• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.14 no.6
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• pp.12-17
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• 2000

IN induction heating system the high frequency operation allows a rapid response to current fluctuation in the inverter and result in improved welding quality. To work induction heating of nonferrous metals, a welding power supply is need high working frequency and high power. This paper is shown design technique for increasing working frequency in induction heating for welding coppers. A series-parallel resonate inverter consists of H-type bridges, each of whose arms is composed of a combination of two parallel IGBTs. Inverter operating with the fixed frequency is controlled by pulse width modulation (PWM). As switching adapted the Zero-Voltage Switching technique to reduce switching losses the system is high efficiency. The propose inverter has feature which is high efficiency for very wide load variations with a narrow range of duty cycle ratio control and load short circuit capability. Detailed experimental results obtained from a 48[V] output, 500[W] experimental inverter are presented to verify the concept.

• The Transactions of the Korean Institute of Power Electronics
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• v.19 no.6
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• pp.538-548
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• 2014

This study provides a robust control of a grid-connected three-phase two-level photo voltaic inverter. The introduced control method uses the cascade control strategy to regulate AC-side current and DC-link voltage. A robust controller with integration action is used for the inner-loop AC-side current control, which maximizes the convergence rate using a linear matrix inequality-based optimization design method and eliminates the offset error. The robust controller design method considers the parameter uncertainty set to accommodate parameter mismatch and un-modeled components in the inverter model. An outer-loop proportional-integral controller is used to regulate DC-link voltage with linearization of DC/AC relation. The proposed control strategy is applied to a grid-connected 100 kW photo voltaic inverter.

• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.1
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• pp.85-92
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• 2012

In this paper, a 300[W] class boost type single-phase inverter system which can compensate voltage sag on source side is designed and implemented. This system is a two-stage conversion system composed of a boost converter and a PWM inverter. If the voltage sag has appeared at the point of common coupling, the boost converter would be operated to compensate it. The boost converter and the inverter were constructed on single smart power module(SPM) to implement low cost system. The system is designed for that the THD of output voltage is below 5[%]. Finally, the validity of the design for the inverter system is verified by both simulations and experiments.

• Journal of Power Electronics
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• v.17 no.4
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• pp.892-904
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• 2017

A design of a Class-E inverter with only one inductor and one capacitor is presented. It is operated at the optimal operation mode for domestic cooker. The design principle is based on the zero-voltage derivative switching (ZVDS) of the Class-E inverter with a parallel load network, which is a parallel resonant equivalent circuit. An induction load characterization is obtained from a large-signal excitation test bench, which is the key to an accurate design of the induction cooker system. Consequently, the proposed scheme provides a more systematic, simple, accurate, and feasible solution than the conventional quasi-resonant inverter analysis based on series load network methodology. The derivative of the switch voltage is zero at the turn-on transition, and its absolute value is relatively small at the turn-off transition. Switching losses and noise are reduced. The parameters of the ZVDS Class-E inverter for the domestic induction cooker must be selected properly, and details of the design of the components of this Class-E inverter need to be addressed. A 1,200 W prototype is designed and evaluated to verify the validation of the proposed topology.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.52 no.4
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• pp.172-178
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• 2003

This paper examines the application of high voltage static var compensator(SVC) with cascade multilevel inverter which employs H-bridge inverter(HBI). This method has the primary advantage that the number of voltage levels can be increased for a given number of semiconductor devices when compared to the conventional control methods. The SVC system is modeled using the d-q transform which calculates the instantaneous reactive power. This model is used to design a controller and analyze the SVC system. From the mathematical model of the system, the design procedures of the circuit parameters L and C are presented in this thesis. To meet the specific total harmonic distortion(THD) and ripple factor of the capacitor voltage, the circuit parameters L and C are designed. Simulated and experimental results are also presented and discussed to validate the proposed schemes.

• Advances in Computational Design
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• v.2 no.4
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• pp.283-291
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• 2017

High frequency full bridge series resonant inverters have become increasingly popular among power supply designers. One of the most important parameter for a High Frequency Full Bridge Series Resonant Inverter is optimal coil design. The optimal coil designing procedure is not a easy task. This paper deals with the New Approach to Optimal Design Procedure for a Real-time High Frequency Full Bridge Series Resonant Inverter in Induction Heating Equipment devices. A new design to experimental modelling of the physical properties and a practical power input simulation process for the non-sinusoidal input waveform is accepted. The design sensitivity analysis with Levenberg-Marquardt technique is used for the optimal design process. The proposed technique is applied to an Induction Heating Equipment devices model and the result is verified by real-time experiment. The main advantages of this design technique is to achieve more accurate temperature control with a huge amount of power saving.

• The Transactions of the Korean Institute of Power Electronics
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• v.13 no.2
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• pp.96-102
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• 2008

In a large screen sized LCD-TV, a backlight system with only one cold cathode fluorescent lamp(CCFL) can not meet brightness specification. Thus, considerable numbers of CCFLs are used to meet brightness specification. In this paper, the design guide for the inverter transformer which can drive 4 CCFLs instantaneously is presented. With the presented design, the inverter transformer that guarantee identical lamp currents under the nonidentical lamp characteristic condition, can be implemented easily. The developed inverter transformer is adopted in a 42" LCD-TV backlight. The experimental results are presented to show the validity of the presented design guide.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1261-1264
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• 1996

This paper presents the design of a neural network based PWM technique for a three level inverter of electric trains. A three-level inverter has several advantages compared with a two-level inverter in this application. In viewpoint of correcting unbalance of DC-link voltage, a novel method is developed and verified in computer simulation.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2003.02a
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• pp.140-142
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• 2003

We have designed a SFQ (Single Flux Quantum) D2 Cell and Inverter(NOT) for a superconducting ALU (Arithmetic Logic Unit). To optimize the circuit, we have used Julia, XIC and Lmeter for simulations and layouts. We obtained the circuit margin of larger than $\pm$25%. After layout, we drew chip for fabrication of SFQ D2 Cell and Inverter. We connected D2 Cell and Inverter to jtl, DC/SFQ, SFQ/DC and RS flip-flop for measurement.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.6
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• pp.1013-1018
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• 2016

In this paper, three kinds of the inverter topologies for the variable speed drive of 2-phase induction motor are compared and analyzed. The 2-phase inverters are classified into 2-leg, 3-leg, and 4-leg types depending on the number of power switching devices. And they use the output voltage vectors of the different forms according to the inverter topologies. Based on the comparative analyzed results, the effective values of output voltage have been defined by the linear modulation range. Therefore, the motor design guideline is proposed in order to decide a rated voltage of 2-phase induction motor according to the inverter topologies. Also, the computer simulations are carried out to verify the output voltage and current characteristics of each inverter topology.