DC High-voltage Supply Research Articles

A Prototype High-Voltage Pulsed Power Supply for Control of the ITER Shattered Pellet Injection System Flyer Plate Valve

A high-voltage pulsed power supply (HVPPS) has been designed, prototyped, and tested for driving an eddy current actuated propellant valve for the International Thermonuclear Experimental Reactor (ITER) disruption mitigation system. The high-voltage (HV) dc supply output voltage is software programmable, and the energy storage capacitor bank can be readily reconfigured as 200, 400, 600, and 800 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{F}$ </tex-math></inline-formula> , enabling testing and optimization of both the valve drive and valve systems. Multiple system parameters are monitored before, during, and after each firing of the valve. The system parameters are both displayed and stored for further analysis. Control of the setup, firing sequence, and data collection is automated using a LabVIEW-based control program. The programmability and reconfigurability of this system collectively provide a flexible and robust platform for system refinement and optimization. In this article, a summary of the system will be provided including operational sequences, HV switching and associated triggering methods and circuits, and results measured while firing a solid frozen pellet. In addition, planned refinement activities toward meeting all requirements for ITER integration will be discussed.

Design and development of water-immersible two-channel high-voltage spike pulser for under-water inspection and gauging of pipes.

A water-immersible two-channel high-voltage (HV) spike pulser has been designed, developed, and mounted inside the IP 67 (Ingress Protection 67) grade enclosure, and it is suitable for the ultrasonic Pipe Inspection and Gauging (PIG) system utilized in the petrochemical industry. Such a critical and strategic application requires a portable, miniaturized, and water-immersible water-tight pulser module, which resides inside the pipe carrying water or liquid petrochemicals. The developed spike pulser printed circuit board (PCB) generates a HV negative spike pulse up to -300V and 100ns half-amplitude pulse width, required for the energization of ultrasonic immersion transducers of 5-10MHz frequency. The water-immersible pulser is mounted inside the water-tight IP 67 grade enclosure, and it is operated through an external DC power supply/lithium batteries. The evaluation of the module was carried out using a two-channel water-immersible HV spike pulser, in-house developed preamplifier, and inspection head supported by four sets of spring-loaded Teflon balls for centering, and the inspection head carries two ultrasonic immersion transducers placed 180° apart and a sample SS pipe with a length of 400mm, Inner Diameter of 200mm, and Wall Thickness of 9mm. The two-channel pulser module was evaluated in water to measure the dimensions of the sample SS pipe. This two-channel water-immersible novel spike pulser has dedicated circuitry, and each channel is a standalone PCB and it operates through external LV and HV DC supplies. The module can be scaled up to 256 channels for dimension measurement and flaw detection of long length pipes. In the absence of any literature available on the water-immersible pulser for PIG systems, the present two-channel pulser module has been designed and developed, and the module was evaluated by gauging of the SS pipe from inside. This paper provides the details of the water-immersible HV spike pulser module suitable for the gauging of metallic pipes.

Design of power supply and EHD system for ion-propulsion drone

An initial preparation stage for the design of an ion-propulsion drone with no moving parts is presented in this study. Ion-propulsion drone technology is still not significantly mature; however, the technology has the potential to bring about evolution in the drone and aerospace industries. An essential part of the system is to generatea high-voltage (HV) DC power supply in order to propel the drone. This study presents the design of a power supply circuit to generate a HV DC supply system along with the design of electrohydrodynamics is presented in this study.

Design of Power Supply and EHD System for Ion-Propulsion Drone

An initial preparation stage for the design of an ion-propulsion drone with no moving parts is presented in this study. Ion-propulsion drone technology is still not significantly mature; however, the technology has the potential to bring about evolution in the drone and aerospace industries. An essential part of the system is to generate a high-voltage (HV) DC power supply in order to propel the drone. This study presents the design of a power supply circuit to generate a HV DC supply system along with the design of electrohydrodynamics is presented in this study.

