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Explosive current opening switches (EOSs) operate based on the principle of the conductors mechanical destruction of the inductive energy storage system by detonation products of the high explosive charge. The EOSs are used for current pulse sharpening of the magnetocumulative generators (MCG). These explosive single-acting devices constructively match each other; both operate in the physical limit and provide maximum specific characteristics. This paper describes several basic schemes of the EOS constructions that were experimentally checked in different laboratories of the world. The investigation results on the flat and cylindrical models and also full-scale experiments on the current pulses sharpening of the helical and disc MCG are presented. [ABSTRACT FROM AUTHOR]

This paper presents the current research trends and future issues for industrial electronics related to transportation electrification. Specific emphasis is placed on electric and plug-in hybrid electric vehicles (EVs/PHEVs) and their critical drivetrain components. The paper deals with industry related EV energy storage system issues, EV charging issues, as well as power electronics and traction motor drives issues. The importance of battery cell voltage equalization for series-connected lithium-ion (Li-ion) batteries for extended life time is presented. Furthermore, a comprehensive overview of EV/PHEV battery charger classification, standards, and requirements is presented. Several conventional EV/PHEV front-end ac/dc charger converter topologies as well as isolated DC/DC topologies are reviewed. Finally, this paper reviews various EV propulsion system architectures and efficient bidirectional DC/DC converter topologies. Novel DC/AC inverter modulation techniques for EVs are also presented. The architectures are based on the battery voltage, capacity, and driving range. [ABSTRACT FROM PUBLISHER]

Based on the urgent needs for modularization and miniaturization of the inductive pulsed power supply system, this paper proposes the conceptual design and comparison of 100-kJ inductive storage power modules including four circuit topologies, three of which are proposed in our previous researches. The four circuit topologies are the STRETCH meat grinder, the XRAM with STRETCH meat grinder unit, the XRAM with strongly coupled inductors, and the XRAM with magnetic flux compression effect. The maximum load current of each constructed module is set to be 50 kA and its pulsewidth is at least 5 ms, which are the same as the main electrical properties of an existing 100-kJ capacitive module. A comparative study on energy density among the constructed inductive modules and the existing capacitive module is carried out in depth. Results show that the inductive modules, considering the volume of semiconductor switches and their control circuits, have higher energy density than that of the capacitive module. Among four constructed inductive modules, the XRAM with strongly coupled inductors module has the highest inductive energy density, and the XRAM with magnetic flux compression effect module has relatively better comprehensive performance. This paper offers the theoretical analysis foundation for investigating the inductive pulse power supply with higher energy. [ABSTRACT FROM PUBLISHER]

The aim of the paper is the study of an optimal integration of a supercapacitor-based storage system and inductive power transfer system for the free-catenary operation of a tramway. Starting from the definition of the topology of inductive power transfer system, we propose and analyze a design procedure for the pads of the inductive power system. In the second part of the paper, an optimal integration strategy for the correct size of on-board supercapacitors and the power of the inductive energy transfer are proposed. The results obtained by means of numerical simulations are discussed. [ABSTRACT FROM AUTHOR]

Slow transfer of energy through capacitive hybrid (STRETCH) meat grinder circuit, which was proposed by the Institute for Advanced Technology, added a capacitor into the traditional meat grinder circuit. Even though its energy density is slightly less than the corresponding pure inductance system, it can reduce the voltage across the opening switch and maintain the high multiplication factor of the opening current. The performance of the STRETCH meat grinder circuit depends on multiple parameters. The inductance ratio ( n=L1 / L2) and the capacitance (C) are the two vital factors, which have a crucial influence on the system performance, such as the voltage over the opening switch ( V_{\rm Sopm}) , the current multiplication factor ( m$ ), and the ratio of the maximum capacitive energy over the total inductive energy ( $\eta )$ . Thorough studies have been carried out in this paper on the relationship between the above two factors and the three performance criteria. This paper also discusses and analyzes the chosen of the key parameters ( $n$ and $C$ ) for a single-stage STRETCH meat grinder with 2-mH total inductance, which is made up of two serial coils with 0.95 coupling factor. The opening current of the main switch is 1 kA, which constitutes a 1-kJ inductive pulsed-power supply. It fully takes the advantage of the STRETCH meat grinder topology, intensifies the study of the inductive pulsed-power supply with higher energies, and is easy to be utilized for practical application. [ABSTRACT FROM PUBLISHER]

