基于改进EKF的DC/DC转换器电感电流观测器  

A DC/DC Converter Inductor Current Observer Based on Improved EKF

作　　者：陈晨[1] 童乔凌[1] 谢文[2] 刘政林[1] 

机构地区：[1]华中科技大学光学与电子信息学院,湖北武汉430074 [2]中国人民解放军第二炮兵指挥学院通信系信息作战教研室,湖北武汉430012

出　　处：《微电子学与计算机》2014年第6期125-128,132,共5页Microelectronics & Computer

基　　金：国家自然科学基金项目(61202469);教育部博士点基金(20120142120102)

摘　　要：为了减小电磁干扰(Electromagnetic Interference,EMI)引起的DC/DC转换器输出电压噪声,消除负载变化引起的稳态误差,提出了一种基于改进的扩展卡尔曼滤波器(Extended Kalman filter,EKF)的电感电流观测器.首先,介绍了Boost型转换器的状态空间方程和扩展卡尔曼滤波器;之后提出负载估算算法,对EKF进行改进.利用改进EKF的输出电压、电感电流和占空比即可估算出实际负载值,从而实时更新改进EKF的参数,使电流观测器可以准确估计电感电流;最后对提出的电流观测器进行了仿真验证.仿真结果表明,在负载突变时,改进EKF可以对EMI引起的输出电压噪声进行有效滤波,同时准确估计电感电流,保证了DC/DC转换器输出电压的准确性.This paper presents a DC/DC converter inductor current observer based on improved extended Kalman filter ,which can reduce output voltage noise caused by electromagnetic interference and eliminate the steady state error when load changes .Firstly ,the State-space equations of boost DC/DC converter and extended Kalman filter are introduced .Secondly ,the load estimation algorithm is proposed to improve the extended Kalman filter .The improved extended Kalman filter can use output voltage ,inductor current and duty radio to estimate actual load value .Therefore ,the parameters of improved EKF can be updated in real time and current observer can estimate inductor current accurately .Finally ,the validity of the proposed approach has been demonstrated by simulation . The simulation results show that the improved extended Kalman filter can filtering the output voltage noise caused by electromagnetic interference effectively ,and estimate inductor current precisely ,which ensures the accuracy of the output voltage .

关 键 词：DC/DC转换器 改进的扩展卡尔曼滤波 电流模式控制 电流观测器 

分 类 号：TM46[电气工程—电器]