Method of and apparatus for determining fundamental frequency component of the grid voltage

摘要

A method and arrangement of estimating the fundamental frequency component of the grid voltage (ν̂S,1) of a single phase network. The method comprises the steps of measuring the grid voltage (νS) of the single phase network, forming an adaptive estimator (AQSG) having a parameter (Ω̂) having the information on the fundamental frequency (ω0) of the grid voltage, the adaptive estimator producing an estimate of the fundamental frequency component of the grid voltage, forming an adaptation law (FFE) receiving parameters from the adaptive estimator (AQSG) for producing an estimate for the parameter (Ω̂) having the information on the fundamental frequency of the grid voltage, feeding the estimated value for the parameter (Ω̂) having the information of the fundamental frequency to the adaptive estimator from the adaptation law to be used in the estimation of the fundamental frequency component of the grid voltage (ν̂S,1).