一种变频器相电流采样重构技术

Phase Current Sampling Reconstruction for Inverter

在变频器交流调速的闭环控制方案中,对电动机三相电流进行采样是一个核心环节。为了降低控制低成本、减少体积、高效率,本文根据相电流、直流母线电流及逆变器开关状态之间的关系,提出了一种基于单电阻采样直流母线电流的方式进行电机相电流的重构方案。该方案通过空间电压矢量移相的方法解决了三相电流重构的难点。仿真和试验结果表明了该方法的有效性和正确性。

In the closed-loop control program of inverter control,the motor phase current sampling is a core part.In this paper three-phase current measurement using only a single current sensor in the inverter dc link is proposed based on the relationships among the phase current,DC bus current and inverter switch states.It can minimize the number of current sensors,reduce sensor cost,weight,and volume.The new single current sensor algorithm can solve the difficulty in three-phase current reconstruction by space voltage vector phase-shifting.Simulation and experimental results show that the method is effective and correct.