Study on control of ladder-type storing and releasing energy for off-grid wind turbine

As far as the currently used lead-acid battery has poor abilities of self-resistance to overcharge and over-discharge, it is unsuitable for a dedicated storage device of wind turbine. This paper proposed a control strategy of storing and releasing energy about off-grid wind turbine by analyzing and studying the ideal characteristic curve of charging voltage and current of lead-acid battery. The strategy adopts the whole control-type turn-off thyristor (GTO) to constitute switch circuit for controlling battery charging voltage and current size, and multi-stage charging signal generator controls switch circuit through monitoring battery reserves, thus completing the battery charge current ladder-type regulating, making it close to the ideal characteristic curve, and releasing the excess wind energy by diode load slowly. This strategy achieved the integration functions of charging control and load consumption.