HV System Research Articles

Efficient degradation of sulfonamides by introducing sulfur to magnetic Prussian blue analog in photo-assisted persulfate oxidation system

The peroxynitrite photocatalytic degradation system was considered a green, convenient, and efficient water treatment process, but not satisfying against some antibiotics, e.g. sulfonamides (SAs). To improve the photocatalytic degradation efficiency of SAs, sulfur was introduced to a magnetic Fe-MOF (Fe-metal organic framework) Prussian blue analog to achieve a heteroatomic material CuFeO@S, which was applied in heterogeneous visible light photo-assisted catalytic process with persulfate (PS) as an oxidant. The characterization results of CuFeO@S by XRD and XPS confirmed the presence of Fe3O4 (for magnetic separation), Cu+ (for activation of PS) and S2− (for narrowing the energy band and prolonging the lifetime of photo-generated electronics). Through systematic optimization of reaction conditions in CuFeO@S + PS + hv system, efficient degradation of four tested SAs was achieved in 30 min (removal rate of 97–100% for the tested 4 SAs). Moreover, the material could be magnetically recycled and reused for over 7 cycles with a removal rate of >90% for sulfamerazine. Furthermore, the removal rate of sulfamerazine in pond water reached 99% at a mineralization rate of about 34% (decrease in total organic matter), demonstrating its potential in the treatment of antibiotic-containing wastewater.

Design and Control of a Modular Integrated On-Board Battery Charger for EV Applications with Cell Balancing

This paper presents operation and control systems for a new modular on-board charger (OBC) based on a SEPIC converter (MSOBC) for electric vehicle (EV) applications. The MSOBC aims to modularise the battery units in the energy storage system of the EV to provide better safety and improved operation. This is mainly achieved by reducing the voltage of the battery packs without sacrificing the performance required by the HV system. The proposed MSOBC is an integrated OBC which can operate the EV during traction and braking, as well as charge the battery units. The MSOBC is composed of several submodules consisting of a full-bridge voltage source converter connected on the ac side and SEPIC converter installed on the battery side. The SEPIC converter controls the battery segments with a continuous current because it has an input inductor which can smooth the battery’s currents without the need for large electrolytic capacitors. The isolated version of the SEPIC converter is employed to enhance the system’s safety by providing galvanic isolation between the batteries and the ac output side. This paper presents the necessary control loops to ensure the optimal operation of the EV with the MSOBC in terms of charge and temperature balance without disturbing the required modes of operation. The mathematical analyses in this paper are validated using a full-scale EV controlled by TMS320F28335 DSP.

The high voltage system of the novel MPGD-based photon detectors of COMPASS RICH-1 and its development towards a scalable High Voltage Power Supply System for MPGDs

The COMPASS RICH-1 detector has undergone a major upgrade in 2016 with the installation of four novel MPGD-based photon detectors. They consist of large-size hybrid MPGDs with multi-layer architecture composed of two layers of Thick-GEMs and bulk resistive MicroMegas. A dedicated high voltage power supply system, based on CAEN HV modules, has been built and put in operation: it controls more than 100 HV channels. The system is required to protect the detectors against errors by the operator, monitor voltages and currents at a 1 Hz rate and automatically react to detector misbehavior. It includes also a HV compensation system against environmental pressure and temperature variation to grant the detector stability. The operation of a MPGD based single photon detector poses challenging requirements to the high voltage power supply systems employed in terms of high-resolution diagnostic features and dynamic voltage control. Systems satisfying all the needed features are not commercially available; for this reason a novel single channel high voltage system matching the MPGD needs has been designed and realized. In this article the COMPASS RICH-1 MPGD HV system implementation is described as well as its performance in terms of stability of the novel MPGD-based photon detectors during the physics data taking at COMPASS. The design, implementation and performance of a novel HV power supply system based on DC to DC converters and controlled by a FPGA device is presented. The capabilities of the first prototype of the new single HV channel power supply are illustrated when operated with a MPGD based single photon detector during a test beam exercise. The preliminary result of the multi channel system are briefly discussed.

