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A computer model, including analytical and FEM formulations, was developed to calculate the starting performance of synchronous motors with solid rotor salient poles. Using quasi-steady state equations, the average and the envelope of the oscillating electromagnetic torque as well as the stator rms current are calculated. With the stator current, the rotor pole losses are evaluated by FEM. The complete simulation process is performed by self-contained software composed by several computational modules properly tiled to simplify the work of a design engineer. The calculated starting performance was compared to experimental results showing satisfactory consistency.

A model allowing the simulation of induction machines with different rotor bars configurations is presented. The electrical machine is modeled by using two-dimensional (2-D) finite-element method and its equations are directly coupled with those of the circuit. A general and new contribution is added for the consideration of special rotor bars topologies. The movement is taken into account by means of the moving band technique, the Maxwell stress tensor, and the mechanical oscillation equation. The model is applied to a brushless doubly fed induction motor.

This paper presents and analyses a 350kW brushless doubly fed three-phase induction machine with its wound rotor circuit connected to flat plane rotary transformers. It presents the advantages of substituting brushes and slip-rings by rotary transformers. In addition, it shows rotary transformer design and presents the doubly fed induction machine operation. The steady state model considers electrical circuit techniques to provide information about current, power factor and efficiency on load. Equivalent circuit parameters used on simulations were obtained through analytical calculation of a prototype.

This paper analyses design and performance aspects of a brushless doubly fed three-phase induction machine with wound rotor circuit accessed by rotary transformer. It focuses firstly on the advantages of substituting brushes and slip-rings by rotary transformers. Secondly it shows the device operation conditions and rotary transformer calculation by using Finite Element Software in 2D domain. In sequence are presented analytical dynamic and steady state models for prediction of machine behavior. The analytical dynamic model is obtained by transforming the equations written in machine variables into equations written in arbitrary reference frame. The steady state model considers electrical circuit techniques to obtain information about current, power factor and efficiency on load. Design data of a 90kW prototype were considered for numerical results presented on this study.

Induction machines temperature rise measurement is certainly a common demand of customers and manufacturers. The manufacturers have to optimize the product to be competitive, while the user wants to be sure that the motor is in accordance with the insulation temperature class limit. The most accepted condition to measure temperature rise in induction motors is under full load since it simulates the real operating conditions. However, it requires the use of dynamometers and sources of same or sometimes greater power than the rated power of machine under test. Additionally the coupling of high power, high speed or vertical machines can consume considerable time and investment. For these cases it is necessary to consider the use of alternative methods to measure the electrical machine temperature. In these alternative methods the load torque applied by the dynamometer is smaller than the motor nominal torque or even no load torque applied. This paper will present a comparison between the most common induction machines temperature rise methods.

This paper presents an analysis of a 75 kW brushless doubly fed induction generator (BDFIG) prototype. Experimental results are presented for the prototype in the cascade mode that enables a comparison in terms of efficiency and power factor with an equivalent wound-rotor doubly fed induction generator. The generator's control system is based on vector control principles which enable to decouple active and reactive power control. The power flow in the two stator windings (power and control windings) and in the grid is analyzed with and without the reactive compensation capacitor bank in the grid using a MatLab/Simulink simulation model. Four cases were studied: (a) the reactive power compensation of the machine is realized only by the control-side converter; (b) the reactive power compensation is realized by both converters (control-side and grid-side converters); (c) the reactive power compensation of the machine is performed only by the control- side converter and a capacitor bank connected at the grid terminals and (d) the reactive power compensation is performed by both converters and a capacitor bank is connected at the grid terminals. The main advantage is obtained with the last case resulting in a significant improvement of the overall system efficiency.

This paper analyses performance aspects of a brushless double fed cage induction motor as a new driving alternative to the classical wound rotor induction motor used in a car shredder drive. It focuses in a real application of 3150 kW - 4160 V - 60 Hz - 514 rpm wound rotor induction motor. Firstly it analyses the car shredder duty and compares the performance of the two motors without a controller. The starting condition is analyzed and a Matlab/Simulink simulation is used to show the advantages of the brushless double fed cage induction motor over the classical wound rotor induction motor, in rated operation condition. The performance of the two drives is compared using the simulation results

Applied to the analysis of complex electromagnetic problems, the finite element method (FEM) often gives good simulation results. On the other hand, it is often time-consuming and of a difficult use. The purpose of our study is to create an interface between two of the main used software for design of electrical machines: solid works, uses to create mechanical draws, and ANSYS, finite element software used for electromagnetic calculation. Using the properties of this software, the final goal is to perform the simulation of 3D complex electromagnetic models, with a modeling and computing time short enough to make the process viable for industry application. The study is based on a permanent magnet claw-pole generator, used as auxiliary exciter in high-voltage generator. Results are validated by experiments.