On a Three-Phase Modular Double Salient
Linear Motor's Optimal Control
Ioan-Adrian VIOREL – SZABÓ Loránd
TECHNICAL UNIVERSITY OF CLUJ
P.O. Box 358
3400 Cluj, Romania
Fax: +40-64-192-055
e-mail: Ioan.Adrian.Viorel@mae.utcluj.ro
Keywords
Linear drives, permanent magnet motors, variable speed drives, control, modelling.
Abstract
The three-phase modular double salient permanent magnet linear motor (DSPMLM) has several
advantages over the classical hybrid linear motor. In this paper an adjustable speed control system is
proposed for this motor. The motor is energised simply from a low cost readily available standard
three-phase compact converter, which is connected to a microcontroller-based intelligent speed
control unit. A sensorless closed-loop control strategy based on the so-called back-EMF-voltage
detection of the un-energized command coils is proposed. All the drive system's characteristics are
analysed by means of simulation. The SIMULINK programs are based on a circuit-field mathematical
model of the motor. The results obtained prove the ability of the motor and confirm the usefulness of
the presented control strategy.
1. Introduction
In general terms, direct-drive linear motors have a lot of benefits [1]. As their name implies, the motor
and load are directly and rigidly connected. The direct-drive linear motors can replace ballscrews,
gear trains, belts, and pulleys, all off these being limiting factors for engineers trying to improve the
linear drive system’s performance. In the same way it is possible to suppress elasticity, backlash,
hysteresis, and maintenance, too. All these create advantages in simplicity, efficiency, and positioning
accuracy. The acceleration available from these motors is especially remarkable compared to
traditional motor drives, which convert rotary motion to linear motion. Therefore these motors are
ideal for applications that require high position accuracy and repeatability.
The three-phase modular double salient permanent magnet linear motor