H. Dahmardeh; M. Ghanbari; S.M. Rakhtala
Abstract
In this paper, a novel combined Direct Torque Control (DTC) method and Stator-Flux Oriented Control (SFOC) system to increase general performances of Three-Phase Induction Motor (TPIM) drives is proposed. The introduced control scheme includes merits of DTC for instance simple structure, less dependent ...
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In this paper, a novel combined Direct Torque Control (DTC) method and Stator-Flux Oriented Control (SFOC) system to increase general performances of Three-Phase Induction Motor (TPIM) drives is proposed. The introduced control scheme includes merits of DTC for instance simple structure, less dependent on PI controller coefficients, fast dynamics, and merits of SFOC such as high precision and constant switching frequency. Specifically, the proposed control scheme includes a table-based variable structure developed on DTC strategy and a PI controller in connection with a Pulse Width Modulation (PWM) algorithm based on SFOC strategy. To confirm the usefulness of the introduced controller, simulation studies are accomplished for a 2.5kW TPIM in different situations. Results under the presented control system approve the good performances of this technique in comparison with classic DTC and classic SFOC. Investigation in TPIM performances under the introduced control system indicates relatively quick dynamic responses with low torque and stator flux ripples.
Electric Mechinces & Drive
S. Sadr; D. Arab Khaburi; M. Namazi
Abstract
This paper presents the movement dynamic of the train and the relationship between the speed of wheel and train, as well as a discussion about the concept of wheel slip. There are two different operation regions designated as creep and wheelspin areas for wheel slip. Creep and wheelspin areas have stable ...
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This paper presents the movement dynamic of the train and the relationship between the speed of wheel and train, as well as a discussion about the concept of wheel slip. There are two different operation regions designated as creep and wheelspin areas for wheel slip. Creep and wheelspin areas have stable and unstable characteristics, respectively. Wheels and rails are constructed from iron, and thus the friction between them is negligible. Therefore, operation point of speed control system may be in either creep or wheelspin areas. The place of the operation point depends on the values of driving torque compared with the value of maximum adhesion torque. As described, in this article too, in order to minimize the acceleration time, the best operation point is maximum adhesion point. To provide a situation to study algorithms of adhesion control, this paper presents a complete model for simulation the adhesion control. Adhesion coefficient is a non-measurable quantity; therefore, an estimator, previously used, for its estimation is used. The traction motor which is used in this study is an induction motor. The speed control system of this traction motor is field oriented control. The presented model is used in operation in creep/wheelspin area and on maximum adhesion point. The simulation results approve the model.
