• Journal of Power Electronics
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• v.17 no.1
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• pp.115-126
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• 2017

This paper presents a new cascaded asymmetrical single phase multilevel converter with a reduced number of isolated DC sources and power semiconductor switches. The proposed inverter has only two H-bridges connected in cascade, one switching at a high frequency and the other switching at a low frequency. The Low Switching Frequency Inverter (LSFI) generates seven levels whereas the High Switching Frequency Inverter (HSFI) generates only two levels. This paper also presents a solution to the capacitor balancing issues of the LSFI. The proposed inverter has lot of advantages such as reductions in the number of DC sources, switching losses, power electronic devices, size and cost. The proposed inverter with a capacitor voltage balancing algorithm is simulated using MATLAB/SIMULINK. The switching logic of the proposed inverter with a capacitor voltage balancing algorithm is developed using a FPGA SPATRAN 3A DSP board. A laboratory prototype is built to validate the simulation results.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.196-197
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• 2010

This paper investigates a high performance converter topology for hydrogen gas generation electrolysis system. The proposed converter topology consists of full-bridge inverter, medium frequency transformer, and diode rectifier. Hydrogen gas generation electrolysis process considered in the paper is analyzed and characterized by its equivalent circuit. The electrolysis cell is modeled as effective resistance, capacitance, inductance, and internal emf voltage source. The proposed converter topology provides enhanced efficiency of hydrogen gas generation process under the operating condition of dc output voltage with high frequency ripple on it. The high performance operation of proposed converter is confirmed through the simulation with the electrolysis cell considered in the equivalent circuit model.

• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.3
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• pp.354-359
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• 2012

A transformerless converter suitable for multiphase drive application is presented in this paper. The topology employs a cascaded H-bridge rectifier as the interface between the grid and multi inverters which drive the multiphase motor. Compared with the conventional structure, the new topology eliminates the input transformer and also has the advantages such as four quadrant operation, simple configuration, low cost, high efficiency, and so on. The control strategies for the grid-side cascade H-bridge rectifier and the motor-side inverter are studied accordingly. Based on the multi-rotational reference frame, modular control scheme is developed to regulate the multiphase drive system. Simulation results show the proper operation of the proposed topology and the corresponding control strategy.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.509-512
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• 2000

LCD displays for flat monitors the backlit using Cold Cathode Flourescent Lamps(CCFLs) In this paper a low-cost series resonant half-bridge inverter for LCD backlight is proposed as a CCFL ballast. It is regulated by asymmetric control for its fixed frequency soft switching model. The attractiveness of this topology is primarily its low cost because of using BJT switches and reduction of anti-parallel diode. Design procedure and experimental verification from 5W 15"LCD backlight are presented.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.317-320
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• 2000

This paper proposes a voltage compensation method to improve the control performance of B4 inverter which is studied for low-cost drive systems. The B4 inverter employs only four switches and it has a center-tapped connection in the split dc-link capacitors to one phase of a three-phase motor. In the B4 topology unbalan-cd three-phase voltages will be generated by the dc link voltage ripple. To solve this problem we present a voltage compensation method which adjusts switching times considering dc link voltage ripple. The proposed method is verified by simulation results,

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.388-390
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• 2008

본 논문에서는 새로운 H-bridge 멀티레벨 인버터 구조를 제안한다. 제안된 구조는 기존의 H-bridge 멀티레벨 인버터 구조보다 사용하는 스위칭 소자수가 적어 시스템 크기, 비용, 전력 손실, 노이즈 감소로 보다 효율적인 동작이 가능하다. 또한 레벨 수가 증가할수록 스위칭 소자는 비례적으로 감소하여 High level에서 보다 더 효율적인 동작이 가능하다. 제안된 H-bridge 멀티레벨 인버터 구조의 타당성을 검증하기 위해 PSpice 시뮬레이션을 수행하였고 제안된 구조의 우수성을 검증하였다.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.989-991
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• 2001

The new converter topology using full bridge inverter for the switched reluctance motor drives is proposed. The proposed SRM drives are supplied by the pulse voltage source, while the conventional drives are supplied by dc voltage source. Proposed converter maintains the characteristics of asymmetric bridge converter and has advanced characteristics.

• Proceedings of the IEEK Conference
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• 2003.07b
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• pp.1023-1026
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• 2003

An electronic ballast for driving automotive HID lamps is presented. The circuit topology is composed of a fly back converter, a Ful bridge inverter, and an igniter. A prototype was developed and tested on a 35W lamp with a 12V input voltage. To avoiding the acoustic resonance, the full bridge inverter is operated at 250Hz and provided a squared-wave voltage source to the lamp. The transient and steady state characteristics of the tested HID lamps are measured and analyzed.

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.335-337
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• 2001

The new converter topology using half bridge inverter for the switched reluctance motor drives is proposed. The proposed SRM drives are supplied by the pulse voltage source, while the conventional drives are supplied by de voltage source. Proposed converter does not lose the characteristics of classic converter though the total no. of power switches are reduced.

• International Journal of Railway
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• v.1 no.3
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• pp.94-98
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• 2008

Static inverters are essential devices onboard of rolling stock. State-of-the-art static inverters have an impact on both rail infrastructure and vehicle maintenance due to their new topology with new features. The paper describes two important aspects as examples of new features available in state-of-the-art static inverters: active input current control and the effects on the rail infrastructure as well as the detection of the state of charge and the state of health of batteries to simplify vehicle maintenance.