A bit-stream based PWM technique for variable frequency sinewave generation

This paper presents a unique technique suitable for the generation of variable frequency sinusoidal waveforms with high quality. Arithmetic operations on the bit streams are performed through digital blocks. The proposed technique is simple and can be implemented on an field programmable gate array (FPGA). Results of a prototype single-phase inverter module with custom built power stage, are presented with simulations. Experimental results indicate that the technique can generate sinusoidal waveforms of frequencies from 20 Hz-60 Hz with total harmonic distortion (THD) 1.4-4%, respectively, and therefore the technique would be an ideal candidate for variable speed motor applications.