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This paper proposes a new developed switched-capacitor converter to achieve high-voltage pulses with adjustable voltage level and frequency. The proposed topology generates repetitive high-voltage pulses by using low-voltage power supply with reduced number of components, including power semiconductors and capacitor. Therefore, a converter based on switched-capacitor units with high voltage gain and high efficiency can be achieved. Operation principles and design steps of the converter as well as comparative study with conventional converters are described in this paper. Finally, simulation and experimental results of a two-stage structure of the proposed circuit validate the operation principles and features of this topology. [ABSTRACT FROM AUTHOR]

This paper discusses a novel methodology to increase the voltage droop compensation range in generalized solid-state bipolar high-voltage Marx modulators with one resonant stage. To maintain the modularity characteristic of bipolar Marx modulators, the imbedding of additional resonant stages is not straightforward. Nevertheless, this paper proposes to add a second resonant stage to the already existing resonant-type voltage droop compensation stage. This second stage increases the voltage droop compensation percentage of a generalized solid-state bipolar Marx generator. The compensation of the bipolar pulse voltage droop is now achieved by adding two auxiliary synchronous compensation resonant voltages, to the output capacitive decaying voltage. Simulation and experimental results are presented for six Marx plus two resonant stages, 16% voltage droop, with 3-kV pulse amplitude, 100- $\mu \text{s}$ pulsewidth, 40-ms relaxation time, and 10-Hz pulse repetition rate. [ABSTRACT FROM AUTHOR]

This paper presents the design and construction of a sample of Marx pulsed generator based on boost converter (BC) pulse-forming networks (BCPFNs). BCPFN is used instead of the conventional Marx floors for constructing this pulsed generator. BCPFN is carried out by connecting inductors and capacitors in series and parallel modes, respectively, by using solid-state switches, and during this procedure the pulsed generator converts to BC temporarily and increases the voltage of capacitors uniformly to a considerable value. This technique causes an increase in the discharging voltage level to the load that is many times more than its dc voltage source by charging the capacitors to a greater level. In order to take advantage of the benefits of Marx generator and PFN, this paper suggests a new circuit with the minimum number of switches. It means, to compose BCPFN and Marx, we have tried to design the circuit with fewer switches and instead of it we have achieved our desired performance with changing the operating mode in the states of BC, PFN, BCPFN, and BCPFN Marx. The results are simulated with MATLAB software. At the end, the experimental results of the construction of the above-mentioned system at low-power levels are presented, and the topology’s accuracy is proved by comparing them to the results of simulation. [ABSTRACT FROM AUTHOR]

This paper presents a model predictive current control (MPCC) for three-phase four-switch converters (TPFSC) connected to surface permanent magnet synchronous generators (SPMSGs) in oscillating water column (OWC) wave energy plants, that brings some benefits over the existing control methods used in this type of plants. The proposed MPCC for TPFSC follows the current references with great accuracy, whereas the switching frequency of the insulated-gate bipolar transistor (IGBTs) is fixed and low. This method minimizes the current reference tracking error, and its fast response makes it suitable for the power take-off systems present in wave energy converters. Furthermore, the system features a fast capacitor voltage offset suppression control. The dynamic performance and the voltage offset control of the proposed strategy for TPFSC feeding a SPMSG is evaluated in the Simulink environment. Later, experimental studies are carried out on an 8.7 kW laboratory SPMSG prototype. Finally, the capability of the proposed method to harvest the maximum energy from irregular waves is assessed using an OWC power plant emulator. [ABSTRACT FROM AUTHOR]

Compulsators are ac generators which are used for electromagnetic launch applications over the past few decades. This paper presents the work carried out by the authors to design a compulsator for a railgun which has been built and tested with a capacitor bank of 20 kJ as the pulsed-power source in the author’s laboratory. The generator topology selected for the compulsator is a single phase, two-pole machine with iron core and passive compensation. The design is based on the criterion of achieving maximum projectile exit velocity with the additional condition that natural current zero is synchronized with the instant of the projectile’s exit. The effect of varying the different parameters of the compulsator on the performance of the system has also been studied and discussed in this paper. By means of performance analysis, the necessary background for the design of the actual compulsator has also been achieved. [ABSTRACT FROM PUBLISHER]

Repetitive high pulsed electric field (PEF) is an effective method to kill microorganisms and bacteria in water treatment applications. The PEF can be generated by applying high-power electromagnetic pulse across the sample to be treated. There are two main types of high-voltage pulse generators, namely, unipolar and bipolar. In this paper, a full-bridge submodule-based modular high-voltage pulse generator, having the ability to generate unipolar and bipolar high-voltage pulses with different shapes from a relatively low-voltage input dc supply, is proposed. In the proposed configuration, relatively low-voltage insulated gate bipolar transistors (IGBTs) are required to generate the high-voltage bipolar pulses. A thyristor rated at the level of the pulsed output voltage is required in the proposed configuration to bypass the load during the charging process of capacitors. In the proposed approach, a thyristor is used instead of the self-commutated high-voltage switch (e.g., series-connected IGBTs), as thyristors are available with high-voltage ratings and possess inherent reverse voltage blocking capability. A detailed illustration of the proposed configuration and its operational concept are introduced in this paper. Simulation and experimental results are presented to validate the proposed approach. [ABSTRACT FROM AUTHOR]

