Low Voltage Power Supply Research Articles

Design of a universal low-temperature rotary apparatus for making meat and vegetable products considering the integrated adaptive mechanism

The object of this study is the implementation of low-temperature processes for the production of meat and vegetable products under the conditions of adding a dried semi-finished product of a high degree of readiness to the recipe when using the designed universal rotary device of continuous action. The rotary device of continuous action for low-temperature processing of meat and vegetable products with a cylindrical working chamber is heated by a film-like resistive electronic heater of the radiating type. It has a stationary wall (with a technical door for unloading and loading the device) and a technical wall (with an opening angle of 90°). On the inner surfaces of the walls, inclined converging ribs with an angle of 25° are installed, which are covered with an electric heater. Semi-finished meat and vegetable products are loaded onto carts with technological containers and mounted on a frameless drum (rotation frequency 0.03...0.06 s–1). The device converts secondary thermal energy into low-voltage power supply voltage (~3...8 W) for autonomous operation of fans. The proposed integrated adaptive mechanism for the system of complex interaction of the agricultural, processing, and production sectors implies the formation of resource efficiency of production processes from "farm to table". The designed device implements the process of frying meat-vegetable bread under conditions of reaching 80 °C in the center of the product. The obtained temperature field data confirm the uniformity of the temperature field during frying of the product (cooking readiness of the product at the initial weight of 650±20 g – 4.0 hours). The introduction of a multicomponent dried fraction based on potatoes, Jerusalem artichokes, zucchini, and carrots into the recipe of meat-vegetable bread reduces the weight loss of the semi-finished product during frying by 12.3 %. It increases the content of calcium, phosphorus, vitamin C accompanied with a decrease in energy value by 28.1 %

Modeling and Experimental Validation of Broad Input-Output Range Three-Voltage-Level Rectifier

A new type of single–conversion–step wide–input–range versatile step–up/down three–voltage–level power–factor correction stage is presented in this manuscript. The rectifier can operate both in continuous–conduction mode and discontinuous–conduction mode. First, the rectifier’s principle of operation is described, and then the innovative rectifier is analyzed in continuous and discontinuous–conduction modes. After, an average model for the innovative rectifier is developed. Lastly, the proposed theory is experimentally validated using a multiplier–less dual–control–loop mode at discontinuous–conduction modes. It is shown that although no multiplier is used in the control circuitry, the power factor is near unity. It is revealed that the rectifier can swing the output voltage from 50 V to 900 V while the input voltage is 230 Vrms. Although the rectifier output has a split DC bus with three voltage levels, the required control effort is low, and the output voltage is balanced. The innovative topology suits any standard power–factor correction rectifier application, dual–stage low–voltage power supply, and three–level voltage supplement for low–harmonic inverters. Since the rectifier’s output–voltage swing is extremely wide, energy storage systems and electric vehicle batteries are suitable applications.

Low power silicon evaporation source—Construction, performances, and applications

The construction of a low power silicon evaporation source for thin film deposition applications is proposed in this article. A few differently shaped tungsten filaments were mounted inside a quartz glass crucible, which assured an effective heating of silicon wafer pieces. The sublimation process was monitored at filament powers in the range of 8–22 W, which corresponds to temperatures far below the melting point of Si. The operation of the evaporation source requires only the use of a low voltage power supply. All considered models of evaporation sources are characterized by an easy construction. The measurements carried out with the use of a quartz crystal microbalance sensor enabled to determine the deposition rate at different filament powers for all constructed Si sources and confirm the long-term stability of the silicon flux. The experimental data exhibit the Polany–Wigner dependence of the deposition rate as a function of inverse of power at higher filament powers. Auger electron spectroscopy was used to monitor the deposition of Si on Ag(100) under constant silicon flux. The Auger signal recorded from Si and Ag reflects the growth of subsequent silicon layers. This enabled the determination of the Frank–van der Merwe growth mode of Si on Ag(100) at early stages of growth, the formation time of one Si monolayer, and, thus, the deposition rate. The presented designs of the Si source exhibit long time stable evaporation fully controlled by the applied filament power, which is crucial in the precise adsorption of ultrathin Si layers.

