International Journal of Power Electronics and Drive Systems (IJPEDS) Vol. 13, No. 1, March 2022, pp. 390~400 ISSN: 2088-8694, DOI: 10.11591/ijpeds.v13.i1.pp390-400  390 Journal homepage: http://ijpeds.iaescore.com Novel multi-device unified powerquality conditioner for powerquality improvement Naarisetti Srinivasa Rao, Pulipaka Venkata Ramana Rao Department of Electrical and Electronics Engineering, Acharya Nagarjuna University, Guntur, India Article Info ABSTRACT Article history: Received Jul 24, 2021 Revised Jan 25, 2022 Accepted Feb 1, 2022 This paper describes the customizable multi-device unified power-quality conditioner (MD-UPQC) is designed especially for multi-feeder distribution networks. The proposed MD-UPQC can exchange the power between the multi-feeders and proficiently mitigates all voltage-current associated power-quality problems, make sure to maintain balanced power-flow to consumers. At recent days, various manufacturers recommend the provision of multilevel inverters in mid-range customized compensation devices with desirable control schemes. In distinct, the 5-level diode-clamped multi-level inverter (DCMLI) is best suited for MD-UPQC over traditional 3-level voltage source inverter (VSI) topology for attaining enhanced features. In this paper, MD-UPQC has been proposed with three 5-level DCMLI modules interfaced as back-to-back with a common direct current (DC) capacitor. The simplified phase-dispositional modulation technique is easily assembled with proposed universal voltage-current reference controller for significant functioning of DCMLI-MDUPQC device. The operation and performance of proposed model and its control scheme is evaluated with MATLAB/Simulink computational tool, simulation results are presented. Keywords: Diode-clamped MLI Multi-carried Based PWM Multi-device UPQC Power-quality Universal voltage-current Reference controller This is an open access article under the CC BY-SA license. Corresponding Author: Naarisetti Srinivasa Rao Department of Electrical and Electronics Engineering, Acharya Nagarjuna University Guntur, Andhra Pradesh, India Email: nsrinivasarao.eee@gmail.com 1. INTRODUCTION The power-quality (PQ) in multi-feeder distribution networks has been crucially proliferated, affecting the loads connected at common feeding point of distribution network due to several deviations and distortions [1]. The increased use of non-linear power-electronic converters, short-circuits, switching of massive loads and electric motors takes-place in secondary distribution networks are the frequent examples causing the PQ distortions [2]. It initiates the injection of harmonic currents, reactive-power extraction, load unbalancing, and poor power-factor. Moreover, the effect of voltage-quality initiates the voltage harmonics, voltage sag-swells, voltage unbalance and voltage deviations which imply the power-pollution at common-feeding point of distribution network [3]. These critical loads are connected to a network with unfortunate PQ then customized flexible alternate current transmission system (FACTS) devices should be introduced to compensate these deficits [4], [5]. The multi-feeder customized FACTS devices are categorized as many groups based on definite PQ problems and its affects such as interline dynamic-voltage restorer [6], interline power-flow controller [7], and interline-unified power-quality controller [8], so on. Particularly, multi-device unified power-quality conditioner (MD-UPQC) is designed especially for PQ enrichment in multi-feeder distribution systems. It can exchange power between multi-feeders and proficiently mitigates both voltage-current associated PQ problems and make