ESTIMATION OF ENERGY INDICATORS OF A MULTI MOTOR TRACTOR ELECTRIC DRIVE FOR PUBLIC TRANSPORT

Abstract

The purpose of the work is to analyze the energy parameters of a multi-motor asynchronous traction electric drive in a city vehicle to ensure a reduction in electric energy losses when driving along the route. The research was carried out for a lightweight double-decker bus, the maximum number of passengers transported is set at 100 people. To achieve the goal, mathematical modeling was used in the MatLab package, in which energy losses were calculated in the multi-engine electric drive of a bus with a different number of traction asynchronous motors. The calculation was carried out for the most characteristic sections of the city cycle of the bus: constant modes of movement with different speeds and transient modes of acceleration. To control the speed of the engines, a proportional law was used to change the voltage on the stator winding and frequency, which correspond to the voltage frequency values at the stator winding of 25 Hz and 50 Hz and, respectively, the standard phase ratio of 110 V and 220 V. The change in the loading moment of the vehicle engines due to the change in the rolling friction force of the wheels for three cases of a complete, half-complete and empty bus is taken into account. The load change due to air resistance when the speed changes is taken into account. In operation it is shown that application of multi-motor asynchronous electric drive allows to reduce energy losses in traction asynchronous electric motors when vehicle is moving at constant speed and at acceleration at different number of carried passengers. Moreover, in order to achieve energy saving, the number of engines used in a multi-motor electric drive must vary depending on speed and acceleration, as well as on the total load moment of the multi-motor electric drive.