Doświadczenia z eksploatacji napędów pomp dużych mocy z silnikami zasilanymi z przemienników częstotliwości średniego napięcia 6kV - efektywność eksploatacji napędów regulowanych dużych mocy

The paper presents results of experiences from applications big power electrical drives in Poland. In electrical drive was applying frequency converter to medium voltage - 6kV. Very well project and applying of new frequency converter medium voltage 6kV, motor and pomp drive and keeping the input and output currents and supplying voltage in sinusoidal wave from allow to increase the efficiency of pomp and the efficiency electrical energy of pomp or ventilators drive. The paper describes different main circuits of frequency converters with selecting inputs of converter for decreases of losses and influencing to the supply network. In the paper also describes criteria's to projects and to applying these electrical drives and economical effects.