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This article describes a 3-kW simmer and 30-kV dc trigger power supply system for driving xenon flash lamps in large-area processes. Simmer power supply is designed to output maximum of 3 kV for maintaining the lighting state of the lamp after having triggered and to supply low ripple current continuously for maintaining the ignited state. It is designed based on an LCC resonant converter and design and implementation of the high-voltage transformer and output rectifier are presented. For igniting xenon lamps, dc trigger is designed to output a maximum of 30 kV auxiliary trigger voltage. The system that both power supplies is operated by one main inverter is presented. Through the resistive-load test, it is verified that the simmer outputs 600 V, 5 A under rated-load condition and 120 V, 1 A under light-load conditions. It is also verified that the simmer outputs 3 kV and the dc trigger outputs 30 kV under the no-load condition.Finally, the simmer and dc trigger power supply system is applied to lighting various xenon lamps from single lamp (306 mm, 8Φ) to three series lamps (400 mm, 26Φ). Required output voltages for stable driving various types of xenon lamps in the lighting mode are presented. [ABSTRACT FROM AUTHOR]

This article presents a bipolar pulse power modulator for high-efficiency production of plasma activated water (PAW). The proposed modulator is designed based on a power cell structure that has structural advantages of a power loop and control loop. Full-bridge based power cells are designed and 12 cells are connected in series. A power loop transformer is designed to deliver isolated power to all cells simultaneously without additional charging switches. A bipolar control loop structure is designed to supply the isolated power and signals required for 48 discharge switches through a pair of high voltage cables. The specifications of the modulator based on the proposed design produces a maximum output voltage and current of 10 kV/100 A, a pulsed width ranging from 0.6 to 10 μs, a maximum repetition rate of 3 kHz, and an average power of 2 kW. The bipolar modulator is tested under resistive and plasma reactor load conditions. In addition, a comparative experiment on the production efficiency of PAW between the proposed modulator and the existing modulator is performed under the same output power condition. Finally, the nitrate generation efficiency is 3.03 g/kWh, which is 1.7 times higher than the existing modulator. [ABSTRACT FROM AUTHOR]

When designing solid-state Marx modulators (SSMMs) with fast-rising nanosecond pulses, the gate-driving scheme for pulse discharge switches is one of the most important aspects to be considered. In this article, we propose a nanosecond current-loop gate-driving circuit for a synchronized fast gate drive of pulse discharge switches. The proposed circuit comprises an inverter, a current-loop cable, and discharge switch drivers. The inverter generates bipolar pulses that simultaneously provide driving power and fast triggering signals to all discharge switch drivers through the cable. The triggered discharge switch drivers rapidly turn on/off all discharge switches with accurate synchronization. In the inverter and discharge switch drivers, the fast gate-driving methods were used to overcome parasitic inductances and realize nanosecond operation. The concept and operational principles of the proposed gate-driving scheme are presented. To validate the performance and reliability of the SSMM using the proposed current-loop gate-driving circuit, a laboratory test on a 10-kV–70-A–50-kHz SSMM prototype was conducted, and the results were discussed. [ABSTRACT FROM AUTHOR]

This article describes a modification and an experiment conducted on a solid-state pulsed power modulator (SSPPM) for medical linear particle accelerator (LINAC) applications. Depending on the operating condition of the magnetron, an existing design of an insulated-gate bipolar transistor (IGBT)-based modulator is modified, from a positive pulse generator to a negative pulse generator. The design of the gate driver circuit of the pulse discharging IGBTs is also slightly changed to secure reliability against the arc condition. The developed modulator has the following maximum output—pulse voltage of −40 kV, pulse current of −100 A, pulsewidth of 5 μs, and pulse repetition rate of 250 Hz. By adapting the proposed design to the pulsed power modulator for driving the magnetron, high peak and average power densities of 43 kW/L and 48.9 W/L, respectively, can be achieved. The experimental results from various tests conducted using a resistor load, including a rated operation and an arc protection, verify the robustness and utility of the developed SSPPM for medical LINAC applications. An experiment using a 9.3-GHz 1.7-MW X-band magnetron is also conducted. The developed modulator achieved a successful arc protection operation for the arc generated in the waveguide during the magnetron drive test. [ABSTRACT FROM AUTHOR]

