A simple variable step size method for maximum power point tracking using commercial current mode control DC-DC regulators

This paper proposes a method to achieve maximum power point tracking (MPPT) function by “tricking” inexpensive commercial-off-the-shelf (COTS) current mode control regulators. In the commercial market, there are many such inexpensive regulators, but they are designed for the output voltage control. The proposed method utilizes a voltage signal from an additional external microcontroller to regulate the compensation pin of the DC-DC regulator to achieve the MPPT function by using perturb and observe (P&O) with variable step size. A prototype is designed, built, and tested. Because the COTS hardware is simple to implement, MPPT can be achieved without complete system design, making MPPT accessible to hobbyists and non-experts in power supplies.