Design of SPWM generator based on the algorithm of area equivalent

According to the theory of effect of impulse is invariant, an algorithm of three phases SPWM waves is developed with the direct equivalent area method. Then a high accuracy generator is designed based on FPGA. The SPWM generator designed in simple circuit not only has stronger reliability, but also can be programmed more easily .The result of simulation indicates that the SPWM waves generated with this method is excellent, and the frequency of the output waves is controllable. It can satisfy variable frequency speed control system well.