Output Voltage Pulse Research Articles

Pulse Power Nanosecond-Range DSRD-Based Generators for Electric Discharge Technologies

New design of power nanosecond-range generators for electric discharge in gases is described. These generators are based on semiconductor opening switches-Drift Step Recovery Diodes (DSRD). The main advantages of DSRD are very short switching-off time (<;3 ns), high commutated power (>500 kW for single DSRD with 2 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> of semiconductor structure), and high reliability of high voltage stacks consisting of many connected in series DSRD. The experimental results of DSRDbased generator application for ozone production and waste gas cleaning are presented. The main parameters of the generators: output pulse voltage up to 36 kV, pulse rise time <;4 ns, pulse repetition rate up to 3.5 kHz, output pulse power >4.5 MW.

Experimental results from droop compensation for the high voltage converter modulators

The High Voltage Convertor Modulators are used to power the RF klystrons used throughout the linear accelerator at the Spallation Neutron Source. The output voltage of the modulator has significant voltage droop and ripple which, combined with low level RF system limitations, affect performance and stability of the accelerator cavities. In conjunction with the progress in the development of the new controller, different modulation techniques were implemented and studied on the test modulator rated at 75 kV, 125 A. This paper presents experimental results from implementation of frequency sweep, phase sweep and combined phase and frequency sweep modulation on the modulator output voltage pulse. Thermal measurements were carried out to determine the effect of these modulations schemes on long term reliability of the modulator. Future plans are also discussed.

A Power Control Scheme for Multiple Load Induction Cooking with Constant Switching Frequency in Class-E Resonant Inverter

In this paper an effective and simple power control scheme is presented for two load induction cooking application with constant switching frequency in class-E series resonant inverter. The proposed configuration operates in synchronization with load switch switching pulse and inverter output voltage. Each load output power is controlled individually by duty ratio variation with each load switching device separately. The proposed configuration can be extended to multiple loads. It is more reliable for multiple load induction cooking application with output power control of each load independently. The class-E series resonant inverter operates with constant switching frequency and constant duty ratio. The proposed class-E series resonant inverter configuration can be operating at stable and efficient ZVS operation. The proposed configuration for multiple load induction cooking application with independent control of each load is simulated in MATLAB/Simulink environment.

고전압 펄스 발생 장치의 회로에 관한 이론적 연구

The high-voltage pulse generator is consist of transformers of fundamental wave and harmonic waves, and shunt capacitances. The pulse has the fundamental wave and the harmonic waves that have been increased as a series circuit by the transformers to make high voltage pulse. This paper shows that pulse generator circuit is analyzed using Miller‘s theorem and network theory(ABCD Matrix) and simulated in frequency and time domain using Matlab program. The output voltage of pulse were obtained to 2.5kHz, 1.8kV. Output pulse voltage increases as L<SUB>m</SUB> increases in low voltage circuit. In high voltage circuit, outer capacitors are related to frequency band pass characteristics.

Transformerless Three-Level DC-DC Buck Converter with a High Step-Down Conversion Ratio

For high power high step-down dc-dc conversion applications, conventional three-level dc-dc converters are subject to extreme duty cycles or increased volume and cost due to the use of transformers. In this paper, a transformerless three-level dc-dc buck converter with a high step-down conversion ratio is proposed. The converter comprises two asymmetrical half bridges, which are of the neutral point clamped structures. Therefore, the output pulse voltage of the converter can be obtained in terms of the voltage difference between the two half bridges. In order to realize harmonious switching of the converter, a modulation strategy with capacitor voltages self balance is presented. According to the deduced output dc voltage function, transformerless operation without extreme duty cycles can be implemented. Experimental results from a 1kW prototype verify the validity of the proposed converter. It is suitable for ship electric power distribution systems.

