Stationary Power Quality Disturbances Research Articles

Estimation of insulation overheating in Medium Voltage and Low Voltage conductors and transformers due to stationary disturbances

This paper presents a method to estimate the insulation lifetime reduction for Medium Voltage (MV) and Low Voltage (LV) conductors and transformers due to the presence of stationary power quality disturbances. Insulation aging can be accelerated by temporary increases of rms values of voltages and currents caused by stationary disturbances, i.e. harmonics. A short duration increase of rms values cannot cause a significant reduction of insulation’s lifetime, but its recurrent presence during long time periods will produce a cumulative effect. Currently available models for insulation aging are employed.

Effects on lifetime of low voltage conductors due to stationary power quality disturbances

<p>This paper presents a methodology to estimate the effects of heating and lifetime in Low Voltage conductors (LV) due to the presence of stationary power quality disturbances. Conductor overheating and cable insulation accelerated aging can be caused by temporary increases in the rms values of the voltages and currents due to stationary disturbances. Waveform distortion, unbalance and phase displacements can be considered among the stationary disturbances. For disturbances with short duration, there is no significant reductions in the insulation lifetime, but disturbances acting for long time periods will cause cumulative and detrimental effects. Currently valid models for insulation aging are employed; the expected power quality disturbance levels are extracted from power quality data bases. A discussion about the effects on insulation lifetime is presented.</p>