Grid Synchronization and Islanding Detection Control Algorithm for Two-stage Three-phase SPV System

Abstract

Integration of distributed energy sources (DER) with the conventional grid through power electronic interface has emerged as a boon for reliable and good quality power to end-users. The existing control algorithms for the power electronic interface are normally feedback algorithms which help in grid synchronization and effective power dispatch. In this work, an adaptive feedforward-feedback control algorithm is proposed for optimal solar power management of two-stage three-phase grid-integrated solar photovoltaic (SPV) system. Proposed control algorithm enables feeding of SPV energy to load and into the grid, and also act to balance grid currents, compensates reactive power, eliminates harmonics and protect load and source during adverse islanding condition. Phase-locked loop (PLL) used in the feedback part of the algorithm facilitates the effective synchronization of the SPV system. Asymmetric fuzzy logic control (FLC) is used for DC-link voltage stabilization during load variation. Feedforward algorithm ensures fast dynamic response for variable atmospheric and grid operating conditions. Moreover, for protection of SPV arrays and the loads coupled at point of common coupling (PCC), islanding detection followed by interfacing inverter shutdown feature is added in the proposed algorithm. Quantitative analysis of the system is provided in order to investigate the effectiveness of the proposed algorithm. The effectiveness of the algorithm is evaluated using simulation studies performed on MATLAB/ Simulink software.

KEYWORDS:

• Control algorithm
• Distributed energy sources (DER)
• Grid-integration
• Phase-locked loop
• Solar photovoltaic (SPV)

Additional information

Notes on contributors

Nikita Gupta

Nikita Gupta received BTech degree in electrical and electronics engineering from National Institute of Technology, Hamirpur, India in 2011 and MTech degree in power systems from Delhi Technological University, Delhi, India in 2014. She completed her PhD degree in Department of Electrical Engineering from Delhi Technological University, Delhi, India in December 2018. Presently, she is working as assistant professor in University Institute of Technology, Himachal Pradesh University, Shimla (H.P), India. Her research interests include power system analysis, power quality, power electronics applications in renewable energy, and microgrid. Dr Nikita received “Commendable Research Award” for excellence in research during the year 2018 at Delhi Technological University, Delhi, India. She is the recipient of the outstanding paper award from the IEEE-GPECOM, in 2020. She is the recipient of the best paper award from the IEEE-INDICON, in 2015. She is a member of various technical communities including IEEE, IEEE Young Professionals and IEEE Women in Engineering. She is a reviewer member of various international conferences and journals conferences including Wiley and IET.

Rachana Garg

Rachana Garg received the BE and ME degree in 1986 and 1989, respectively from National Institute of Technology, Bhopal, India. She obtained PhD in electrical engineering from Delhi University, India in 2009. Presently, she is working as professor in Delhi Technological University, Delhi, India. Her areas of interest is modeling of transmission lines, power system operation and control, smart grid and renewable energy. Email: [email protected]

Parmod Kumar

Parmod Kumar received the BE, ME, and PhD degrees in 1972, 1975, and 1982, respectively. After post-graduation in measurement and instrumentation, he joined MP Electricity Board, MP, India, as an assistant engineer and commissioned telemetry and SCADA instruments at substations, power stations, and the central control room. In 1983, he joined the Central Electricity Authority as a Dy Director (System Engineering) and designed and configured the load dispatch centers for electric utilities. Subsequently, he served on various capacities to Indian Railway Construction Company, IRCON, ESPL, ESTC, and then entered academic life in 1991. His area of interest is smart and intelligent system design, operation and control. Email: [email protected]