Development Of Motor In Range-extended EV And The Influence Of Ambient Temperature On Motor

Range-Extended Electric vehicles (REEV) have become one of the industry’smost-watched rising in new energy vehicles because of high mileage and lessenvironmental pollution. However, some objective technical problems researchershave met when electric automobile operations testing.The influences of ambienttemperature on the electric automobile are not invisible,especially the performanceof electric vehicles will become worse when the EV demonstrating running in lowtemperature environment. Motors are main parts as power system of EV, theproblems about the motor performance affected by temperature need to be studiedand solved. Moreover, APU is as the key spare parts in REEV, whether internalPMSG works for a long time steadily and efficientlyin high temperature and narrowcircumstance, indirectly influences dynamic performance for REEV. So it isvaluable and practical to research the temperature characters of motor and lowtemperature testing.The design method of generator for the structure characteristics ofRange-extended EV is researched in this paper. The motor should be increasedpower density to reduce the place for the motor as much as possible and also beensured the motor high efficiency according to optimize the long-radius ratio andelectro-magnetic load. In accordance with the environment characteristics of themotor, the influence of ambient temperature on electromagnetic parameters is beconsidered when designing the drive motor. Feasibility and practicability of thisdesigned motor have been proved by the contrast between the simulation results andtesting data.This paper researches the temperature characteristic about permanent magnetand copper winding, and combines the analytical expressions and electromagneticsimulation to obtain the change rule of air gap magnetic flux、back EMF、copperlosses、 iron loss and armature resistance at different ambient temperatures.Considering the practical motor temperature rise, the temperature sensitivitycharacteristic of electromagnetic power is analyzed because of limitation ofinfluence about the material temperature characteristics arouse by temperaturedifferences. Theoretical analysis shows that the temperature characteristic ofelectromagnetic power of drive motor is determined by the proportions betweenback EMF temperature characteristic and armature resistance temperaturecharacteristic. At the same time, thermal field simulation calculation andtemperature rise tests are carried out in order to ensure the security of insulation heat-resistant.This paper tests and analyzes starting characteristic of testing motor、motoroperational efficiency and load capacity of motor under different temperatureconditions through constructing high-low temperature test platform in order toobtain motor low temperature characteristic,also analyzes the cause of motorefficiency was affected significantly with the temperature changes when motor is atlow speed(under1000rpm).The motor interior temperature is be controlled to nomore than1degree in order to prevent the interference of temperature rise. Finally,a motor preheating system is given in this paper based on automatic car preheatingsystem and the preheating principle is also analyzed.