Bipolar junction transistors (BJTs) have been widely studied and used in nanosecond high-voltage pulse generators due to the advantages of fast switching speed and high repetitive frequency. Usually the Marx-type circuit is used to raise the peak value of output pulses. In this paper, a traditional BJT-Marx circuit using charging resistors is analyzed theoretically and experimentally. Based on the results, the structure of a circuit is changed to decrease the isolation voltage across the resistors, and diodes are used to replace charging resistors to block capacitors discharging to resistors. Experimental results showed that the three Marx generators proposed in this paper output pulses with higher voltage amplitude, and the last improved circuit outputs pulses with faster fall times at a higher efficiency. [ABSTRACT FROM AUTHOR]

This paper shows how to use modular Marx multilevel converter diode ( \textM^3 CD) modules to apply unipolar or bipolar high-voltage pulses for pulsed power applications. The \textM^3 CD cells allow the assembly of a multilevel converter without needing complex algorithms and parameter measurement to balance the capacitor voltages. This paper also explains how to supply all the modular cells in order to ensure galvanic isolation between control circuits and power circuits. The experimental results for a generator with seven levels, and unipolar and bipolar pulses into resistive, inductive, and capacitive loads are presented. [ABSTRACT FROM AUTHOR]

In this paper, a modular topology is presented for generating high-voltage pulsed power. The proposed structure consists of Marx-type modules, which are based on the switched-capacitor (SC) concept. This module receives an input voltage and, depending on the requirement of the user, produces an output voltage either equal to the input or twice as much as the input voltage, which shows the flexibility of our model. The capability of the module to produce a doubled output makes it appropriate for applications with low input voltage sources. Also, the topology has the capability of generating combined wide and narrow pulses. The topology was simulated in MATLAB Simulink and a laboratory setup was built to test its operation. The results validate the theoretical basis of the structure. [ABSTRACT FROM AUTHOR]

In this paper, a high-voltage unipolar pulse power generator is introduced for electroporation applications. Operating principle of the proposed structure is based on the buck–boost (BB) converter. The generator is comprised of parallel modules connected to the converter through an SCR and is supplied by a low-voltage dc source. Each module consists of an insulated gate bipolar transistor (IGBT), two diodes, and a capacitor. In fact, the proposed topology is a combination of the Marx generator and BB (MG-BB) converter. In comparison with other modular MG-BB structures, the proposed topology achieves interesting advantages including simpler structure, reduction of IGBTs voltage rating, and reducing number of components (inductors and switches). In order to clarify the features of the proposed structure, it has been compared with other unipolar MGs considering different aspects including the number of circuit components, number of required input supplies, amplitude of the output pulse, and the maximum voltage across switches and diodes. To validate the effectiveness of the structure, simulation and experimental results are presented. The results confirm that the proposed topology is capable of generating unipolar pulses with desirable amplitude and repetition frequency using a low-voltage dc supply. [ABSTRACT FROM AUTHOR]

Self-powered realization for synchronous switching circuits is a hot spot for piezoelectric vibration energy harvesting. Two typical kinds of switches, bipolar junction transistor (BJT) or metal–oxide semiconductor field effect transistor (MOSFET) are popularly used without a clear understanding about the performance difference. In this paper, comparative investigations about adopting these two types of switches based on a case study are performed. It is determined that the performance difference comes from three aspects: the gate parasitic capacitance, the turning-on threshold, and the driven mechanism. In particular, the third one imposes a critical influence on the performance. Investigations are performed on the self-powered synchronous switching circuit of two possible methods: with electronic breakers or with external control units. The results from simulations and experiments show that the current-driven mechanism limits the available performance in the case of the BJT switch in comparison with the case of the MOSFET switch. The difference is especially obvious for the cases of large piezoelectric capacitance and open-circuit voltage. A preliminary design guideline is concluded that the MOSFET is probably a better choice with the same voltage and current ratings in most cases. [ABSTRACT FROM AUTHOR]

