基于DFT的旋转变压器信号偏差矫正方法研究  

Research on Signal Deviation Correction Method for Rotating Transformer Based on DFT

作　　者：许中舰 刘维亭[1] 魏海峰[1] XU Zhong-jian;LIU Wei-ting;WEI Hai-feng(Jiangsu University of Science and Technology,Zhenjiang 212000,China)

机构地区：[1]江苏科技大学,自动化学院,江苏镇江212000

出　　处：《电力电子技术》2024年第1期32-35,共4页Power Electronics

基　　金：国家自然科学基金(51977101);江苏省省重点研发计划产业前瞻性与共性关键技术重点项目(BE2018007)。

摘　　要：解码芯片在对旋转变压器输出的位置信号做处理的过程中,芯片在采样时容易产生各种非理想偏差,这会造成转子位置估算精度的急剧下降。针对该问题,分析了电压信号中的幅值偏差和正交偏差会对旋转变压器解码的输出角度叠加一个2倍频的波动,直流偏差会叠加一个同频波动的问题,提出了一种基于离散傅里叶变换(DFT)的输入矫正法用于实现旋转变压器输出信号的偏差矫正,同时有效降低一次二次波动。该方法首先离散采样信号,通过DFT公式提取旋转变压器输出信号的直流信号和基频信号;然后基于直流信号和基频信号先后计算直流偏差、幅值偏差和正交偏差,通过控制器实现偏差值矫正。最后,仿真和试验结果表明,在芯片采样产生偏差时,所提出的偏差提取方法有效,试验中相应的正余弦输出信号指定阶次的波动更小。During the process of processing the position signal output by the rotating transformer,the decoding chip is prone to various non ideal deviations during sampling,which can cause a sharp decrease in the accuracy of rotor position estimation.In response to this issue,an input correction method based on discrete fourier transform(DFT)is proposed to achieve deviation correction of the output signal of the rotating transformer by analyzing the impact of amplitude deviation and orthogonal deviation in the voltage signal on the output angle of the rotating transformer decoding by adding a 2 fold frequency fluctuation,and the impact of direct current deviation on the same frequency fluctuation.This method effectively reduces primary and secondary frequency fluctuations.This method first discretizes the sampled signal and extracts the direct current signal and fundamental frequency signal of the rotary transformer output signal through the DFT formula.Then,based on the direct current signal and the fundamental frequency signal,the direct current deviation,amplitude deviation,and orthogonal deviation are sequentially calculated,and the deviation value is corrected through the controller.Finally,simulation and experimental results demonstrate the effectiveness of the proposed deviation extraction method when chip sampling generates deviations,and the fluctuation of the corresponding sine and cosine output signals in the specified order is smaller in the experiment.

关 键 词：旋转变压器 解码 离散傅里叶变换 非理想偏差 

分 类 号：TM4[电气工程—电器]