Superconducting pulsed-power supply (SPPS) provides an efficient method for both high-density inductive energy storage and high current pulse generation. An SPPS consisting of eight high-temperature superconducting pulsed-power transformer (HTSPPT) modules with XRAM methodology was designed and simulated in preliminary studies. It recycled the leakage flux energy and reduced the voltage across the opening switch with a capacitor in primary. However, the SPPS with XRAM methodology has two problems. The first one is that it can provide high pulse amplitude, but cannot provide enough width. The other one is that the ratio of the maximum capacitive energy over the total inductive energy is relatively large, which cuts down the overall system energy density. This paper proposes a modified topology of SPPS with capacitor reuse methodology. Multiple HTSPPT modules are divided into several groups. Each group shares the same capacitor. The procedure of the modified SPPS is presented in detail. A 270-kJ SPPS with capacitor reuse methodology is designed and simulated to illustrate the modified topology. With the load parameters of a small railgun, the peak value of the load current is 207.15 kA and the pulse half-height width is 5.56 ms, the ratio of the maximum capacitive energy over the total inductive energy is 11%. The characteristics of the modified topology are also described in detail in this paper. [ABSTRACT FROM PUBLISHER]

In this paper we propose a computational procedure to simulate the magnetic behavior of inductive blocking devices for the mitigation of the induced voltage and current pulses on the aircrafts circuits during a lightning shock. The non linear and hysteretic phenomenon are simulated using a model based on the Preisach theory and implemented in a finite difference scheme in time domain. Using this procedure the performances of the blocking devices can be computed and optimized according to the standard requirements for avionic applications. A dedicated pulse generator is designed and realized for the experimental tests in order to compare numerical results and measurements. [ABSTRACT FROM AUTHOR]

The slow transfer of energy through capacitive hybrid (STRETCH) meat grinder circuit is a widely used topology in inductive pulse power supply. Therefore, it is important to understand the relationship between the STRETCH meat grinder performances and the inductor parameters when improving the system performance and designing the inductor. From the perspective of inductor designing, this paper uses four indicators to present the STRETCH meat grinder performances, i.e., the charging current, the current amplification, the inductor energy density, and the discharge efficiency, and uses two indicators to present the inductor parameters, i.e., the total inductance and the ratio of the inductance L1 to L2 . First, the meanings of the indicators are explained or defined. Second, simulations and experiments are carried out, respectively, to analyze the trends of the four performance indicators along with the changes of two parameters indicators. Finally, both simulation and experiment results show that the increase of the total inductance leads to the decrease of the charging current and the discharge efficiency; moreover, the increase of the ratio of the inductor L1 to L2 leads to the increase of the current amplification and the discharge efficiency, but causes the decrease of the inductor energy density. [ABSTRACT FROM AUTHOR]

Superconducting inductive pulsed power supplies have attracted a lot of attention due to its lower electrical loss and higher energy storage density than traditional inductors. To effectively improve charging rate and output continuous current pulses, a repetitive inductive pulsed power supply circuit topology based on high-temperature superconducting (HTS) pulsed power transformer was proposed and simulated in our previous studies. This paper aims to further study the feasibility of the repetitive inductive pulsed power supply circuit topology through experiments. A small air-core HTS pulsed power transformer and a bridge-type capacitor switching circuit were used to build the experimental platform. The experimental results show that the bridge-type capacitor switching circuit can shorten the charging time of each new cycle and the repetitive inductive pulsed power supply circuit is feasible for continuous current pulse output. [ABSTRACT FROM AUTHOR]

