高精度双向DC电源电流采样电路设计  

A High-Accuracy Bidirectional Current Sensing Circuit Design

作　　者：刘青[1,2] 李铁才 张乃通[1] 

机构地区：[1]哈尔滨工业大学电子与信息工程学院,黑龙江哈尔滨150001 [2]深圳航天科技创新研究院,广东深圳518057

出　　处：《测控技术》2016年第11期111-115,共5页Measurement & Control Technology

基　　金：深圳市科技创新委员会基础研究计划项目(JCYJ20140425113426030)

摘　　要：为适应双向DC/DC功率变换的电流采样需求,一种高精度高边电流采样电路被提出。其基本思想是在功率电路的高边串入采样电阻,借助电流镜原理并引入偏置电流电路,将双向电流均转换为正向电压输出。通过理论分析与仿真结合的方法对电流镜采样原理及4种不同的偏置电流电路方案进行对比,最后通过实验数据验证了高精度高边电流采样电路的有效性。实验数据表明,该采样电路可在-25~75℃的温度工作范围内,针对-10^+10 A范围内的电流采样实现优于5%的采样精度。Current sensing plays an important role in controlling,monitoring or protection functions of power systems.To meet the current sensing requirement of bidirectional DC/DC converters,a high-accuracy bidirectional current sensing circuit is proposed.The proposed current sensing circuit inserts a resistor in the path of the current to be sensed,while the current mirror and biased current circuit are introduced.Therefore,the bidirectional current can be expressed by positive voltage.By theoretical analysis and simulation,the sampling theory is analyzed and four biased current circuits are compared.At last,experimental results verified the proposed method.It is demonstrated that the proposed current sensing circuit can achieve high accuracy better than 5%at the temperature range from-25℃ to 75℃.

关 键 词：DC/DC变换 电流镜 高边电流采样 采样精度 

分 类 号：TM930.1[电气工程—电力电子与电力传动]