Effect of Metal Oxide Semiconductor Field-Effect Transistor Output Parasitic Capacitance on Efficiency in Full-Bridge LLC DC/DC Converters.

This study analyzed the efficiency impact of a MOSFET output parasitic capacitance (Coss) on a full-bridge LLC DC/DC converter. The core of the converter was the control chip for a half-bridge LLC DC/DC converter, and the output signal of the chip controlled the first-arm power transistors of the primary side of the converter. The coupling transformer reversed the output signal to control the primary side of the second arm of the power transistor. The full-bridge converter comprises a half-bridge control chip that converts the high-voltage DC power supply to a low-voltage DC power supply, which is then synchronously rectified and supplied to the load. The primary side of the power transistor achieves a zero-voltage switching (ZVS) state through the resonance of the LLC converter. This design gives the converter high power density and a simple structure. Furthermore, to determine the appropriate output parasitic capacitance for improving converter efficiency, this study analyzed the effect of the output parasitic capacitance on the switching loss and conduction loss of the power transistor on the basis of the output parasitic capacitance of the primary-side power transistor. A 1200 W converter prototype was fabricated in this study, and when the output was 300 W, efficiency increased from 92.603% to 93.462%, a 0.859% increase. The empirical results verified the feasibility of the proposed theory.

Flash sintering of ZnO ceramics with combined power supplies at room temperature

A flash sintering method at room temperature based on combined power supplies is proposed in this paper. Flash sintering is performed in two steps. First, a high voltage is used to break down the sample and then disconnect the power supply. Second, a low-voltage power supply is used to provide a large current to densify the sample. The method does not require changing the properties of the material or the sintering atmosphere. In addition to reducing the capacity of the required power supply, there is no need for external auxiliary equipment. Different types of high-voltage breakdown are also studied. The temperature and grain size corresponding to different currents of low-voltage flash sintering are studied. The results show that the sintered ZnO ceramics reach 98.5% relative density. A possible mechanism of flash sintering using combined power supplies is analysed.

Commissioning of MW class Gyrotron Test Facility at ITER-India & Demonstration of ITER relevant RF performance (1MW for 1000 s at 170 GHz)

ITER-India, as a part of its in-kind commitments to ITER project, has a mandate to deliver two “Gyrotron” based RF Source sets with state-of-the-art specifications (170 GHz, 1MW, 1000 s), for ECRH (Electron Cyclotron Resonance Heating) applications. With an aim to bench mark the integrated system performance, a MW class Gyrotron Test Facility has been developed at ITER-India under Phase-1 of the project execution plan. The facility has been developed with all necessary auxiliary systems and services such as the Low Voltage and High Voltage Power Supplies; Control, Protection and Monitoring Systems; RF Diagnostic Systems; Cooling and Vacuum Services etc. Further, a test Gyrotron with ITER relevant specifications (1MW, 170 GHz, 1000s) along with a set of dummy loads and waveguide components have been procured from M/s. Gycom, Russia, and fully integrated with the test facility. Detailed Site Acceptance Tests of the Test Gyrotron have been conducted at the newly developed ITER-India Gyrotron Test Facility (IIGTF). An output RF power of 1MW at 170 GHz for 1000 s with RF efficiency of about 50% has been successfully demonstrated during these tests there by validating the ITER relevant performance

Switched CMOS current source compared to enhanced Howland circuit for bio-impedance applications.

