Step-Up Battery Charger for Stand-Alone Wind Power System

In this paper, a step-up battery charger for the stand-alone wind power system is proposed. In general, maximum power point tracking (MPPT) is investigated to harvest the maximum wind energy. However, most of standalone type wind turbine systems adopt batteries and it is hard to apply a MPPT strategy on a battery-charging type wind turbine system. The proposed power converter can harvest the maximum power from the wind turbine while generating pulsating current for the battery bank. Based on the circuit analysis, the maximum power point tracking function is realized by the circuit parameter design of the power converter and the characteristics of wind turbine. Also, with the interleaved operation between the step-up power converters, the current ripple of the input can be reduced. Advantages of the proposed converter include: maximum power tracking, control circuit simplicity, low voltage stress, no current sensor, and high reliability. Hardware experimental results from a 100 W prototype circuit are presented to verify the performance of the proposed power converter.