Conducted and radiated emission from pantograph arcing in AC traction system

One of the most common and yet unavoidable problems in electrified railways are because of pantograph arcing. The intensity of arcing increases during winter because of the ice layer on the overhead contact wire. In AC traction system, pantograph arcing distorts the sinusoidal waveforms of the supply voltage and current. It also generates transients at the current zero crossings (CZC). All these result in a net DC component, harmonics and radiated emission. In this paper we will present an experimental investigation to understand pantograph arcing and influence of power factor on conducted and radiated emission. We found that pantograph arcing generates both conducted and radiated emission in a wide band, starting from DC. Both the DC component and higher order conducted and radiated emission increases with line speed. Running the train at lower power factor can reduce the DC component and emerging as the most preferred solution against problems due to ice in cold weather.