Abstract
Purpose: In the work [1], an experimental study of the energy efficiency of electric locomotive asynchronous traction drive under changing load has been carried out. In this article, the task is to develop a method for calculating the losses in an asynchronous traction motor (ATM) when powered by a converter, depending on the changing load. Methods: When ATM is powered by a converter and voltages and currents are non-sinusoidal, the determination of losses is a difficult problem, since a significant number of factors must be taken into account. An approach based on the separation of losses and the utilization of experimental results has been employed. To calculate the losses, an approach used in the theory of electrical machines has been applied. It is based on the separation of losses, which consist of electrical (losses in copper), magnetic (losses in steel), mechanical and additional ones. Since the stator current contains higher harmonics, the electrical losses in the stator winding are determined taking into account the effect of current displacement. To ascertain the magnitude of magnetic losses, the harmonic composition of the flux linkage in the air gap is determined, the losses from each harmonic are calculated and summarized. Additional losses in the nominal mode are considered equal to 0.5% of the ATM power. The total loss in the ATM is determined by the summation of all the specified losses. The results of the DTA-1100 type traction motors tests according to the mutual load scheme given in [1] have been used as initial information for calculating the losses. Results: First of all, the losses in the DTA-1100 traction motor have been calculated when operating in the nominal mode. The obtained efficiency value, equal to 0.962, is in good agreement with the passport data of the engine, which is declared as 0.96. Further, the losses in the ATD when operating in variable modes are determined by calculation. A pattern of calculated losses depending on the power on the motor shaft has been established, which practically coincide with the losses found during tests on the stand, in the entire range of loads. Practical significance: The proposed method is inherently universal, and the reliability of the results obtained is confirmed by comparison with the experiment. The technique can be used to determine the energy efficiency of asynchronous traction motors of domestic electric and diesel-electric locomotives and electric trains.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.