Khudobin K. Improving the performance of asynchronous electric drive of scraper conveyor

Dissertation is devoted to the issues of improving the efficiency of drive of scraper conveyor, for the reducing of dynamic loads through the use of variable frequency drive, with quasi-frequency control regulation of supply voltage. A mathematical model of the scraper conveyor, components of which are: the model of the asynchronous motor on the basis of an improved method for the decomposition of the rotor shaft into layers, supplemented by numerical-field calculations of the magnetic field, which enables to take into account the effect of current displacement, and saturation of the magnetic system; models of different variants of formation voltage, which are provided corresponding pulse-phase control pulse phase control systems thyristors; load model traction organ scraper conveyor as a system of finite elements, each of which operates the friction force and the linear elastic-dissipative coupling between the elements – scrapers drawbar organ. The work proposed and justified: the quasi-sinusoidal voltage formation laws, which provide the best performance of the drive; the study its effect on engine startup process after jamming of drawbar organ; methods of improving the stability of the drive on reduced speed of movement of the drawbar organ and developed requirements for the pulse phase control systems. Were done experimental studies of the sample of model drive, which confirmed the adequacy of the developed mathematical models, and were established that the use of quasi-sinusoidal power supply provides two-speed drive mode, reduced the dynamic loads at startup and during emergency modes of works.