• Journal of Electrical Engineering and Technology
• /
• v.12 no.3
• /
• pp.1177-1186
• /
• 2017

This paper presents a torque ripple reduction method of direct torque control (DTC) using fuzzy controller with optimal selection strategy of voltage vectors in a five-phase induction motor. The conventional DTC method has some drawbacks. First, switching frequency changes according to the hysteresis bands and motor's speed. Second, the torque ripple is rapidly increased in long control period. In order to solve these problems, some/most papers have proposed torque ripple reduction methods by using the optimal duty ratio of the non-zero voltage vector. However, these methods are complicated in accordance with the parameter. If this drawback is eliminated, the torque ripple can be reduced compared with conventional method. In addition, the DTC can be simply controlled without the use of the parameter. Therefore, the proposed algorithm is changing the voltage vector insertion time by using the designed fuzzy controller. Also, the optimized voltage vector selection method is used in accordance with the torque error. Simulation and experimental results show effectiveness of the proposed control algorithm.

• Journal of Drive and Control
• /
• v.12 no.1
• /
• pp.9-14
• /
• 2015

In the early of 1950, the high response magnetic torque motor was developed for driving electro-hydraulic servo valves. Since then it has been broadly used for industrial application and the research of development or improvement of the torque motor is still being conducted. The purpose of this study is to present useful design criteria for the torque motor design. For this, torque motor is modelled and linearized. The static characteristics of the torque motor are investigated by direct computation of the derived linearlized equations. The dynamic characteristics of the torque motor are investigated with the derived transfer function by using Matlab and compared with the results of the linearlized analysis by using AMESim simulation with actual values of the physical parameters. Finally, the design criteria obtained from the analysis are reviewed.

• Journal of Advanced Marine Engineering and Technology
• /
• v.35 no.8
• /
• pp.1105-1110
• /
• 2011

This paper presents an improved direct torque control based on artificial neural networks technique. The major problem that is usually associated with DTC drive is the high torque(speed) ripple. To overcome this problem a torque hysteresis band with variable amplitude is proposed based on artificial neural networks. The artificial neural networks proposed controller is shown to be able to reducing the torque(speed) ripple and dependency on motor parameter and to improve performance DTC especially at high speed and reversal running.

• Proceedings of the KIPE Conference
• /
• 2002.07a
• /
• pp.431-434
• /
• 2002

This paper presents an implementation of direct torque control(DTC) of Reluctance Synchronous Motor(RSM) with an efficiency optimization using the 32bit DSP TMS320C31. The influence of iron loss can not neglected as high speed and precision torque control of RSM, so the optimal current ration between torque current and exiting current analytically derived to drive RSM at maximum efficiency For RSM, torque dynamics can be maintained even with controlling the flux level because the generated torque is direct]y proportional to the stator current. The experimental results for an RSM are presented to validate the applicability of the proposed method. The developed control system is shown high efficiency features with 1.0Kw RSM having 2.57 ratio of d/q reluctance.

• Proceedings of the KIPE Conference
• /
• 1998.10a
• /
• pp.45-49
• /
• 1998

In this paper, the direct thrust control of PWM Inverter-fed Single-sided Linear Induction Motor (hereinafter referred to as "SLIM") is achieved with Space Vector control and PI control. The trembling of air gap length which is occured between the primary winding core and the secondaty structure of the SLIM must be minimized in order to get quick response characteristic. First, voltage equations of SLIM are shown on the suitable d-q axis equivalent circuits which analyze characteristics of the thrust and the normal force. Also, modeling and analysis of the d-q axis equivalent circuits are able to make robust transient thrust from the current regulation in the equivalent circuits. These results exemplified the direct drive of SLIM with the reference speed and thrust were verified by the experiments.periments.

• Journal of Power Electronics
• /
• v.16 no.3
• /
• pp.994-1003
• /
• 2016

Two major obstacles in the utilization of electrical vehicles are their price and range. The collaboration of direct torque control (DTC) with induction motor (IM) is preferred for its low cost, easy implementation, and parameter independency. However, in terms of edges, the method has drawbacks, such as variable switching frequency and undesired current harmonic distortion. These drawbacks result in acoustic noise, reduced efficiency, and electromagnetic interference. A feed-forward approach for stator-flux-oriented DTC with space vector pulse-width modulation is presented in in this paper. The outcome of the proposed method is low current harmonic distortion with fixed switching frequency while preserving the torque performance and simple application feature of basic DTC. The method is applicable to existing and forthcoming IM drive systems via software adaptation. The validity of the proposed method is confirmed by simulation and experimental results.

• Journal of Power Electronics
• /
• v.17 no.2
• /
• pp.358-367
• /
• 2017

This paper presents a novel filtering method for speed measurements to improve the low-speed performance of the direct-drive permanent magnet traction machines for elevators. Based on the theory of nonlinear tracking differentiator (NTD), this method, which can act as a high performance filter of a raw speed signal, obtains a more accurate speed feedback signal when applying a low-resolution encoder. In addition, it can relieve the interference caused by the position derivative for speed sampling. By analyzing the frequency response of the NTD, the influence of its parameters on the performance of the speed filtering is investigated. Compared with different types of low-pass filters, the proposed method shows a shorter time delay and a stronger ability in terms of noise suppression when the parameters are selected carefully. In addition, when using the measured speed signal through a nonlinear tracking differentiator as the feedback of the system, the motor runs more steadily at low speeds. As a result, the riding comfort of a direct-drive elevator can be improved. The feasibility of the proposed strategy was verified on an 11.7kW elevator traction machine using a commercial inverter.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2013.05a
• /
• pp.821-822
• /
• 2013

• 전기의세계
• /
• v.39 no.9
• /
• pp.39-45
• /
• 1990

전자 액츄에이터의 일종인 LPM(linear pulse motor)은 직선왕복 운동을 필요로 하는 모든 응용기기의 구동에 적합한 선형 전동기로서 직접구동(direct drive)방식을 채택함으로써 회전형 전동기를 사용하는것과는 달리 감속장치, 동력전달 기구가 불필요하여 전체시스템의 구성에서 부품의 수를 줄일 수 있기 때문에 제품의 신뢰성이 향상되고 소형경량화 할 수 있다. 또한 LPM은 기계적 구조가 간단하고 비접속 직접구동이 가능하므로 기기의 특성 변화가 적고 보수성이 우수한 성능을 가지고 있다.

• Proceedings of the Korean Magnestics Society Conference
• /
• 2008.12a
• /
• pp.96.1-96.1
• /
• 2008