摘要
为了降低空间矢量调制算法的开关切换频率,减少开关损耗,在αβ'平面上,利用特征四边形和特征网络的概念,采用基本切换沿特征网络遍历扇区各个顶点的调制算法,对逆变器开关频率进行优化。由于特征网络的封闭性以及特征四边形之间的切换关系,利用特征网络遍历扇区的各个顶点能得到很低的开关切换次数。针对n级逆变器,分析参考电压调制系数变化产生的特征四边形和特征网络多样性,根据特征网络研究逆变器开关的切换路径,给出了开关切换次数的计算方法。以3级7电平逆变器为例,给出了仿真和实验结果,其中相电压实验波形能很好地逼近参考电压,且开关切换次数仅为同相层叠正弦调制算法的38.6%。
In order to reducing the switching frequency of space vector modulation and decreasing switching loss, based on the concepts of characteristic quadrangle and characteristic network on the a＇fl＇ plane, a modulation algorithm adopting the traversal over the vertices of the sector by basic switches along the characteristic network was proposed to optimize the inverter switching frequency. Because of the closeness of the characteristic network and the properties of switching between characteristic quadrangles, very small number of switching could be obtained by traversing the sector vertices along the characteristic network. For n-cell inverters, the diversity of the characteristic quadrangles and characteristic networks produced by the varying reference voltage modulation coefficient was analyzed. The switching routes for inverters based on the characteristic network were studied. The method to calculate the number of switching was given. Simulation and experimental results on a three-cell seven-level inverter were presented. The results show that the phase voltage results in a good approximation to the reference voltage, and the switching frequency is only 38.3% of that given by the phase disposition sine pulse-width modulation （PD SPWM）.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2011年第36期46-52,共7页
Proceedings of the CSEE
关键词
多电平
空间矢量调制
基本切换
开关频率
特征网络
multi-level
space vector modulation （SVM）
basic switching
switching frequency
characteristics network
