Study on the charging and discharging control strategy of ultracapacitor in series hybrid bulldozer

An equivalent circuit model of ultracapacitor is established based on analyzing its working principle. The ultracapacitor's charging and discharging control strategy for the series hybrid bulldozer system is proposed, and then the charging and discharging process of the ultracapacitor is simulated at the bulldozer working conditions. The results show that, in the case of the bulldozer's frequent power fluctuation, the ultracapacitor can provide a large instantaneous power and timely supply the lack of the DC bus required power to ensure the normal work of the bulldozer. The simulation experiment provides reference for the application of ultracapacitor in engineering machinery.