• Journal of the Korean Society for Railway
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• v.3 no.1
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• pp.1-11
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• 2000

In this paper, the IGBT VVVF inverter for 1C4M propulsion system of railway traction is studied. The inverter is consisted of IGBT stacks, a DB unit, and a control unit. The test results of the combined system is given, which shows an excellent performance of the overall system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.3
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• pp.36-44
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• 2006

In general, the generated harmonics and noise of the PWM inverter are affected by PWM switching method, switching frequency, dv/dt and di/dt. Since multilevel inverters are often applied to the high power system, and operates with low switching frequency, theyproduce large size of harmonic contents and noise. Thus it is necessary to install output filters in the multilevel inverter. In this paper a filter design approach for the harmonic and noise reduction the three phase induction motor driving system using H-bridge 7-level inverter system is presented. The passive filter that has low cost and simple structure and can effectively reduce harmonics and noise, is designed and applied to the three phase induction motor drive having multilevel inverter system. The designed system is implemented and verified by simulation and experiments.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.681-684
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• 2005

This paper presents a useful multilevel PWM inverter scheme based on a (3$^{n-1}$+2) level generation technique. It consists of a PWM inverter, an assembly of LEVEL inverters, and cascaded transformers. To produce high quality output voltage waves, it synthesizes a large number of output voltage levels using cascaded transformers, which have a series-connected secondary. By a suitable selection of secondary turn-ration of the transformer, the amplitude of an output voltage is appeared at the rate of an integer to an input dc source. Operational principles and analysis are illustrated in depth. The validity of the proposed system is verified through computer-aided simulations and experimental results using prototypes generation output voltages of an 11-level and a 29-level, respectively. And their results are compared with conventional counterparts.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.611-614
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• 1991

In variable speed driving system of three phase induction motor controlled by an inverter, because of the switching of semiconductor devices in inverter, an appreciable amount of harmonic components of voltage waveform can cause the motor to generate losses, torque ripple, acoustic noise and oscillation of semiconductor devices. In this paper a new PAM type PWM inverter using IGBT is described. The output waveforms in the proposed PAM type PWM inverter are investigated both theoretiically and experimentally. The line-voltage waveform is composed of fundamental component and the sidebands of carrier frequency. The lower order harmonics are not included in the output wave form. As each inverter arm does not operate during two-thirds period, the heats, generated in the devices are reduced. That is, the size of the inverter system can he minimized because of the reduction in the heat dissipating equipment.

• Journal of Electrical Engineering and Technology
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• v.6 no.2
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• pp.255-262
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• 2011

This paper proposes a grid-tied power conditioning system for fuel cell, which consists of three-phase current-fed DC-DC converter and three-phase PWM inverter. The three-phase current-fed DC-DC converter boosts fuel cell voltage of 26-48 V up to 400 V with zero-voltage switching (ZVS) scheme, while the three-phase PWM(Pulse Width Modulation) inverter controls the active and reactive power supplied to the grid. The operation of the proposed power conditioning system with fuel cell model is verified through simulations with PSCAD/EMTDC software. The feasibility of hardware implementation is verified through experimental works with a laboratory prototype with 1.2 kW proton exchange membrane (PEM) fuel cell stack. The proposed power conditioning system can be commercialized to interconnect the fuel cell with the power grid.

• Journal of IKEEE
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• v.23 no.4
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• pp.1182-1186
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• 2019

This paper discussed the research results on the development and output characteristics of single-phase direct drive 20W BLDC motor with ADC converter. It is designed to drive the rotor through PWM inverter switching and position the back electromotive force of the motor electrically 30° ahead of the hall sensor phase angle signal to ensure optimum switching time. As a major result of the characteristics evaluation, the maximum inverter efficiency was 92[%], the system efficiency was 53.34[%,] and the motor efficiency was 57.85[%].

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.281-283
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• 1995

Deadbeat controlled PWM Inverter is realized. This PWM inverter performs the instantaneous control method which is based on the real-time digital feedback control and the microprocessor-based deadbeat control. For the deadbeat current controller, the system's order becomes a high order and increases computation delay time. Therefore, The delay tine produces current ripple. To minimize the current ripple, a new method based on deadbeat control theory for current regulation is proposed. It is constructed by a reduced-order state observer which predicts the output current in next sampling instant.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.2
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• pp.259-267
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• 1994

This paper describes a current control of a single-phase PWM inverter. The proposed PWM inverter utilizes the instantaneous control method which is based on the real-time digital feedback control and the microprocessor-based deadbeat control. The deadbeat current controller is proposed to control the output current regardless of load component variations by the same method as voltage control. That is, in current control, with a very short sampling time and the successive feedback of the output current, the load current is mainly effected by the magnitude of load impedance rather than load component, the load current is mainly effected by the magnitude of load impedance rather than load component. Therefore, by treating the load as an impedance, the system's order is reduced and the instantaneous current control using the proposed deadeat controller is simplified.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1175-1177
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• 2003

In this paper, an application of the ZVT-PWM(zero-voltage-transition) boost converter, which has great advantage on miniaturization and high power density, to the power factor correction circuit of the EFL(electrodeless fluorescent lamp) inverter is studied. The operation principles of the converter are described to identify the power factor correction characteristic of the inverter. Experimentally obtaining the high power factor above 0.99, it is verified that the power factor correction of the EFL inverter successfully achieved.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.163-166
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• 2001

In this paper, a two-level switching algorithm ov the deadbeat to control PWM inverter is proposed. A modified algorithm of the deadbeat is suitable for the UPS system. Two levels in the pulse pattern are used. This scheme allows the use of higher switching frequency for a given computation time delay, which results in lower total harmonic distortion at the output. The proposed control scheme is implemented using TMS320F240 DSP for controlling on inverter.