Experimental and numerical analysis of a tribo-electrostatic separation process of micronized plastic particles using rotating disk electrodes

ABSTRACT This paper reports an experimental and numerical analysis of a tribo-electrostatic separation process based on a fluidised bed tribo-charging system and two rotating disks connected to two high-voltage DC supplies of opposite polarities. The experiments were performed using a granular mixture composed of µm-size white Polyvinylchloride particles (WPVC) and grey Polyvinylchloride particles that contain a small percentage of carbon (GPVC). A numerical analysis supported the experimental results. It was deduced that the separation outcome is efficient and depends on the high-voltage level, the rotating speed of the electrodes and the fluidisation rate.

Simulation and Experimental Analysis of an Impulse Voltage Generator

This paper presents the simulation and experimental analysis of an impulse voltage generator (IVG) used for atmospheric discharge voltage tests. The electrical equivalent circuit of the IVG was simulated using the electromagnetic transients program EMTP-VR. Besides the simulation of the generator operation, it was necessary to make a detailed revision of the IVG components and determine their working condition to carry the laboratory experiments. The lack of a high DC voltage source to feed the IVG led to developing a high-voltage dc supply. Although the IVG was designed and built in February 1982, this equipment was out of operation due to its DC power supply failure. Due to the interest in rehabilitating the equipment to perform high voltage experiments, and with the need to characterize insulation materials and electrical equipment subject to electrical stress, it was decided to put it back into operation. Capacitor tests were carried out for each IVG stage to determine if they fulfilled the electrical charging function. Other components were also repaired, such as damaged resistances and sphere gaps. The impulse generator was configured with a maximum of six stages which is half of the original design. Before doing an experiment with the IVG, a simulation analysis was made to study the IVG. The simulation results allow evaluating before the experimentation whether the impulse generator is working correctly; the model allows to analyze the charge and discharge of each capacitor and the electrical currents at each branch of the IVG equivalent circuit. Performance Simulation and experimental results are presented to demonstrate the IVG functionality. The IVG will be used for carrying out insulation tests made by power engineering graduate students.

MODELLING AND OPTIMIZATION OF THE WASTE MICRONIZED PLASTICS RECOVERY BY TRIBOELECTROSTATIC SEPARATOR

Triboelectrostatic separation of millimeter-size particles is widely used in the recycling industry of plastics. However, the separation of micronized particles needs still improvement due to the aerodynamic forces of such small particles. This paper is aimed to carry out an experimental investigation of a triboelectrostatic separation process based on a pair of rotating disks supplied by two high-voltage DC supplies of opposite polarities. The granular samples used in this paper are composed of micronized white pure virgin PolyVinyl Chloride particles (WPVC) and gray PolyVinyl Chloride particles (GPVC) of average size 50 m. Moreover, the methodology of experimental designs was used for the experimental modelling and optimization of the separation process. It was deduced that the separation recovery is efficient and depends on several factors: the high-voltage level, the rotating speed of the disks, the fluidization rate and inter-electrodes spacing. The results obtained showed that the applied voltage remains the most significant factor in the separation process. The best separation performance was obtained for an applied voltage of 20 kV and a disk rotation speed of 100 rpm.

Power Scalable Bi-Directional DC-DC Conversion Solutions for Future Aircraft Applications

With the introduction of the more electric aircraft, there is growing emphasis on improving overall efficiency and thus gravimetric and volumetric power density, as well as smart functionalities and safety of an aircraft. In future on-board power distribution networks, so-called high voltage DC (HVDC, typically +/−270VDC) supplies will be introduced to facilitate distribution and reduce the associated mass and volume, including harness. Future aircraft power distribution systems will also very likely include energy storage devices (probably, batteries) for emergency back up and engine starting. Correspondingly, novel DC-DC conversion solutions are required, which can interface the traditional low voltage (28 V) DC bus with the new 270 V one. Such solutions presently need to cater for a significant degree of flexibility in their power ratings, power transfer capability and number of inputs/outputs. Specifically, multi-port power-scalable bi-directional converters are required. This paper presents the design and testing of such a solution, addressing the use of leading edge wide-band-gap (WBG) solid state technology, especially silicon carbide (SiC), for use as high-frequency switches within the bi-directional converter on the high-voltage side.