In automotive systems, reliability and cost are paramount for the success of electrical drive systems. Considering the switched reluctance motor (SRM), the power electronics cost dominates the total cost of the electrical drive. In this respect, especially the dc-link capacitor significantly contributes to the total bill of the material. This paper proposes the use of a dc-excited winding in an 8/6 SRM as a means of reducing the capacitor. The energy conversion of the motor is analyzed intensively. The control algorithm of the field winding is investigated and an active control algorithm is proposed to provide and absorb the energy in parallel with the dc-link capacitor. The effectiveness of this control method is confirmed by the cosimulation between the finite-element method and the Simulink. [ABSTRACT FROM PUBLISHER]

Inductive charging is based on the operating principles of a transformer; energy is transferred through an air-gap from a primary coil incorporated in the charging station to a secondary coil incorporated in the electric vehicle (EV). Dynamic inductive charging allows the vehicle to wirelessly receive energy while moving on the road and appears to be an ideal solution for the increase of the limited travel range of EVs. However, currently developed dynamic inductive power transfer (IPT) solutions limit the application of this method when the EV rapidly moves over the charging station. The aim of this paper is to propose a novel optimization procedure, in order to define the values for the variables involved in the electrical operation of a dynamic IPT system. The optimization procedure considers constraints associated with the operational conditions in the primary and secondary sides of the IPT system, in order to define the movement section, where the energy transferred to the EV is maximized at a considerably high system efficiency. The values derived from the optimization method are implemented in the control of the secondary side of the IPT system. Moreover, a control method is proposed that effectively eliminates the need for a detection mechanism and the continuous data transfer between the primary and secondary side. The suggested control scheme requires the operation of the charging station at a low-efficiency movement section without significant energy losses in this specific section. The proposed optimization procedure is applied in the case of a 60-cm-diameter circular pad, and the suggested control scheme is validated by simulating the operation of the dynamic IPT system over the whole EV movement range. An experimental setup has been used to study the application of the optimization procedure and investigate the effective operation of the system. [ABSTRACT FROM AUTHOR]

This work presents an analytical approach for optimizing the single-ended (SE) and differential (DF) reader coils and miniature rectenna designs in near-field inductive power transfer (IPT) systems. In this design context, the appropriate operation frequency is in the gigahertz range, and the nonuniform current distribution on the reader coil and the radiation resistance must be considered and are included in this paper. Utilizing the rectenna miniaturization, the reader coil and the rectenna designs can be decoupled and their figure of merits (FOMs) are identified. The equation-based approach optimizes the IPT design rapidly, and the optimized reader-coil FOM and the optimized rectenna FOM, both plotted versus the IPT frequency, co-decide the optimal IPT frequency and the coil geometries for the highest RF-dc power transfer efficiency. The analytical method is verified by EM-simulation and measurement, and the DF reader coil topology is demonstrated to be more efficient than the commonly used SE coils. An optimized 2.2-mm IPT with a DF coil is realized at 4.8 GHz and significantly outperforms the previous works. Under a total RF power of 33.1 dBm, the CMOS rectenna, with a coil size of only 0.01 mm2, harvests the designed dc conditions of 1 V/0.1 mA. [ABSTRACT FROM PUBLISHER]

Inductive pulsed power supply (IPPS) based on multiple high-temperature superconducting pulsed power transformer (HTSPPT) modules is a novel technology for electromagnetic launching. In a compact multimodule IPPS, the mutual couplings between HTSPPT modules are unavoidable. In this paper, an IPPS with the method of improved pulse-forming process which proved to be feasible by preliminary experiment is proposed to analyze the effect of the mutual couplings. The characteristics of the mutual coupling effect on the IPPS are presented in detail by theoretical analysis and parametric simulations. The evaluation indices reflecting performances of the IPPS under the mutual coupling effect are derived from simulations, including the energy storage capacity, flux linkage, axial tensile force, output current amplitude, and so on. Parametric simulations are executed with respect to the module arrangement, the number of modules, and the arrangement radius. Finally, the analysis of mutual coupling effect is summarized, and a strategy for exploiting mutual couplings between modules is put forward to improve IPPS performance. [ABSTRACT FROM PUBLISHER]