Bio-impedance Spectroscopy (BIS) is a technique that allows tissue analysis to diagnose a variety of diseases, such as medical imaging, cancer diagnosis, muscle fatigue detection, glucose measurement, and others under research. The development of CMOS integrated circuit front-ends for bioimpedance analysis is required by the increasing use of wearable devices in the healthcare field, as they offer key features for battery-powered wearable devices. These features include high miniaturization, low power consumption, and low voltage power supply. A key circuit in BIS systems is the current source, and one of the most common topology is the Enhanced Howland Current Source (EHCS). EHCS is also used when the current driver is driven by a pseudo-random signal like discrete interval binary sequences (DIBS), which, due to its broadband nature, requires high performance operational amplifiers. These facts lead to the need for a current source more compatible with DIBS signals, ultra-low power supply, standard CMOS integrated circuit, output current amplitude independent of input voltage amplitude, high output impedance, high load capability, high output voltage swing, and the possibility of tetra-polar BIS analysis, that is a pseudotetra-polar in the case of EHCS. The objective of this work is to evaluate the performance of the Switching CMOS Current Source (SCMOSCS) over EHCS using a Cole-skin model as a load using SPICE simulations (DC and AC sweeps and transient analysis). The SCMOSCS demonstrated an output impedance of more than 20 MΩ, a ± 2.5 V output voltage swing from a +3.3 V supply, a 275 μA current consumption, and a 10 kΩ load capacity. These results contrast with the + 1.5 V output voltage swing, the 3 kΩ load capacity, and the 4.9 mA current of the EHCS case.

Comprehensive Study of Failure Mechanisms of Field-Aged Automotive Lead Batteries

Modern vehicles have increasing safety requirements and a need for reliable low-voltage power supply in their on-board power supply systems. Understanding the causes and probabilities of failures in a 12 V power supply is crucial. Field analyses of aged and failed 12 V lead batteries can provide valuable insights regarding this topic. In a previous study, non-invasive electrical testing was used to objectively determine the reasons for failure and the lifetime of individual batteries. By identifying all of the potential failure mechanisms, the Latin hypercube sampling method was found to effectively reduce the required sample size. To ensure sufficient confidence in validating diagnostic algorithms and calculating time-dependent failure rates, all identified aging phenomena must be considered. This study presents a probability distribution of the failure mechanisms that occur in the field, as well as provides insights into potential opportunities, but it also challenges diagnostic approaches for current and future vehicles.

Comparison of Low Pulse-Repetitive-Frequency Pulsed Power Supplies With Extremely Small Storage Capacitor

In active phased array radar, the T/R modules are powered by a low-voltage pulsed power supply (PPS). When the pulse repetitive frequency (PRF) is quite low, bulky storage capacitor or input <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LC</i> filter is often used in the PPS, resulting in a low power density. The two-stage PPS and the active capacitor converter (ACC) based PPS can greatly reduce the storage capacitor by intentionally increasing its voltage ripple. In this paper, the two kinds of PPSs with extremely small storage capacitor are compared in terms of the configuration, operating principle, main components and efficiency, and it is shown that the ACC- based PPS is more superior for low PRF than the two-stage PPS.

Revaluation Method of Sensor Power Supply

This study proposes an approach for wireless sensor power supply voltage early warning using statistical models. Experimental and statistical analysis of electrical parameters and battery discharge characteristics were conducted to establish a reliable evaluation process. A linear regression model was employed to analyze and fit known temperature and voltage data, establishing a relationship model between voltage and temperature and using it to predict unknown voltage threshold data. This solves the problem of the inability to real-time predict the warning voltage threshold of wireless sensors as the actual working temperature changes and ensures their reliability. The results of experiments and statistical analysis demonstrate the effectiveness and accuracy of this method. Compared to the traditional method of using fixed voltage thresholds for warning, the proposed method offers a practical solution that can timely address the issue of low power supply voltage in wireless sensor networks.

