Daily Archives: 8 January 2020

Determining Idle Running and Short-Circuit Operating Characteristics of an Asynchronous Traction Motor

Abstract

Abstract – It is proposed the possibility to simulate the idle running and short-circuit characteristics of an asynchro-nous traction motor. Based on the results, the motor pa-rameters can be determined. In the modern design of asyn-chronous motors, the simulation of these characteristics is required as a mandatory stage. On this basis, the electro-magnetic stresses and the constructive solutions are finally established, so that the engine corresponds in operation. The tests are important, as they allow for a computation of the motor parameters. There still exists the possibility to simu-late the stationary and dynamic modes, in order to deter-mine the behavior of the motor while running. The compari-sons between the simulated and the data provided in the motor datasheet proves that the occurring errors are under the 2.1 % level accepted as precision level. The correctness of the simulations performed is important in operation, be-cause with the parameters and the results obtained we can anticipate the behavior of the machine in the dynamic or stationary modes. The operating, starting and speed charac-teristics of the asynchronous traction motor must meet the high demands imposed by the complex equipment used in modern transport vehicles. Concerns related to the devel-opment of new methods and procedures to optimize the construction of the asynchronous motors used in traction, to find new mathematical models for the correct simulation of the operating characteristics, are a permanent activity. The simulations and experimental tests were carried out consid-ering a traction motor from a diesel electric locomotive. images

Identification and Sensorless Control Using Embedded System of PMSM Based on FOC Strategy and Power Factor Correction

Abstract

This article presents the procedure for identifying the electrical and mechanical parameters of the PMSM (Permanent Magnet Synchronous Motor). The parameter identification procedure is required in the event that the motor’s electrical and mechanical parameters are unknown, or in industrial applications at the beginning of a drive cycle due to variations of the PMSM parameters with the tem-perature. The parameter identification procedure is imple-mented in the Matlab/Simulink environment. This proce-dure was also implemented in an embedded system and the results of the two (offline and online) identification methods of the nominal parameters of the PMSM are presented comparatively to the parameters in the datasheet. It pre-sents the block structure of the PFC together with the nu-merical simulations achieved in Matlab/Simulink, on the improvement of the PF (Power Factor) of the supply circuit. It also presents the block structures of the FOC (Field Ori-ented Control) strategy and of the back-EMF (back Elec-tromotive Force) sliding mode, MRAS (Model Reference Adaptive System), and PLL (Phase Locked Loop) type ob-servers. The numerical simulations show the superiority of rotor speed estimation when using the back-EMF sliding mode observer compared to the rotor speed estimate pro-vided by MRAS and PLL observers. images