The superconducting inductive pulsed-power supply (IPPS) is considered to have broad application prospects in the field of electromagnetic launch because of its low electrical loss. In order to obtain a higher efficiency in continuous electromagnetic launch, a repetitive IPPS circuit topology based on a high-temperature superconducting pulse power transformer (HTSPPT) has been proposed in our previous studies. It can recover most of the remaining energy for generating continuous current pulses by using a bridge-type capacitive switching circuit. As a follow-up work, this paper presents a multimodule repetitive superconducting IPPS model for a railgun system. This multimodule model consists of 24 HTSPPT modules connected to an XRAM-like circuit topology. In order to verify the feasibility of the repetitive superconducting IPPS and study its driving characteristics, the dynamic launching process of a simple 4-m-long railgun system was simulated. The influence of the capacitance in the bridge-type capacitive switching circuit on the main performance of the system, such as the maximum output current, the maximum primary voltage, the launch efficiency, the maximum capacitive energy ratio, and the remaining energy recovery ratio, was analyzed. The simulation results show that the repetitive superconducting IPPS is suitable for driving the simple railgun. In addition, it also concluded that the system performances conflict with each other and the optimal capacitance value for each HTSPPT module should be determined by the tradeoff of system performances. [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]

The energy density of the inductive energy storage systems is one order of magnitude higher than that of the capacitive ones. The slow transfer of energy through capacitive hybrid (STRETCH) meat grinder with inverse current commutation with semiconductor (ICCOS) devices put forward by Tsinghua University is a typical inductive pulsed-power supply for electromagnetic launch system, which has remarkable current amplification ability as a single module. However, one module cannot provide enough amplitude and width for the load current of the railgun launching. Therefore, the collaborative work of multiple inductive source modules is necessary for practical usage. In this paper, the designed inductive power supply system of about 1 MJ is composed of 40 STRETCH meat grinders with ICCOS modules. All the main switches are opened simultaneously to reduce the magnetic field coupling among the modules and make the current rising edge steep. The modules are divided into several groups. The triggering delays of the thyristors between every two adjacent groups are carefully designed. After the first triggers for all the modules, the energy stored in the capacitors can be further utilized with the second triggers. The numerical simulation results show that the appropriate collaborative triggering delay can increase the adjustability of the output current width and the second triggers can further increase the current width and the system efficiency. Therefore, the load current with flat shape, appropriate amplitude, and longer duration can be provided with modular design and collaborate triggering discharge of the multiple modules. This can provide a theoretical foundation for the future study and implementation. [ABSTRACT FROM PUBLISHER]

Inductive pulsed power supply (IPPS), especially superconducting pulsed power supply (PS), has been the focus of research in recent years due to its high energy density and low power requirement for the input PS. Quite a lot of fantastic work regarding two or multiple IPPS modules has been presented. But they disregard the mutual inductance between modules. This paper establishes a double-module IPPS based on two high-temperature superconducting pulsed power transformers and takes the mutual inductance between modules into consideration. The influence of the mutual inductance between two modules on three discharge modes of the system is researched. Simulations and experiments on synchronous discharge, time-delay discharge, and asynchronous discharge are carried out, respectively. The results demonstrate that taking the mutual inductance into consideration, the amplitude and the pulsewidth of the output currents are both improved a lot, especially the obtainable energy of load is improved by nearly half. For time-delay discharge, the mutual inductance makes the delay time slightly increase. However, for asynchronous discharge, the mutual inductance increases the positive maximum value of the primary current of the second module. It may exceed the critical current and lead to quench. Consequently, the mutual inductance between modules has positive impacts on synchronous discharge and time-delay discharge of the IPPS system while it brings both advantages and disadvantages to asynchronous discharge. [ABSTRACT FROM AUTHOR]

