• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 전력전자학술대회 논문집
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• pp.77-81
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• 2002

In many high performance engineering systems such as automated production system and transportation systems, AC-servo drives are employed as the most Important driving parts. And the faults of servo drives result in overall system performance deterioration or an unscheduled shutdown In critical situations. The real-time fault detection and isolation(FDI) scheme Is very useful to prevent them and to guarantee the desired reliability of the overall system. In this paper, the FDI schemes which can be applied to AC servo drives are introduced and some new results are presented.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 전력전자학술대회 논문집
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• pp.10-13
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• 1998

In this paper, a control strategy of the three phase ZVT inverter for ac motor drives is proposed. The topology of ZVT inverter analyzed with a description of the control conditions dependent on the load current and MSVM(Modified Space Vector Modulation). The detailed simulation results indicate that zero-voltage operation during transition of the MSVM algorithm can be achieved.

• 대한전기학회논문지
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• 제39권9호
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• pp.928-933
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• 1990

In the vector controlled induction machine drives, mechanical speed sensors such as shaft encoder and resolver have been used. However, the mechanical speed sensors present some problems and restrict the wide applications of high performance AC drives. This paper describes the vector strategy with the speed estimation algorithm in which motor slip frequency is calculated. Also, the angle deviation of the rotor flux vector is calculated and instantaneously compensated to keep the q axis flux zero in the rotational reference frame.

• Journal of Power Electronics
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• 제11권3호
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• pp.279-284
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• 2011

Network-based controls for ac motor drive systems are becoming increasingly important. In this paper, an ac motor control system is implemented by a motor control module and three sensor modules such as a voltage sensor module, a current sensor module, and an encoder module. There will inevitably be network time delays from the sensor modules to the motor control system, which often degrades and even destabilizes the motor drive system. As a result, it becomes very difficult to estimate the network delayed ac sensor data. An algorithm to reduce the effects of network time delays on sensor data is proposed, using both a synchronization signal and a simple method for estimating the sensor data. The algorithm is applied to a vector controlled induction motor drive system, and the performance of the proposed algorithm is verified with experiments.

• 전기학회논문지P
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• 제55권2호
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• pp.62-66
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• 2006

This thesis focuses on the design of control schemes for highly efficient BLDC motor drive applications using drives with output capacity of 1Hp. The control system was designed and implemented on a PIC micro-controller and applied to an electric vehicle as a viable replacement to the existing a high phase induction motor that is currently being used for these low cost, small traction drive applications. This paper for the brushless drive research has shown the optimization of the drive system for improved drive design and switching techniques that can improve the entire drive system efficiency for electric vehicle both large and small traction applications using sinusoidal PWM techniques for synthesizing the AC waveforms needed to control these traction drives. In addition, Numerical simulation was conducted to evaluate the performance of designed BLDC Motor using MotorPro simulator.

• 대한전기학회논문지
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• 제36권1호
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• pp.3-8
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• 1987

The conventional autosequentially commutated current-fed inverter (ASCI) is widely employed with the induction motor drives for speed control. Howener, this inverter has a limit of high power and high frequency indution motor drives. One of the limitations is to be found in the commutation capacitors in the main circuit of this inverter. A new current-fed gate turn-off thyristor (GTO) inverter is developed. This inverter is composed of the main GTO bridge configuration and the improved energy rebound circuit (ERC)without the commutation capacitor. This inverter works stable at high frequency from light load to heavy one. The improved ERC is used not only to rebound the load reactive power to the dc link, but also to return the power in the load to the ac source. The new GTO inverter circuit and the characteristics of the inverter induction motor drives are explained and analyzed.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.529-534
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• 1998

In this paper, control strategies of the bridge-type ZVT inverter for AC motor drive application were discussed. The topology of the ZVT inverter is analyzed with a description of the control conditions based on the load current. And a new resonant control algorithm by using load current feedback and modified SVM algorithm for the proposed ZVT inverter is proposed in order to achieve the ZVT switching condition in full control range. The detailed computer simulation and experimental results represent that ZVT and ZCT operation for the main and auxiliary switch, respectively, was achieved.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.660-667
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• 2001

Power electronics plays an important role in providing an interface between fuel cells and loads. Furthermore, power electronic converters ensure that the power is reliably and efficiently delivered to the load in the required DC or AC form. In this paper, major types of fuel cells are presented. Basic structures, operating principles, and different applications of fuel cells are described. In addition, current status and future trends in the areas of power electronics for fuel cell applications are explained. A review of fuel cell power electronic system topologies and basic requirements are given as well.

• 조명전기설비학회논문지
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• 제22권3호
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• pp.79-87
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• 2008

This paper presents a simple circuit topology of the auxiliary active quasi-resonant DC link snubber-assisted three phase voltage source soft-switching inverter for small scale PM motor drive applications. The pulse processing drive circuit interface and its soft-switching operation are discussed from an experimental point of view. Moreover, its conductive noise is measured and evaluated for electrical AC servo motor drive as compared with that of the conventional hard switching inverter.

• 전력전자학회논문지
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• 제24권4호
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• pp.273-278
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• 2019

This study proposes a method for improving the overmodulation performance of a three-phase inverter to obtain an enhanced output torque for the AC motors. In the inverter-fed AC motor drives, the output torque of the motor can be enhanced by utilizing the overmodulation region as well as the linear modulation regions of the inverter. The overmodulation method is used for this overmodulation operation of the inverter. However, the voltage gain, the ratio of the output voltage of the inverter to the reference voltage achieved by the conventional overmodulation methods becomes nonlinearly smaller than unity. Therefore, the effect of improving the output torque of the AC motors is insignificant even when the overmodulation region is utilized. In this study, we propose a method that improves the overmodulation performance of the inverter by compensating the limited amount of the reference voltage in the overmodulation operation to enhance the output torque of the AC motors. The effectiveness of the proposed method is verified through the simulations and experiments with an 800 W permanent magnet synchronous motor.