Voltage Generator Research Articles

Energy harvesting and ANFIS modeling of a PVDF/GO-ZNO piezoelectric nanogenerator on a UAV

Abstract The aim of this study is to energy harvesting and modeling from a soft and flexible nanogenerator based on nanofibers (PVDF/ZnO-RGO) on the arm of a multi-rotor UAV. The nanogenerator modeling was done to improve the usability of piezoelectric nanogenerators to provide part of the electric energy required by drones. Tests were conducted on the experimental setup and practical flight conditions. In each test and a period of 30 s, the vibration signals of the UAV arm were stored, and the vibration data extracted in the time domain and the electrical voltage of the nanogenerator were obtained through the vibrations of the drone, and its values were recorded in each experiment. After signal processing, the best vibration features were used for modeling. In the modeling process, some data were considered for training and testing in ANFIS network. The ANFIS inputs included the selected vibration features and the outputs included the stored voltage. The modeling results were analyzed based on increasing the amplitude of vibrations and the duration of exposure of the nanogenerator to vibration led to higher voltage generation. The maximum voltage recorded during the 30-s flight time of the tested UAV was 64 mV at 3.54, 49.8, and 0.48 Hz along the x, y, and z axes, respectively. The results showed that the application of energy harvesting on different vibration systems could be improved through modeling. It can be used to predict the amount of electric energy produced according to the vibrations of the drone in the future.

Synergistic optimization of the water state and transport pathway in hydrogels via pullulan and directional Freezing-Assisted salting out for efficient evaporation

Improving the evaporation efficiency of solar-driven hydrogel evaporators is crucial for addressing water scarcity. Traditional efforts have been focused on increasing the intermediate water content or shortening the evaporation route through hydrogel structure design. However, rare attempts have been made to combine these two approaches. Here, we report the simultaneous achievement of high intermediate water content and short water transport paths in a hydrogel for efficient solar-driven evaporation. By introducing pullulan and MXene nanosheets into a poly(vinyl alcohol) (PVA) system that is subjected to directional freezing-assisted salting-out, we achieve a considerably high intermediate water to free water ratio of 2.11. Meanwhile, low- tortuosity yet compact channels within the hydrogel formed during directional freezing-assisted salting-out accelerate water transport during evaporation. Consequently, the hydrogel evaporator achieves an energy conversion efficiency of 93 % under one sun illumination, with a high vapor generation rate of 3.92kg m−2h−1. Even in highly saline water, an evaporation rate of 2.93 kg m−2h−1 is preserved, accompanied by voltage generation through water-driven ion migration. Moreover, the hydrogel evaporator can be recycled by heating using the remoulade properties of PVA without deteriorating the evaporation rate, holding great potential in sustainable and recyclable water collection.

Enhancing visible light absorption of form-stable CH3COONa·3H2O composite phase change material and its application in thermoelectric power generation

The utilization of Phase Change Material (PCM) for solar heat storage represents an effective solar energy storage method. Nevertheless, this promising technology encounters several obstacles, particularly PCM leakage and dissatisfied solar absorptance. This study focuses on the development of a photothermal conversion composite PCM tailored for solar energy storage and its subsequent integration into a thermoelectric power generation system. The composite PCM was synthesized using an evaporation-impregnation method, with melamine foam (MF) serving as the adsorbent material, graphene oxide (GO) as the light-absorbing component, and sodium acetate trihydrate (SAT) as the thermal storage medium. It is shown that the MF demonstrates an exceptional adsorption capacity for SAT, whose mass fraction exceeds 99 % in the final composite. The composite PCM exhibits a remarkable melting enthalpy of 251.5 J/g, comparable to that of pure SAT. The integration of GO into MF/SAT improves the solar absorptance of the composite, elevating it from 23.3 % to 81.5 %, thereby enhancing the photothermal conversion performance. To assess the practical solar energy storage potential of the prepared PCM, a thermoelectric power generation system was designed and underwent a continuous 22-hour performance test in a real outdoor enviornment. The results reveal that the system is able to maintain voltage generation for about 10 hours after the sun disappears. This proves the superior photothermal conversion and heat storage capabilities of the prepared materials. This research offers a viable approach for direct solar energy storage and conversion to electricity, advancing renewable energy technologies.