Repetitive high-voltage square pulses are of great importance for producing long-pulse electron beams and high-power microwaves. One of possible technologies for the generation of such pulses is a Marx generator using pulse forming network (PFN) stages, often combined with a pulse sharpening technique to reduce the rise time to a few nanoseconds (peaking stage). This paper presents an innovative design, named the “zigzag design,” for the optimization of the compactness and of the rise time of 400-kV–85-ns PFN-Marx. Thanks to this design, the 16 stages of this generator, which delivers an open circuit output voltage of 720 kV, fit in a 650-mm length. For a slightly overmatched load ($Z_{\mathrm {load}} = 100 ~\Omega$), the output voltage reaches 400 kV with a rise time as less as 5 ns. The inductance reduction associated with the innovative zigzag design, which allows this sharp rise time with no need for a peaking stage, is described. The 85-ns plateau duration of the pulse is given by the PFN construction of each stage, which is based on six ceramic capacitors (2.1 nF–45 kV) connected within a strip line. The 16 PFN stages are housed in a 360-mm diameter gas pressurized vessel. Burst mode operation for a duration of 10 s at a pulse repetition frequency of 100 Hz is reported, for a resistive load and for the electron beam diode of a X-band relativistic backward-wave oscillator (BWO). To reach further compactness, the BWO system is integrated on side of the generator vessel and a U-shaped gas pressurized line connects both systems through a compact conical vacuum insulator. [ABSTRACT FROM AUTHOR]

In this paper, we propose and design a novel generator for the high voltage square pulses with the changeable polarities in order to reach the requirements and the needs for the intended experiments on sterilization of microorganism. The major component of our circuits is a non-trivial combination between a half bridge Marx generator and an H bridge in series, combining with the DSP control unit, which can adjust the voltages, frequencies, pulse widths and polarities, and also tolerate various loads. More precisely, we illustrate the design and operation principles for each module in the constructed circuit and analyze the system performance with various loads. The effectiveness and correctness of our proposed circuit and methodologies have been verified and demonstrated by both PSIM simulation results and our own prototype. In this paper, we also show the stability and reliability of the pulse generator we proposed in terms of various load conditions and operation safety respectively. Furthermore, we also observe that the key parameters based on our constructed pulse generator can be easily adjusted which include voltages, frequencies, pulse widths and polarities. We hope that our work will stimulate the further investigations on design and analysis of pulse generators with a focus on modularization and miniaturization. [ABSTRACT FROM PUBLISHER]

High-voltage (HV) pulses are used in electroporation to subject pulsed electric field (PEF) onto a sample under treatment. Pulse-waveform shape, voltage magnitude, pulse duration, and pulse repetition rate are the basic controllable variables required for particular PEF application. In practice, a custom-made pulse generator is dedicated for each PEF application with limited flexibility in changing these variables. In this paper, a universal pulse-waveform generator (UPG) is proposed, where the controller software algorithm can manipulate a basic generated multilevel pulse waveform to emulate many different PEF pulse waveforms. The commonly used PEF HV pulse waveforms can be generated as bipolar or monopolar with controllable pulse durations, repetition times, and voltage magnitudes. The UPG has the ability to generate multilevel pulses that have controllable $dv/dt$, which allows reduction of the electromagnetic interference generated by the converter. The UPG topology is based on half-bridge modular multilevel converter (HB-MMC) cells forming two transition arms in conjunction with two bistate arms, together creating an H-bridge. The HB-MMC cell capacitors provide a controllable energy source which charge from the dc input supply and discharge across the load, while the two bistate arms allow charging the HB-MMC cell capacitors. Hence, the UPG topology offers modularity, redundancy, and scalability. The HB-MMC individual cell capacitance is low and the cell voltages are balanced by employing the sorting and rotating algorithm used in conventional HB-MMC topologies for HV dc transmission applications. The viability of the proposed UPG converter is validated by MATLAB/Simulink simulation and scaled-down experimentation. [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]

High-voltage (HV) pulses are used in pulsed electric field (PEF) applications to provide an effective electroporation process, a process in which harmful microorganisms are disinfected when subjected to a PEF. Depending on the PEF application, different HV pulse specifications are required such as the pulse-waveform shape, the voltage magnitude, the pulse duration, and the pulse repetition rate. In this paper, a generic pulse-waveform generator (GPG) is proposed, and the GPG topology is based on half-bridge modular multilevel converter (HB-MMC) cells. The GPG topology is formed of four identical arms of series-connected HB-MMC cells forming an H-bridge. Unlike the conventional HB-MMC-based converters in HVdc transmission, the GPG load power flow is not continuous which leads to smaller size cell capacitors utilization; hence, smaller footprint of the GPG is achieved. The GPG topology flexibility allows the controller software to generate a basic multilevel waveform which can be manipulated to generate the commonly used PEF pulse waveforms. Therefore, the proposed topology offers modularity, redundancy, and scalability. The viability of the proposed GPG converter is validated by MATLAB/Simulink simulation and experimentation. [ABSTRACT FROM PUBLISHER]

