Comparisons of Maximum Power Tracking Strategy of Solar Cell Output and Control Characteristics using Step up/down Chopper Circuit

Abstract

As well known, a solar cell has an optimal operating point to be able to get the maximum power P_max. But it may vary depending on the miss match between the solar cell output and the load. So, many P_max tracking controllers using microprocessor have been popularly used. In the conventional control system, the solar cell output power is used as a control variable.
In this paper, we investigate the possibilities of P_max control using the output power, the output voltage and the output current instead of the solar cell output power. And we also examine about the optimal power converter using step up and down chopper circuit to operate the solar cell at an optimal voltage using these variables. And then, we show some experimental results to confirm the successful operation.
From the investigations, we may be concluded that the control variables using the output voltage and the output current is useful and for general applications connecting to the DC load composed of the resistive load and the voltage source, the output current control is better than the others.