Nature of transient currents and voltages in the power chain for a Highly Segmented Fast Detector run by Low Voltage Power Supply

Supplying power at low voltage to the front-end electronics of very fast and highly segmented detectors, typical in the experiments at the Large Hadron Collider, involves several issues, including transient currents and voltages. This study investigates a power chain that involves long cables, DC-DC converters, and input filters. Due to the presence of a common ground close to the input of the DC-DC converter, the power chain can run with a lower value of the input supply. It is seen that the capacitor in the input filter plays a significant role in the process of voltage growth at the input of the DC-DC converter. The effects of the ramp during turning ON and OFF the input supply have been studied thoroughly. It is observed that the voltage/current spikes are reduced due to the application of the ramp. It is also observed that the current/voltage, both at the input and the output of the DC-DC converter, goes through some intermediate oscillations due to the existence of threshold voltage for the converters. The choice of the ramp is critical in reducing spikes and should be incorporated into the power supply.

Design of a universal apparatus for heat treatment of meat and vegetable cooked and smoked products with the addition of dried semi-finished products of a high degree of readiness to the recipe

The object of the study is the process of smoking a molded meat-vegetable product with the addition of a dried semi-finished product of a high degree of readiness based on Jerusalem artichoke, zucchini, and carrots. Combined health products will satisfy the demand of end users for functional products of the new generation and will solve the technological problems of manufacturers in accordance with European competitiveness procedures. They will expand the offer of products with rational nutritional, taste, aesthetic characteristics that will meet the modern trends of craft producers, NoReCa business, and consumer expectations. A universal device for heat treatment of meat and vegetable products under hot and cold smoking conditions has been designed based on a film-like resistive electric heater of the radiating type. The device uses Peltier elements placed on the outer surface of the smoke generator and, at a temperature of 45 °C, they form a low-voltage power supply (~3...4 W) from the conversion of secondary heat. Cold smoking is carried out in the temperature range up to 25 °С, provided that the outer surface of the heater is covered with a coil heat exchanger through which the coolant passes. During hot smoking, the air medium is in the heat exchanger (additional thermal insulation of the chamber). The uniformity of the temperature field of the meat-vegetable product (meatloaf with a diameter of 0.08±0.01 m) during hot smoking has been confirmed, provided that the center of the loaf reaches 65 °C and the total duration of the process is 5.5 hours. The introduction of dried semi-finished products of a high degree of readiness into the recipe of meat loaves increases the yield of the product by 18 % and the mass fraction of protein by 25 %. The moisture retention capacity of the experimental meat product increases by 11 % with a 33 % decrease in calorie content, which indicates an improvement in its quality indicators compared to the analog

Easy-to-install battery storage based residential power supply with contactless power transfer

Solar energy with battery storage has enormous potential for residential power supply applications. However, the installation is often complicated with lots of wiring. The wireless power transfer (WPT) interface can greatly reduce the complicated wiring part, facilitating easier installation, with additional benefits like electrical isolation, lower maintenance cost, better reliability. However, rigorous proof-of-concept of WPT for LV household power supply still remains to be largely unexplored. This work fills the research gap by presenting application of contactless power transfer system with battery storage for the solar-powered low-voltage (LV) power supply. Various resonant topologies for inductive power transfer (IPT) are studied, and a complete theoretical model of an LCL compensated IPT system integrated with a battery energy storage system is presented. The voltage and current characteristics are investigated to understand the operation of the proposed integrated IPT system at LVDC level. The setup is first realized and analysed in details in simulation using MATLAB/Simulink. Hardware experiments proves the feasibility of the contactless power transfer capability at the high efficiency of the integrated IPT battery system. The results show that the proposed system can maintain a constant load voltage of 48 V for a load variation of around 25%, with an efficiency of 92% at 85 kHz switching frequency.