Recently, the pulsed power systems have found wide applications. For this reason, using the pulsed power generators that in addition to responding to the needs of the user, are providing the advantages of compactness, high flexibility, high repetition rate and cost efficiency is inevitable. This paper proposes a converter which is a combination of Marx topologies and solid state voltage multipliers. It is capable of producing high voltage pulses with varying amplitudes at different frequencies where is modular and flexible. The resonant circuit used in this structure can reduce the stress on switching element and increase the output voltage while providing a zero current switching for the full bridge converter. Its analytical design is described and its verification is proved by the simulation results in MATLAB\SIMULINK. As a proof of concept, the measurement results taken from the experimental prototype, are presented as well. [ABSTRACT FROM AUTHOR]

This paper proposes a novel current link topology with a diode rectifier and magnetic energy recovery switch (MERS) using a current source inverter for offshore-wind-farm application. Despite the use of a diode rectifier, the proposed topology is capable of regulating individual turbine torque partially. Because offshore wind condition is more stable and has less turbulence intensity (typically 0.08) than that of onshore wind, the individual full-range controllability realized typically by pulse-controlled converters is not necessary. Instead of them, the proposed scheme, a diode rectifier with MERS, has only partial controllability of the individual generator torque which is estimated to be sufficient to achieve the maximum power point tracking operation for offshore-wind-farm application. The proposed topology is aiming to be applicable for offshore wind farms where maintenance reduction is conclusively a critical issue because of the inaccessibility. In this paper, experimental results represent the effectiveness of the topology. Moreover, a new control strategy for offshore wind farms with the proposed topology is also proposed. [ABSTRACT FROM PUBLISHER]

There are many different definitions of the risetime of a transient waveform. In the context of high-altitude electromagnetic pulse (HEMP) standards, the 10–90% risetime of an idealized double exponential waveform has been defined and used for many decades. However, such a risetime definition is not strictly applicable to the transient voltage out of a pulse generator, since no practical switch can close in zero time. In this paper, we discuss various definitions and their applicability. More importantly, pulse power technology has evolved over five decades and the achievable risetimes have come down from 10s of nanoseconds to 10s of picoseconds. As a corollary, the highest achievable voltage gradient has been going upwards of 10^15 V/s. In this paper, we review the definitions of risetime, and trace the evolution of technology and HEMP Standards, exclusively for the E1 environments. [ABSTRACT FROM AUTHOR]

This paper presents a new high-voltage pulse generator, which is based on positive and negative buck-boost (BB) converters fed from a relatively low voltage dc supply. The proposed generator is able to generate unipolar or bipolar high-voltage pulses via operating the BB converters with series or parallel connected outputs respectively using a common input dc source. The components of each converter are rated at half of the pulsed voltage magnitude in the unipolar mode. The converters in the proposed pulse generator operate in discontinuous conduction mode. This enhances system efficiency, as the circuit only operates when it is desired to generate a pulsed output voltage, otherwise the circuit is switched to idle mode with zero current. Detailed illustration of the proposed approach is presented along with a full design of the system components for given output pulse specifications. Finally, simulation and experimental results are presented to validate the proposed concept. [ABSTRACT FROM PUBLISHER]

This paper presents a novel technique for the voltage droop compensation of long pulses in solid-state bipolar high-voltage Marx generators. Considering the modularity of Marx generators the compensation consists in adding one extra stage to perform as a pulsewidth modulation circuit. This stage voltage is added to the output positive or negative pulses, and an output LfCf filter is included to smooth the voltage pulse waveform. A five-stage laboratory prototype of this circuit has been assembled using 1200-V Insulated Gate Bipolar Transistors and diodes with 1000-V dc input voltage. The circuit was operated at 50-Hz bipolar pulse rate, giving 4-kV bipolar pulses, into a resistive load, with 100- \mu \texts pulsewidth and 9.5-ms relaxation time. The circuit was able to compensate 10% of bipolar pulse voltage droop. [ABSTRACT FROM PUBLISHER]

This paper presents a power electronics converter to generate bipolar high-voltage pulses using low-voltage dc source. Converter is designed based on charging of different capacitors by a predetermined switching pattern and their discharging on the load for pulsed power applications. Low number of power electronics devices and bulky transformer elimination are main advantages of the proposed converter. According to new findings, bipolar high-voltage pulses may lead to higher efficiency in many applications, such as food sterilization industry. The proposed pulse generator generates bipolar controllable pulses with a modular circuit structure based on a capacitor-switched network. Experimental results are presented to verify the analysis. [ABSTRACT FROM AUTHOR]