Phase Transformation Experimental and Theoretical Study of Micro-power Generator Supplying Source for IC Chip Based on Ferroelectric Ceramic

We demonstrated both experimentally and in theory analysis and calculation that the PSZT ferroelectric ceramic generator system can perform as a micro power supplying source for IC chip. The ceramic phase transition under transverse shock wave compression can charge external storage capacitor. The ferroelectric micro pulsed power system is capable of generating low output voltage pulses with amplitudes 50.3 V and with transferred energy 1.12 mJ, and supplying IC chip with micro power sources. We developed the methodology for theory analysis and experimental operation of the ferroelectric generator. The experimental results were in good agreement with the theory analysis.

An adaptive hysteresis dead-band-based SVPWM method for multi-level inverter

The fast rise time of output voltage pulses (dv/dt) in PWM multi-level inverters (MLI) is one of the major factors of the increase of electromagnetic interference EMI and the shortness of motor useful life. Moreover, irregular voltage pulses, which only appear for critical modulation indexes, can deepen this interference phenomenon. To overcome this problem, this paper proposes an adaptive hysteresis dead-band (AHDB)-based space vector PWM (SVPWM) method for MLI. The proposed scheme is developed for multilevel cascaded H-bridge (CHB) inverters. In the proposed strategy, general dwell-time equations were derived to achieve the SVPWM for any n-level inverter. Moreover, the dwell-times calculation was made easy by using only two parameters defining regions for a given sector. Furthermore, to remove all irregular pulses from the output voltage, the dead-band of the hysteresis was made variable. Both theoretical analyses and simulation results are presented to show the effectiveness of the proposed method.

Design of a High-Efficiency 40-kV, 150-A, 3-kHz Solid-State Pulsed Power Modulator

This paper deals with the detailed design of a pulsed power modulator using insulated gate bipolar transistor (IGBT) switches for industrial applications. Output specifications of the proposed modulator are as follows: variable output pulse voltage 1~40 kV; pulse width 0.5~5 μs ; maximum pulse repetition rates 3 kHz, and average output power of 13 kW. The proposed pulsed power modulator consists of a high-voltage capacitor charger based on a high-efficiency resonant inverter and pulse generator part including a series of connected 24 pieces power cells. To verify the proposed design, PSpice modeling was performed. Finally, experimental results proved the reliability and robustness of the proposed solid-state pulsed power modulator.

A Repetitive Solid State Marx-Type Pulsed Power Generator Using Multistage Switch-Capacitor Cells

This paper reports on the novel development of a fully solid state Marx-type circuit to achieve output voltage pulses with adjustable voltage levels, pulse width, and frequency using a series connection of half-bridge or full-bridge switch-capacitor cells (SCC). Modularity of the circuit allows independent control of each SCC, resulting in more freedom to control the pulsed power parameters. A 3-kW laboratory prototype of the proposed generator topology was implemented using 1700-V insulated gate bipolar transistors (IGBTs) and a 1-kV power supply. The SCC unit circuit board is stacked to increase the maximum output voltage. The control unit for the output pulse parameters was performed using an field-programmable gate array unit.

Miniature 100-kV Explosive-Driven Prime Power Sources Based on Transverse Shock-Wave Depolarization of PZT 95/5 Ferroelectric Ceramics

Our previous efforts were focused on designing, constructing, and investigating miniature shock-wave ferroelectric generators (FEGs) based on Pb(Zr <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.52</sub> Ti <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.48</sub> )O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> poled ferroelectric ceramics (that is widely used in modern technology). In this paper, we extended our efforts by exploring a different type of ferroelectric materials, i.e., Pb(Zr <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.95</sub> Ti <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.05</sub> )O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> (PZT 95/5), for designing miniature autonomous shock-wave FEGs. The performance of autonomous ultrahigh-voltage FEGs based on transverse explosive shock depolarization of poled PZT 95/5 ferroelectric ceramics was studied. As a result of this paper, miniature generators (38 mm in diameter) that are capable of producing output voltage pulses with amplitudes exceeding 120 kV and pulsewidths of 3 μs were developed.

