Mathematical and Experimental Investigation on Advanced PLL for Cascaded H-Bridge Multilevel Inverter in Active Filtering Application

Abstract

Cascaded H-bridge multilevel inverter (CHB-MLI)-based shunt active power filter (SAPF) is one of the finest solutions for power quality improvement in case of medium-voltage distribution sector. Performance of SAPF degrades due to the presence of DC offset and harmonics in the grid voltage since this will result phase angle and frequency error. Therefore, modified single-phase synchronous reference frame theory comprising of advanced PLL is presented in this article. The advanced PLL can track frequency and phase angle accurately even though source voltage is having DCor harmonic content. A detailed mathematical modeling and stability analysis of this PLL is presented using Routh-Hurwitz criteria. A novel systematic design procedure using gravitational search algorithm (GSA) and an Eigen value analysis is proposed for calculating optimal PLL parameters. Closed-loop SAPF control stability is tested using root-locus analysis. An extensive experimental analysis of the proposed control applied to CHB-MLI-based SAPF has been performed under distorted source voltage and non-linear loading conditions to show the effectiveness of the proposed control over recently published work. Source current maintains its sinusoidal shape, properly synchronized with grid voltage and having distortion limit in compliance with IEEE-519 standard irrespective of source voltage conditions during the operation of SAPF.

Keywords:

• multilevel inverter
• cascaded H-Bridge
• shunt active power filter
• phase-locked loop
• gravitational search algorithm

Additional information

Notes on contributors

Soumyadeep Ray

Soumyadeep Ray graduated in Electrical Engineering from College of Engineering and Management, Kolaghat in 2011. He did his M.Tech. in Power Electronics from Kalinga Institute of Industrial Technology (KIIT) University, Bhubaneswar in 2014. Currently he is pursuing Ph.D. degree in Electrical Engineering Department of Malaviya National Institute of Technology (MNIT), Jaipur as full time research scholar under MHRD scholarship. His areas of interest are power electronics application in industry, power quality, active power filters, multilevel inverters and renewable energy grid integration.

Nitin Gupta

Nitin Gupta graduated in Electrical Engineering from Government Engineering College Kota, in 2000. His did his Master of Engineering in Power Electronics in 2008 from College of Technology and Engineering (CTAE), Udaipur and Ph.D. degree in Electrical Engineering from Indian Institute of Technology (IIT) Roorkee, Roorkee as full time research scholar under MHRD in 2012. Presently, he is Assistant Professor in the Department of Electrical Engineering, Malaviya National Institute of Technology (MNIT), Jaipur. His areas of interest are power electronics & drives, power quality, renewable energy grid integration, active power filters, multilevel inverters etc.

Ram Avtar Gupta

Ram Avtar Gupta received B.E. (Electrical) and M.E. Degrees from the University of Jodhpur, India in 1980 and 1984, respectively. He did his Ph.D. in 1996 from IIT Roorkee. In 1982, he joined as an Assistant Professor in the Department of Electrical Engineering, JNV University. In 1990, he joined as a Reader and became Professor in 1999 in the Electrical Engineering Department, MNIT, Jaipur. He has around 30 years of teaching experience, completed several research projects and guided many Ph.Ds. His field of interest includes power electronics, electrical machines and drives, power quality and renewable energy integration.