摘要
提出了一种基于现场可编程门阵列（FPGA）的特定谐波消除算法（SHEPWM）全数字实现方案。首先,利用计算机辅助设计软件,离线计算稳态时消除特定次谐波的开关角,并得到0.055~1.155范围内的调制度与开关角的关系曲线。采用3次多项式对调制度-开关角曲线进行分段线性拟合,计算出拟合系数,并将其存入FPGA的逻辑单元中。在矢量控制中,通过控制环得到参考电压矢量的幅值与相位,由幅值与直流母线电压计算调制度,并通过拟合系数实时计算出开关角,判断参考电压矢量相位所处的开关角区间,并输出相应的开关状态。实验结果证明了方案的有效性。
A digital implementation of SHEPWM（Selective Harmonic Elimination Pulse Width Modulation） based on FPGA（Field Programmable Gate Arrays） is proposed.The switching angles for eliminating the selective harmonics are calculated off-line with computer-aided design software and the relationship curve of modulation index（from 0.055 to 1.155） and switching angle is obtained,which is fitted piecewise and linearly by three-order polynomial,and the fitting coefficients are calculated and stored in the logic cells of FPGA.The amplitude and phase of reference voltage are generated by the control loop in vector control,the modulation index is calculated by the generated amplitude and DC-bus voltage,and the switching angle is calculated in real time by the fitting coefficient.The PWM switching states are determined according to the switching angle sector where the reference voltage phase angle locates.Experimental results show the effectiveness of the proposed method.
出处
《电力自动化设备》
EI
CSCD
北大核心
2012年第2期67-70,共4页
Electric Power Automation Equipment
基金
国家自然科学基金资助项目(51077124)
江苏省“青蓝工程”资助项目
中央高校基本科研业务费专项资金资助项目(2010QNB32)~~
关键词
PWM
FPGA
分段线性技术
拟合
调制
谐波分析
pulse width modulation
Field Programmable Gate Arrays（FPGA）
piecewise linear technique
fitting
modulation
harmonic analysis
