METHOD AND APPARATUS FOR ESTIMATING ELECTRIC LOAD COMPOSITION CONSIDERING TRANSFORMER AND DIGITAL POWER METER ADOPTING SAME

摘要

A recent increase of facilities including power electronics and electric machinery devices has resulted in an increase in voltage or current waveform distortion. Thus, quick and correct evaluation of electric load composition having a power system signal distorted as a result of not only intermittent switching operations of nonlinear loads but also harmonics is required. The present invention suggests modeling for estimating electric load composition ratios for an electric power consumer having a distorted current signal considering an actual transformer. A Kalman filter algorithm or a conjugate gradient method, which is an optimization method, is applied to evaluate electric load composition. In particular, since the Kalman filter optimization method has robust blocking capability against process distortion and measurement distortion, a nonlinear electric load composition ratio in each waveform due to nonlinearity and complexity in an actual environment can be estimated.