PV Fed Grid Power Control by Discrete CUK Converter and SPWM Inverter Control Techniques

Abstract

In this paper the power supplied to the grid is regulated with the help of Discrete Sliding Mode Controlled (DSMC) CUK converter and Sinusoidal Pulse Width Modulation (SPWM) topology controlled 3-phase Inverter. The CUK converter is used in the input side to Buck or Boost the PV (Photo Voltaic) array voltage to the required value of the 3 -phase Inverter. Natural isolation of source and load is obtained in the CUK converter with the help of capacitor energy transfer so that the ripple content is less in both load and source side. These CUK converters are operating in continuous current mode so that regulation of power from the solar panel is easy and efficient compared to Buck-Boost converters. In this paper DSMC CUK converter topology is implemented so that converter is feasible to incorporate with any digital controller with less hardware requirements, it has flexibility in control characteristics and guaranteed stability of highly fluctuating solar power under different climate conditions. The simulation model has battery back-up which is charged during high irradiation time and provides power to load during less irradiation climate conditions. The 3-phase Inverter is controlled by SPWM technique to reduce the switching losses of the Inverter so that the harmonics in the load side is less and it is easy to implement. So that the overall system is efficient, ease of implementation, robust and economical.