Statistical characterization of DFT-based waveform distortion evaluations in power systems

The paper deals with the statistical characterization of the so-called r.m.s. value of a harmonic subgroup defined in the Standard IEC 61000-4-7 regarding harmonics and interharmonics measurements and instrumentation for power supply systems and equipment connected thereto. A complete statistical characterization is provided in terms of probability density function, cumulative distribution function, and statistical moments by exploiting the properties of noise propagation through the discrete Fourier transform.