Simulation of a three-phase SPWM command system with microcontroller

This paper proposes a dynamic system based on microcontroller, that generates a three-phase SPWM command, with variable frequency which is needed to an inverter designed to operate at U/f = const. It is presented a original simulation system, whose implementation and testing has allowed the establishment of directions of action necessary for the design of the software for programming the microcontroller. In the research carried out has always been analyzed how external commands can be sent to the microcontroller. There are considered as essential three external prescriptions: the frequency of the three-phase sinusoidal voltage, the maximum voltage to the inverter output and the multiplication factor for frequency of the triangular wave used to generate SPWM modulation.