Glinka, Tadeusz, Polak, Artur, Decner, Adam, Sikora, Andrzej
Abstract:An equivalent circuit of the insulation system in power transformers comes in many forms. In tests for the dielectric loss tangent (tgδ) of the main insulation, the equivalent circuit has been simplified to two-terminal RC series connected or parallel connected circuits. For direct current tests of groundwall insulation modelling, two two-terminals circuits are required – one for charging and shorting, the other for the voltage recovering after shorting. The model turn-to-turn insulation may also be presented by two-terminal circuits. The parameters of the two-terminal circuit can be determined by direct current. The tested winding is energized by DC voltage, the current is interrupted and the voltage waveform on the terminals of the winding is recorded. The parameters of turn-to-turn insulation (equivalent circuit parameters) are calculated from the voltage waveform and they can be used for diagnostic purposes.
Abstract:This paper deals with the results of experimental investigation into a six-pole single-phase line start permanent magnet synchronous motor. The influence of the running capacitor capacitance on the motor running properties was investigated. The influence of the starting capacitor capacitance and its switch-off time on the motor starting properties was investigated.
Abstract:A new design of a brushless direct current motor is introduced in this paper. In the BLDC motor, a high-pressure vane pump is built into the rotor. The motor is excited by neodymium magnets. Its nominal power is 2.5 kW. The motor is built in such a way that the magnetic field does not penetrate the pump. A magnetic structure field analysis of the motor was performed. Demagnetization resistance of the magnets was determined. By the use of time stepping, finite element method waveforms of the electrical and mechanical parameters in the BLDC motor–inverter system were determined.
Abstract:Induction motors with some degrees of freedom (more than one) belong to unconventional drives which offer wider possibilities of motion than traditional drives. These motors constitute a small group of electric drives, however, new requirements for mechatronic devices are the cause of growing interest in their steady and regular development. As far as rotary-linear motors are concerned, they can be used in devices dedicated to mixing and drilling ensuring both rotary and linear movements. Because of the complex construction of such motors, their manufacturing process is expensive. In order to reduce these costs, the authors develop and propose the concept of the 3-phase rotary-linear machine built-up on the basis of a standard 3-phase squirrel-cage motor. This approach results in the significant reduction of manufacturing costs through the use of prefabricated parts (e.g. complete stator, stack of stator sheets, motor housing), as well as allowing the partial adoption of technologies used for standard induction motors.
Abstract:The work concentrates on the thermal calculations and tests of the permanent magnet machine with an external rotor and cooled with liquid flowing around the inner surface of the stator frame. The distribution of the temperature in the cross-section of the machine, obtained as a result of the thermal net solutions in a steady state is presented. The calculation results are compared with the test results.
Kamiński, Grzegorz, Jakubowski, Rafał, Kupiec, Emil
Abstract:This paper presents thermal calculations and tests of a linear induction motor for a model of a personal rapid transit vehicle drive. Various air and liquid cooling systems are analyzed. Laboratory test results of selected solutions are presented. The thermal equivalent circuit model of selected solutions were made. The calculation results were compared with the test results and the most effective solution was selected.
Abstract:The steady state response of a synchronous machine to the torque with angle dependent pulsating component is of great practical importance for the piston drive. Determining such a response is not easy due to the necessity of solving the system of nonlinear differential equations. This paper describes an algorithm that allows directly determining the steady states of a synchronous machine driven by an internal combustion engine (e.g. diesel engine). To create such an algorithm, the harmonic balance method and the iterative Newton–Raphson procedure are used. This approach allows obtaining steady-state solutions directly in the frequency domain. Exemplary calculations are performed for synchronous generators derived from the four-stroke internal combustion engine.
Abstract:The work presented in this paper relates to an Interior Permanent Magnet Synchronous Motor (IPMSM) experimental results and optimization procedure programed in Matlab and Maxwell environments. The stator of the machine is a conventional stator with distributed winding. The subject of the first optimization stage was the geometry of the IPM machine, concerning average torque value maximization and maximum cogging torque value minimization under physical and technological constraints. The optimized rotor core is made of from Magnetic Powder (SMC). It was tested in a generator regime.
Ferreira, José Gregorio, Sobczyk, Tadeusz J., Warzecha, Adam
Abstract:This paper discusses the detection of internal faults in the stator and rotor windings of synchronous machines. Using current signature analysis, it is demonstrated how by using low cost equipment, it is possible to detect the fault by monitoring the currents. The process of detection is totally optimized, and the processing time is enough to identify the fault before the total machine damage. Using the spectrum of the healthy machine as a reference, the followed methodology allows the timely and reliable detection of faults.
Abstract:This paper concerns a circuital model of a 5.5 kVA salient pole synchronous generator with damping bars, with and without the rotor skew. The paper presents an influence of the stator to rotor self and mutual inductance distribution on the induced voltages in the no-load steady state. Inductance distributions used in the circuital model are determined in the FEMM program for linear and nonlinear magnetic circuit. Simulation and experimental verification are presented.