Measurement of network harmonic impedances: practical implementation issues and their solutions

Determination of network harmonic impedances using pre- and post-disturbance steady-state waveforms is a well-known technique. Due to practical constraints, however, it is not quite straightforward to implement the technique for real-life applications. Using an actual utility case as an example, this paper presents practical implementation issues involved and their solutions. Improvements are made to the technique by applying α-β-0 transformation on three-phase measurements. The usefulness of the improved technique is demonstrated with simulation and field measurement results. Since the technique only requires steady-state data, it can be easily implemented with many common power quality meters. One of the applications of the technique is to determine the existence of resonance conditions for shunt capacitor applications