The limitation of constant voltage method is that its efficiency is low as the PV panel has to be disconnected from the load for measurement of the open circuit voltage (Voc). A voltage based MPPT technique which is capable of tracking MPP has been selected because of numerous advantages it offers such as: simple and low cost of implementation. The current-voltage and power-voltage characteristics being nonlinear, the SAPV system require maximum power point techniques (MPPT) control techniques to extract maximum power available from the PV cell. The SAPV system as presented in the paper consists of solar PV panel, a DC-DC converter, a controller and a PMDC motor. Stand-alone photovoltaic (SAPV) systems are being used in remote areas and are being seen as one of the promising solution in this regard.

Cuk converter based solar system has given satisfactory outcome which reflects its utility compared to other types of dc-dc choppers. Under different solar irradiances, MPPT has shown good performance. Both the MPPT and the converter efficiency are significantly improved. The simulation result shows that there exists only 0.06795 percent of ripple in the PV side current which is almost ripple free and 0.0026 percent ripple in the output current with respect to the average value of current. The overall system efficiency, amount of ripple current on both PV side and load portion, power on both sides and investigation on system stability under several conditions have been considered. For all kinds of simulation and development, MATLAB Simulink is used. Voltage can be stepped up or stepped down and the overall performance will be smooth. The energy transfer from source to load is continuous regardless of the state of the MOSFET switch.

This converter is the most suitable DC chopper for evaluating ripple free current in PV side. For the purpose of assessing the duty cycles of cuk, MPPT controller is used. Cuk converter has been used in this particular system with the purpose of extracting solar power out of PV arrays with greater stability. The I-V characteristic curve of solar PV system shows non-linearity where the desired maximum power point can easily be found.

Efficiency of cuk converter efficiency