A bipolar pulse has been proved to be more advanced in the treatment of tumor because of the elimination of muscle contractions and the effect for ablating nonuniform tissue. In this paper, a new type of modular bipolar pulsed-power generator based on Marx generator with double power charging is proposed. The concept of this generator is charging the two series of capacitors in parallel by two power sources, respectively, and then connecting the capacitors in series through solid-state switches with different control strategies. Utilizing a number of fast solid-state switches, the capacitors can be connected in series with different polarities, so that a positive or negative polarity pulse will be delivered to the load. The simulated models of this generator have been investigated in a PSPICE platform, and a laboratory prototype has been implemented in a laboratory. The simulation and test results verify the operation of the proposed topology in different switching modes. The development of this pulse generator can provide the hardware foundation for the research on biological effect without muscle contraction when the tumors are applied with bipolar pulse electric field. [ABSTRACT FROM AUTHOR]

Pulsed electric field (PEF) can be used effectively in water treatment applications by passing infected water through two electrodes excited from a high voltage pulsed power supply which guarantees killing the harmful germs. In this paper, a new high-voltage pulse-generator with closed loop control of its output voltage is presented for treating water via underwater pulsed streamer corona discharge. The proposed generator is fed from a low AC voltage source (utility mains 220 V, 50 Hz) which makes it suitable for domestic applications. The proposed topology provides transformer-less operation which reduces the system size and enhances the overall efficiency. The proposed topology is based on capacitor-diode voltage multiplier (CDVM) circuits in conjunction with DC-DC converters (Boost and Buck-Boost converters). The simulation and experimental results elucidate the proposed configuration. [ABSTRACT FROM AUTHOR]

This paper describes a compact high storage density inductive–capacitive storage module. The module is based on high-power opening switches using inverse current commutation with semiconductor devices commutation principle and a high storage density Brooks inductor. These opening switches, being able to switch-OFF pulse currents up to 14.5 kA by the counter-current subcircuit, make use of the general property of a standard high-power thyristors impedance transition from closing state to blocking state. The experimental results show that with the primary capacitor and counter-current commutation subcircuit charged voltage 3 and 2.5 kV, respectively, the charged current of the Brooks-type inductor is about 14.5 kA, with a charged time of about 4.5 ms. The output peak current of the inductive storage module is about 21 kA. The total stored energy is about 54.9 kJ while the energy density of the inductor is approximately 6.69 MJ/ \textm^3 , which is not including the primary storage and commutation unit. [ABSTRACT FROM PUBLISHER]

Many research fields need special high-voltage pulses in pulsed power applications, which are different from typical rectangular pulses. In this paper, a high-voltage waveform modulator of two methods using a solid-state Marx generator has been developed and tested. Instead of manufacturing a generator with a specialized structure, the modulator can control a general Marx generator by low-voltage programmable logic devices to produce an irregular but controllable high-voltage triangular pulse with pulse length of ~4.5 μs and peak voltage of ~123 kV. [ABSTRACT FROM PUBLISHER]

The electromagnetic radiation effect of high-voltage, subnanosecond pulsed electric fields attracts strong interest from researchers because of its significant development potential in biological treatments, particularly in noninvasive diagnosis and treatment. But up to now, high-voltage subnanosecond pulse generators are widely used for national defense and military, and they are difficult to implement successfully in the civil medical field. A compact, self-contained, repetitive frequency, high-voltage subnanosecond pulsed power source is proposed in this paper. It was designed, built, and tested successfully. Based on a four-stage, low-inductance Marx generator, the pulsed source produces subnanosecond rise-time pulses. A chopping switch was designed to cut off unformed signals and generate subnanosecond pulses. A measurement device, based on the principle of a capacitive voltage divider, was also constructed to determine both the amplitude and the rise-time of the pulse delivered by the source. Preliminary tests show that the source can produce repetitive frequency pulses with a peak value that exceeds 30 kV, as well as rise-time and pulse width (full wave at half maximum) within 1 ns under atmospheric pressure conditions. The pulse amplitude may be extended to hundreds of kilovolts by filling the switch system with an inert gas. The rise-time would be shortened as well. The pulsed power source shows optimistic prospects in the biological fields. [ABSTRACT FROM PUBLISHER]

Many approaches exist for energy storage and delivery to the load, including high-power relativistic applications. One of the best solutions for the driver of high-power relativistic applications is the Marx generator. This paper describes the design, fabrication, and experimental validation of a Marx generator consisting of capacitors, spark-gap switches, and resistors. It is designed as an eight-stage Marx circuit to reach an output voltage level as low as −500 kV, and it is directly connected to the Blumlein pulse-forming line (PFL) to achieve more than 100 ns of the full-width at half-maximum. Experiments are performed with a solution load in a manner similar to having a coaxial structure in a high vacuum with a pressure of below 0.5\, \times \, 10^-5 torr, to prevent breakdown and measure the amplitude of the negative high-voltage pulse waveform. The solution load is designed to capture the short-pulse output of the PFL with a rise time of less than 25 ns and a voltage level of approximately −500 kV. The experimental results show that the output pulse can be used as a source to generate an intense relativistic electron beam at the gun for high-power relativistic applications. [ABSTRACT FROM PUBLISHER]

