• Journal of the Korean Institute of Telematics and Electronics
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• v.14 no.1
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• pp.23-28
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• 1977

This paper describes the practical design of a SCR inverter which is suposed to be very much suitable for high frequency induction heating power source. In this design an optimum control technique was applied to maintain constant output power and constant power factor to various heating load by the use of frequency control. Some appreciable characteristics was obtained for some design guide of large ndstrial heating power sources by the test of the 3KHz, 3KW inverter which was designed in this study.

• Journal of Electrical Engineering and Technology
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• v.2 no.3
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• pp.358-365
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• 2007

This paper deals with a novel solid state controller (NSSC) for parallel operated isolated asynchronous generators (IAG) feeding 3-phase 4-wire loads in constant power applications, such as uncontrolled pico hydro turbines. AC capacitor banks are used to meet the reactive power requirement of asynchronous generators. The proposed NSSC is realized using a set of IGBTs (Insulated gate bipolar junction transistors) based current controlled 4-leg voltage source converter (CC-VSC) and a DC chopper at its DC bus, which keeps the generated voltage and frequency constant in spite of changes in consumer loads. The complete system is modeled in MATLAB along with simulink and PSB (power system block set) toolboxes. The simulated results are presented to demonstrate the capability of isolated generating system consisting of NSSC and parallel operated asynchronous generators driven by uncontrolled pico hydro turbines and feeding 3-phase 4-wire loads.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.1312-1314
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• 2001

This paper presents a constant power controller for doubly-fed. Induction generators used in wind turbines. When the stator side of the generator is connected to the grid, the generated power depends on the rotor current. To control the rotor current based on it's average value, a cost effective SPC (Slip Power Controller) was developed and is ready for testing with an actual 660KW generator system. Experiment results are presented and discussed.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.26 no.3
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• pp.275-281
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• 1990

This study suggests a new type shaft generator driven by hydraulic power suitable for small size vessels. Since the shaft generator system is very easy to be affected by disturbances such as speed variation of the main engine and the load variation of the generator, a robust servo control must be performed to obtain stable electric power with constant frequency. So, in this study the robust servo control method is adopted to the controller design. Dynamic characteristics on the frequency variations of the electric power output according to the disturbances are investigated by computer simulations. From the considerations of the computer simulation results, it is ascertained that the shaft generator system proposed in this study had good control performances.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.8 s.227
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• pp.1152-1158
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• 2004

In this study a MRAC(model reference adaptive control) for fluid power elevator model system was designed. The MRAC was compared with PI control in case of applying to the elevator model system with constant external load and changing external load. In this case external load was produced by a single fluid power cylinder combined with pressure control valve. In conclusion the MRAC control performance was better than PI control performance because overshoot and steady state error of the elevator model system controlled by the MRAC were not appeared for constant and changing external load.

• Proceedings of the KIEE Conference
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• 1990.07a
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• pp.393-396
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• 1990

This paper represented constant voltage power source equipment using voltage fed inverter. This system drived syncronizing power source, charged battery connected to DC side, and constantly maintained regardless of power source voltage variation and load variation. Output made good wave with PWM method and we proved stabile constant voltage output when AC power source is failure.

• Proceedings of the KIEE Conference
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• 2002.04a
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• pp.139-142
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• 2002

A resonant type voltage source and power device and a control method using Pulse Density Modulation(PDM) power control and Pulse Width Modulation(PWM) voltage control for Ozone Generator are described. For the stability of discharge in the generating tube, it is desirable that the peak apply voltage is constant. The PDM power control is employed for sustaining the voltage constant at any generating tube input power. Moreover, to avoid the influence of input AC voltage fluctuation etc., PWM voltage control with generating tube peak voltage feedback is used. Both functions were confirmed by the experiment with 6.5[kHz], 1.8[kW] inverter and generating tube. The effect of input synchronous PDM method for input current stabilizing is confirmed also.

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.358-359
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• 2018

본 논문에서는 태양광 시스템에서 전 범위 전력점을 추종하기 위한 Constant Power Generation (CPG) 알고리즘을 구현하였다. 기존의 최대 전력점 추종 (MPPT) 알고리즘은 고출력의 태양광 시스템을 위해 광범위하게 사용되고 있지만, 변화하는 계통상황에 대한 유연한 제어가 불가능하다. 구현한 알고리즘은 MPPT 제어를 수행하면서도 상황에 따라 원하는 전력을 출력할 수 있다. 전 범위의 전력점 추종이 가능한 계통 연계 태양광 컨버터를 구성하였으며 CPG 알고리즘의 두 가지 기법을 소개하였다. 시뮬레이션을 통해 두 CPG 알고리즘을 구현하고 그 성능을 비교 및 분석하였다.

• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.3
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• pp.274-281
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• 2012

This paper discusses the issues associated with the design of high speed machines for applications with a wide constant-power region requirement. Using described multi-domain design environments which put equal weight on the electromagnetic, thermal and mechanical considerations, the suitability and power density achievable using Induction Machines (IM) and Permanent Magnet Synchronous Machines (PMSM) are compared.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.437-440
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• 2000

In this study, the interfacial dielectric breakdown phenomenon of interface between Epoxy and Rubber was discussed, which affects the stability of insulation system of power delivery devices. The breakdown strength of specimens are observed by applying high AC voltage at the room temperature. The breakdown times under the constant voltage below the breakdown voltage were gained. As constant voltage is applied, the breakdown time is proportion to the breakdown strength. The life exponent n is gained by inverse power law and the long time breakdown life time can be evaluated.