现在很好的画图工具，也要有很好的程序用实现的驱动。-I have been blessed to meet a wonderful man who at the very least is now a great friend," she said.

利用mathcad编写的特定谐波消去法的仿真程序，并且可以给出shepwm图形-To mathcad written in a specific harmonic elimination method simulation program, and can give shepwm graphics