High-performance trigger generators with high amplitude, fast rise time, low jitter are essential for large-scaled pulsed-power systems. Most of the trigger generators are also tiny multistage pulsed-power systems with complicated structures. In this paper, a high-performance trigger generator was proposed by combining the advantages of low-jitter semiconductor switch and high-power gas switch. An avalanche transistor Marx circuit was developed. It was used to trigger a two-stage Marx generator based on trigatron switch. The output characteristics of the Marx circuit based on avalanche transistors and the two-stage Marx generator were studied. The experimental results show that a subnanosecond jitter, nanosecond rise time, high-voltage trigger generator can be achieved by triggering trigatron switch with an avalanche transistor circuit. [ABSTRACT FROM PUBLISHER]

Two-electrode graphite spark gap switch (TGSGS) is used as the main discharge switch and triggered by a reliable trigger generator in pulsed power conditioning system (PPCS). There would be 108 energy modules in PPCS working at the same time. The reliable operating and jitters of the trigger generators will have impact on the PPCSs performance. In this paper, the working modes of the TGSGS are discussed and the performance of trigger generators in PPCS is tested and presented. A protection strategy of the trigger generator in PPCS is introduced, and effect of the blocking capacitor on the trigger pulse transmission is analyzed and tested. The protection strategy of the trigger generator based on blocking capacitor and fuse can effectively prevent the energy anti-irrigation failure when the pulse transformer core saturated. The blocking capacitor has some effect on the trigger pulse transmission, and has the larger capacitance, getting the higher peak amplitude on the cathode of the TGSGS. It is tried to discuss the working characteristics of the thyristors, and proposes a selection reference of the thyristors in this and other similar applications. The combination of analysis and measurement would be useful for the selection of thyristors and other components. [ABSTRACT FROM PUBLISHER]

A number of high-power applications require a transportable high-energy, high-current GW generator to drive a pulsed power system at the output. A first prototype, based on exploding wire technology and using an H-bridge circuit configuration, was developed at Loughborough University a few years ago and has been previously reported. The present stage of the work has necessitated the development of a more powerful and energetic source, and this is now based on inductive storage technology. A 400 kJ capacitor bank is connected by a high-Coulomb explosively driven closing switch with an air-cored 0.6 MV transformer, an exploding wire array, and a high-power diode based on a polarity-dependent spark-gap completing the arrangement. The GW generator, including the command and control module, is accommodated in two ISO containers. The various components of the generator are described in this paper, together with results obtained from full-scale tests. [ABSTRACT FROM PUBLISHER]

A repetitive 0.6 MV, 10 GW Tesla-driven Blumlein pulsed power generator, with an overall energy efficiency in excess of 90%, has been designed, manufactured and demonstrated by the Pulsed Power Group at Loughborough University. This paper describes the application of various numerical techniques used to design a successful generator, such as filamentary modeling and electrostatic and transient circuit analysis. All the major parameters of both the Tesla transformer and the Blumlein pulse-forming line were determined, enabling accurate modeling of the overall unit to be performed. The wide-bandwidth embedded sensors used to monitor the dynamic characteristics of the overall system are also presented. Experimental results obtained during this major experimental program are compared with theoretical predictions and the way ahead toward generating faster output voltage impulses is considered. [ABSTRACT FROM PUBLISHER]

In this paper, we investigated a water treatment method that sprays waste water droplets into a pulsed discharge space. To increase energy efficiency of this method, a pulsed power generator should output a pulsed power of a high peak and a short pulse width and be low circuit loss, high repetition rate, high power, and high stability. An inductive energy storage circuit using a semiconductor opening switch was studied to satisfy the above-mentioned requirement. Initially, effect of turn ratio of a pulse transformer (PT) in the circuit was investigated. Energy transfer efficiency and the pulsewidth of the output voltage increased with the PT turn ratio, resulting in an increase of the efficiency of the water treatment system. Then, the effect of the load impedance was investigated. The result showed that an optimum resistance to maximize the efficiency exists. From these results and a previous experimental report, we concluded that the optimization conditions are summarized below. The turn ratio and the inductance in the secondary circuit should be as high as possible under the condition, which does not output the very long pulse. The impedance of the discharge at an electrode for the water treatment should be a value that maximizes the energy transfer efficiency. Capacitance of capacitors in the circuit should be adjusted to obtain optimal peak voltage for the generation of active species. [ABSTRACT FROM PUBLISHER]