Noise Performance of a Regulated Cascode Transimpedance Amplifier for Radiation Detectors

A low noise transimpedance amplifier (TIA) is used in radiation detectors to transform the current pulse produced by a photo-sensitive device into an output voltage pulse with a specified amplitude and shape. We consider here the specifications of a PET (positron emission tomography) system. We review the traditional approach, feedback TIA, using an operational amplifier with feedback, and we investigate two alternative circuits: the common-gate TIA, and the regulated cascode TIA. We derive the transimpedance function (the poles of which determine the pulse shaping); we identify the transistor in each circuit that has the dominant noise source, and we obtain closed-form equations for the rms output noise voltage. We find that the common-gate TIA has high noise, but the regulated cascode TIA has the same dominant noise contribution as the feedback TIA, if the same maximum transconductance value is considered. A circuit prototype of a regulated cascode TIA is designed in a 0.35 μm CMOS technology, to validate the theoretical results by simulation and by measurement.

A modularized pulse forming line using glass-ceramic slabs

In our lab, a kind of glass-ceramic slab has been chosen to study the issues of applying solid-state dielectrics to pulse forming lines (PFLs). Limited by the manufacture of the glass-ceramic bulk with large sizes, a single ceramic slab is hard to store sufficient power for the PFL. Therefore, a modularized PFL design concept is proposed in this paper. We regard a single ceramic slab as a module to form each single Blumlein PFL. We connect ceramic slabs in series to enlarge pulse width, and stack the ceramic Blumlein PFLs in parallel to increase the output voltage amplitude. Testing results of a single Blumlein PFL indicate that one ceramic slab contributes about 11 ns to the total pulse width which has a linear relation to the number of the ceramic slabs. We have developed a prototype facility of the 2-stage stacked Blumlein PFL with a length of 2 ceramic slabs. The PFL is dc charged up to 5 kV, and the output voltage pulse of 10 kV, 22 ns is measured across an 8 Ω load. Simulation and experiment results in good agreement demonstrate that the modularized design is reasonable.

Modeling Double Blumlein with Variable Duration and Polarity using Orcad PSpice

Double Blumlein generator is an excellent technique in generating high voltage short pulsed power with fast rise time signal. However properties of fixed pulse duration and polarity of Blumlein configuration limits the generator flexibility and efficiency. A modeling of double Blumlein with double switching configuration with controlled delay is proposed in this paper to solve the limitation problem. The circuit is modeled in PSpice environment and the result successfully showed double output pulse voltage of flat top square waveform with adjustable duration and polarity.

500 kV全固态Marx发生器

The paper presents a 500 kV all-solid-state Marx generator adopting Z type circuit. In this Marx generator, twenty-eight isolated gate bipolar transistors(IGBTs) serial modules were utilized as controllable switches. The maximum working voltage of each IGBTs module was designed as high as 22 kV, and the repetition rate at full load condition was designed as high as 200 Hz. The ladder type pulse-forming-networks (PFNs) consisting of metallized film capacitors and wound inductors were designed as energy storage and pulse-forming components. Experimental results indicate that the Marx generator can run with 500 kV output pulses and 50 Hz repetition rate in burst-mode successfully. The peak output pulse voltage of this generator is approximately the same as that of the highest power solid-state Marx generator ever reported, while the peak current is almost twice, reaching 1 000 A. The maximum pulsed power of the generator is as high as 500 MW. As the capacitors were utilized as energy storage components, the pulse width can be adjusted from 3 s to 10 s continuously.

Low Frequency Measurements in Amorphous Wire for Studying GMI Effect

When a soft ferromagnetic material is flown by an ac current and a magnetic field is applied at the same time, a major change of its impedance is occurred. The aim of this paper is to investigate the influence of low frequency (1KHz-12KHz) ac current and the applied magnetic field on an amorphous magnetic wire (Co68Fe4.35Si12.5B15) without glass coating. For this purpose an experimental configuration has been setup, based on a Wheatstone bridge which receives an ac input signal from a frequency generator. The output is connected to the amorphous wire wrapped with a coil supplied by a dc voltage for the generation of the magnetic field. The output voltage pulse is measured for two cases a) The value of ac frequency is changing while the value of dc voltage applied to the coil remains constant (the magnetic field remains unchanged) and b) the magnetic field is changing while the ac frequency remains constant to a predefined value. Experimental results of the first scenario showed that when the frequency is altered a non-linear increase of the ac signal is observed at the output which shows an increase of the GMI effect and is related to the non-linearity of the wire’s permeability. For the second scenario the results showed an increase of the output signal offset (voltage) which also indicates an increase of the GMI effect.