Inductive energy storage for pulsed power supplies is considered to have great potential because its energy density is 1 order of magnitude higher than that of capacitive one. Associating with the superconducting technology and the STRETCH meat grinder circuit, which proposed by the Institute of Advanced Technology, a superconducting inductive pulsed power supply (SPPS) circuit has been proposed by using an air-core high-temperature superconducting pulsed power transformer (HTSPPT) in our previous study. It can not only recapture the energy in the leakage flux and slow down the current change in inductors by using a capacitor, but also reduce the coil loss and the power requirement of the primary source by using superconducting inductors. However, it can be found that the SPPS may generate a large residual current during the discharging phase, which results in an adverse influence on the working frequency and the energy transfer efficiency of the whole system. This paper proposes a modified circuit based on the bridge current switching circuit and HTSPPT. The main principle of the circuit is that the recaptured energy in the capacitor and the residual energy in the secondary are used to precharge the primary inductor for the next cycle, which shortens the charging time, generates continuous current pulses, and improves the energy transfer efficiency. The procedure of the repetitive SPPS is analyzed in detail, and simulations are carried out to explain how the circuit works clearly. [ABSTRACT FROM AUTHOR]

This paper focuses on the interoperability analysis of a resonating contactless charging system for electric vehicles (EVs). The design uses different inductive loops realized by industrial partners. It highlights an advanced electromagnetic modeling (EM) concerning the geometrical characteristics, the resonant topologies, and the control loop. It is shown that the EV chassis plays a major role in the calculation of the electrical parameters and the radiation of the interoperable system. Furthermore, the position of the interoperable magnetic couplers with respect to the EV (middle or backend) has an important effect on the values of the coupling factor and also for the radiation of the system. Finally, an efficiency of 90% is realized in the experimental test with the interoperability which gives flexibility for the driver to use charging stations with different technologies. [ABSTRACT FROM AUTHOR]

The superconducting inductive pulsed-power supply (SPPS) circuit consists of a high-temperature superconducting pulsed-power transformer (HTSPPT) and an auxiliary capacitor. The electrical losses and the power of the primary source can be cut down with the superconducting inductive energy storage. Although its energy density is slightly less than a purely superconducting inductive system, it can reduce the maximum voltage of the opening switch by the capacitor and achieve a high degree of current amplification factor. However, during the discharge process, the magnetic leakage flux energy stored in the primary of the HTSPPT requires the capacitor to have a certain capacity. The higher the ratio of the capacitive stored energy over the total inductive stored energy, the more the dominant position of inductive energy storage reduces. The current amplification factor ( \gamma ), the maximum voltage of the opening switch ( V_{S\max } ), and the ratio of capacitive stored energy ( \eta ) are the three main properties of the SPPS circuit, which depends on several intertwined critical parameters, such as the inductance ratio n = L2 /( L2+LL ) and the capacitance ( $C_{{\mathbf {1}}}$ ). This paper studies the influence of the critical parameters on the main circuit performance with a 1-kJ SPPS system. The detailed selection method of the critical parameters for the specific system is also discussed with a coupling coefficient of 0.95. Such a system is easy to be utilized for the basic experimental study of a small railgun. [ABSTRACT FROM PUBLISHER]

This paper introduces a novel power management architecture (PMA) and its on-chip implementation, designed for battery-powered portable applications. Compared to the conventional two-stage PMA, consisting of a front-end inductive converter followed by a set of point-of-load buck converters, the presented PMA has drastically improved power density. The new architecture, named multioutput switched-capacitor convertor–differential-input buck (MSC–DB) convertor, is based on a novel hybrid converter topology that combines a fixed ratio MSC and a set of DB converters, to achieve low volume and high power processing efficiency. The front-end switched-capacitor stage has a higher power density than the conventionally used inductive converters. The downstream DB converters enable tight output voltage regulation, and allow for up to four times reduction of output filter inductors without the need for increasing switching frequency, hence limiting switching losses and improving the efficiency of the system. Furthermore, the new PMA is able to balance the state-of-charge of the input battery cells, a feature not existing in conventional systems. The PMA architecture is implemented both as a discrete prototype and as an application-specific integrated circuit (IC) module. The on-chip implemented architecture is fabricated in a standard 0.13-μm CMOS process and operates at 9.3-MHz switching frequency. Experimental comparisons with a conventional two-cell battery input architecture, providing 15 W of total power in three different voltage outputs, demonstrate up to two times reduction in the inductances of the downstream converter stages and more than two times reduction in losses, equivalent to the improvement of the power processing efficiency of a 12%. Moreover, the fabricated IC module is copackaged with low-profile thin-film inductors to demonstrate the effectiveness of the introduced architecture in reducing the volume of PMAs for portable applications. [ABSTRACT FROM AUTHOR]

