Analysis of the influence of electrical damage in field magnetizing coil on synchronous round-rotor motor vibration

Relevance. Powerful high-voltage synchronous motors with STD and STDP round rotor series are the main elements of oil gathering system and maintaining reservoir pressure. This fact increases the operational reliability demands. Vibration condition is one of the key parameters controlled in operation. The vibration sources are mechanical and electrical. Generally, a small number of field-turns in the field magnetizing coil leads to a slight change in the symmetry of a magnetic pull. Because of the fact that a short circuit can have the intermittency of stimulation and exist in the motor for a long period of time without exerting marginal impact on operating mode, such damages are checked only at engine overhaul. Thus it is necessary to consider a number of negative effects caused by short circuits in the field magnetizing coil, such as increased wear of the bearings and a sharp decline in bearing lube oil resource due to transverse parasitic currents. The article analyzes the degree of influence of electrical damage on vibration condition of synchronous round-rotor motor. The aim of the research is to assess the degree of influence of electrical damage in a field magnetizing coil of a synchronous round-rotor motor on vibration condition of the latter. Methods. The authors have used the calculation methods adopted in the theory of electrical machines to assess the influence of electrical damages in the field magnetizing coil of the synchronous round-rotor motor. Results. It was found that the turn-to-turn short-circuit in the rotor winding leads to vibration level changes not so much because of the magnetic pull changes as due to the uneven heating of the rotor body. The vibration state change is affected by a slight temperature difference. In case of a vibrostatus changes, it is required to check the electrical machine for electric damage occurrence in a drive winding.