The high voltage system the novel MPGD-based photon detectors of COMPASS RICH-1 and its development towards a scalable HVPSS for MPGDs

The COMPASS RICH-1 detector underwent major upgrade in 2016 with the installation of four novel MPGD-based photon detectors. They consist of large-size hybrid MPGDs with multi-layer architecture composed of two layers of Thick-GEMs and bulk resistive Micromegas. A dedicated high voltage power supply system, realized with commercial devices, has been put in operation to protect the detectors against errors by the operator, monitor and log voltages and currents at a 1 Hz rate, and automatically react to detector misbehavior; it includes also the HV compensation for the detector gas pressure and temperature variations.The needs posed to the high voltage power supply systems by the operation of Micro Pattern Gaseous Detectors pushed the development of a novel single channel HV system able to overcome the performance of the commercial devices in terms of high-resolution diagnostic features and intelligent dynamic voltage control. In this talk the COMPASS HV system and its performance are illustrated, as well as the stability of the novel MPGD-based photon detectors during the physics data taking at COMPASS. The performance of the novel single channel power supply system when connected to a single photon Micro Pattern Gaseous Detector is presented in realistic working condition during a test beam with the preliminary results of multiple channels operation.

When Mosquito HV bites Biomark HD: An automated workflow for high-throughput qPCR.

Automation solutions can significantly improve sample processing efficiency and can be of particular help in core facility settings. Centralized core facilities are being established world-wide aimed at strengthening institutions' clinical and research enterprises and at addressing the need to process large volumes of samples on expensive cutting-edge technologies in a limited time. High-throughput qPCR profiling is a service offered by most genomics facilities. Several platforms have been developed to process large numbers of samples in a short time, including the Fluidigm Biomark HD, which has also been proved useful to increase the SARS-CoV-2 testing capacities. Several automation systems are currently available to miniaturize volumes and improve bioanalytical workflows, including the SPT Labtech Mosquito HV system. Here we have applied the Mosquito HV platform for the automation of the sample preparation of the Fluidigm gene expression workflow. We have successfully automated the pre-amplification and exonuclease cleanup steps with the aim of reducing manual error and sample processing time. We show consistency in the expression of reference genes when assessing pooled RNA control samples for the manual and automated workflows of Fluidigm gene expression profiling.

Photodegradation performance and mechanism of sulfadiazine in Fe(III)-EDDS activated persulfate system

In order to overcome the shortcomings in traditional Fenton process, Fe(III)-EDDS activated persulfate advanced oxidation process under irradiation is carried out as a promising technology. The photodegradation of sulfadiazine (SD) in Fe(III)-EDDS activated persulfate system was investigated in this paper. The results showed that SD could be effectively degraded in Fe(III)-EDDS/S2O8 2-/hv system. The effect of Fe(III):EDDS molar ratio, the concentration of Fe(III)-EDDS and the concentration of S2O8 2- on SD degradation were explored. At neutral pH, when Fe(III):EDDS = 1:1, Fe(III)-EDDS = 0.1 mM, S2O8 2- = 1.5 mM, the best SD degradation was achieved. The experiment of external influence factors showed that the degradation of SD could be obviously inhibited by the presence of CO3 2-, SO4 2-, while the degradation of SD almost unaffected when Cl- added. The degradation of SD could be slightly inhibited by the presence of humic acid and NO3 -. The effect of pH on SD degradation was investigated, and SD could be degraded effectively in the pH range of 3-9. ESR proved that 1O2, ·OH, SO4 ·− and O2 ·− were produced in the process. SO4 ·− and ·OH were identified as the main radicals while O2 ·− also played non-ignorable role. Eleven intermediate products of SD were analyzed. The C = N, S-N and S-C bonds of SD were attacked by radicals firstly, leading to a series of reactions that eventually resulted in the destruction of SD molecules and the formation of small organic molecules.

Research on power management and allowed propulsion control in pure electric vehicle

For the optimization of vehicle mode management, the vehicle safety and the system efficiency, seven states which include initialization, the CPSR off, the CPSR on, HV contactor on, HV current enable, pre-crash and crash are presented based on the pure electric vehicle. The timing sequence of power up and power off in the normal working condition, the reset condition, the crash condition, OBC charge condition and emergency conditions are defined based on the states. Then the allowed propulsion is presented based on the ready driver, the ready HV system status, the immobilizer system and the feedback active drive cycle signal. Finally, the vehicle test result shows that the propulsion system manager can improve the driver’s comfort and reduce start time especially with a fast start which can be finished in 0.6 s of the whole power on process.