Junctionless-accumulation-mode stacked gate GAA FinFET with dual-k spacer for reliable RFIC design

This study investigates how incorporating a dual-k spacer (SiO2 + HfO2) affects the RFIC design feasibility of a junctionless-accumulation-mode (JAM) stacked-gate (GS) gate-all-around (GAA) FinFET in the sub-10 nm range. The proposed device is compared with a conventional FinFET and those without a spacer, air, and a single-k spacer (SiO2). At a low voltage power supply, fringing field effects raise the proposed device's on-current by 35.34% and reduce the off-current by more than 76 times compared to conventional FinFET, thereby improving electron velocity, energy band profiles, transconductance, device efficiency, etc. Thus, the proposed device is well-suited for high-performance CMOS circuits. Further investigation shows that integrating a dual-k spacer reduces the output conductance, which boosts the intrinsic gain and early voltage by five times the value recorded for conventional FinFET. Although the cut-off frequency drops by 15.98%, the GTFP and GFP soar by 475.67% and 352.25%, respectively. Consequently, JAM-GS-GAA FinFET with dual-k spacer is an encouraging device for low-power RFIC circuits.

AGATA: mechanics and infrastructures

The successful operation of AGATA requires a complex mechanical support structure for the safe and reliable operation of the detectors. Three mechanical structures were designed for the scientific campaigns at LNL, GSI and GANIL, each accommodating an increasing number of detectors. The present phase of the project, to increase the number of detectors from 60 to 180 (the 4pi spectrometer), required a new concept in mechanical support. The detectors also require a suite of associated instrumentation, infrastructures and good system design for their optimum performance. This includes the automatic liquid nitrogen filling system, high and low voltage power supplies, and a series of signal cables and distribution systems. A well-designed electromagnetic compatibility across all the sub-systems is essential. An additional requirement is an easily accessible database that records the status of the wide range of components utilised on the project. This article describes all aspects of the mechanics and infrastructures.

A New Electronically Tunable Transimpedance-Mode OTA-Based First-Order Universal Filter and its Quadrature Oscillator Application

This paper suggests a new operational transconductance amplifier (OTA) based electronically tunable transimpedance-mode first-order universal filter (FOUF). The suggested FOUF produces all-pass (AP), high-pass (HP) and low-pass (LP) filter responses simultaneously. It employs three OTAs, two grounded resistors and only one grounded capacitor. Owing to use of grounded passive elements, the suggested FOUF is suitable for integrated circuit implementation. It operates at low power supply voltages. Additionally, the resonance frequency of the suggested AP filter can be adjusted in a wide frequency range. However, the suggested FOUF consists of only one matching condition. Moreover, a sinusoidal quadrature oscillator (QO) application that is derived from the suggested FOUF topology is given. The suggested FOUF and its QO application are simulated by using 0.18-[Formula: see text]m TSMC technology parameters in the SPICE program to validate the presented theory. Finally, an experimental test is performed to demonstrate workability of the suggested AP filter.

Active Disturbance Rejection Control of Five-Phase Motor Based on Parameter Setting of Genetic Algorithm

Five-phase induction motors have the characteristics of high torque density, low torque ripple, and flexible control, making them suitable for medium- and low-voltage power supply situations. However, with the expansion of application scenarios, five-phase motors need to cope with increasingly complex operating conditions. Five-phase motors for propeller propulsion will face various complex sea conditions during actual use, and five-phase motors for electric vehicles will also face various complex road conditions and operating requirements during use. Therefore, as a propulsion motor, its speed control system must have strong robustness and anti-disturbance performance. The use of traditional PI algorithms has problems, such as poor adaptability and inability to adapt to various complex working conditions, but the use of an active disturbance rejection controller (ADRC) can effectively solve these problems. However, due to the significant coupling between the variables of induction motors and the large number of parameters in the ADRC, tuning the parameters of the ADRC is complex. Traditional empirical tuning methods can only obtain a rough range of parameter values and may have significant errors. Therefore, this paper uses ADRC based on genetic algorithm(GAADRC) to tune the parameters of the control and design an objective function based on multi-objective optimization. The parameters to be adjusted were obtained through multiple iterations. The simulation and experimental results indicate that GAADRC has lower startup overshoot, faster adjustment time, and lower load/unload speed changes compared to the empirically tuned PI controller and ADRC. Meanwhile, using a genetic algorithm for motor ADRC parameter tuning can obtain optimal control parameters while the control parameter range is completely uncertain; therefore, the method proposed in this paper has strong practical value.

