Design and Implementation of Position-Based Repetitive Control Torque Observer for Cogging Torque Compensation in PMSM

Abstract

In permanent magnet machines, the cogging torque caused by reluctance variations in the air gap may degrade the speed control performance in low speed and will undoubtedly limit its operational range. In order to reduce the cogging torque, this paper proposes a position-based repetitive control observer aiming at cogging torque estimation and further rejection. This new scheme of observer design possesses the capability of repeatedly learning the observed clogging torque in each rotation to achieve higher estimation accuracy. An online/offline feedforward compensation strategy that employs the forgetting factor principle and position-based average generates the cogging torque compensation lookup table learned from the position-based repetitive control observer. To verify the overall control performance of the proposed observed design technique, a hardware in the loop control device is employed, and then an experimental setup with a permanent magnet synchronous motor and its power drive was adopted.

Modeling of Conduction and Switching Losses for IGBT and FWD Based on SVPWM in Automobile Electric Drives

“…The permanent magnet synchronous motor (PMSM) is widely used in electric vehicles due to its high power density and excellent control performance [1][2][3], and it is usually driven with the pulse width modulation (PWM) inverters. The overall efficiency of the electric drive system is of vital significance for the operation reliability and the cost.…”

Cogging torque analysis in permanent magnet synchronous generators using finite elements analysis

“…As this study will focus on machine-based optimizations, information about studies conducted with control-based methods can be accessed in the literature. [16][17][18][19][20] In the machine-based studies, on the other hand, optimizations on stator, rotor, magnet geometry or material type are performed. In Popescu et al, 21 the change in the cogging torque in relation to magnet radius change, combinations of pole/rotor slot numbers and skew amount of the rotor was examined.…”

“…The studies conducted on cogging torque optimization in the literature can be categorized in two groups, which are control‐based methods and machine‐based methods. As this study will focus on machine‐based optimizations, information about studies conducted with control‐based methods can be accessed in the literature 16‐20 . In the machine‐based studies, on the other hand, optimizations on stator, rotor, magnet geometry or material type are performed.…”