International Journal of Electrical and Computer Engineering (IJECE) Vol. 10, No. 6, December 2020, pp. 6268~6275 ISSN: 2088-8708, DOI: 10.11591/ijece.v10i6.pp6268-6275  6268 Journal homepage: http://ijece.iaescore.com/index.php/IJECE MPPT oscillations minimization in PV system by controlling non-linear dynamics in SEPIC DC-DC converter M. Vaigundamoorthi 1 , R. Ramesh 2 , V. Vasan Prabhu 3 , K. Arul Kumar 4 1,4 Department of Electrical and Electronics Engineering, Madanapalle Institute of Technology & Science, India 2 Department of Electrical and Electronics Engineering, CEG, Anna University, India 3 Department of Electrical and Electronics Engineering, St. Joseph’s College of Engineering, India Article Info ABSTRACT Article history: Received Feb 27, 2019 Revised May 2, 2020 Accepted Jun 17, 2020 Solar PV power generation has achieved rapid growth in developing countries which has many merits such as absence of noise, longer life, no pollution, less time for installation, and ease of grid interface. A maximum power point tracking circuit (MPPT) consists of DC-DC power electronics converters that are used to improve the energy attainment from solar PV array. This paper presents a detailed analysis to control of chaos, a non-linear dynamic in SEPIC DC-DC converter interfaced solar PV system, to minimize the oscillations near to MPP. In SEPIC DC-DC converter, the input inductor current is continuous and capable of sweeping the whole I-V curve of a PV module from open circuit voltage (Voc) to short circuit current (Isc) operating points. To trace the true maximum power point and to nullify the oscillations near to MPP, the yield output voltage needs to ensure period-1 operation. Keywords: Adaptive controller Chaos MPPT SEPIC converter Solar PV module Copyright © 2020 Institute of Advanced Engineering and Science. All rights reserved. Corresponding Author: M. Vaigundamoorthi, Department of Electrical and Electronics Engineering, Madanapalle Institute of Technology & Science, Madanapalle, Andhra Pradesh-517325, India. Email: bacyavaigo2000@gmail.com; drvaigundamoorthim@mits.ac.in 1. INTRODUCTION Solar power is a Green energy sources that employs DC-DC converter to harvest maximum power. The efficiency of the energy conversion process is declined due to climate variable temperature, partial shading, and atmospheric irradiation change and load conditions. The PV current changes with irradiation greatly and the atmospheric temperature affects PV voltage [1-4]. The MPP is detected by Adaptive perturb and observer MPPT algorithm which is embedded in Microcontroller, generate gate pulse which is applied to the DC-DC converter switches [5-8]. The various types of DC-DC converters [9-12] such as buck, boost, buck boost, Cuk and SEPIC are implemented in PV system by considering suitability factors such as cost, efficiency, maximum power flow, ease of drive system, Positive output voltage, system stability and concluded that SEPIC converter is commonly used in PV system to track maximum power from PV panel. Higher order converter such as SEPIC and Cuk are widely used for MPPT charge controller because of their excellent steady state performance, isolation, over current limit protection [13-21]. Quamruzzaman [17] has argued that the PV current with less ripple and improved dynamic response can be achieved by SEPIC converter also proved that high input current ripple content of the converter reduces the average value of current which may leads to wrong true MPP tracking. Non-linear dynamics in power electronics circuits was put forward in [22-24] undergo sub-harmonics, quasi-periodic oscillations, and chaotic mode of operation. The chaos is experienced in DC-DC converters and its control methods are conducted in power electronics circuits. This abnormal operation would affect converter tracking efficiency since the period -1 operation need to be ensured for MPP tracking in order to minimize oscillations near to MPP. Several studies [25-27] have suggested many control methods that are mitigated to