Reliability-Based Robust Design Optimization for Maximizing the Output Torque of Brushless Direct Current (BLDC) Motors Considering Manufacturing Uncertainty

Abstract

In recent years, the deterministic design optimization method has been widely used to improve the output performance of brushless direct current (BLDC) motors. However, it does not contribute to reducing the failure rate and performance variation of products because it cannot determine the manufacturing uncertainty. In this study, we proposed reliability-based robust design optimization to improve the output torque of a BLDC motor while reducing the failure rate and performance variation. We calculated the output torque and vibration response of the BLDC motor using the electromagnetic–structural coupled analysis. We selected the tooth thickness, slot opening width, slot radius, slot depth, tooth width, magnet thickness, and magnet length as the design variables related to the shape of the stator and rotor that affect the output torque. We considered the distribution of design variables with manufacturing tolerances. We performed a reliability analysis of the BLDC motor considering the distribution of design variables with manufacturing tolerances. Using the reliability analysis results, we performed reliability-based robust design optimization (RBRDO) to maximize the output torque; consequently, the output torque increased by 8.8% compared to the initial BLDC motor, the standard deviation in output performance decreased by 46.9% with improved robustness, and the failure rate decreased by 99.2% with enhanced reliability. The proposed reliability-based robust design optimization is considered to be useful in the actual product design field because it can evaluate both the reliability and robustness of the product and improve its performance in the design stage.

Reliability of Mechatronic Systems and Machine Elements: Testing and Validation

“…In [7], an optimization method for brushless direct current (BLDC) motors that takes manufacturing uncertainty into account is presented. The authors demonstrated a reduction in the motor failure rate and variation by the proposed method.…”

Design and Analysis of a Permanent Magnet Brushless DC Motor in an Automotive Cooling System

“…To further enhance the performance of BLDC motors, numerous researchers have conducted extensive research. Jeon Kyunghun et al [22] conducted a reliability-based robust design optimization (RBRDO) of BLDC motors utilizing a reliability analysis in an effort to maximize output torque. V Bharanigha et al [23] proposed a multifunctional APID controller for BLDC motor speed regulation to reduce the generation of motor torque pulsation.…”

Analysis of Inverter Circulating Current and Magnetic Potential for Flux-Weakening Drive of BLDCM

“…With the advancement of diverse driving and control technologies for BLDCMs, these motors have gained significant popularity in various high-performance fields. Consequently, research on BLDCMs has become more comprehensive and extensive [4][5][6][7]. Due to the influence of back electromotive force, when operating the BLDCM at high speeds exceeding the base speed, it becomes necessary to employ advanced trigger angle control to facilitate field weakening in the BLDCM [8].…”