For electromagnetic emission applications that need a very high amplitude and an appropriate pulsewidth, a pulsed power supply based on multiple high-temperature superconducting pulsed power transformer (HTSPPT) modules is verified in this paper. First, the working processes of multiple HTSPPT modules are analyzed and two small experimental HTSPPTs are described in detail. Then, simulation is carried out to show the major pulse characteristics of two different discharge methods. To verify the feasibility of two discharge methods, high-current testing is carried out with the two HTSPPTs. The results show that a higher amplitude of current pulse can be achieved using synchronous parallel discharge and a larger pulsewidth of current pulse can be achieved using asynchronous parallel discharge. [ABSTRACT FROM AUTHOR]

A new design of powerful high-voltage high-current impulse source for nanosecond megavolt charging of short forming lines (SFLs) is proposed. The first stage of the device is based on inductive energy storage. It accumulates energy supplied by the current of magnetic flux compression generator (MCG), whereas the electro-explosive opening switch is used for the energy output into intermediate SFL. In the second stage, we use a Tesla transformer with oil insulation. The results of the earlier experimental study of submegavolt charging of intermediate forming line as well as the results of calculations of the two-stage facility given in this paper demonstrate the feasibility of the device based on MCGs for nanosecond charging of SFL up to about 3 MV. [ABSTRACT FROM PUBLISHER]

Current profiles of a cylindrical ringing theta-pinch are compared with SPICE simulations of an established circuit model and a least squares estimate is performed to determine plasma resistance and inductance for argon, hydrogen, and xenon plasmas with prefill pressures ranging from 10 to 100 mTorr. Plasma resistance is found to vary from 25.8 to 51.6 m \(\boldsymbol{\Omega }\) with the lowest resistance occurring at 10 mTorr. Argon and xenon follow a similar trend with the xenon resistance averaging 4.2-m \(\boldsymbol{\Omega }\) (12.3%) larger than argon from 40 to 100 mTorr. Hydrogen resistance is found to increase rapidly as prefill pressure increases above 40 mTorr. Calculated plasma resistivity of 214–429 \(\boldsymbol{\Omega }\) - \(\mu \) m agrees with established literature. Plasma inductance varies from 41.3 to 47 nH and is minimized at 30 mTorr for argon and hydrogen, whereas xenon inductance is minimized at 20 mTorr. Hydrogen yields the highest inductance, averaging 1.9 nH (4.5%) more than argon over the pressure range tested. Temporal evolution of the energy partitioning into capacitive, inductive, and resistive loads is presented. Plasma inductive energy is found to be maximized when discharge current reaches its peak negative value of −23.5 kA. Xenon shows the greatest amount of inductive energy storage with a peak of 6.4 J (8.1%) of the initial 79.2 ± 0.1 J while argon dissipates the least energy through ohmic losses at most pressures. Hydrogen has the least inductive energy storage at all pressures and greatest ohmic losses above 60 mTorr. Xenon presents the largest ohmic losses over the 10–60-mTorr range. [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]

This paper presents the analysis of an arrangement with the load upstream of the plasma opening switch. For a linear increasing switch resistance in the current interruption phase, the analytical expressions for determination of the load pulse parameters are developed. Descriptions of two designs of the load connection upstream of the switch are given, and the obtained experimental results are presented. A comparison between experimental and calculation results are also given for an ideally operating switch which opens with constant resistance rise rate determined from experimentally obtained resistance time history at switch opening. [ABSTRACT FROM AUTHOR]

This paper presents the analysis of experiments carried out on the GIT-4 and GIT-12 installations with microsecond megaampere plasma opening switches. Switches with axial and radial plasma injection are considered. It is shown that the conduction current, depending on the switch geometry and plasma density, is given by the magnetohydrodynamic scaling. The experimentally observed switch features in the opening stage can be explained in frame of the modified erosion model of switch opening. [ABSTRACT FROM AUTHOR]

