Analysis and Design Optimization of a Permanent Magnet Synchronous Motor for a Campus Patrol Electric Vehicle

Abstract

This work presents the analysis, design and optimization of a permanent magnet synchronous motor (PMSM) for an electric vehicle (EV) used for campus patrol with a specific drive cycle. Firstly, based on the collected data like the parameters and speed from a test EV on the campus road, the dynamic calculation of the EV is conducted to decide the rated power and speed range of the drive PMSM. Secondly, according to these requirements, an initial design and some basic design parameters are obtained. Thirdly, optimization process is implemented to improve the performance of the designed PMSM. The permanent magnet (PM) structure, airgap length and stator core geometry are optimized respectively in this step. Different optimization processes are proposed to meet multiple optimization objectives simultaneously. Based on the finite element analysis (FEA) method, it is found that the harmonic of the optimized PMSM is lower than that of the initial design, and the torque ripple is reduced by 24%. The effectiveness of optimization on the core loss and PM eddy loss is validated and the temperature rise is suppressed effectively. Finally, a prototype is fabricated for the optimized PMSM and an experimental platform is developed. The test results verify that the optimized PMSM meets the requirements of the specific campus patrol EV well.

Optimization of the Biofuel Supply Chain With Capital-Constrained Farmers Under Government Subsidies

“…The second part is total companies' profit π C1 + π C2 . The third part is the consumer surplus (q 1 ε) 2 2 + (q 2 ε) 2 2 . The last part is the government expenditure cs(q 1 ) 2 + cs(q 2 ) 2 .…”

“…1 + r − rs)(a − 2w 2 ) −εσ 2 (bw 1 +2w 2 )) c 2 (1+r − rs)2 = 0.Combining the above two equations, we can get the optimal wholesale price arew * 1 = w * 2 = ac(1+(1−s)r) (2+b)σ 2ε +2c(1+(1−s)r) , then q * 1 = q * 2 =aε 2c(1+r−rs)+(2+b)εσ 2 . Further we get the expected profit function of the farmers and the companiesπ * F1 = π * F2 = a 2 cεF (ε) (1 + r − rs) (2c(1 + r − rs) + (2 + b)εσ 2 ) 2 , π * C1 = π * C2 = a 2ε (c(1 + r − rs) +εσ 2 ) (2c(1 + r − rs) + (2 + b)εσ 2 ) 2 .C.…”

“…where A 11 = (32c 3 (1 +ε(F (ε) − 1))(1 + r) − a 11 , a 11 = 8c 2 (4ε 2 (1 +F (ε)), A 12 = 4(−1 + b)(1 + r) +ε(b(−1 +F (ε))(1 + r), A 13 = 4(1 +F (ε) + (−1 +F (ε))r)))σ 2 ,…”

Design and Analysis of Permanent Magnets in a Negative-Salient Permanent Magnet Synchronous Motor

“…The flux density of permanent magnets (PM) is related to motor design, PM materials and operating environment [1]- [3]. When a permanent magnet synchronous motor (PMSM) operates in the flux-weakening state, a large d-axis fluxweakening current is required at high speed, which decreases the flux density of PM and even causes PM irreversible demagnetization [4]- [6]. PM demagnetization will decrease the no-load back electromotive force (EMF) amplitude, increase the torque ripple and decrease the efficiency.…”

Analysis, Design, and Preliminary Evaluation of a Parallel Elastic Actuator for Power-Efficient Walking Assistance

“…Since the gait is a periodic process, compliant elements can store the energy wasted as negative work in the period when the motor must brake the load actively and recycle it as positive work for accelerations in the opposite direction. Such characteristics of compliant elements can be used to enrich the dynamics of traditional electric motors [2], [3] for walking assistance [4]. Compliant actuation, such as elastic actuators (EAs), adding the elasticity element to the RA, is widely studied in robotic applications.…”