Simplified Design of a Solid State Pulsed Power Modulator Based on Power Cell Structure

Jang, Sung-Roc,Yu, Chan-Hun,Ryoo, Hong-Je Institute of Electrical and Electronics Engineers 2018 IEEE transactions on industrial electronics Vol.65 No.3

<P>This study presents a simplified design for a solid state pulsed power modulator (SSPPM) based on a power cell structure. Similar to the Marx generator, the power cell structure has advantages such as reliability and modularity. In addition, the proposed SSPPM includes a capacitor charger that is simple and compact. The operating principle of, and the design considerations taken for, the SSPPM are discussed from a practical viewpoint. Based on a reasonable approximation, simplified design equations are developed for a capacitor charger and a high-voltage pulse-switching part, which are comprised of an <I>LCC</I> resonant converter and a power stage, respectively. Accordingly, detailed design procedures are proposed to develop the SSPPM with the following specifications: 40 kV, 20 A, 300 <I>μ</I>s, 200 Hz, and 50 kW. The experimental results verify the specifications at the rated operating condition with an efficiency of 92.4%, and also confirm reliable arc-protection performance. Finally, the proposed design methodology, which utilizes simplified equations, can be used for designing an SSPPM based on the power cell structure for extensive applications.</P>

A 120-kV, 5-kA Multipurpose Pulsed-Power Generator Using a Semiconductor Switch and Magnetic Pulse Compression

Jang, Sung Roc,Rim, Geun Hie,Cho, Chan Gi,Song, Seung Ho,Park, Su Mi,Ryoo, Hong Je IEEE 2017 IEEE transactions on plasma science Vol.45 No.10

<P>This paper describes a high-frequency pulsed-power generator for various industrial applications such as water treatment, food and medical apparatus for sterilization, or polluted gas treatment. The system is made of silicon-controlled rectifier as a main trigger switch, capacitors, two-stage magnetic pulse compression stages, and a linear transformer to generate a maximum of 120-kV, 5-kA pulse. The parameters obtained through the development are: output voltage: 120 kV (maximum), pulse repetition ration: 300 pulse per second, pulsewidth: 0.25 mu s, and mean power: 30 kW. The designed pulsed-power generator is confirmed to be used effectively for many high-voltage pulsed-power applications related to environmental industry by simulation and experiments.</P>

Development of 50-kV 100-kW Three-Phase Resonant Converter for 95-GHz Gyrotron

Jang, Sung-Roc,Seo, Jung-Ho,Ryoo, Hong-Je Institute of Electrical and Electronics Engineers 2016 IEEE transactions on industrial electronics Vol. No.

<P>This paper describes the development of a 50-kV 100-kW cathode power supply (CPS) for the operation of a 30-kW 95-GHz gyrotron. For stable operation of the gyrotron, the requirements of CPS include low output voltage ripple and low arc energy less than 1% and 10 J, respectively. Depending on required specifications, a three-phase series-parallel resonant converter (SPRC) is proposed for designing CPS. In addition to high-efficiency performance of SPRC, three-phase operation provides the reduction of the output voltage ripple through a minimized output filter component that is closely related to the arc energy. For allowing symmetrical resonant current from three-phase resonant inverter, the high-voltage transformers are configured as star connection with floated neutral node. This facilitates balanced voltage on each secondary winding. In addition, distinctive design of the high-voltage rectifier is introduced, taking into consideration the effective series stacking of diodes by means of the parallel resonant capacitor. In particular, the implementation of the high-voltage part including transformer and rectifier is presented in detail. For providing high power density and high reliability, effective methods for winding the high-voltage transformer and stacking rectifier diodes are discussed. Finally, the developed CPS achieves 95.5% of maximum efficiency, 0.92 of maximum power factor, 500 W/liter of power density, 0.6% of output voltage ripple, with 8.3-J arc energy.</P>

Pulsed-Power System for Leachate Treatment Applications

Jang, Sung-Roc,Ryoo, Hong-Je,Ok, Seung-Bok The Korean Institute of Power Electronics 2011 JOURNAL OF POWER ELECTRONICS Vol.11 No.4

This paper presents a water treatment system for leachate from sewage-filled ground that uses a pulsed-power modulator developed based on semiconductor switches in order to realize a long life, a high repetition rate, and a fast rising time. The specifications of the developed pulsed-power modulator are the pulsed output voltage, the output current, the pulse repetition rate (PRR), the pulse width, and an average output power of $60\;kV_{max}$, $300\;A_{max}$, 3000, $50\;{\mu}s$, and 15 kW, respectively. The pulsed-power water treatment system was introduced and analyzed using an equivalent electrical circuit model to optimize the output voltage waveform. The experimental results verify that the proposed water treatment system can be effectively used for industrial applications.

Development and Optimization of High-Voltage Power Supply System for Industrial Magnetron

Sung-Roc Jang,Hong-Je Ryoo,Suk-Ho Ahn,Jongsoo Kim,Geun Hie Rim IEEE 2012 IEEE transactions on industrial electronics Vol.59 No.3

