实现spwm的fft频谱分析，数据计算的范例程式。-Achieve spwm FFT spectrum analysis, data sample program.

实现spwm谐波消除方法滤波器的设计模型搭建。-To achieve the spwm harmonic elimination filter design and the model structures.

用脉冲宽度按正弦规律变化而和正弦波等效的PWM波形即SPWM波形控制逆变电路中开关器件的通断，使其输出的脉冲电压的面积与所希望输出的正弦波在相应区间内的面积相等，通过改变调制波的频率和幅值则可调节逆变电路输出电压的频率和幅值-With pulse width according to the sine law of change and equivalent sine wave inverter PWM waveform of SPWM waveform control circuit swit