Design Of A4Platform C-EPS Permanent Magnet Brushless Motor

With the serious environmental pollution increasing, energy saving and emission reduction hasbecome an important issue for the automotive industry. In recent ten years, Electric power steeringsystem(EPS) instead of hydraulic power steering system(HPS) has become the mainstream ofmodern steering technology, as the power source of electric power steering system, EPS motorplays a crucial role in the operation of the whole system. In this paper, combined with thecharacteristics of the EPS motors, which have low voltage with high current, high power density,high torque, small torque fluctuation and so on, designed and researched on a permanent magnetbrushless motor for C-EPS.Firstly, combined with design features in this kind of special motor and the actual requirementfor industrial mass production, determine the motor stator and rotor structure, and aiming at theimportant parameter corresponding to calculation and analysis, then design a practical highpermanent magnet brushless motor for EPS.Compare motor air gap magnetic density under different pole and slot combinations withAnsoft, simulation analysis the motor performance which has been designed. Because of the motortorque fluctuation characteristics is small, using Rotor skewing method to reduce the coggingtorque, simulation analysis by transient three-dimensional field. The air gap flux density is animportant index of motor design, which affects the performance of the motor, oblique pole of therotor have a great influence on the distribution of air gap magnetic flux density, calculate anddetermine the equivalent air gap density waveforms under the condition of different slopingmagnetic pole, and then harmonic analysis, experiment and simulation are compared to verify thatthe air gap magnetic density and the no-load back electromotive of the motor which has beendesigned.Study on the temperature rise of the motor for EPS. Access to relevant information can see thatexisting domestic EPS motor work by using the short-time work system. With the development ofmodern transportation, Short time work system is difficult to satisfy the actual the current workingform of the steering motor. Analysis and research the loss of each part in this motor. Combined withthe temperature rising characteristics and the actual condition of vehicle steering system operation, determine a new working system for the working characteristics of the EPS motor, and thenanalyzed by temperature field.