• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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• pp.987-993
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• 2003

The module UPS can flexibly implement expansion of power system capacities. Furthermore, it can be used to build up the parallel redundant system to improve the reliability of power system operation. To realize the module UPS, load sharing without interconnection among parallel connecting modules as well as a small scale and lightweight topology is necessary. In this paper, the three-arm converter/inverter is compared with the general full-bridge and half-bridge topology from a practical point of view and chosen as the module UPS topology. The switching control approaches based on a pulse width modulation of the converter and inverter of the system are presented independently The frequency and voltage droop method is applied to parallel operation control to achieve load sharing. Two prototype 3kVA modules are designed and implemented to confirm the effectiveness of the proposed approaches. Experimental results show that the three-arm UPS system has a high power factor, a low distortion of output voltage and input current, and good load sharing characteristic.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 A
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• pp.325-329
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• 1994

This paper describes a compact design and control method of PWM inverter-mounted induction motor especially designed for reducing the size and weight considerably, which may be applied to the speed control system such as air conditionr,conveyor and textile mill, etc. To obtain higher power density without derating performance, a new mechanical configuration unifying the inverter circuit and motor is proposed. Also, through the use of current minimization control method during V/f operation it is possible to reduce the size of heat-sink related to the losses of power circuit. By the proposed design method, a compact inverter-mounted induction motor system of 1Hp is built and its validity can be verified through the experimental results.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제48권8호
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• pp.417-425
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• 1999

This paper presents an effective control scheme with the voltage-fed half-bridge series resonant inverter for induction heating system, which is based upon a load-adaptive tuned frequency tracking control strategy using PLL(Phase Locked Loop) and its peripheral control circuits. The proposed control strategy ensures a stable operation characteristics of overall inverter system and ZVS(Zero Voltage Switching) irrespective of sensitive load parameter variations, specially in the non-magnetic materials as well as power regulation. The detail operation principle and the characteristics of inverter system with the proposed control scheme are described and its validity is verified by the simulation and the experimental results for a prototype induction cooking system rated at 1.2kW.

• 한국정보통신학회논문지
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• 제8권2호
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• pp.407-412
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• 2004

태양광발전 및 소단위 풍력발전에 사용할 수 있는 변압기 없는 인버터를 설계하였다. 멀티 스위칭 방법에 의한 승압쵸퍼회로와 단상 풀브리지 인버터로 구성하였으며 소형화, 저 비용화를 위하여 변압기 없는 방식으로 설계하였다. 변압기 없는 시스템에서 문제가 될 수 있는 접지누설전류의 저감을 위해서는 승압쵸퍼의 스위칭기법 및 인버터 스위칭 등을 통하여 해결하였다

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.110-113
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• 2005

This paper proposes high speed SRM drive system for blower with a new 4-level inverter and precise excitation position generator. For the high speed blower, a proper 12/8 SRM is designed and analyzed. In order to get a fast build-up and demagnetization of excitation a current, now 4-level inverter system is proposed. The proposed 4-level inverter has additional charge capacitor, power switch and diode in the conventional asymmetric converter. The charged high voltage is supplied to the phase winding for fast current build-up, and demagnetization current is charged to additional capacitor of 4-level inverter. In addition, a precise excitation position generator can reduce turn-on and turn-off angle error according to sampling period of digital control system. The proposed high speed SRM drive system is verified by computer simulation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 F
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• pp.1963-1965
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• 1998

In this paper, a new simplified configuration for a multi-level PWM inverter is proposed. The proposed inverter consists of an auxiliary circuit with one switching device, and 3 phase full-bridge inverter. The proposed inverter, in spite of reduction of the switching devices, offers characteristics similar to the NPC(Neutral - point - clamped)- PWM inverter. Also, since the reduction of the switching devices, the control strategy is simplified. And switching loss is reduced. In addition to, it is possible that reliable DC level voltage than former multi-level inverter. And load power application is same to conventional NPC-PWM inverter. The performance of the system is verified by simulation. In this paper, show the simulation result of the single phase full bridge inverter application.

• 한국방사선학회논문지
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• 제4권3호
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• pp.31-37
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• 2010

본 논문에서는 태양광 발전시스템을 이용한 PWM(Pulse Width Modulation) 전압형 인버터를 전력변환기로 구성하였고, 안정된 변조를 위해서 동기신호와 제어신호를 56F8323 마이크로프로세서에 의해서 처리하였다. PWM 전압형 인버터는 태양전지가 연속 발전할 수 없는 단점을 보완하기 위해 일반 상용전원과 연계함으로써 약 10~20[%]의 전력 절감 효과를 얻을 수 있는 에너지 절약 전원 복합형 전력변환장치로 구성하였다. 그리고 PWM 전압형 인버터와 위상동기를 위해서 계통전압을 검출하고 계통전압과 인버터 출력을 동상 운전하므로 잉여전력을 계통과 연계할 수 있게 하였다. 또한, 고조파를 절감한 출력을 유지함으로써 부하와 계통에 전력이 안정하게 공급될 수 있도록 제어 시스템을 적용하여 좋은 결과를 얻을 수 있었다.

• 전력전자학회논문지
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• 제4권4호
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• pp.325-331
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• 1999

계통연계형 태양광발전시스템에서는 계통과 태양광시스템을 연계하기 위해 PWM 인버터가 이용된다. 인버터 시스템을 연속전류모드로 운전하면 맥동이 발생하게 되고, 직류전류의 맥동발생은 교류전류파형의 왜형을 가져온다. 본 연구에서는 직류입력전류의 맥동을 감소시키기 위하여 불연속모드 승강압초퍼로 인버터를 운전한다. 직류 전류에 포함된 고조파성분을 리플성분과 직류성분으로 분리하여 해석하고, 맥동이 없는 일정한 직류전류를 태양 전지로부터 인버터로 공급한다. 제안하는 인버터시스템은 단위 역률로 부하와 계통에 교류전류를 공급한다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2006년도 전력전자학술대회 논문집
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• pp.488-491
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• 2006

In this paper proposed method of maximum power point tracking using boost converter for a connected single phase inverter with photovoltaic system. The maximum power point tracking control is based on generated circuit control MOSFET switch of boost converter and single phase inverter uses predicted current control to control four IGBT's switch in full bridge. The predicted current control provide current with sinusoidal wave shape and inphase with voltage. The generation control circuit allows each photovoltaic module to operate independently at peak capacity, simply by detecting of the output power of the system. Furthermore, the generation control circuit attenuates low-frequency ripple voltage, which is caused by the full-bridge inverter, across the photovoltaic modules. Consequently, the output power of system is increased due to the increase in average power generated by the photovoltaic modules. The effectiveness of the proposed inverter system is confirmed experimentally and by means of simulation.

• 제어로봇시스템학회논문지
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• 제10권5호
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• pp.411-414
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• 2004

In this paper, a power controller and 3 phase voltage source inverter are proposed for the improvement of weldability of large scaler Mash seam welder. The welder system is designed for the low cost and the improvement of weldability. For this system, the thyristor convertor has performed constant current controlling in the output terminal by using PAM type inverter. We have simulated our algorithm and made a prototype welder for experiment. Through the experiment, we have confirmed the improvement of weldability of our system.