: 08-06-2018 Date of acceptance: 23-06-2018 --------------------------------------------------------------------------------------------------------------------------------------- I. INTRODUCTION In an ac power systems related with moving of the voltage or current from the desired ideal sinusoid of constant amplitude and frequency for an analysis of power quality. Unfiltered harmonics cause interference in other facilities, making undesirable and abnormal behavior of electrical equipments and transformer overheating. Fractious reactive power enlarge transmission conduction losses and go down the performance of voltage regulation. Therefore, it is desired to reduce these effects through sufficient medium, i.e. harmonics current compensation (HCC) and reactive power compensation (RPC). Multiple technologies, having advanced power capacities rooted on power electronics theory have aimed to renovate grid power quality and compensate reactive power at the transmission and distribution system level. Flexible alternating current transmission systems (FACTS) have been studied by commercial and classical researchers since 1990s. A.C. transmission system unifies power electronics based compensators and other static controllers largely enlarge controllability and enhance power transfer caliber. During FACTS technologies, the static VAR compensators (SVC), static synchronous compensator (STATCOM), and unified power quality conditioner (UPQC) all obtain the capacity to compensate reactive power . Active power filter configurable with several power topologies can be exploit for improving power quality through harmonic current compensation and reactive power compensation. Albeit static VAR compensators, static synchronous compensators, unified power quality compensators and active power filters exhibit outstanding performance, but they may not be the best solution for improvement of power quality of an overall power system due to high capital and operating costs, as well as additional power losses due to long distance transmission of reactive power. To discover extra lucrative key, the demand of improving power quality have continuously stimulate power electronics engineer to include HCC and RPC capabilities as consequential services in bidirectional power converters. As power converter for non-conventional energy sources become more renewed in ac power systems, the potential for HCC and RPC will increase, as these control design can be employed in existing topologies without hardware changes. Nevertheless the increased utility and cost savings, the number of non- conventional power converters adequate of fulfilling these function is still confined.