• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.23 no.5
• /
• pp.408-412
• /
• 2010

The single-phase switched reluctance motor(SRM) generates the positive torque in the restricted section. So, it can not started by itself and the torque ripple is heavier than poly-phase. For self-starting and fixing rotating direction, the rotor should be placed at the rising inductance slope when stationary. The parking permanent magnet locates the rotor in the fixed position, which can be started by it-self. It is very simple and cost effective but has some drawbacks. It affects the rotor during the operation, so the characteristics of motor, such as a torque, speed, and ripple are changed to go bad. This paper presents the detent torque of parking magnet starting device through the finite element analysis and experiments. The finite element analysis is performed at incremental rotor positions over one detent torque cycle for any one pole. The prototype, fabricated in the previous research, is used for the experiments. The inductance, instant torque, and detent torque are calculated using the terminal voltage and phase current. Finally, the finite element analysis result and the experiment result are compared for analysis and validity.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.27 no.12
• /
• pp.125-132
• /
• 2013

This paper has done a three-dimensional FEM analysis of the PM claw pole stepping motor. As magnetization happens in the z-axis, which does not have a constant value, three-dimensional FEM analysis is necessary for characteristic analysis of PM claw pole stepping motors. Because it is a type of permanent magnet motor, the PM claw pole stepping motor naturally has a detent torque. This torque is known to show negative effects on motor performance. To improve motor performance, reducing the detent torque is very important during the motor design. This paper applied DOE for optimization of stator pole design of the motor. Also, we compared motor performance by applying a different type of rotor shape, dividing the permanent magnet. To verify the simulation results, an experiment was done.

• Proceedings of the KIEE Conference
• /
• 2007.07a
• /
• pp.1005-1006
• /
• 2007

This paper analyzed the characteristics of the claw pole permanent magnet(PM) stepping motor by using 3D Finite element method(FEM). In this motor, magnetization is occurred along the z-axis, therefore it is necessary to apply 3D FEM for analysis of the claw pole motor. A phase difference of the two stacks's detent torque is 180 degrees. When the center of a permanent magnet is identical with the middle of a pole, small detent torque is produced in order to cancel each of detent torques. However, there are construction errors which are a discrepancy between one and the other phase section in the manufacturing process, thus the detent torque is increased. Moreover, it is confirmed that the proportion of the detent torque is considerably arisen according to the error. Analysis of the construction error is studied by changing the error $0^{\circ}$ to $3^{\circ}$.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.16 no.5
• /
• pp.14-21
• /
• 2002

This paper did the study target for modeling, characteristics analysis and harmonic reduce with the detent torque of a 4 phase and 5 phase hybrid type step motor. For this, it was attempted to derive the mathematical modeling and used the permeance method for flux field analysis. Through this analysis result, this paper acquired the detent torque of this model. To compare the characteristics analysis of phase difference with two motors structure it have obtained to derive the operating detent torque with this model. Here, 5 phase motor has known the harmonic reduce of detail torque compare with 4 phase motor. Also, that has showed to improved the step response. The analysis result has represent the effect that a fundamental component of the permeance distribution produces the average torque and that harmonic components produce the ripple torque.

• Proceedings of the KIEE Conference
• /
• 2009.04b
• /
• pp.85-87
• /
• 2009

Linear motor is an energy conversion device which makes kinetic energy from electrical energy. This paper presents a method to reduce torque ripples by variation of the current. The torque ripples are basically caused by detent force so this method has a focus on reducing detent force. The torque ripples were calculated by finite element method.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• v.12B no.1
• /
• pp.1-6
• /
• 2002

The severe problem in improving the positioning precision of a permanent magnet linear synchronous motor (PMLSM) is the large detent farce caused by the permanent magnet arrangement. It is generally an undesired effect that contributes to the torque ripple, vibration and noise of machine. The detent force is arisen from the difference of the position of a permanent magnet end and a tooth position. In this paper, the four methods to reduce detent force were studied and analyzed. The methods are adjusting the width of permanent magnet, varying the shape of armature teeth, relocating the permanent magnet, and adjusting the width of permanent magnet and relocating the permanent magnet at the same time. To analyze the detent farce according to flour methods, a two-dimensional Finite Element Analysis [FEA] was used and we compared with the ratio of reduction of the detent farce according to the flour methods.

• Proceedings of the KIEE Conference
• /
• 2002.07b
• /
• pp.802-804
• /
• 2002

An analysis of the skeleton type BLDC motor is presented. The single phase skeleton type BLDC motor consists of the stator, rotor with the permanent magnet, and drive circuit with hall sensors that detect the rotor position. The major factors for the initial starting, efficiency, and torque ripples of the skeleton type BLDC motor are the detent groove of the stator and the lead angle of the phase voltage. The performance characteristics according to the angle and height of the detent groove is analyzed. The optimum lead angles of the phase voltage with the torque ripple and motor efficiency is described using the finite element method.

• Proceedings of the KIEE Conference
• /
• 1999.07b
• /
• pp.785-787
• /
• 1999

In this paper, recursive least square algorithm is presented to estimate the parameters of step motor under low-speed operation. Parameter estimation is important for compensating the input current by calculating the ratio of the motor torque constant and detent torque constant that causes torque-ripple in low-speed applications. On-line parameter estimation process is a preliminary procedure to apply step motor to adaptive control. Computer simulation shows that the estimated parameters converge in finite time.

• Proceedings of the KIEE Conference
• /
• 2005.10c
• /
• pp.132-134
• /
• 2005

The severe problem in improving the positioning precision of a permanent linear synchronous motor(PMLSM) is the large detent force caused by the PM. It is generally an undesired effect that contributes to the torque ripple, vibration and noise of machine. In this paper, the method to reduce detent force according to the mover skew is studied and analyzed using the analytical method. The analytical results are validated by finite clement analyses.

• Proceedings of the KIEE Conference
• /
• 1998.11a
• /
• pp.37-39
• /
• 1998

The hybrid step motor has found applications in a wide range of mechanical systems as a low cost, open-loop positioning device. The step motor provides good stiffness at rest against disturbing load influences, a combination of moderate speed fine resolution, high reliability and simplicity. In recent years, considerable competition has arisen over the technological issue of wheather the device should be applied as a 2-Phase or 5-Phase machine. In this paper, to compare two systems, we have atempted to derive the mathematical. model, and analysed operating detent torque with this model. The analysis shows that a fundamental component of the permeance distribution produces the average torque and that harmonic components produce the ripple torque.