• Proceedings of the KIEE Conference
• /
• 1990.11a
• /
• pp.332-335
• /
• 1990

There are several methods in controlling resonant converters to regulate the output with low switching losses. In this paper, Pulse-width modulation method or current controlled method is applied to regulate the output with low switching losses. In digital implementation of resonant converter systems, the speed of the applied processor is very critical since the switching frequency is very high. Thus the various possible candidates of microprocessors are evaluated for the implementation of resonant converter systems. Then too design methods and techniques are desioribed when single chip processor is used to simplify hardware requirements.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.54 no.7
• /
• pp.343-350
• /
• 2005

Conventionally, for transferring the primary power to the secondary one, the high frequency series resonant converter has been widely used for the contactless power supply system. However, the high frequency series resonant converter has the disadvantages such as the low efficiency, the high voltage gain characteristics and deviation of the phase angle in the overall load range. To improve this disadvantages, In this paper, the characteristics of the high efficiency and unit voltage gain as well as in-phase are revealed in the proposed three-level LCLC (Inductor-Capacitor- Inductor-Capacitor) resonant converter. The results are verified on the simulation based on the theoretical analysis and the 4kW experimental Prototype.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.35 no.7
• /
• pp.272-277
• /
• 1986

The system that follows to the resonance frequency of high frequency MOSFET inverter and varies according to the changes of load characteristics is proposed. Also we suggested a method how to select the resonant load type between series and parallel circuit for a given inverter type. It leads to the conclusion that in the case of high impedance loads, parallel resonant circuits are preferable, on the other hand, for low impedance loads, series resonant circuits are more preferable. For frequency tracking, a PLL circuit is used as main control element to detect the phase difference of current and voltage of load. The realized apparatus composed of control circuit and voltage type full-bridged MOSFET elements as main parts of inverter. A stable frequency follow-up characteristics are obtained for 1.2MHz, 1.5KW high frequency output and power is always supplied to the load with unity power factor.

• Proceedings of the KIEE Conference
• /
• 1997.07f
• /
• pp.2007-2009
• /
• 1997

This paper proposes the LCC type high frequency resonant DC-DC converter using Power MOSFET as switching devices, and describes the characteristics and operating principles. LCC converter has the resonant capacitor instead of a source decoupling capacitor in the conventional half bridge parallel resonant converter. We performed an experiment to prove the propriety of proposed converter.

• Proceedings of the KIEE Conference
• /
• 2003.10b
• /
• pp.181-183
• /
• 2003

In this paper, phase controlled series resonant converter(PCSRC) system for control power supply in base station is suggested. PCSRC system is robust to load variations because it is POSR(parallel output series resonant) type. And it provides stable output voltage by changing phase angle of MOSFET switches to input voltage variations. Firstly, operation analysis about suggested series resonant converter system was carried. Then Computer simulations using PSIM were carried to prove characteristics of suggested system.

• Proceedings of the KIPE Conference
• /
• 1997.07a
• /
• pp.417-422
• /
• 1997

This paper proposed that a AC-DC Converter topology of high power factor with soft switching mode operates with four chopper connecting a number of parallel circuit. To improve these, a large number of soft switching topologies included a resonant circuit have been proposed. And, some simulative results on computer is included to confirm the validity of the analytical results. The partial resonant circuit makes use of a inductor using step up and a condenser of loss-less snubber. The result is that the switching loss is very low and the efficiency of system is high. And the snubber condenser used in partial resonant circuit makes charging engergy regenerated at input power source for resonant operation. The proposed conversion system is deemed the most suitable for high power applications where the power switching devices are used.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.13 no.3
• /
• pp.124-128
• /
• 1999

The object of the present study is to obtain a 20[kHz], 10[kW] rating, high efficiency induction heating system by high frequency serises-resonant inverter. Proposed is a topology that minimize a reactive power, by which direct iOIrt voltage is variable corresponding to the variation of the load, heated-object, and by which the switching of inverter is forced to follow a resonant frequency. And assured that the power foctor of the inverter in a induction heating system is proper about O.96 through the simulation and results.esults.

• Proceedings of the KIPE Conference
• /
• 2001.10a
• /
• pp.236-241
• /
• 2001

This paper presents a novel prototype of active voltage-clamping capacitor-assisted edge resonant soft switching PWM inverter operating at a constant frequency variable power (VPCF) regulation scheme, which is suitable for consumer high-power induction-heating cooking appliances. New generation IGBT with a trench gate is particularly improved in order to reduce conduction loss due to its lowered saturation voltage characteristics. The soft switching load resonant and quasi-resonant inverter designed distinctively using the latest IGBTs is evaluated from an experimental point of view.

• Proceedings of the KIPE Conference
• /
• 2001.10a
• /
• pp.304-308
• /
• 2001

This paper presents a novel prototype of ZCS-PFM high frequency series resonant inverter using IGBT power module for electromagnetic induction eddy current-heated roller in copy and printing machines. The operating principle and unique features of this voltage source half bridge inverter with two additional soft commutation inductor snubber are presented including the transformer modeling of induction heated rolling drum. This soft switching inverter can achieve stable zero current soft commutation under a discontinuous and continuous resonant load current for a widely specified power regulation processing. The experimental results and computer-aided analysis of this inverter are discussed from a practical point of view.

• Journal of KSNVE
• /
• v.7 no.6
• /
• pp.937-943
• /
• 1997

Viscoelastic materials have the characteristics of elasticity and viscosity. Unlike the metals which show negligible damping characteristics, the damping characteristic of viscoelastic materials like rubber mounts is very important in the analysis of the dynamic system. So there has been a great interest in measuring the damping characteristics of the material can be measured. One is the resonant method which loss factor can be measured only in the resonant frequency. The other is the nonresonant method. In this paper, the test procedure and the physical meaning of the impedance method are introduced. The impedance test results, the loss factor by the impedance method, are compared to the results of the resonant method including some recommendations in the experimental setup.