engleski

Possibilities to increase input impedance or power factor of line side converters supplied by dc or ac railway network

The presented results are a part of comprehensive research and development of 50 kVA multi-system voltage and frequency converter VIS-50, which were made by Končar Group, Zagreb, Croatia. The purpose of this line side converter is voltage supply of devices in modern passenger coaches in European international railway traffic, where the following standardized UIC (International Railways Union) electric heating voltages apply: DC supply: 1500 V and 3000 V ; AC supply 1500 V, 50 Hz and 1000 V, 16 2/3 Hz. The strict requirements of line side converter influence on DC and AC railway supply network are solved at the converter input according to UIC 550 regulations. The solution was the choice of DC/DC boost converter in function of active filter because of its simple structure and good control characteristics. The research was performed on mathematical models and a physical model of boost converter of 2.5 kW. In order to maintain the converter input impedance high, when converter operates on DC supply network or the input power factor higher than 0.95 when converter operates on an AC supply network, it is necessary to control the input current, UIC-Kodex. In the same way the current disturbance level in the supply network is maintained lower than the prescribed one, according to UIC 550 (the frequency range from 1 to 10.000 Hz).

boost converter; input impedance; power factor

nije evidentirano