This paper describes a study on the high-voltage compact solid-state pulsed-power modulator for parallel reactor operation. The current capacity of the pulsed modulator has been improved to drive multiple reactors in parallel. The pulse discharge switch uses the IXYK120N120C3 (1200 V/120 A) insulated-gate bipolar transistor for a high current output. The gate driver has been improved according to the characteristics of the replaced switch. The output specifications of the modified pulsed-power modulator are a maximum output voltage of 40 kV, a maximum output current of 300 A, a pulsewidth ranging from 1.5 to $5~\mu \text{s}$ , a maximum repetition rate of 3 kHz, and an average power of 13 kW. The modulator has the dimensions of $450 \times 475 \times 600$ mm3, a maximum peak power of 12 MW, and a maximum power density of 93 kW/L. A resistive load experiment and a plasma reactor parallel drive test were performed. Four parallel reactors were driven using one modulator. In addition, a 50% reduction in the concentration of toluene was obtained through the experiment of the toluene gas treatment using only parallel plasma reactors. [ABSTRACT FROM AUTHOR]

This paper addresses the design of a solid-state bipolar pulsed-power modulator based on a series of stacked power cells that realize a simple and robust structure. Each cell is charged in parallel by an LCC resonant converter independently of the discharging loop. A passive cell-balancing design is implemented. The power cell using insulated gate bipolar transistors (IGBTs) can operate in bypass mode without an additional component, and the circuit operation was analyzed. A simple gate driving method, which provides synchronized gate signals without an extra power source of each gate driver using two control loops and isolation transformers, is implemented for the proposed bipolar pulsed-power modulator based on stacked cells. Moreover, an unexpected gate turn-on problem was solved by an additional off signal. To validate the proposed structure and the gate driving scheme, a three-cell, 1.2-kV, 110-A, 1.5- to 4- $\mu \text{s}$ , 3-kHz laboratory experimental prototype test was conducted. The results proved the reliability of the proposed solid-state bipolar pulsed-power modulator. [ABSTRACT FROM AUTHOR]

This paper presents a 2.5-kW (500 V/5 A) simmer circuit for a xenon flash lamp driver. The simmer circuit is based on an LCC resonant converter to take advantage of minimal arc energy from the current source characteristic. The output under no load condition was analyzed. The converter minimizes filter size with high switching frequency through the use of zero-voltage switching and SiC power devices. A gate driver with variable dead time to assist soft switching was designed. The design criteria of variable dead time implemented through a simple RC circuit are presented. A PSpice simulation was performed to verify the parameter design. The simmer circuit was implemented based on the designed LCC converter. The circuit was tested at a resistive load under rated conditions (500 V/5 A) and open condition (1400 V/0 A). The Xenon flash lamp driver was implemented using the developed simmer circuit and trigger circuit. The prototype was tested to maintain the lamp under various simmering current conditions. The influence of the arc energy on the reliability of the triggering operation was proven by comparing the waveform for filter capacitor values. The experimental results verify that the designed circuit can be effectively used for simmering xenon flash lamps. [ABSTRACT FROM AUTHOR]

This paper presents an investigation of trigger circuits for xenon flash lamp drivers from the viewpoint of breakdown voltage, high-voltage isolation, and reliability. A comparative study of pulse trigger and DC trigger circuits is provided, focusing particularly on the circuit structure of each driver for high voltage isolation. Two kinds of trigger circuits for xenon flash lamp drivers are developed with a 2.5 kW (500 V/5 A) simmer circuit for maintaining the xenon lamp ionization. The structure of each trigger circuit is the series trigger type to obtain the advantages of the isolation structure. The outputs of the pulse and DC trigger circuits are measured as 21 kV 1.8 μs half-sine wave pulse and above 10 kV DC, respectively. The tests of xenon lamp ignition and the results of the comparison are discussed. The results prove that the both developed trigger circuits can be effectively used as xenon flash lamp drivers. [ABSTRACT FROM AUTHOR]

