“Severalmaz” Company (Arkhangelsk, Russia):

Prigodin V. A., Chief Power Engineering Specialist of Lomonosov Ore-dressing and Processing Enterprise
Galyshev V. V., Deputy Chief Power Engineering Specialist of Lomonosov Ore-dressing and Processing Enterprise, e-mail: vgalyshev@severalmaz.ru

This article shares the ideas of application and technical decisions, which were accepted by Lomonosov ore-dressing and processing enterprise for power supply of electric motors of pump units of the pit sump and dewatering wells due to the frequency converters. The most modern technical decision is an application of double-insulating scheme for power supply of high voltage motors with frequency transformation by the side of 0,4 kilowatt.
The exploitation experience shows that due to the frequency converters, there was appeared the possibility of not only smooth start and finish of pump units, but also the regulation of the pump units productivity with the purpose of the decreasing of the quantity of pump unit startings. If the inflow is more low than the nominal output of the pump unit, the frequency of the rotor spinning of electric motor could be found, without the pressure losses and lower costs of energy during the pumping in the inflow volume. In that way, the necessity of the periodic finishing of the pump unit is the water conservation in the water header.
Due to the application of frequency converters, the operation regime of the pumping plants became more constant. So, the problems with the power losses in the starting time are solved and the steady state load on the diesel engine power plants is supplied.