DYNAMIC ONLINE MEASUREMENT OF EQUIVALENT PARAMETERS OF 3-PHASE SYSTEMS FOR HARMONIC FREQUENCIES

A method of an on-line measurement of equivalent parameters for harmon ic frequencies of a three-phase distribution system with harmonic gene rating loads is discussed in the paper. The impedances of the supply a nd the load, the complex RMS (CRMS) values of the load generated curre nt harmonics, and the CRMS values of the distribution voltage harmonic s are the subject of the measurement. It is shown that the on-line mea surement of these parameters requires that the line voltages and curre nts ave measured at least in three different states of the system. The se states of the tested system are changed by disturbing the system wi th a current harmonics generating device, built in a form of a fast th yristor switch. The method is illustrated with measurements in a physi cal system.