• Proceedings of the KIEE Conference
• /
• 1997.11a
• /
• pp.10-12
• /
• 1997

For a given brushless DC linear motor, we analyze the thrust characteristics. We measure the back-EMF and then calculate the thrust with it. To compare the thrust, we measure it direct with force-torque meter and we calculate it from Lorentz equation. As the thrust and the back-EMF vary linearly according to the current and the velocity respectively, we define the thrust constant and the back-EMF constant. To match the motor to its controller, we calculate the thrust constant and the back-EMF constant. The result calculated with the back-EMF differs from that of the measurement by only 4.4%.

• Journal of the Korean Society for Precision Engineering
• /
• v.15 no.8
• /
• pp.183-192
• /
• 1998

In this paper, we measure the back-EMF and the thrust of a linear brushless DC motor along the relative position between coils and magnets in various speed environments in order to obtain the back-EMF and the thrust as a function of a motor position. The measured back-EMF function and thrust function of the position differ from the analytical ones within 5%. The measured back-EMF and thrust function can, then, be employed in controlling the thrust ripple of the linear motor. Furthermore, to minimize the torque ripple of the linear motor, we suggest the design method to shape the back-EMF and thrust function of the linear motor.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• v.2B no.4
• /
• pp.162-167
• /
• 2002

This paper presents the dynamic analysis method for a slotless permanent magnet linear synchronous motor (PMLSM) using the 3-D space harmonic method. Instantaneous emf and thrust are considered by movement of the PM and instantaneous armature current instead of $K_E$ (back-emf constant) and $K_F$(thrust force constant) for accurate results. The results of magnetic field distribution, back-emf, inductance, and thrust are in agreement with 2-D FEM and experimental results. To confirm the validity of this method, the calculated results are compared to measured ones.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.51 no.7
• /
• pp.379-386
• /
• 2002

This paper deals with dynamic analysis method of a slotless type permanent magnet linear synchronous motor(PMLSM) using 3-dimensional space harmonic method. The results are good agreement with FEA results because that slotless type PMLSM has simple structure and no saturation of core. And then, Under open-loop control, starting characteristic is analyzed by voltage equation combining with dynamic equation. In order to obtain more accuracy results, this paper use instantaneous back-EMF and thrust instead of back-EMF constant and thrust constant.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.55 no.1
• /
• pp.21-26
• /
• 2006

This paper deals with the dynamic analysis and experiments of moving-magnet linear actuator with/without spring. On the basis of two dimensional (2-D) analytical solutions and experiments, control parameters such as thrust constant, back-emf constant, inductance and resistance are obtained. And then, dynamic simulation algorithm is established from the voltage and motion equation. Finally, for various values of frequency, dynamic simulation results for characteristics of current and displacement of moving-magnet linear actuator with and without spring are presented and confirmed through the experiments. In particular, This paper applies the PWM voltage waveform obtained from a DSP for bidirectional voltage drive to the actuator.

• Proceedings of the KIEE Conference
• /
• 2005.10c
• /
• pp.129-131
• /
• 2005

This paper deals with an electromagnetic analysis and control parameter estimation of a moving-coil linear oscillatory actuator (MCLOA). Analytical solutions for electromagnetic characteristics of the MCLOA are obtained from transfer relations derived in terms of a magnetic vector potential and two-dimensional (2-d) rectangular coordinate systems. And then, on the basis of 2-d analytical solutions, control parameters such as the thrust constant, the back-emf constant and winding inductances are estimated. Finally, analytical results for both electromagnetic characteristics and control parameters of the MCLOA are validated extensively by finite element (FE) analyses. In particular, test results such as static thrust, resistance and inductance measurements are given to confirm the analyses.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.49 no.3
• /
• pp.180-187
• /
• 2000

A moving-coil-type linear oscillatory actuator(LOA) consists of the NdFeB permanent magnets with high specific energy as the stator, a coil-wrapped nonmagnetic hollow rectangular structure. The LOA system was represented by the voltage equation of coil and the mechanical equation of motion. This set of equations was manipulated in state-space form. The EMF constant kE of equation parameters in state-space form can be obtained by using the induced voltage in armature coils at open circuit test. kE and other parameters provide the system matrices and transfer function for frequency response and dynamic simulation. Voltage source inverter-fed LOA is examined aiming to compare with results of simulation.

• Proceedings of the KIEE Conference
• /
• 2009.04b
• /
• pp.41-43
• /
• 2009

This paper deals with determination of parameters of permanent magnet linear synchronous machine(PMLSM) for high thrust and improvement of speed performance. To satisfy these characteristics, PMLSM with double-sided PM mover and slotless ring-winding stator is presented. And using multilaver method, this paper analyzes the electromagnetic field phenomena and estimates parameters such as back-EMF and thrust constant. These parameters are used to derive DC link voltage of voltage source inverter with space vector pulse width modulation(SVPWM) using a digital signal processor and encoder pulse signal. The DC link voltage is one of the most important factor for accurate design. It enables to determinate dynamic operating range of system. Hence, performance evaluation is performed through dynamic modeling. Finally, in this paper, dynamic characteristics according to DC link voltage are presented as experiment result.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.54 no.11
• /
• pp.533-539
• /
• 2005

In the previous work, we performed the analysis of a tubular type moving-magnet linear oscillatory actuator (LOA) with cylindrical Halbach array by using 2-d analytical formulas and confirmed validity of analytical results by comparison of those with both finite element (FE) computation and experimental results. This paper deals with the dynamic characteristic analysis of the moving-magnet LOA with cylindrical Halbach array. Control parameters such as the thrust constant, the back-emf constant, resistance and inductance are obtained from both analytical and experimental results. And then, the dynamic simulation algorithm is established by the state and output equation obtained from voltage and motion equation. Finally, for various values of frequency, the dynamic simulation and experimental results for the characteristics of the voltage, current and displacement of moving-magnet LOA are presented. The simulation results are validated extensively by experiments. The experimental and simulation results for the variation of stroke according to control voltage are also presented for various values of frequency.