HARMONIC IMPEDANCE MEASUREMENT USING 3-PHASE TRANSIENTS

In this paper, a technique is presented for measuring the harmonic imp edances of an unbalanced three-phase distribution feeder. The techniqu e uses transients in bus voltages and feeder currents generated by sev eral close-trip operations of the shunt capacitor bank. The work is ba sed on the assumption that the impedance of feeder does not change ove r time during which the switching operations are performed. Mathematic al development of the technique is verified with the laboratory and th e field tests. The technique provided good measurements of the harmoni c impedances up to 1.5 kHz for the given capacitor sizes. Statistical indices were developed to assess the accuracy of the estimated impedan ce values.