Investigation of energy characteristics of the electromechanical control system of 4-drive electric vehicle

Abstract

Purpose. To determine for the developed electromechanical control system of a 4-drive electric vehicle, the power of the drives and the coefficients of the gearboxes that ensure the minimum energy consumption during acceleration from 0 to 100 km / h in 5 s. Research methods. Mathematical analysis and modeling. Findings. The proposed solution is to determine, for a given vehicle dynamics (acceleration from 0 to 100 km / h in 5 s), by mathematical modeling, values of drive powers and gear ratios, which increase the efficiency of the electromechanical system. The condition for increasing the efficiency is to minimize the consumption of electrical energy for acceleration. The developed computer model of the electromechanical control system of the 4 - drive electric vehicle allows to carry out researches on definition of electromechanical parameters of the control system providing the minimum energy consumption at dispersal from 0 to 100 km / h for 5 s. The current consumed by the drives was determined by studying the energy characteristics of the drives obtained on a previously developed laboratory stand. Gear ratios and drive power have been found to provide minimum power consumption when accelerating a 4-wheel drive electric vehicle. From the obtained data it is seen that for each power studied there are minima in the range of gear ratios 1-3,4. Also in the course of the research it was found that among the studied powers of 30-160 kW there is a drive that uses less energy. For the studied electric vehicle, these are four drives of 75 kW with a reduction factor of 3,3. The presence of minima in the interval between the gear ratios and the interval of the studied drive powers is explained by the variability of the engine efficiency in the load ranges varying from 0.3 to 2 times and the engine shaft speed of 0-3000 rpm, due to varying degrees of loss impact, the dynamic modes of the drive. Originality. The study of energy characteristics based on the developed control system for a 4-wheel drive vehicle makes it possible to find the electromechanical parameters of the system that provide a minimum of energy consumption during acceleration from 0 to 100 km/h in 5 s. Practical value. The electromechanical parameters of the control system of the 4-drive electric vehicle obtained as a result of research allow to receive economy of electric energy at dispersal from 0 to 100 km / h for 5 s in 2-3% within one experimental nominal power of the engine.