Discussion of "Flicker produced by harmonics modulation"

The authors of the original paper (see ibid., vol. 18, p.387-92, 2003) studied the harmonic-flicker effect and show that, under different conditions, the modulation of voltage harmonic components might cause flicker in voltage supply even if the harmonic distortion accomplishes the compatibility levels proposed in the different international standards. The author of this paper argues that the results presented in the paper and obtained in the case studies reported, where different harmonic components are synchronously modulated with the same modulation index and the same modulation frequency, are not very realistic. He states that it seems improbable that nonlinear loads, such as cycloconverters, static frequency converters, arc furnaces, induction motors, arc welders, etc., could generate such a synchronous harmonic modulated pattern in practice.