Flicker Transfer in Radial Power Systems

Loads which exhibit continuous and rapid variations in their current can cause voltage fluctuations that are often referred to as flicker. One good example for such loads is arc furnaces which are usually fed by dedicated feeders from the high voltage busbars in transmission systems. The flicker generated from such loads will propagate to the upstream HV point of common coupling (PCC), and from there to the downstream through the transmission and sub transmission systems. This paper demonstrates how the generated flicker is propagated from the HV PCC to the downstream in radial networks exhibiting different levels of attenuation depending upon the load composition of the downstream. Theoretical investigations on flicker transfer have been carried out using simple and more advanced modelling of loads and simulations of radial transmission and sub transmission networks having different load types. The behaviour predicted by the theoretical work is supported through field measurements that have been carried out in an actual network.