<P>This paper describes the design and analysis of a 42-kW (14 kV, 3 A) high-voltage power supply for a 30-kW industrial magnetron drive. The design is based on a series resonant converter in discontinuous conduction mode (DCM) to take advantage of both the superior arc protection stemming from the current source characteristics and the high power density owing to the use of parasitic elements such as the leakage inductance in the high-voltage transformer. The detailed design procedure for the resonant tank and high-voltage transformer with respect to the input and output specifications is described on the basis of a simplified analysis of the DCM series resonant converter. Special considerations for designing high-power high-voltage power supplies are provided, such as series stacking of diodes for a voltage doubling rectifier and insulation between each winding of the high-voltage transformer. In addition, a comparative study using theoretical equations, simulation, and experimental results was carried out. This study yielded the output voltage and current characteristics at different switching frequencies and verified the advantages of this topology, such as arc protection without an additional protection circuit and high efficiency due to zero-current or zero-voltage switching. Moreover, the parallel operation of two converters with phase shifted gating signal is proposed to reduce the output current ripple and increase power capability for higher power magnetron drive. Additionally, the design considerations of two auxiliary power supplies (a filament power supply: 15 V, 150 A and a magnet power supply: 50 V, 5 A) are also provided and optimized for effective driving industrial magnetron. Finally, the developed power supply was tested with a 30-kW industrial magnetron, and the results prove the reliability and robustness of the proposed scheme.</P>

Comparative Study of MOSFET and IGBT for High Repetitive Pulsed Power Modulators

Sung-Roc Jang,Hong-Je Ryoo,Goussev, G.,Geun Hie Rim IEEE 2012 IEEE transactions on plasma science Vol.40 No.10

<P>This paper presents an investigation of semiconductor switches for high voltage solid-state pulsed power modulators from the viewpoint of pulse rising time, efficiency, and reliability. A comparative study of insulated gate bipolar transistor (IGBT) and metal oxide semiconductor field effect transistor (MOSFET) devices is provided, focusing particularly on the characteristics of each device for pulsed power applications. Two kinds of stacks for 10-kV pulses are developed with a high voltage capacitor charger in order to experimentally compare the characteristics of each device. Although the structure of each stack is similar, the number of power cells for the 10-kV pulse is different due to the device voltage rating. The power cell voltage for IGBT and MOSFET-based stacks is about 840 V and 560 V, respectively. Therefore, two types of transformer, with six secondary windings for the IGBT stack and nine secondary windings for the MOSFET stack, are also designed for storage capacitor charging. Moreover, the ease of varying the pulse repetition rate and the pulse width shows the advantages of the developed modulators in facilitating the measurement of device characteristics in different pulse output conditions. The experiments are performed with noninductive resistor loads, and the results of the comparison tests are discussed. In addition, the results prove that the developed modulator can be effectively used for high repetitive pulsed power applications.</P>

Pulsed-Power System for Leachate Treatment Applications

Sung-Roc Jang,Hong-Je Ryoo,Seung-Bok Ok 전력전자학회 2011 JOURNAL OF POWER ELECTRONICS Vol.11 No.4

This paper presents a water treatment system for leachate from sewage-filled ground that uses a pulsed-power modulator developed based on semiconductor switches in order to realize a long life, a high repetition rate, and a fast rising time. The specifications of the developed pulsed-power modulator are the pulsed output voltage, the output current, the pulse repetition rate (PRR), the pulse width, and an average output power of 60 ㎸max, 300 Amax, 3000, 50 ㎲, and 15 ㎾, respectively. The pulsed-power water treatment system was introduced and analyzed using an equivalent electrical circuit model to optimize the output voltage waveform. The experimental results verify that the proposed water treatment system can be effectively used for industrial applications.

Trapezoidal Approximation of LCC Resonant Converter and Design of a Multistage Capacitor Charger for a Solid-State Marx Modulator

Jang, Sung-Roc,Yu, Chan-Hun,Ryoo, Hong-Je Institute of Electrical and Electronics Engineers 2018 IEEE transactions on power electronics Vol.33 No.5

<P>This paper describes the circuit of a capacitor charger for a solid-state Marx modulator. A high-efficiency <I> LCC</I> resonant inverter is proposed for the simultaneous charging of many capacitors in parallel using a multistage transformer and rectifier. Using a high-voltage insulation cable, the charging loop, which represents the primary winding of transformer, is implemented to transfer the power from the resonant inverter to each stage. In addition to the simultaneous charging of separate capacitors, the advantages of the proposed circuit and structure include compact design and reliable insulation performance against high-voltage pulses. Based on the relevant approximation, the simplified analysis of an <I>LCC</I> resonant converter with a trapezoidal shape of resonant current is provided and a 50-kW high-voltage capacitor charger is designed for a 40-kV solid-state Marx modulator. The power stage, which consists of a transformer with four voltage-doubled rectifiers, is designed, and six power stages are configured for generating a pulse output of 40 kV. The detailed implementation of the multistage transformer and rectifier is presented in accordance with the design requirements of a high voltage modulator. Finally, the developed charger achieves 96% of the maximum efficiency and 0.96 of the maximum power factor. The experimental results verify that the proposed circuit and structure can be effectively used for a solid-state Marx modulator.</P>

한국전기연구원 고전압 전원 기술

장성록(Sung-Roc Jang),김형석(Hyung-Suk Kim),유찬훈(Chan-Hun Yu),김태현(Tae-Hyun Kim),손성호(Seong-Ho Son),권창현(Chang-Hyun Gwon) 대한전기학회 2022 대한전기학회 학술대회 논문집 Vol.2022 No.10

반도체 스위치 기반 고전압 펄스전원 연구 동향

장성록(Sung-Roc Jang) 한국조명·전기설비학회 2021 조명·전기설비학회논문지 Vol.35 No.9

This paper describes the research trends of the high voltage pulsed power modulator based on semiconductor switch. The research on the solid-state pulsed power modulator technology can be classified into three topics that were performed for introducing the topology of pulsed power modulator to overcome the ratings of semiconductor device, increasing the rated power with long pulse width and low voltage droop, minimizing rising/falling time with short pulse width. This paper provides a brief overview of these three research topics and introduces the developed pulsed power modulator in Korea Electrotechnoloy Institute(KERI).