Design of Low-Cost BLAC Motors for Integrated Electric Brake Systems

During motor production processes, the influence of motor manufacturing tooling costs on motor prices is mostly negligible and considered to be insignificant. The manufacturing cost, particularly the molding cost, may not be a significant issue for mass production, but it would become a crucial issue for modern small-scale application-oriented design. When the total number of motors produced per motor manufacturing tool such as stator and rotor pressing tool is reduced, the effect of the motor manufacturing tool cost on the motor price can be greatly increased. To reduce the cost, we present a new design approach of a brushless AC (BLAC) motor that shares motor manufacturing tools, unlike many previous studies on low-cost designs. The design approach of a BLAC motor is applied to integrated electric brake (IEB) systems of various specifications. In addition, to analyze the motor performances in IEB systems, the BLAC vector control system, FEM, design of experiment, and moving least square method are used. Furthermore, to predict the available operating time of a motor, a heat compensation coefficient that uses the experimental data of an existing motor is proposed. By implementing this design approach, we have effectively designed motors that satisfy performance requirements such as speed response, available operating time, and total harmonics distortion (THD) of back EMF with minimum stator core volume, in the IEB systems, and achieve a 25.5% reduction in cost through sharing of motor manufacturing tools.