Harmonic voltages and lightning equipment flicker caused by pumping station - measurements, analysis and mitigation

This paper discusses cause and effect of harmonic voltages and severe lighting equipment flicker that were observed by low voltage end consumers in connection with the operation of a pumping station connected to a 22 kV radial line of a typical MV distribution network of a Norwegian utility. The pumping station, consisting of three wound-rotor induction motors rated at 1.75 MW, 6.6 kV, forms part of a local medium-size hydro power scheme. The voltage disturbance is a 7.harmonic (and partly 5.harmonic) component fluctuating with a frequency of approximately 2 Hz, resulting in considerable flicker problems in lighting equipment at end customers, causing customer complaints.