Comparison of the FPGA Implementation of Two Multilevel Space Vector PWM Algorithms

Multilevel converters can meet the increasing demand of power ratings and power quality associated with reduced harmonic distortion and lower electromagnetic interference. When the number of levels increases, it is necessary to control more and more switches in parallel. Field programmable gate arrays (FPGAs), with their concurrent processing capability, are suitable for the implementation of multilevel modulation algorithms. Among them, space vector pulsewidth modulation algorithms offer great flexibility to optimize switching waveforms and are well suited for digital implementation. In this paper, two algorithms, 2-D and 3-D, are analyzed and implemented in an FPGA. In order to carry out the implementation, both algorithms have been described in very high speed integrated circuit hardware description language, partly hand coded, and partly automatically generated using the system generator tool. Both implementations are compared in terms of implementation complexity and logic resources required. Finally, test results with a neutral-point-clamped inverter are presented.