Conventional power supply systems for xenon lamps have only limited applicability in sintering, because sintering needs to drive the lamp itself as well as enable instantaneous and strong discharge of voltage and current for generating intense light. This implies that, for sintering applications, a method should be developed that would enable instantaneous and strong discharge of energy. In this paper, we propose a new xenon lamp sintering system with an additional capacitor charger and bank. The proposed system features three power supplies. Two power supplies, called the trigger and the simmer, ionize gaseous xenon using a 23-kV trigger pulse output and sustain the ionized xenon gas using a 2.5-kW simmer power supply. The used trigger is also specially designed to conduct high current through its transformer, and it makes the proposed system an outstanding high voltage blocking capability. Another 36-kW power supply charges a 130-mF capacitor bank with a high-efficiency resonant converter. In addition, some components such as the simmer blocking diode and the trigger output capacitor are introduced, because combining different power supplies causes operational problems. These components are analyzed with some circuits that show its features, and finally, the validity of the suggested system was confirmed in two steps. First, the simmer power supply and the capacitor charger were tested for the rated operating performance by using a resistive load condition. As a result, the rated operation of the simmer power supply was confirmed under the 2.5-kW output condition, and the efficiency of the capacitor charger was found to be greater than 96% at the rated 36-kW rated load condition. In addition, a pulse discharge current of 900 A was also observed with the equivalent resistor load through a pulsed discharge experiment of the capacitor bank, which was charged at 1500 V. The trigger power supply, whose equivalent resistive load was difficult to realize, was experimented directly using the real xenon lamp to check the stable trigger operation of the xenon lamp at its 23-kV output pulse voltage. After the verification using the resistive load condition, the real operation and performance of the combined xenon lamp power supply system that includes three kinds of power supplies were finally tested and verified by using the actual xenon lamp as a total system. [ABSTRACT FROM AUTHOR]

This paper describes the design and implementation of novel trigger circuit (23 kV, $1.7~\mu \text{s}$ , and 0.66 J/pulse) for xenon flash lamp driver. The design is based on a modified flyback circuit in the discontinuous conduction mode to take advantage of both generating the high voltage from the resonance with output capacitor and connecting the series with main pulse circuit using the flyback transformer which can carry the full current of several kiloampere at high-voltage side. This design eliminates the requirement for additional high-voltage protection devices in a xenon flash lamp driver. In addition, the unique high-voltage flyback transformer is designed with high turn ratio and low leakage inductance. The detailed design procedure for the resonant circuit at the output side of the flyback circuit with the permissible range of the parasitic component of the transformer is described on the basis of simplified analysis of resonant circuit. To verify the proposed design, computer simulation based on PSpice software and experiments for the proposed triggering circuit with a main pulse circuit was performed. For the experiment, the trigger circuit is developed with the specification of maximum 23-kV, 0.66-J/pulse output and tested with a xenon flash lamp (Heraeus P4101) driver consisting of a 1.5-kV, 36-kJ/s main pulse circuit and a 2.5-kW (500 V, 5 A) simmer circuit. The experiment is performed in both triggering without the simmer mode and combining the simmer mode. From the simulation and experimental results, it is verified that the triggering circuit can be used effectively, as it exhibits reliable ignition. [ABSTRACT FROM AUTHOR]

Ship building companies are exposed to increasingly strict regulations on exhaust air from painting facilities, which current exhaust air treatment methods cannot adequately meet. We propose the use of a plasma system using a pulsed-power supply, which we constructed and tested at the painting facility of a ship building factory. Through gas chromatography and facility efficiency analysis, we found flexibility in design of the plasma system. We demonstrate the efficiency and safety of our plasma system, and emphasize the importance of posttreatment facilities for the secondary pollutant treatment. [ABSTRACT FROM AUTHOR]