Implementation of the DCS System for the validation of MM HV Boards and the DCS System of the new BIS78 Chambers for the upgrade of muon system of the ATLAS Experiment

The ATLAS Muon Spectrometer is going through upgrades on the Phase I in order to achieve higher rates for the upcoming LHC runs. The two main projects of this Phase I upgrade are the New Small Wheels (NSW), which are expected to complement the ATLAS muon spectrometer in the end-cap regions and a smaller size project, known as BIS78 (Barrel Inner Small sectors).The NSW is expected to replace the Small Wheel (SW) and it will be installed in the ATLAS underground cavern during the summer by the end of the LHC Long Shutdown 2. This new system will be consisted by two prototype detectors, the sTGC (small Thin Gas Chambers) and the resistive Micromegas (MM).In order to cope with higher LHC luminosities, the installation of NSW will help the reduction of the trigger rate in the forward region. With half of the rate in the barrel-endcap transition region reduced by the existing TGCs, the other half of the fake trigger rate in transition region will be reduced by the new BIS78 stations. The BIS78 subproject foresees the replacement of the existing Monitored Drift Tubes (MDTs), used for the precise position measurement in this area, with muon stations formed by integrated smaller diameter tubes (sMDT) and a new generation of RPCs, capable of withstanding the higher rates and provide a robust standalone muon confirmation. The existing BIS7 and BIS8 MDT Chambers will be replaced by 16 new muon stations of one small (sMDT) chamber and two RPC triplets, and it will be the pilot project for the Phase II BI Upgrade.This work is divided into two parts. First will be presented the development and the implementation of a Detector Control System (DCS) for the HV system for the MM detectors of NSW and specifically the validation of a new type of HV Boards (A7038AP). Second, the development of the DCS for the monitoring and operation of the new sMDT chambers of the MDT Sub-System will be presented.

Electromagnetic interaction between the power distribution grid and thE HV system of an electric vehicle

In the paper it will be presented the history of electric vehicles (EVs), compared to conventional combustion engine cars. Environmental impacts produced the necessity of a cleaner transportation by reintroducing electrical cars in the automotive market. By increasing the EVs used in transportation, the level of pollution is decreased, but some major issues concerning electromagnetic compatibility are raised. The ambient electromagnetic field was described, focusing on simulation of a MV power distribution line. Afterwards, it was analyzed the electromagnetic interaction between an electric vehicle and the power distribution line, simulating the magnetic field distribution.

Assessing the annual power reliability of a residential building in relation to its ventilation system type: The case study of the off-grid container house in Shanghai.

In developing countries, electrification of rural and remote areas is an essential need for improving socio-economic conditions. However, increased access to adequate electricity and upgraded facilities may double or even triple present greenhouse gas emissions related to residential buildings operation. From both socio-economic and environmental perspective, implementation of solar-powered houses is widely considered as a sustainable. Power reliability is a key indicator used in assessing the annual performance of the off-grid housing operation. The primary objective of this article is to ascertain the impact of three main ventilation system types: natural (NV), mechanical with heat recovery (MV) and hybrid (HV) on annual power reliability of the case, off-grid building located in Shanghai. Firstly, three scenarios of hourly electricity loads profiles were calculated from an annual simulation via building performance software (BPS). Secondly, electrical load profiles were integrated into a developed model of alternating current (AC) coupled battery off-grid energy system model. The results indicate that the HV system provided the lowest annual electricity consumption (2847 kWh) and the best annual power reliability (98.6%) when compared to MV (2935kWh, 98.5%) and NV (2901kWh, 98.0%). The article discusses correlation between building ventilation scenarios, electrical loads and resultant annual power reliability. In conclusion economic viability of mechanical/hybrid ventilation implementation in off-grid housing is called into question.

The high voltage system with pressure and temperature corrections for the novel MPGD-based photon detectors of COMPASS RICH-1

The novel MPGD-based photon detectors of COMPASS RICH-1 consist of large-size hybrid MPGDs with multi-layer architecture including two layers of Thick-GEMs and a bulk resistive MicroMegas. The top surface of the first THGEM is coated with a CsI film which also acts as photo-cathode. These detectors have been successfully in operation at COMPASS since 2016. Concerning bias-voltage supply, the Thick-GEMs are segmented in order to reduce the energy released in case of occasional discharges, while the MicroMegas anode is segmented into pads individually biased with positive voltage while the micromesh is grounded. In total, there are about ten different electrode types and more than 20000 electrodes supplied by more than 100 HV channels, where appropriate correlations among the applied voltages are required for the correct operation of the detectors. Therefore, a robust control system is mandatory, implemented by a custom designed software package, while commercial power supply units are used. This sophisticated control system allows to protect the detectors against errors by the operator, to monitor and log voltages and currents at 1 Hz rate, and automatically react to detector misbehaviour. In addition, a voltage compensation system has been developed to automatically adjust the biasing voltage according to environmental pressure and temperature variations, to achieve constant gain over time. This development answers to a more general need. In fact, voltage compensation is always a requirement for the stability of gaseous detectors and its need is enhanced in multi-layer ones. In this paper, the HV system and its performance are described in details, as well as the stability of the novel MPGD-based photon detectors during the physics data taking at COMPASS.

