用于纯电驱液压挖掘机的双向DC/DC变换器储能系统

Research on Energy Storage System of Bidirectional DC/DC Converter for Electric Hydraulic Excavator

为进一步提高纯电驱液压挖掘机的能量利用率且降低电源功率波动,针对变转速纯电驱液压挖掘机的动力系统,使用非隔离双向DC/DC变换器及超级电容组进行电力能量回收及利用。在SimulationX中,使用全纹波建模方法,建立了基于等效电阻的半桥变换器及超级电容组储能系统的模型,设计了各元件参数及其控制器,提出了一种适应性控制方法。仿真过程中,通过给定伺服电机设定的变转速信号及转矩信号模拟电机功率波动,使双向DC/DC变换器储能系统自动补偿或吸收电源功率。仿真结果表明,采用该控制器,在保证电机功率与超级电容效率的前提下,能够较好地维持恒定的输出电源功率,并能保证较快的动态响应及减小切换过程中的功率波动。

In order to improve the energy utilization rate of electric hydraulic excavator and reduce the fluctuation of power supply,this paper focuses on the power system of variable speed electric hydraulic excavator using non-isolated bidirectional DC/DC converter and super capacitor group.In SimulationX,the model of half-bridge converter and supercapacitor energy storage system based on equivalent resistance was established by using full ripple modeling method.The parameters of each component and its controller were designed,and the adaptive control method was proposed.During simulation process,motor power fluctuation was simulated by variable speed signal and torque signal set by servo motor,so that the energy storage system of the bidirectional DC/DC converter automatically compensated or absorbed the power of power supply.The simulation results show that the proposed controller maintains a constant output power under the premise of ensuring the power of motor and the efficiency of supercapacitor,ensuring a fast dynamic response and reducing power fluctuations during switching process.