Shkurpela A. Increasing of efficiency traction asynchronous drive with autonomous energy sources

The dissertation is devoted to solving the scientific and practical problem of increasing the efficiency of traction asynchronous electric drive (TAED) with autonomous power supply by the criterion of maximizing the ratio of moment to current (MTPA) by optimizing the control system of asynchronous motor (AM). Existing approaches to optimization with and without the influence of AM magnetization characteristics are considered. It is established that the existing approaches to optimization by the criterion of MTPA were created under the condition of full use of the standalone inverter by voltage and do not take into account the modes of operation under conditions of power limitation of AM. Component simulation models and a general TAED model have been developed, adapted for conducting research on selected tasks. The simulation model of the power source is simplified, since the transients of the diesel generator set have much greater inertia than the processes of the growth of emergency and abnormal modes in the electrical and mechanical parts of the TAED. In the simulation of the system, the standalone inverter-AM is tested for the implementation of the nonlinearity of the magnetization curve of the AM simulation model by simulating the idling test for eight values of the linear AM voltage. As an estimate, the obtained idling characteristic was compared with the results of bench tests of eight serial AMs of AD906 type (manufactured by SE "ELEKTROVAZhMASH"), which allowed to reflect the statistical deviation of the parameters of the existing AM samples from the calculated, not exceeding 5%. In order to confirm the adequacy of the general model of TAED, a comparative analysis of the simulation results and the results of train tests of the basic sample was carried out when driving at a speed of 5 km / h and at acceleration to a speed of 50 km / h in a flat section of the road. It is established that the deviations of the simulation results from the results of the Fisher F-test do not exceed 5%. In solving the problem of synthesis of the control system AM, optimized by the criterion of MTPA, analytical expressions of calculating the angle of position of the vector of AM current are proposed, the value of the module of the vector of coupling of the rotor AM, taking into account the change of the magnitude of the input power. The rational for choosing of the method for constructing a characteristic flux linkage of the AM rotor in the field attenuation mode, obtained during the study of transients in the system autonomous voltage inverter-AM in the field attenuation mode. For TAED, a mathematical description of the block of correction and distribution of tasks current AM was proposed, depending on the current rotational speed of the AM rotors, which allowed to limit the acceleration of rotation frequencies, to control the dynamics of movement or to create effective protection against excessive slippage of wheel pairs (boxing, yuz). An optimized TAED simulation model was developed and it was found that using the MTPA criterion optimization, taking into account the magnitude of the AM power, allows to increase the AM electromagnetic moment by 53% in the start mode, and the power factor by 17.6%, which confirms the efficiency of the proposed solutions.