Compact and high repetitive pulsed power modulator based on semiconductor switches

This paper describes the design of a compact and highly repetitive pulsed power modulator based on semiconductor switches. Output specifications of the proposed modulator are as follows: variable output pulse voltage, 1-10 kV; width, 1-10 μs; pulse repetition rate (PRR), 1-50,000 pps; and average output power, 10 kW. The proposed solid-state pulsed power modulator has two main parts: an IGBT stack that hasa gate drive circuit for the pulse output with a variable pulse width and repetition rate, and a capacitor charger that has a controllable output voltage. To connect all the storage capacitors in a series for high voltage pulses, a simple and reliable IGBT stack structure was proposed based on the Marx generator. In addition, the gate driver circuit, which supplies power and signals to all the IGBTs simultaneously, was introduced. This providesa superior protection function against the arc and the short. To charge the storage capacitors, a novel 10 kW (10 kV, 1 A) high voltage capacitor charger with the combined advantage of a series-loaded resonant converter and a ZVS (zero-voltage-switching) full-bridge pulse width modulation (PWM) converter was proposed and designed especially for the solid-state pulsed power modulator. Theexperiment results verified that the proposed scheme and structure can be used effectively for a high voltage pulsed power modulator that requires variable voltage, repetition rate, and pulse width, depending on the process of the applications.

High voltage pulse shaping of e-beam diode using perveance variation

This paper presents a new high voltage pulse shaping methodology for pulsed power applications. The aim is to generate high voltage square pulse across anode cathode gap of e-beam diodes. The non-linear time varying perveance characteristics of e-beam diodes are used for shaping of output voltage pulse across it, generated directly from Marx generator. Analytically, it has been shown in the paper that under certain conditions, if achieved, Marx generator feeding an e-beam diode can produce a square-like pulse at the output, without any extra pulse shaping arrangements. Experimental results to support the analysis are also presented in the paper.

Note: Miniature 120-kV autonomous generator based on transverse shock-wave depolarization of Pb(Zr0.52Ti0.48)O3 ferroelectrics

The design of autonomous ultrahigh-voltage generators with no moving metallic parts based on transverse explosive shock wave depolarization of Pb(Zr(0.52)Ti(0.48))O(3) (PZT 52∕48) poled ferroelectrics was explored and studied. It follows from experimental results that the output voltage produced by the shock-wave ferroelectric generators (FEGs) is directly proportional to the number of PZT 52/48 elements connected in series. It was demonstrated that miniature FEGs (volume less than 180 cm(3)) were capable of reliably producing output voltage pulses with amplitudes exceeding 120 kV which is the record reported in open literature.

Pulsed-Power System for Leachate Treatment Applications

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 <TEX>$60\;kV_{max}$</TEX>, <TEX>$300\;A_{max}$</TEX>, 3000, <TEX>$50\;{\mu}s$</TEX>, 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.

The depolarization of Pb(Zr0.52Ti0.48)O3 ferroelectrics by cylindrical radially expanding shock waves and its utilization for miniature pulsed power

The effects of depolarization of Pb(Zr(0.52)Ti(0.48))O(3) (PZT 52∕48) poled ferroelectrics by cylindrical radially expanding shock waves propagated along and across the polarization vector P(0) were experimentally detected. Miniature (total volume 100 cm(3)) autonomous generators based on these effects were capable of producing output voltage pulses with amplitudes up to 25 kV and output energies exceeding 1 J.