Selected Problems of $k$ -Factor Estimation Related to the IEC Flickermeter’s Nonlinearity

International Electrotechnical Commission flickermeter is an apparatus intended to indicate the correct flicker perception level for all practical voltage fluctuation. The architecture of this apparatus is described by the standard block diagram included in IEC 61000-4-15. On the basis of the standard specification, this paper describes the method of k-factor determination. Following the specification, it has been assumed that the voltage fluctuations correspond to amplitude modulation with rectangular modulating signal. The dependency of the P
_st
indicator on modulation depth has been presented. The nonlinearity error of this dependency has been calculated for fluctuation rates specified in the standard. Charts have been provided depicting the influence of input voltage carrier's initial phase on the P
_st
indicator value for fluctuation rates specified in the standard as well as for additional values. The presented results of numerical simulations, confirmed by laboratory tests, and also compliant with the proposed analytical model, describe the operation of flickermeter as defined by IEC 61000-4-15.