一种母线全电流采样策略的研究

Research on a DC-current sampling strategy

针对传统母线电流采样存在调制系数可控范围受限,电流重构算法复杂,对电流反馈通道带宽要求严格等缺点,提出一种电流采样策略,并对其原理、电路拓扑结构、电流转换和电流重构等环节进行分析。与传统母线电流采样方法相比,所提出的电流采样方法可采集包括续流电流在内的全部电流信息,因此可用于电磁转矩的精确控制;在调制系数m∈[01,]范围内实现准确电流采样,解决传统方法中调制系数受限的问题;可以有效降低对电流反馈通道带宽的要求。该方法硬件可以集成到功率模块中,从而实现功率驱动与电流检测的集成。实验结果表明该采样策略具有良好的性能。

To solve those problems of modulation index being neither high nor low,the reconstruction strategy being complex,and bandwidth of current feedback being high in DC-link current sampling,a current sampling strategy is proposed in this paper.The topology,current conversion and current reconstruction of the current sampling were detailedly discussed.It can sample all the current including freewheeling current which makes it possible to control the torque accurately,and sample precise value when m∈.The demanded bandwidth of current feedback path can be efficiently descended by this current sampling strategy.This scheme can also be integrated into power switches based on the concept of power electronic system integration.Experimental result shows that the novel strategy has excellent performance.