A 31–300 Hz Frequency Variator Inverter Using Space Vector Pulse Width Modulation Implemented in an 8-Bit Microcontroller

With the advancement in power electronics technology, variable-frequency drives have been widely adopted for motor operation due to their inherent benefits: control performance, extending equipment life, and energy savings. The most used technique is Sine Pulse Width Modulation, as it solely requires the modification of the reference signal (sine wave). However, Space Vector Pulse Width Modulation offers lower total harmonic distortion. Therefore, this study presents a technique for the control of induction motors operating in open-loop mode, utilizing a two-level voltage source inverter with a frequency range of 31 to 300 Hz. The proposed control system is modified to encompass between 930 and 1848 switching periods, varying the number of switching periods along with the frequency variation. This approach allows the use of a single LCL filter across the whole frequency spectrum. It is adapted for implementation in an 8-bit microcontroller, which has its inherent limitations, yet it achieves performance levels similar to those found in high-level processors like FPGAs and DSPs. The signals generated by the microcontroller are captured by a DAQ card and input into a MATLAB/Simulink model to observe and analyze the performance of the proposed control system.