• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.929-930
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• 2006

This paper presents a direct instantaneous torque control (DITC) of Switched Reluctance Moto (SRM) with a novel 4-level converter to obtain smooth torque and dynamic performance improvement. The DITC method can reduce the high inherent torque ripple of SRM drive system, but driving efficiency and dynamic performance are somewhat low due to the slow excitation current build-up. Since the 4-level converter can obtain a addition high voltage to get fast excitation current and demagnetization current, so, it can improve dynamic performance easily. As a high performance SRM drive system with low torque ripple and high dynamic performance can be implemented. The validity of proposed method is verified by some computer simulations and comparative experiments.

• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.3
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• pp.397-403
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• 2012

This paper describes a control method of turn-on/off angles to improve the efficiency of the switched reluctance generator(SRG) with a power closed-loop control system, and the inner-loop of the system is current hysteresis control. The SRG control system is constituted by the PI power controller and the two-level current hysteresis controller. By measuring and analyzing the system losses of different reference powers, speeds and turn-on/off angles, selection strategy of optimal turn-on/off angles is discussed. The proposed method is simple, reliable, and easy to achieve.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.12
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• pp.697-703
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• 2002

Interior permanent magnet synchronous motor(IPMSM) is widely used in many applications such as an electric vehicle, compressor drives of air conditioner and machine tool spindle drives. In order to maximize the efficiency in such applications, this paper is proposed the optimal control method of the armature current. The controllable electrical loss which consists of the copper loss and the iron loss can be minimized by the optimal control of the armature current. The minimization of loss is possible to realize efficiency optimization control for the proposed IPMSM The optimal current can be decided according to the operating speed and the load conditions. The proposed control algorithm is applied to IPMSM drive system, the operating characteristics controlled by efficiency optimization control are examined in detail by simulation.

• Journal of Power Electronics
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• v.11 no.3
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• pp.285-293
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• 2011

This paper proposes two SRM driving systems using a variable dc-link voltage controlled by a single-phase inverter. Two SRM converter topologies of a half bridge type and a full bridge type are proposed according to the power circuits of an inverter. The phase current can be controlled by means of a PWM controller at the inverter, and the turn-on/off angle at the phase switches can be controlled by a position sensor at the converter in the drive system. The inverter acts as a peak-current limiter if the transient current exceeds its maximum value. SRMs using the proposed topologies maintain high efficiency due to energy regeneration after the turn-off of power switches. The operational modes of the proposed topologies are verified by simulation and experimental results.

• Proceedings of the KIEE Conference
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• 2005.10c
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• pp.56-59
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• 2005

This paper describes a novel method of detecting excitation position in Switched Reluctance Motor(SRM) drive. Some strategics for position sensorless control methods of the SRM include the measurement of phase current. The principle of the rotor position estimation is based on the defection of phase current according to rotor position. This sensorless method is very simple to detect excitation position estimation and gives efficient control of drive system. The suggested method is verified by some simulations and experimental tests

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.8
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• pp.33-39
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• 2005

The maximum output torque and power developed by the machine is ultimately depended on the allowable inverter current rating and maximum voltage which the inverter can supply to the machine. Therefore, considering the limited voltage and current capacities, it is desirable to consider a control method which yields the best possible torque per ampere. In this paper, we propose fuzzy neural network(FNN) controller that combines a fuzzy control and the neural network for high performance control of induction motor drive. This controller composes antecedence of the fuzzy rules and consequence by a clustering method and a multi-layer neural networks. This controller is compounding of advantages that robust control of a fuzzy control and high-adaptive control of the neural networks. Also, this paper is proposed control of maximum torque per ampere(MTPA) of induction moor. This strategy is reposed which is simple in structure and has the honest goal of minimizing the stator current magnitude for given load torque. The performance of the proposed induction motor drive with maximum torque control using FNN controller is verified by analysis results at dynamic operation conditions.

• Journal of Power Electronics
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• v.11 no.3
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• pp.294-303
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• 2011

In this paper an effective five-phase induction motor (IM) and its drive methods are proposed. Due to the additional degrees of freedom, the five-phase IM drive presents unique characteristics for enhancing the torque producing capability of the motor. Also the five-phase motor drives possess many other advantages when compared to traditional three-phase motor drives. Some of these advantages include, reducing the amplitude and increasing the frequency of the torque pulsation, reducing the amplitude of the current without increasing the voltage per phase and increasing the reliability. In order to maximize the torque per ampere, the proposed motor has concentrated winding, the produced back electromotive force (EMF) is almost trapezoidal, and the motor is supplied with the combined sinusoidal plus the third harmonic of the currents. For demonstrating the superior performance of the proposed five-phase IM, the motors are also analyzed on the synchronously rotating reference frame. To supply trapezoidal current waveform and to exclude the effect of the $3^{rd}$ harmonic current, a new control stratagem is proposed. The proposed control method is based on direct torque control (DTC) and rotor flux oriented control (RFOC) of the five-phase IM drives. It is able to reduce the acoustical noise, the torque, the flux, the current, and the speed pulsations during the steady state. The DTC transient merits are preserved, while a better quality steady-state performance is produced in the five phase motor drive for a wide speed range. Experimental results clearly demonstrated a more dynamic steady state performance with the proposed control system.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.7
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• pp.1166-1173
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• 1997

Due to progress in manufacturing techniques, the performance of the harmonic drive has been improved but not sufficiently. One of the important problems which the current harmonic drive has is that while there is the potential for having a wider tooth contact area, the total number of teeth engaged simultaneously is still small. This is mainly due to the involute tooth profile. Hence, in this study, the cycloid-type tooth profile is developed to improve this problem. This paper represents the design methodology and performance evaluation f the cycloid-type harmonic drive. Cycloide tooth profile was derived by analyzing geometry of the tooth engagement and the contact mechanisms of the tooth which were examined and analyzed by load analysis. The stress due to elastic deformation of a flexspline was also obtained by approximate formula and computer analysis. Finally, the cycloid-type harmonic drive with 1:100 speed ratio was manufactured and the performance of the harmonic drive was evaluated.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.54 no.10
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• pp.455-460
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• 2005

A simple construction and low cost, fault tolerant power electronic drive has made the switched reluctance drive a strong contender for many applications. But, switched reluctance drive does exhibit higher levels of vibration and acoustic noise than that of most competing drives. The main source of vibration in the switched reluctance drive is generated by rapid change of radial magnetic force when phase current is extinguished during commutation action. In this paper,2 excitation method is proposed and compared to reduce vibration and acoustic noise of the switched reluctance drive. The excitation strategies considered this research are 1-phase, 2-phase and hybrid excitation method. 1-phase method is a conventional and 2-phase method is excited 2 phases simultaneously. The hybrid excitation has 2-phase excitation by long dwell angle as well as conventional 1-phase excitation. The vibration and acoustic noise are compared and tested. Suggested 2-phase and hybrid strategies reduce acoustic noise because the scheme reduces abrupt change of excitation level by distributed and balanced excitation.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.1
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• pp.25-29
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• 2004

This paper is to research about design and drive system of a switched reluctance motor for a pallet truck application. SRM is suitable for a pulse type source and is researched for home and industrial applications owing to the advance of power electronics technology. An SRM for a pallet truck drive is developed and tested. The drive system has to operate with low voltage and high current. The small size, robustness and high efficiency make it possible to replace with DC motor which is used in a pallet truck conventionally. Test results show that pallet truck with SRM has better drive characteristics than that of the DC motor performance.