一种快速SVPWM算法及其过调制策略研究

Research of fast SVPWM algorithm and its overmodulation method

针对传统SVPWM算法结构复杂、运算量大等问题,提出一种基于三扇区矢量空间的快速SVPWM算法。该算法无需进行坐标变换,有效避免了传统算法中多次三角运算和开方运算,减少了逻辑判断次数。通过简单四则运算便能快速实现精准调制,从而极大地简化了SVPWM的算法结构,减少了算法的执行时间。此外,分析并提出基于分段非线性拟合的SVPWM算法过调制策略。该策略避免了传统算法过调制策略中复杂的保持角和控制角的计算,并减少了查表法带来的内存消耗和调制误差,进一步提升了直流母线电压利用率。仿真和实验验证了该SVPWM算法及其过调制策略的有效性和优越性。

To solve the problems of complex structure and large computation of the traditional algorithm,a fast SVPWM algorithm based on three-section vector space is put forward.Without coordinate transformation,it uses the arithmetic in stead of complicated trigonometric operation,so it can reduce the number of logic judgment and get more accurate modulation.As a result,the algorithm structure of SVPWM is greatly simplified and the operation time is reduced.Besides,to improve the utilization ratio of DC bus voltage further,an over-modulation method based on piecewise nonlinear fitting is analyzed and raised,which can avoid the complex calculation of the holding angle and the control angle as well as the error of the modulation caused by look-up table method is also reduced.The results of simulation and experiment indicate that the fast SVPWM algorithm and its over-modulation method are effective and superior.