Low‐Power Charge Trap Flash Memory with MoS2 Channel for High‐Density In‐Memory Computing

AbstractWith the rise of on‐device artificial intelligence (AI) technology, the demand for in‐memory comptuing has surged for data‐intensive tasks on edge devices. However, on‐device AI requires high‐density, low‐power memory‐based computing to efficiently handle large data volumes. Here, this study proposes a reliable multilevel, high gate‐coupling ratio memory device with MoS2 channel tailored for high‐density 3D NAND Flash‐based in‐memory computing. The MoS2 channel, featured by its small bandgap and high‐mobility, facilitates reliable memory window of approximately 8 V thanks to erase operation through hole injection. This not only suppresses vertical charge loss but also alleviates the burden on voltage generator circuits, indicating the suitability of MoS2 as channel material for 3D NAND Flash architecture. Additionally, a low‐k (≈2.2) tunneling layer deposited via initiated chemical vapor deposition increases the gate‐coupling ratio, thereby reducing the operating voltage. Utilizing Au nanoparticles as the charge storage layer, MoS2 memory devices show synaptic plasticity with 6‐bit, endurance (104 cycles), read disturbance (105 cycles), and retention times (105 s). Furthermore, device‐to‐system simulations for neural networks based on MoS2‐memory devices have successfully achieved a fingerprint recognition of 95.8%. These results provide the foundation to develop multi‐bit MoS2‐memory devices for AI accelerators and 3D NAND Flash memory.

Preliminary Verification of the PHITS Code Applicability to Conversion Efficiency Calculation of Direct Charge Nuclear Battery

A direct charge nuclear battery, or DCNB, is one of the nuclear batteries based on direct energy conversion and is characterized by exceptional high voltage generation and conversion efficiency higher than other nuclear batteries. For studying potential applications of DCNB, a preliminary estimation of DCNB electrical power and performance is required; hence, conversion efficiency analysis is crucial. For preliminary verification purposes, an ideal DCNB conversion efficiency was calculated under the simplified electron transport model by using the general-purpose Monte Carlo particle transport calculation code PHITS. The result was compared with a reference experimental efficiency for a T-loaded parallel plate DCNB, and the resulting relative error was approximately 12%. Considering the relative error of 20% or less in DCNB conversion efficiency shown by preceding studies, the resulting error was comparable, and it was concluded that the PHITS code is sufficiently applicable to DCNB conversion efficiency analysis.

Non-Linear Phenomena in Voltage and Frequency Converters Supplying Non-Thermal Plasma Reactors

Atmospheric pressure cold plasmas have recently been the subject of intense research and applications for solving problems in the fields of energy, environmental engineering, and biomedicine. Non-thermal atmospheric pressure plasma sources, with dielectric barrier discharges, plasma jets, and arc discharges, are non-linear power loads. They require special power systems, which are usually designed separately for each type of plasma reactor, depending on the requirements of the plasma-chemical process, the power of the receiver, the type of process gas, the current, voltage and frequency requirements, and the efficiency of the power source. This paper presents non-linear phenomena accompanying plasma generation in the power supply plasma reactor system, such as harmonic generation, resonance, and ferroresonance of currents and voltages, and the switching of overvoltages and pulse generation. When properly applied, this can support the operation of the above-mentioned reactors by providing improved discharge ignition depending on the working gas, thus increasing the efficiency of the plasma process and improving the cooperation of the plasma-generation system with the power supply.