Utilization of power electronics converters in pulsed power applications introduced a new series of reliable, long life, and cost-effective pulse generators. However, these converters suffer from the limited power ratings of semiconductor switches, which necessitate introduction of a new family of modular topologies. This paper proposes a modular power electronics converter based on voltage multiplier as a high voltage pulsed power generator. This modular circuit is able to generate flexible high output voltage from low input voltage sources. Circuit topology and operational principles of proposed topology are verified via experimental and simulation results as well as theoretical analysis. [ABSTRACT FROM PUBLISHER]

In this paper, a compact rep-rate GW pulsed power generator is developed. First, its three key subsystems are theoretically analyzed, engineering designed, and experimentally investigated, respectively. The emphases are put on these four problems: the theoretical analysis of the voltage distribution across the conical secondary windings of the high-coupling transformer, the investigation of the high energy storage density dielectric used in the pulse forming line, the choice of the gas flow velocity of the gas blowing system, and theoretical analysis of the passive stability of the pulsed power generator operated in rep-rate mode. Second, the developed pulsed power generator is described in detail. It has a 0.2-m diameter, a 1.0-m length, and a 20-\Omega wave impedance. Across a 100-\Omega resistive dummy load, it can steadily operate at a 300-kV output voltage in 50-Hz rep-rate and 250 kV in 150 Hz without gas blowing system. The average power is \sim1~kW. Finally, the pulsed power generator is applied to drive a relativistic backward-wave oscillator, generating a high-power microwave with peak output power of 200 MW and duration (full-width at half-maximum) of 5 ns in 150-Hz rep-rate. These efforts set a good foundation for the development of a compact rep-rate pulsed power generator and show a promising application for the future. [ABSTRACT FROM AUTHOR]

Vienna rectifier as generator-side converter of wind energy conversion system (WECS) using a permanent-magnet synchronous generator (PMSG) has several advantages compared to conventional back-to-back inverter, such as higher efficiency and improved total harmonic distortion. On the other hand, direct torque control (DTC) of the generator in WECS is of interest, particularly for low-power applications due to several merits, including fast torque response, insensitivity to PMSG model and associated parameters, elimination of rotor position sensor, and reduced computations. In this paper, the effects of Vienna rectifier voltage vectors on instantaneous PMSG torque and stator flux are derived, and DTC of PMSG by the Vienna rectifier is implemented, considering the constraints imposed by the Vienna rectifier. Experimental tests for a 1-kW prototype are presented, which confirm the simulations and theoretical results. [ABSTRACT FROM PUBLISHER]

This paper presents a new control strategy for power factor correctors (PFCs) used to drive high-brightness light-emitting diodes (HB-LEDs). This control strategy is extremely simple and is based on the use of standard peak-current-mode integrated controllers (PCMICs), reducing its cost and complexity in comparison to traditional PFC controllers. In fact, this method is an alternative implementation of the one-cycle control to PFCs belonging to the flyback family of converters, without introducing high complexity for reducing the total harmonic distortion. In this case, the use of a simple exponential compensation ramp instead of a linear one is the proposed solution for drawing a sinusoidal input current. Moreover, the line current is cycle-by-cycle controlled, and therefore, the input-current feedback loop is extremely fast, which allows the use of this type of control with high-frequency lines. The proposed idea is to apply this simple control to a one-stage PFC in order to design a low-cost ac–dc HB-LED driver. However, the application of this control strategy to PFC belonging to the flyback family of converters is not obvious. Design-oriented considerations about its implementation in PCMIC will be provided. Finally, an experimental prototype of this driver was developed. [ABSTRACT FROM PUBLISHER]

Starting from the updated requirements of an advanced laser system, a switch–trigger system for a 2.0-MJ pulsed power supply (PPS) module is developed. This paper discusses the design, construction, and testing of this switch–trigger system. The two-electrode construction for the spark gap switch is selected because of its superiority in terms of long working life, high peak currents, and fast rise time of currents. The trigger generator based on resonant charging of a pulse transformer is constructed. A magnetic isolator and a pressure controller are the auxiliary equipment of this system. In the section based on mathematical principles, the equations of the lifetime and stability of this spark gap switch with graphite electrodes are given. These expressions can be regarded as the design basis of the same type of switch. As for the trigger generator, the analysis states that an appropriate ratio can be obtained when using the resonant charging based on a core-type pulse transformer. The charging time is dependent on the leakage inductance and the capacitance of the primary and secondary capacitors. Extensive testing proves the operating parameters of the switches and the trigger generator. The measured discharge current waveform of the 2.0-MJ capacitive PPS module is demonstrated to be over 500 kA peak current and 500 \mus pulse width. The life test proves that the switch–trigger system can support more than 200 kC transfer charge. By replacing the electrodes, the lifetime of this switch can be extended furthrer. [ABSTRACT FROM PUBLISHER]