Long-term outdoor performance of grid-connected photovoltaic power plant in a desert climate

In this paper, a 2.25 kWp grid integrated with the tied solar park has been implanted in the Renewable Energy Applied Research Unit (URAER) in a dry and harsh desert region. The PV plant uses micromorph thin-film solar modules (a-Si/μc-Si) technology. The photovoltaic module systems (PVS) were evaluated from May 2015 to December 2020 (around five and a half years of operation), and the electricity was injected into the internal network of the low-voltage power supply. Performance evolution has been conducted in this work as stated by the IEC61724 guideline. The monthly and annual performance indicators analyzed and assessed consist of reference yield, array yield, final yield, system losses, capture losses, PV module efficiency, system efficiency, inverter efficiency, capacity factor, and performance ratio. The annual electricity production is 3688.28 kWh, 3188.25 kWh, 3306.28 kWh, 3136.05 kWh, and 2952.81 kWh for 2016, 2017, 2018, 2019, and 2020 operating periods, respectively. The solar park's total produced energy yield over the monitored period and the quantity of CO2 emissions avoided are 16,271.67 kWh and 14.17 tons, respectively, which can significantly contribute to and help in purifying the environment from pollution. In addition, the energy results produced by the PVS were compared to those found by the four widely used PV simulation tools (PVsys, PVGIS, NREL's PVWatts® Calculator and Solar Med-Atlas). Furthermore, this work investigates and quantifies the degradation phenomenon of solar PVS power output after five years and a half years of outdoor exposure. There is around 0.22 % degradation per year. When this rate was compared to other studies conducted worldwide, it was shown to be highly appropriate. Technical-economic research was also conducted, revealing that the system's PVS period, which establishes its sustainability, is between 9 and 12 years. The results demonstrate that micromorph thin-film modules perform better and are more efficient under harsh real-world outdoor environmental conditions. Inventux modules preserve most of their better performance even with increasing module temperature. This kind of PV module technology is low-insensitive to the highest PV module temperature. Compared to the literature, micromorph thin-film technologies are better and preferable than crystalline modules under desert environmental conditions. The results also indicate that grid-connected solar park plants using this kind of technology are feasible in the hot arid climate to produce electricity and may participate in future energy projects in the country.

On load voltage regulating device of long-distance mine low-voltage power supply system based on solid-state voltage regulator

In order to solve the problem of voltage loss caused by long-distance power supply system, considering the solid state power boost (SSPB) of solid-state voltage regulator, this paper proposes an on load voltage regulating device for long-distance mine low-voltage power supply system based on solid-state voltage regulator, which aims to solve the problem of voltage loss and fluctuation caused by line voltage drop and coal mining equipment startup and shutdown. Firstly, the terminal voltage of the line is deduced through the mathematical model of the motor under different working conditions, and a terminal voltage prediction algorithm is proposed, which calculates the terminal voltage state according to the electrical parameters at the head side of the substation; Then, an on load voltage regulation technology based on solid-state voltage regulator is designed and implemented, which compensates by controlling the output voltage of the inverter in series into the first end of the line. When the motor is in rated operation and start-up and stop stages, the motor voltage operates within a reasonable range; Finally, the simulation model of on load voltage regulation technology is built by using MATLAB/SIMULINK software, and the feasibility of this technology is verified by different experimental settings.

99%, 15W/cm&lt;sup&gt;3&lt;/sup&gt; Capacitively Coupled Modular DCPET for Low-Voltage DC Power Supply Systems

99%, 15W/cm&lt;sup&gt;3&lt;/sup&gt; Capacitively Coupled Modular DCPET for Low-Voltage DC Power Supply Systems