Flat-Top space-vector modulation implemented on a fixed-point DSP

The paper presents the method and implementation steps for space-vector (space-phasor) pulse width modulation, on a fixed-point digital signal processor using MATLAB´s Simulink^reg and the eZdsp development board. Besides the implementation of the simple suboptimal method, there are implemented 4 different Flat-Top (discontinuous) procedures. The simulation results show the improvements brought by the Flat-Top techniques: less commutations, even inside a sampling period, the ability to choose a Flat-Top method in correlation with the character of the inverter´s load in order to reduce furthermore the commutation losses. Also, the design of these Flat-Top techniques is improved by computing the position of the reference phasor without any trigonometric function, by using p.u. values for the on-times of basic vectors and by using the DC link voltage value, which can be compensated in case of the voltage ripples.