A Pseudo-Natural Sampling Algorithm for Low-Cost Low-Distortion Asymmetric Double-Edge PWM Modulators

In this paper, a pseudo-natural sampling algorithm for correcting the harmonic distortion produced by asymmetric double-edge uniform-sampling pulse-width modulation is proposed. The algorithm uses the decomposability of the asymmetric double-edge pulse-width modulation process and the Lagrange numerical differentiation method for calculating the pseudo-natural sampling points to obtain a harmonic distortion correction effect. The computational complexity of the algorithm is low because it requires only three shifts, six additions and three multiplications to calculate each of the pseudo-natural sampling points. A complete experimental system based on a single field programmable gate array was built to verify the effectiveness of the proposed algorithm and to compare it with other reported kindred algorithms. The results obtained show that the proposed algorithm has lower hardware requirements and better harmonic distortion correction than other related algorithms.