Characteristics of a pulse corona reactor driven by an inductive energy storage (IES) pulsed power generator are described in this paper with focusing on the influence of streamer-to-glow transition on NO removal efficiency. A pulsed high voltage with a short rise time of under 30 ns is employed to generate streamer discharges homogeneously in whole the discharge region. Fast recovery diodes are used as semiconductor opening switch (SOS) to shorten the rise time. The various resistors are employed as dummy load to clarify a suitable circuit parameter such as the capacitance of a primary energy storage capacitor and/or the inductance of a secondary energy storage inductor. The energy transfer efficiency of the pulsed power generator has a maximum value of 50% at 714 Ω dummy load resistance. A co-axial cylinder type discharge chamber was used as the corona discharge plasma reactor driven by the IES pulsed power generator. The pulsed power generator supplies 30 kV pulse with 300 pps repetition rate. The co-axial cylinder plasma reactor consists of 1 mm diameter tungsten wire and 19 mm i.d. copper tube with 30 cm length. NO removal from the simulated diesel engine exhaust gas (N2:O2=9:1, Initial NO concentration=200 ppm) increased with input energy into the reactor. The energy efficiency for NO removal was obtained to be 25 g/kWh at 30 % removal in gas flow rate of 2 L/min. However, the energy efficiency decreased to 5 g/kWh with increasing capacitance of the primary capacitor from several hundreds pF to several nF. This decrease was caused by a streamer-to-glow transition. The efficiency was affected by oxygen concentration in the gas mixture. [ABSTRACT FROM AUTHOR]

A new scheme of pulsed voltage adding using inductively charged Blumlein lines has been proposed and experimentally demonstrated. The circuit principle is explained based on the analogy with capacitively charged Blumlein lines. In the experiments, striplines have been used for inductive energy storage, and SiC power devices have been used as the opening switches. The experimental results have proved both the circuit behavior and the voltage adding by using multimodule stack. This circuit method is expected to become a new approach to compact and repetitive pulsed-power generation. [ABSTRACT FROM AUTHOR]

The peak currents between two paralleled SiC MOSFETs could differ significantly due to the mismatch in threshold voltages $V_{{\rm{th}}}. The method described herein employs passive compensation (drive-source resistors and coupled power-source inductors) to balance the peak currents using one gate driver, no sensors, and no feedback—without increasing total switching loss when equivalent gate-drive resistance (Rg + 0.5Rk) is kept constant. This solution works for both polarities of V{\rm{th}} mismatch and forces balancing from the first current peak. The extra voltage stress from this solution is mitigated by negative coupling. The passive components (resistance, self-inductance, and mutual inductance) are determined by an equation involving the magnitude of $V_{{\rm{th}}}$ mismatch, current rise time, and unbalance percentage. The influence of other parasitic inductances on current sharing is analyzed. The robustness of this passive balancing method is experimentally verified by a prototype with a significant amount of parasitic inductances. Test results show that the difference of peak currents can be reduced from 15% to 3% without changing the switching loss and voltage stress. [ABSTRACT FROM PUBLISHER]

Two methods of output voltage adding using pulse forming lines (PFLs) have been studied and compared. Both methods use inductive energy storage (IES) instead of traditional capacitive energy storage (CES), which means that the PFLs are charged by current instead of voltage. One of the methods (Type A) used an additional transmission-line-transformer (TLT) to achieve the output voltage adding from multiple PFLs, while the other method (Type B) combined the functions of PFL and TLT into one set of transmission lines. Both methods have advantages and disadvantages over each other and both methods are believed to have certain significance in pulsed power generation. [ABSTRACT FROM AUTHOR]

A rapid-fire electromagnetic multirail launcher design for sequential acceleration of several projectiles is proposed. A powerful pulsed MHD system is used as the primary source of electrical energy for the launcher. Embodiments of the launcher with direct powering from the MHD system and from an MHD generator with an intermediate inductive energy storage (IES) are considered. The operating modes and performance of the launchers are studied by methods of mathematical modeling. The rate of fire of the launcher, the maximum number of sequentially launched projectiles, and projectile velocities are determined. [ABSTRACT FROM PUBLISHER]