An investigation on mechanisms of equilibrium-stage scour and deposition process around a submerged L-head groyne

ABSTRACT A numerical model based on large eddy simulation code supported with a laboratory experiment was used to explore the mechanism of scour and deposition process around a submerged L-head groyne at equilibrium stage of flow. The numerical model used the equilibrium bathymetry, which was obtained from an experiment conducted in the laboratory. The components of Horse Shoe vortex system (HV) including the presence of aperiodic oscillatory motions between back flow and zero flow modes near the groyne faces junction are explored. Formations of elliptical-shaped vortex tubes along detached shear layer (DSL) and their merging phenomenon at different time scales of flow are also investigated. Increase in vorticity magnitude towards bottom as compared to upper planes for instantaneous and mean flow field is identified. Near bed region, concentration of DSL profile towards submerged mound situated in the wake region emerges as dominating factor over HV system for the production of larger vorticity magnitude. Transportation of DSL eddies, their interaction with wake vortices and flow within reattachment zone are also focussed. To emphasize, this innovative study was conducted first time to fulfil the gap of exploring mechanism of scour and deposition process around such a complex geometry under submerged condition over scoured bed.

A transparent−green−blue electrochromic device based on 2, 2, 6, 6−tetramethyl−1−piperidinyloxy (TEMPO), polyaniline, and HV(BF4)2

A novel hybrid type electrochromic device (ECD) was fabricated, using a stable radical provider, 2,2,6,6−tetramethyl−1−piperidinyloxy (TEMPO) and two electrochromic (EC) materials, polyaniline (PANI) and heptyl viologen (HV(BF4)2). The PANI thin film and HV(BF4)2 solution were chosen as anodically and cathodically coloring materials, respectively. The TEMPO was selected to act as the anion storage species in pair with either of the electrochromic material. This type of assembly thus formed two electrochromic systems in one device, i.e., TEMPO−HV and TEMPO−PANI. The electrolyte for the ECD was composed of 0.1 M TEMPO, 0.05 M HV(BF4)2, 0.1 M TBABF4, and 1.0 mM HClO4 in propylene carbonate (PC), and was placed in between two ITO glasses. By varying the operating voltage between 0 and 1.5 V, the TEMPO−HV system showed a transmittance change (ΔT) of 46.2% at 550 nm. By varying the operating voltage between 0 and −1.0 V, the TEMPO−PANI system showed a ΔT of 45.5% at 700 nm. The complete system activation (both TEMPO−HV and TEMPO−PANI) was achieved by setting the operating voltage between −1.0 and 1.5 V, obtaining a ΔT of 53.3% at 550 nm. The estimated switching times for the total system were 3.1 and 3.4 s for bleaching and darkening, respectively. The coloration efficiencies of the ECD at 700 and 500 nm, for the green to blue transition, were 159.7 and 169.2 cm2C-1, respectively, while 88.8 and 23.5 cm2C-1 for the transparent to green transition. The proposed hybrid ECD was characterized by cyclic voltammetry (CV), UV–Vis absorbance spectra, dynamic transmittance curves, and long-term stability test.

A Novel Shape Representation Method for Complex Trademark Image

Trademark orthogonal representation is an important research field in artificial intelligence technology and has extensive applications in trademark retrieval and recognition. However, the Gibbs phenomenon arises when complex trademark shapes are represented by using traditional methods, such as continuous orthogonal function and wavelet. In order to represent the complex trademark without Gibbs phenomenon, a novel method named hierarchical V-system (HV system) is proposed in this study, which is generated by V-system of multi-degree $k$ ( $k = 0, 1, 2, 3$ ). The hierarchical structure brings more detailed shape representation information. We show that the proposed method in this paper can represent the trademark shapes with fewer finite terms and obtain accurate representation result. This study also proposes the normalized descriptors of hierarchical V-system (HV descriptors). Furthermore, we demonstrate that the HV descriptors satisfy the invariance in rotation, translation, and scale transform. The experimental results show that the hierarchical V-system method can give reasonable descriptors for representing complex trademark without Gibbs phenomenon.

