Research Of Adverse Effects On The Power Network Brought By Electric Railway System

The Zhe-Gan electric railway system will be supplied from the Zhejiang 220/110 kV Power Network. The paper describes the unbalance and harmonic studies carried out of the railway traction system. Traction loads are single phase connected, but because these loads are constantly changing, as trains accelerate and decelerate, the total load on the three-phase supply system is generally unbalanced. In addition, because the traction load is thyristor controlled, a considerable harmonic current spectrum is generated. These harmonics and phase unbalance can have adverse effects on the supply system and on other consumers, so that limits have to imposed on the levels that can be tolerated.