Design and fabrication of a 1-MW inductive power transfer (IPT) system that supplies power to the vehicle in real time without any battery charge is proposed for a high-speed train. The IPT system consists of a 1-MW resonant inverter, a 128-m transmitter, four pickups, including rectifiers, and a wireless feedback network to maintain a constant output voltage of the pickups. The operating frequency of the system is 60 kHz to achieve efficient power transfer with a large air gap. The measured efficiency of the IPT system at the 818-kW output power of the pickups for the 5-cm air gap is 82.7%. The electromagnetic field and the induced voltage at the rail are also measured for safety evaluation. The fabricated IPT system was adapted to the high-speed train, and the train successfully accelerates to a speed of 10 km/h according to startup procedures. [ABSTRACT FROM PUBLISHER]

The dc-link voltage fluctuation problem is more serious for an inverter system which utilizes a single phase ac source. As an effort to reduce the dc-link capacitance, there is a tendency to make torque oscillate in synchronism with the input power. Then, the fluctuating motor power matches the converter power. The key idea is to enforce current oscillation along a constant torque line which only affects the reactive power of the motor. In other words, the proposed method uses the motor as inductive energy storage by controlling the motor flux by the reactive current component. Analytic method for obtaining the current bounds was derived. Also, a practical recursive algorithm was proposed. Simulation and experimental results support the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

A four-stage XRAM generator is built and then applied to a railgun having a caliber of 15\,\times\,15 mm. The XRAM generator is based on 1-mH Brooks coils and on standard high-power thyristors which are employed as opening switches according to the ICCOS countercurrent commutation principle. The coils of the generator are charged with a current of 10 kA, which corresponds to an energy of 200 kJ. The current is successfully commutated and a pulse with a maximum current of 40 kA is applied to the railgun. Consequently, a projectile with a total weight of 33 g is accelerated to 157 m/s within the railgun length of 2.1 m. The semiconductor switches are exposed to a steep voltage rise due to the muzzle flash when the projectile leaves the railgun without their critical limit being exceeded. Thus, the successful operation of the XRAM generator using semiconductor switches during railgun experiments is demonstrated. Furthermore, we are able to show in a further experiment that the muzzle flash of the railgun can be significantly reduced by switching the XRAM back into charging mode when the projectile leaves the bore. This method also allows the conservation of the energy that remains in the coils after the exit of the projectile from the railgun. [ABSTRACT FROM AUTHOR]

Due to the complex relationship between the current history through an electroexplosive opening switch (EEOS) and the switch impedance, numerical modeling methods are required to understand the dynamic switch and circuit behavior of inductive energy storage systems incorporating EEOSs. A method for numerically modeling a compact pulsed-power system consisting of a high-current source, an inductive energy store, an EEOS, and a resistive load is developed. Previous models of switch resistance are extended to recognize restrike conditions and enable modeling of system operation after restrike. In addition, the model is developed such that either a transformer or an uncoupled inductor can be implemented as the inductive energy storage component. The required circuit equations are derived, and a technique to model the dynamic circuit resistance utilizing the time derivatives of circuit currents is described. Thus, a unique modeling method, which is entirely user definable and compatible with a variety of numerical processing software, is developed. Detailed descriptions of the system under consideration, the modeling method, and modeling constraints are provided. The equations describing the switch resistance and circuit response are derived. An example simulation in which restrike occurs is presented, and modeling results are compared to experimentally measured data. [ABSTRACT FROM PUBLISHER]

A formulation of electromagnetism in continuous media is proposed that relies on the identification of the different existing electro-magnetic energy reservoirs and of the flows between them. A structure is so revealed, which constitutes a natural framework to establish the partial differential equations ruling electromagnetic systems. This energy-based formulation, which unlike Maxwell's equations also integrates the material aspects, clarifies several issues related to dissipative and coupled phenomena in magnetic materials, dielectrics and conductors. [ABSTRACT FROM AUTHOR]