• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.7
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• pp.49-56
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• 2009

A new class of electronically commutated brushless motors, the flux-switching motor (FSM), is gradually emerging for use in power tools and household appliances especially fan and pump application thanks to green policies, This motor offers such advantages as high-power density and relatively high efficiency compare to induction motors, and low cost and simple motor structure compare to the BLDC motor. This paper presents the principle of the FSM and design of the 12/6 pole FSM drive system for fan application. Test results of the prototype motor are provided to verify the validity of the fan application with a TMS320F2812 DSP and inverter.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.2
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• pp.126-133
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• 2004

In this paper, a new current control algorithm is proposed for four-switch three-phase brushless DC(BLDC) motor drives, which are suitable for low cost applications. A current reference generation scheme is developed and implemented to obtain high performance characteristics in the four-switch system, such as small torque ripple and fast dynamic speed/torque response. Especially, the proposed scheme can successfully reduce the torque ripple during commutations, so that it can be expected that the four-switch system can be much more practically applied for the industrial application areas.

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.345-348
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• 2001

In this paper, the development of input power factor and harmonic distortion of line current were showed in the proposed single-stage SRM inverter. It is verified from the experiments that the proposed encoder and logic controller can be a powerful candidate for the practical low cost SRM drive.

• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.3
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• pp.354-359
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• 2012

A transformerless converter suitable for multiphase drive application is presented in this paper. The topology employs a cascaded H-bridge rectifier as the interface between the grid and multi inverters which drive the multiphase motor. Compared with the conventional structure, the new topology eliminates the input transformer and also has the advantages such as four quadrant operation, simple configuration, low cost, high efficiency, and so on. The control strategies for the grid-side cascade H-bridge rectifier and the motor-side inverter are studied accordingly. Based on the multi-rotational reference frame, modular control scheme is developed to regulate the multiphase drive system. Simulation results show the proper operation of the proposed topology and the corresponding control strategy.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.485-486
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• 2006

This paper proposes a novel low-cost CMOS temperature sensor for controlling the self-refresh period of a mobile DRAM. In this temperature sensor, ring oscillators composed of cascaded inverter stages are used to obtain the temperature of the chip. This method is highly area-efficient, simple and easy for IC implementation as compared to traditional temperature sensors based on analog bandgap reference circuits. The proposed CMOS temperature sensor was fabricated with 80 nm 3-metal DRAM process. It occupies a silicon area of only about less than $0.02\;mm^2$ at $10^{\circ}C$ resolution with under 5uW power consumption at 1 sample/s processing rate. This area is about 33% of conventional temperature sensor in mobile DRAM.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.63 no.4
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• pp.345-350
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• 2014

DC electrolytic capacitor is widely used in the power converter including PWM inverter, switching power supply and PFC Boost converter system because of its large capacitance, small size and low cost. In this paper, basic characteristics of DC electrolytic capacitor vs. frequency is presented and the real-time estimation scheme of ESR and capacitance based on the bandpass filtering is adopted to the single phase boost converter of uninterruptible power supply to diagnose its split dc-link capacitors. The feasibility of this real-time failure prediction monitoring system is verified by the computer simulation of the 5[kW] singe phase PFC half-bridge boost converter.

• Journal of Power Electronics
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• v.11 no.6
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• pp.931-937
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• 2011

This paper presents a method for the performance improvement of a shunt active power filter (SAPF) using the indirect current control (ICC) scheme. Compared to the conventional direct current control (DCC) scheme, the ICC gives better performance with a lower number of sensors. A simplified and efficient control algorithm using a low cost Intel 80C196KC microcontroller is implemented using only two current sensors for the source current and one voltage sensor for the DC-link voltage of the SAPF circuit. The objective is to eliminate harmonics and to compensate the reactive power produced by non-linear loads such as an uncontrolled rectifier feeding an inductive load. The APF is realized using a three phase voltage source inverter (VSI) with a dc bus capacitor. Experimental results are presented to prove the better performance of the ICC method over the DCC one.

• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.64-66
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• 1999

Switched reluctance motor(SRM) has the advantages of simple structure, low rotor inertia and high efficiency. However, position sensor is essential in SRM in order to synchronize the phase excitation to the rotor position. The position sensors increase the cost of drive system and tend to reduce system reliability. This paper investigates the speed control of sensorless SRM in which the phase current and change rate are utilized in position decision, and the period of dwell angle is variable by compensating the rotor angle. The proposed system consists of position decision, phase locked loop controller, switching angle controller and inverter. The performances in the proposed system are verified through experiments.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1042-1045
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• 2000

Speed control without speed sensor is expected strongly to progress reliability, simplicity and cost performance of I.M and to expand its application part. This paper investigates a novel speed estimation method of I.M considering the secondary resistance identification based on the transientless torque control technique. Especially, this paper aimed at the identification of the secondary resistance simultaneously with speed estimation. For this, the secondary flux with some frequency is controlled independently on torque. The proposed speed estimation method is derived from a motor circuit equation theoretically and also it can be conducted easily by detecting primary motor currents and primary voltage commands at every sampling time. Some numerical simulations with the assumption of using a pulse width modulation(PWM) voltage source inverter and experimental results are performed to verify the proposed method.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.684-686
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• 2000

Switched reluctance motor(SRM) has the advantages of simple structure, low rotor inertia. and high efficiency. However position sensor is essential in SRM in order to synchronize the phase excitation to the rotor position. The position sensors increase the cost of drive system and tend to reduce system reliability. This paper investigates the speed control of sensorless SRM in which the phase current and change rate are utilized in position decision, and the period of dwell angle is variable by compensating the rotor angle for speed control. The proposed system consists of position decision. phase locked loop controller, switching angle controller and inverter. The performances in the proposed system are verified through the experiment.