High‐voltage pulse transformer for IOT modulators

Neutron sources like European Spallation Source consist of linear proton accelerator and beam target. The linear accelerator is supplied by inductive output tubes (IOTs) or klystrons that require high-voltage DC supply (40 kV). This study describes the design and experimental evaluation of high-voltage dry-isolation pulse transformer design evaluation prototype for interleaved IOT supply modules. In order to withstand high-voltage stress, a modular secondary winding module with multistage voltage field equalisation are designed. Inter-winding connections are realised in the air as the separate winding outputs are routed together through common high-voltage isolators. The novelties of the current manuscript are new pulse transformer design and the experimental work. Experiments with full-scale prototype verified the advantages and revealed, also, some drawbacks of this construction. Proposed transformer design could be used not only in IOT or klystron power supplies but also in high-voltage DC/DC or AC/AC converters and power electronic transformers, used in the medium-voltage distribution grids.

Experimental investigation of a tribo-electrostatic separation device using linear moving electrodes

The aim of this paper is to carry out an experimental analysis of a triboelectrostatic separation device constituted of two “back-and-forth” moving horizontal plate electrodes supplied by two high-voltage DC supplies of opposite polarities. The experiments were performed using samples of micronized white pure virgin PolyVinyl Chloride particles (WPVC) and gray PolyVinyl Chloride particles (GPVC) of average size 100 µm. Moreover, a homemade method was developed to estimate the purity of the separated products. It was deduced that the separation outcome, in terms of recovery and purity, is efficient and depends on several factors: the high-voltage level, the movement speed of the electrodes, the fluidization rate and the composition ratio of the granular mixture.

Electrostatic precipitator for fine and ultrafine particle removal from indoor air environments

An electrostatic precipitator was evaluated to reduce nanometric and micron-sized particles in indoor air environments. This process consists in a negative air ionizer assisted by a parallel-plate collector. The ionization stage contained four or eight corona needles, which were supplied by a negative high-voltage DC. The collection stage was designed in a plate-to-plate configuration, of which the plates are alternately connected to a high-voltage DC supply and the ground. Fractional efficiency (expressed in number) was investigated using NaCl ultrafine particles and atmospheric aerosol according to different geometric, environmental and operating parameters (concentration, relative humidity, collector and ionizer voltage, collector length, number of needles, and airflow rates). The results are discussed according to particle size. Under optimized conditions (eight needles, 20 cm collector length, −7 kV ionization voltage, 5 kV collection voltage, 1 m/s air velocity), the process revealed high performance levels. The efficiency of particles of 10–25 nm in diameter was 94%, between 30 and 300 nm the efficiency was 99%, while in the most penetrating particle size, the efficiency was 96%, with an ozone concentration at the outlet of the process less than 5 ppbv. This process generated a very low ozone concentration, which is an essential challenge for indoor air treatment. The results confirmed the existence of the partial charging regime for particles less than a few tens of nanometers for which the efficiency was lower. For these particles, the collection conditions (collection time and voltage) had no influence on the efficiency. For larger particles, both the parameters of the charging phase (ion concentration, charging time) and the parameters of the collection phase (collection time and voltage) had a significant influence on the collection efficiency.

Micronized plastic waste recycling using two-disc tribo-electrostatic separation process

Triboelectrostatic separation of millimeter-size granular mixtures is nowadays widely used in the recycling industry. However, the separation of micronized particles of an average granulometric size of 100 µm is still inefficient. This paper is aimed to carry out an experimental investigation of a triboelectrostatic separation process based on a fluidized bed tribocharging system produced between a pair of rotating aluminum disks supplied by two high-voltage DC supplies of opposite polarities. The granular mixture used in this work is composed of micronized white pure virgin PolyVinyl Chloride particles (WPVC) and gray PolyVinyl Chloride particles that contain a small percentage of carbon (GPVC) of average size 100 μm. Moreover, a homemade method was developed to estimate the purity of the separated products. It was deduced that the separation outcome, in terms of recovery and purity, is efficient and depends on several factors: the high-voltage level, the rotating speed of the disks, the fluidization rate, the total mass of the fluidized bed and the composition ratio of the granular mixture.