This paper presents the design and experimental results of the 36-kW pulsed-power supply for the xenon flash lamp. The continuous conduction mode series-parallel resonant converter is modified. This means that not only the few hundred kilohertz of high switching frequency is introduced to replace the resonant inductor with the leakage inductor of transformer but also the high output current is accomplished by using three-phase delta-connected transformers. In addition, the snubber capacitor of the inverter switches and the power factor correction module is both omitted in the compact structure. Although these main components have changed, the efficiency and power factor of the rated dummy load reach 96% and 0.96%, respectively. Within 36-kW average power, the proposed pulsed-power supply can generate as versatile combination of output pulse. For example, it can generate 20-ms pulse with 1-Hz repetition rate or generate 1-ms pulse with 20-Hz repetition rate. The used insulated gate bipolar transistor is protected from the turn-OFF peak voltage by the snubber circuit, and the effect of the snubber circuit is shown at the actual load condition. [ABSTRACT FROM PUBLISHER]

Treatment of gas and water for environmental applications requires a high-voltage, fast-rising pulse to act on the plasma gas or water treating reactor, but the existing stacked high-voltage pulse generator is arduous to use owing to its large size, high cost, and relatively slow pulse rise time. In this study, we propose a low-cost, small-volume pulsed power modulator that can significantly reduce the cost and volume of the device and shorten the pulse rise time to meet the requirements of gas and water treatment. The proposed pulsed power modulator is based on a discontinuous conduction mode (DCM) flyback converter, and it generates a high-voltage pulse through the resonance of the flyback transformer secondary side inductance and the parallel capacitor. A straightforward spark gap sharpens the generated high-voltage pulse. Finally, a fast-rising, high-voltage pulse with a narrow pulsewidth run on the load is generated. Through PSIM simulation and actual experiments, we validated the feasibility of the proposed pulse generator and obtained 23 kV, 500-Hz pulses with a width of 0.5- $\mu \text{s}$ width and rise time of 5 ns in actual experiments. [ABSTRACT FROM AUTHOR]

An integrated full-bridge inverter circuit with fewer components and lower volume is proposed. The conventional light sintering system uses several independent power supplies, each having an input voltage source and inverting component. However, the structure of the proposed circuit comprises only one full-bridge inverter with two separated transformers for applying independent dc trigger and simmer output voltages. The separated transformers are considered to have the same operation switching frequency because of the integrated inverter part. When designing the system, we considered not only matching the switching frequency but also turning-on of the xenon flash lamp. Some of the considerations are as follows: no-load characteristic of the lamp at the initial moment, voltage-boosting effect of the parasitic inductance and capacitance, additional simmer output current path for continuous conduction, and dc trigger turn-off moment when the 15-kV trigger output voltage changes the lamp impedance. Here, the successful results of the aforementioned considerations for applying the light sintering technology are presented. The simulation and no-load experiment waveforms are consistent with the analysis of the effects of the parasitic inductance and capacitance. In addition, the waveforms show 15- and 1.0-kV stable output voltages for the dc trigger and simmer power supplies, respectively. Finally, the xenon flash lamp load is tested, and the integrated system is observed to be functional for single or series-connected lamps. [ABSTRACT FROM AUTHOR]

This paper proposes a temporary frequency-support scheme of a doubly fed induction generator (DFIG) that can improve the frequency nadir while ensuring rapid frequency stabilization, particularly for high wind power penetration levels (WPPLs). Upon detecting a disturbance, the power reference is increased by the incremental power and maintained for a preset period. The proposed incremental power varies with the rotor speed and WPPL. Then, to force the rotor speed to converge to a stable operating range, the reference decreases with the rotor speed. During the deceleration period, the proposed scheme releases less kinetic energy, which helps in the rapid recovery of the rotor speed. During the acceleration period, to accelerate the rotor speed recovery, the reference smoothly decreases with time and rotor speed until it reaches the maximum power point tracking curve. The test results, which are based on the IEEE 14-bus system, demonstrate that even though less kinetic energy is released, the proposed scheme can improve the frequency nadir while rapidly recovering the rotor speed under various wind conditions and penetration levels, but it is particularly effective for higher penetration levels. The scheme helps providing a promising solution to the ancillary services of a DFIG in a power system with high WPPLs. [ABSTRACT FROM PUBLISHER]

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 \texts , 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. [ABSTRACT FROM AUTHOR]