Development of Double-Sided Interior Permanent Magnet Flat Linear Brushless Motor and Its Control Using Linear Optical Potentiometer
Abstract
A new 6/4 double-sided interior permanent-magnet (IPM) flat linear brushless motor (IPM-FLBM) and novel optical potentiometer mechanism for a linear motion-control system are presented in this dissertation.
For this purpose, new detent-force-minimization methodologies for the IPMFLBM are studied on the basis of the superposition principle. The end-effect force is reduced by a new two-dimensional optimization using the step-shaped end frames. The cogging force is minimized through a destructive interference using the slot-phase shift between the upper and lower stators. A base model prototype with the detent force of only 1.5% of the maximum thrust force is developed using the electrical solid steel. Analytic modeling techniques of the base model prototype with slot-phase shift and alternate teeth windings are investigated. A variable winding function is newly developed to evaluate the inductances of the salient motor with the alternate teeth windings. The steady-state thrust force is modeled for this linear brushless AC (BLAC) motor. Their validities are demonstrated experimentally. The electromagnetic and steady-state performance analyses of a new prototype using a soft magnetic composite (SMC) material are also studied using a simplified nonlinear magnetic equivalent circuit (MEC) analysis. Its iron and copper losses are investigated in terms of the thermal limitation. The feasibility of the IPM-FLBM using the SMC material is demonstrated through the comparisons of the average steady-state thrust and ripple forces for these two prototype linear motors.
A novel low-cost high-precision absolute displacement-sensing mechanism using optoelectronic components is developed. The working principle that is based on the change of the optical power that is reflected off the monotone-colored pattern track from a light emitting diode (LED) to a red-green-blue (RGB) photo diode (PD) is presented. The performance of the proposed optical potentiometer (OP) mechanism is verified by
the bandwidth (BW) of 4.42 kHz and nonlinearity of 2.8% are achieved.
A novel low-ripple 12-step current control scheme using a single current sensing resistor is developed using the six Hall-effect sensors for the force control of the IPMFLBM. Its performances are experimentally verified and compared with a conventional field-oriented control (FOC) scheme. In the end, the position-control loop, which includes the 12-step current control loop, double-sided IPM-FLBM, and linear optical potentiometer (LOP), is designed using a proportional controller with a lead compensator. The performances of the linear motion-control system are demonstrated through the various experiments in the time and frequency domains.
Subject
linear motorsoft magnet composite
asymmetric dual three phase
alternate teeth winding
12-step current control
optical potentiometer
Citation
Kwon, Young Shin (2016). Development of Double-Sided Interior Permanent Magnet Flat Linear Brushless Motor and Its Control Using Linear Optical Potentiometer. Doctoral dissertation, Texas A & M University. Available electronically from https : / /hdl .handle .net /1969 .1 /158922.