Synthesis of a new DLMPPT technique with PLC for enhanced PV energy extraction under varying irradiance and load changing conditions

In this paper, a photovoltaic (PV) energy extraction process with higher efficiency and wider scope of modular and portable programs using programmable logic controller (PLC) is proposed. Under dual layer maximum power point tracking (DLMPPT) concept, energy gains are simultaneously achieved as distributed MPPT (DMPPT) across PV modules and centralized MPPT (CMPPT) across PV arrays with newly modified “incremental conductance algorithm” using adaptive subroutine jump control at an appropriate ramp rate correction, to update pulse width modulation duty cycle for speedy MPPT action and resolving issue pertaining to multimaxima points under partial shading conditions as well. A dynamic energy balance between supply of PV energy to common dc bus and its quick transfer/consumption by load across inverter is a prime factor for enhanced DLMPPT benchmark in the process. This scheme is simulated on MATLAB, followed by hardware (5 kW) implementation for performance data generation and analysis on a yearly basis at a farm house located (lat = 26.397, lon = 74.728) in a village near Ajmer, India. It is found that DLMPPT is ahead in energy gains by 13.26% and 7.88% as compared to CMPPT and DMPPT, respectively.