Generation of High-Resolution 12-Sided Voltage Space Vector Structure Using Low-Voltage Stacked and Cascaded Basic Inverter Cells

This paper proposes generation of a 15-level (14 concentric) dodecagonal voltage space vector structure (DVSVS) for a star connected induction motor drive. The proposed multilevel DVSVS is obtained by cascading two inverters, namely a primary and secondary inverter. The primary inverter is a five-level (5L) structure formed by stacking two three-level flying capacitors with individual reduced dc sources and the secondary inverter is also a 5L structure formed by cascading two capacitor-fed cascaded H-bridges (CHB). The active power is supplied by the primary inverter, while the secondary inverter acts as switched capacitor harmonics filter, and capacitors in the secondary inverter are balanced naturally irrespective of load power factor for entire modulation index. The high-voltage dc supply fed primary inverter is operated in quasi-square wave mode, while the high frequency switching is applied to low voltage CHBs, thus, reducing the overall switching loss. The proposed scheme gives the advantages of both DVSVS and multilevel structure, thus, making it one of the solutions for battery or stacked dc-fed applications. The paper also presents the experimental results as well as comparison study with the existing topologies to support the advantages of proposed scheme.

Calibration of free-space radiometric partial discharge measurements

The present study addresses the calibration of four types of partial discharge (PD) emulators used in the development of a PD Wireless Sensor Network (WSN). Three PD emulators have been constructed: a floating-electrode emulator, and two internal PD emulators. Both DC and AC high-voltage power supplies are used to initiate PD, which is measured using concurrent free-space radiometry (FSR) and a galvanic contact method based on the IEC 60270 standard. The emulators have been measured and simulated, and a good agreement has been found for the radiated fields. A new method of estimating the absolute PD activity level from radiometric measurements is proposed.

Pulsed-high-voltage-supplied variable cross-section cylindrical electrostatic precipitators for fly-ash particles

ABSTRACTThe article evaluates the effect of pulsed-high-voltage energization upon three types of cylindrical electrostatic precipitators that might be installed on the exhaust pipe of household boilers. The three models are similar in that the corona discharge is generated between a thin copper wire (diameter 0.16 mm), coaxial with a 354 mm long aluminum cylinder (inner diameter: 40 mm) that is the collecting electrode. The first model is a “standard” constant cross-section precipitator. The other two models are characterized by the presence of a 17 mm long, reduced cross-section (diameter: 23 or 30 mm) intermediate sector, located at about 1/3 of the precipitator length, from the inlet. The reduced cross-section was achieved by a sleeve made of either aluminum or polyvinylchloride, so that to create, in the latter case, a dielectric-barrier discharge. Pulsed energization of the three models of electrostatic precipitators was provided by positive or negative DC high-voltage supplies and a mechanical rotary spark-gap. The frequency of the high-voltage pulses ranged between 120 and 280 Hz. The experimental results show that the collection efficiency was better for both negative and positive high-voltage pulses. The best collection performances were obtained with the hybrid corona and dielectric-barrier discharge precipitator.

Family of Enhanced ZCS Single-Stage Single-Phase Isolated AC–DC Converter for High-Power High-Voltage DC Supply

AC-DC power supply is essential equipment which builds the connection between the ac grid and the dc loads. In order to achieve high-power density and high efficiency, a family of enhanced zero-current-switched (ZCS) single-stage single-phase isolated ac-dc converters is proposed for high-power high-voltage dc application. Only one resonant capacitor is required for the proposed converters to realize ZCS operation. On the other hand, the over voltage problem which exists in former developed ZCS ac-dc topologies is eliminated. Thus, lower voltage rating IGBTs can be applied. Higher efficiency is realized. At the same time, these converters inherit the feature such as one-stage power conversion, low conduction loss, good total harmonics distortion performance, etc. A 3 kW prototype is built to verify the proposed converters. A comparison is made to show the efficiency improvement clearly.

