Analysis and comparison of real-time sine-wave generation for PWM circuits

Four methods for the hardware and software generation of real-time sine-waves suitable for PWM circuits are presented. The sine-waves are derived from: a truncated modified cosine Taylor series, x(π-x) function, a digitally filtered trapezoid, and a second-order differential equation. Triplen injection is incorporated by the addition of a defined magnitude triangular waveform of three times the fundamental frequency. Each sine-wave generating technique is implemented, as applicable, in a programmable logic cell array and/or in microprocessor-based software. In each case the output spectra and total harmonic distortion are compared with computer simulated results