The purpose of this paper is to propose and analyze the high-performance control strategies for a novel current source converter (CSC)-based wind turbine-superconducting magnetic energy storage system (SMES) hybrid system, which will, in turn, improve the operating performance for the wind farm not only in the grid-connected operation, but also in the islanding mode. The key is to design the effective active power controller and the ac bus voltage controller for the CSC-based hybrid system in grid-connected operation. Thus, better power smoothing and robust operation can be achieved. For the islanding mode operation, the capacitor voltage control scheme is proposed for the CSC hybrid system to offer efficient operation when the wind farm is disconnected from the grid. Based on simulation, the performance of the proposed control for the CSC-type wind turbine-SMES hybrid system in the wind farm has been verified. [ABSTRACT FROM PUBLISHER]

This paper presents a CMOS image sensor with 10-bit column-parallel successive approximation analog-to-digital converters (SA-ADCs). The SA-ADC in each column integrates the binary-weighted references instead of using an internal digital-to-analog converter (DAC) to reduce the area. The area of the column 10-bit SA-ADC is \9\ \mu\m \times \425\ \mu\m. The area of the capacitor array in the SA-ADC is reduced to only 2.8% compared with that of a conventional binary-weighted capacitor DAC. In order to reduce the power consumption, the SA-ADC uses the switched power technique. The constant analog-to-digital conversion time and the switched power technique increase the power saving rate as the frame rate decreases. The proposed image sensor has been fabricated using a 0.13-\mu \m CMOS process. The measured power consumption of the proposed SA-ADC is reduced to 85% and 58% of that in the SA-ADC without the switched power technique at the frame frequencies of 15 and 150 frames/s, respectively. [ABSTRACT FROM PUBLISHER]

A new pulsed-power generator based on a Marx generator (MG) is proposed in this paper with a reduced number of semiconductor components and with a more efficient load-supplying process. The main idea is to charge two groups of capacitors in parallel through an inductor and take advantage of the resonant phenomenon in charging each capacitor up to twice as the input-voltage level. In each resonant half-cycle, one of those capacitor groups is charged; eventually, the charged capacitors will be connected in series, and the summation of the capacitor voltages are appeared at the output of a pulsed-power converter. This topology can be considered as a modified MG, which works based on the resonant concept. The simulated models of this converter have been investigated in a MATLAB/Simulink platform, and a laboratory prototype has been implemented in a laboratory. The simulation and test results verify the operation of the proposed topology in different switching modes. [ABSTRACT FROM AUTHOR]

In this paper, starting from the project requirements, a 1.2-MJ pulsed power supply (PPS) module for a high-power laser system has been developed. The main circuit of this module consists of a high energy density capacitor bank, a spark gap switch, a magnetic switch, a trigger generator, and a load subsystem. Due to the superiority in the stability and service life, the two-electrode construction for the spark gap switch, high peak currents, and rise time of the currents is selected. Since a two-electrode spark gap switch has no separate trigger electrode and must be directly overvolted by the trigger generator, a small Marx generator has been designed and constructed for the advantage of the proven compactness and electrical performance. The effect of the magnetic switch represents a couple of functions. One is to block the triggering pulse produced by the Marx generator. Another is to permit the discharging current coming from the main capacitor bank. Finally, the measured discharge current waveform of the 1.2-MJ capacitive PPS module is demonstrated to be over a 300-kA peak current and a 500- \mu\s pulsewidth. Moreover, the life test has proved that the switch–trigger system can support more than 1500 discharging processes. [ABSTRACT FROM AUTHOR]

This paper describes the construction and experimental tests of a 12-kV high-voltage high-action generator based on reverse-switching dynistor (RSD) assembly. The main RSD unit consists of seven 76-mm-diameter dynistor pieces connected in series with a blocking voltage of about 2.4 kV, a magnetic switch based on a 1K101 amorphous alloy core, the trigger system based on a saturable transformer, and a 16-mm RSD assembly; the trigger current could reach 2 kA in amplitude with 1-\mu\s duration under 10 kV. The working voltage rate of this RSD unit is about 8–12 kV. Experiment on a 2.2-mF capacitor test bed under 12 kV working voltage, the switch current amplitude reached 150 kA with 300-\mu\s duration; the transferred charge is about 26.5 C and the action is 2.94 \MA^2\s, respectively. [ABSTRACT FROM AUTHOR]

This paper presents a novel topology for the generation of high voltage pulses that uses both slow and fast solid-state power switches. This topology includes diode-capacitor units in parallel with commutation circuits connected to a positive buck-boost converter. This enables the generation of a range of high output voltages with a given number of capacitors. The advantages of this topology are the use of slow switches and a reduced number of diodes in comparison with conventional Marx generator. Simulations performed for single and repetitive pulse generation and experimental tests of a prototype hardware verify the proposed topology. [ABSTRACT FROM AUTHOR]