Electro-Hydrodynamics and Kinetic Modeling of Dry and Humid Air Flows Activated by Corona Discharges

The present work is devoted to the 2D simulation of a point-to-plane Atmospheric Corona Discharge Reactor (ACDR) powered by a DC high voltage supply. The corona reactor is periodically crossed by thin mono filamentary streamers with a natural repetition frequency of some tens of kHz. The study compares the results obtained in dry air and in air mixed with a small amount of water vapour (humid air). The simulation involves the electro-dynamics, chemical kinetics and neutral gas hydrodynamics phenomena that influence the kinetics of the chemical species transformation. Each discharge lasts about one hundred of a nanosecond while the post-discharge occurring between two successive discharges lasts one hundred of a microsecond. The ACDR is crossed by a lateral dry or humid air flow initially polluted with 400 ppm of NO. After 5 ms, the time corresponding to the occurrence of 50 successive discharge/post-discharge phases, a higher NO removal rate and a lower ozone production rate are found in humid air. This change is due to the presence of the HO2 species formed from the H primary radical in the discharge zone.

Tribo-aero-electrostatic separation of micronized mixtures of insulating materials using “back-and-forth” moving vertical electrodes

The existing industrial tribo-electrostatic separators have proved their efficiency for sorting mixtures of millimeter-sized granular plastics. The objective of this paper is to validate a new tribo-aero-electrostatic separator designed for processing granular mixtures of insulating materials (average size: 10–100 μm). The device consists of two vertical plate electrodes of dimensions 20 cm × 30 cm, connected to two DC high voltage supplies of opposite polarities. Both electrodes perform “back-and-forth” motions inside a fluidized bed containing the micronized materials to be separated. Fluidization is achieved by injection of air using a variable speed air blower. The experimental study is carried out with samples of white PVC and gray PVC having an average size of 50 μm, and enables the analysis of the effects of several factors on the separation efficiency: the linear speed of the electrodes, the electric field, the mass of processed materials and the fluidization air flow rate. The new separation process is characterized by high product recovery rates. The purity of the separated products, estimated by visual examination, exceeds 90% in all experiments.

Platform Technologies for Directly Reconstructing 3D Living Biomaterials.

Bio-electrospraying and cell electrospinning is explored for reconstructing living biomaterials for regenerative biology and medicine. The investigations carried out in this study demonstrate these approaches as platform biotechnologies for tissue reconstruction for repair, replacement, and rejuvenation of damaged and/or ageing tissues and/or organs.

Improvement of the Industrial Pilot of a Tribo-Aero-Electrostatic Separator for Binary Mixtures of Granular Insulating Materials

New electrostatic separation processes have been developed for the treatment of waste electrical and electronic equipment (WEEE), the amounts of which are increasing from year to year. The objective of this paper is to analyze two possibilities for improving the performance of a semi-industrial tribo-aeroelectrostatic separator for insulating granules: decrease the cross section or modify the wall material of the fluidized bed. The electric field of the separator is generated between two metallic belt conveyors connected to two dc high-voltage supplies of opposite polarities and is orthogonal to the direction of the fluidized air. The experiments were performed on an insulating granular mixture consisting of acrylonitrile-butadiene-styrene (ABS) and high impact polystyrene (HIPS), of 2-mm average size, originating from the processing of WEEE. The first series of experiments was conducted for two cross sections of the fluidized bed (42 cm × 15 cm and 30 cm × 15 cm, respectively) in similar environmental conditions (temperature: 18 °C; relative humidity: 40% ± 1). The decrease of the surface of the fluidized bed was accompanied by an increase in the mass of products recovered in the collecting boxes: 52% for ABS and over 14% for HIPS. The second series of tests demonstrated the role of the lateral walls of the fluidized bed. The walls of poly-methyl metracrylate promote the separation of ABS, whereas those in acetate improve the recovery of HIPS.