| 摘要 |
Method and arrangement for estimating the frequency and the positive sequence of a fundamental component of a measured three-phase voltage (½ ±² ) the method comprising the steps of measuring the three-phase voltage (½ ±² ), calculating estimates of the fundamental frequency voltage component (½ ±²,1 ) and the difference (Õ ±²,1 ) between positive and negative sequence components of the fundamental frequency voltage from the error (½ ±² ) between the measured three-phase voltage (½ ±² ) and the calculated estimate of the fundamental frequency voltage component (½ ±²,1 ) and from an estimate of the angular frequency (É 0 ) of the fundamental voltage component, wherein the estimate of the angular frequency (É 0 ) of the fundamental voltage component is calculated from the estimated difference (Õ ±²,1 ) and from the error (½ ±² ) between the measured three-phase voltage and the calculated estimate of the fundamental component. |
