Distribution system design options for connection of Metro systems

Large Metro systems can introduce significant power quality problems into the local electricity supply company's distribution network. These problems manifest themselves at the point of common connection and down through the supply company's network in terms of voltage fluctuations and harmonic voltage distortion. Two sets of studies are presented for a typical traction system, one for voltage fluctuation and the other for harmonic distortion, to determine the improvements in power quality, which can be achieved. The effect of static VAr compensators (SVCs) and harmonic filters has been analysed, with attention given to their size and location within the Metro's high voltage distribution network.