Joint DSO–TSO reactive power management for an HV system considering MV systems support

This article deals with a joint distribution system operator–transmission system operator (DSO–TSO) reactive power management to support TSO operations at high-voltage level. This management is based on the coordination of several volt-var control schemes of medium-voltage networks able to control the reactive power at the DSO–TSO interface. The coordination is achieved through the resolution of an OPF problem. The definition of this latter is further discussed and recommendations are raised.

The High-Voltage System of Calet Apparatus

CALET (CALorimetric Electron Telescope) is installed on the International Space Station since August 2015, is a mission devoted to measure the intensity of cosmic ray electrons and protons accelerated to near the speed of light. The apparatus is also designed to observe high energy gamma rays, nearby source of high energy radiation and it may even detect signatures of the elusive dark matter.One of the core components of the whole apparatus is the high voltage power supply system. It is based on hundred of independent DC/DC converters providing precise voltage regulation to two sections of CALET detectors.This paper presents the experience gained in the implementation of the CALET HV system: the system design requirements and the technical solutions adopted, the two system sections block schemes and the main characteristics of the DC/DC converters that guarantee the CALET HV system technical performance.

Analysis of PD Pulses in Transmission Wire Line Network

The aim of study is to understand Partial discharge, in order to locate this phenomenon within an HV system. Voltages 110 kV and above are regarded as transmission level voltages. In long lines with light loads, lower voltages like 66 kV and 33 kV are frequently used. These lower voltages are known as sub transmission voltages. For distribution, voltages less than 33 kV are generally used. Voltages above 230 kV are regarded extra high voltage and above 765 kV are considered ultra high voltages. The equipment used at higher voltages is of different design when compared to the equipment used at lower voltages. It is necessary to design and develop a compact and cost effective insulation structure for a proper power transmission at higher voltages. Due to mechanical, thermal and electrical stress, the insulation may breakdown which leads to catastrophic failure of the device. Hence it is necessary for the users to have a warning device which gives advance notice about the potential insulation problems so that they may be repaired during a scheduled shutdown.

Adapting AC Lines to DC Grids for Large-Scale Renewable Power Transmission

All over the world, governments of different countries are nowadays promoting the use of clean energies in order to achieve sustainable energy systems. In this scenario, since the installed capacity is continuously increasing, renewable sources can play an important role. Notwithstanding that, some important problems may appear when connecting these sources to the grid, being the overload of distribution lines one of the most relevant. In fact, renewable generation is usually connected to the nearest AC grid, although this HV system may not have been designed considering distributed generation. In the particular case of large wind farms, the electrical grid has to transmit all the power generated by wind energy and, as a consequence, the AC system may get overloaded. It is therefore necessary to determine the impact of wind power transmission so that appropriate measures can be taken. Not only are these measures influenced by the amount of power transmitted, but also by the quality of the transmitted power, due to the output voltage fluctuation caused by the highly variable nature of wind. When designing a power grid, although AC systems are usually the most economical solution because of its highly proven technology, HVDC may arise in some cases (e.g. offshore wind farms) as an interesting alternative, offering some added values such as lower losses and better controllability. This way, HVDC technology can solve most of the aforementioned problems and has a good potential for future use. Additionally, the fast development of power electronics based on new and powerful semiconductor devices allow the spread of innovative technologies, such as VSC-HVDC, which can be applied to create DC grids. This paper focuses on the main aspects involved in adapting the existing overhead AC lines to DC grids, with the objective of improving the transmission of distributed renewable energy to the centers of consumption.

Electric axle HV components and system

Electric axle HV components and system

Experimental investigations into the application of direct tension indicators with preloaded structural bolting assemblies (HV system) to EN 1090‐2

AbstractEN 1090‐2 provides several tightening methods for the preloading of bolting assemblies. One of the prescribed procedures is the use of direct tension indicators, so‐called DTIs, with lubrication according to k‐class K0. According to the definition of k‐class K0, the lubrication should not have an influence on achieving the required preloading force Fp,C. For this reason, the main focus of the investigations presented here was how the lubrication influences the behaviour of preloaded HV bolting assemblies with and without DTIs. The experimental investigations were carried out on the institute’s own tightening torque testing machine.