Research of the regulator of an expander-generator unit

The relevance of research is determined by the tasks of increasing the efficiency of alternative and renewable energy power plants. The purpose of the work is to develop a method of coordinating the settings of the automatic excitation regulators and the speed of rotation of the rotor of the generator from the vortex installation of the expander-generator unit, which is part of the autonomous power consumption network. To achieve the goal, the methods of mathematical modelling in the MATLAB environment, physical modelling, processing of experimental data, theory of automatic control, theory of magnetic field, theory of electric machines, programming of microprocessor devices were used. Considering the need to expand the base of alternative energy sources, the task of controlling the energy plant for the utilization of excess pressure of gas transportation networks was considered. The study of the regulator of the expander-generator unit was based on a model reflecting the interaction of mechanical and electrical processes. A set of nonlinear differential equations corresponded to the description of these processes. Accurate consideration of nonlinearities of the considered control object complicates the implementation of the corresponding microprocessor control systems. Modelling is aimed at achieving a compromise between the required accuracy of object control and the possibilities of simplifying the object control structure. The use of experimental and datasheet data of the devices made it possible to evaluate the dynamics of turbine rotation and voltage generation, forming the factors for the untying of the control circuits. The use of MATLAB with the Lookup Table option made it possible to perform a multi-point linearization of the nonlinear description of the process, speeding up the modelling and adjustment of the regulator. This is important to incoordinate the settings of the frequency control loops and the output voltage, given the trade-off between the speed of the regulator and the minimization of oscillations in the generation frequency. Based on the obtained results, a regulator of the expander-generator unit was developed, which ensures the stabilization of the initial parameters of the unit under the conditions of electrical load disturbances. In practice, the obtained data can be used in the integration of renewable energy sources into the general energy system through the optimization of the operation of generators

Integrating electrochemically-assisted anaerobic reactors with conductive media for enhanced methanation of greywater

The utilization of bioelectrochemical systems is critical for the generation of methane via anaerobic digestion, and the process is influenced by the applied potential. The trajectory of biogas generation in five batch reactors showed important implications for methane production by synergistic effects of electric fields and conductive media allowing for attached growth of microorganisms. Synthetic greywater which is effective water source converts into methane within 5 days of reactor operation. The experiments emphasized that substrate availability enhanced the attached growth of microorganism in anaerobic settings. Reactor R2, with no microorganism-growing surface, produced only 20 % of the methane produced by reactor R3, which contained Polyvinylidene fluoride (PVDF) media. The presence of current (0.5 V) increased CH4 by 1.35 times in case of non-conductive media (R3) and 1.6 times in conductive media higher than without external voltage. The study indicated a direct correlation between applied voltage and methane generation up to 1.0 V. The ratio of CO2/CH4 changed from 1.16 at 0 V (R1) to 0.362, 0.32, 0.267 and 0.296 for R2-R5 at 1.0 V, respectively. Regardless of surface conductivity, the presence of media for attached microbial growth was favorable for the slow growing methanogens. However, high throughput RNA sequencing showed that electrotrophic methanogens were more abundant with conductive media than non-conductive media under electric fields.

Decentralized Virtual Impedance Control for Power Sharing and Voltage Regulation in Islanded Mode with Minimized Circulating Current

In islanded operation, precise power sharing is an immensely critical challenge when there are different line impedance values among the different-rated inverters connected to the same electrical network. Issues in power sharing and voltage compensation at the point of common coupling, as well as the reverse circulating current between inverters, are problems in existing control strategies for parallel-connected inverters if mismatched line impedances are not addressed. Therefore, this study aims to develop an improved decentralized controller for good power sharing with voltage compensation using the predictive control scheme and circulating current minimization between the inverters’ current flow. The controller was developed based on adaptive virtual impedance (AVI) control, combined with finite control set–model predictive control (FCS-MPC). The AVI was used for the generation of reference voltage, which responded to the parameters from the virtual impedance loop control to be the input to the FCS-MPC for a faster tracking response and to have minimum tracking error for better pulse-width modulation generation in the space-vector form. As a result, the circulating current was maintained at below 5% and the inverters were able to share an equal power based on the load required. At the end, the performance of the AVI-based control scheme was compared with those of the conventional and static-virtual-impedance-based methods, which have also been tested in simulation using MATLAB/Simulink software 2021a version. The comparison results show that the AVI FCS MPC give 5% error compared to SVI at 10% and conventional PI at 20%, in which AVI is able to minimize the circulating current when mismatch impedance is applied to the DGs.

In vivo calcium and voltage mapping of the zebrafish heart

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Research Foundation Flanders (FWO) Purpose Inherited cardiac arrhythmias are characterized by a disturbance in the normal electrical functioning of the heart due to a dysfunction of cardiac ion channels, accessory proteins and/or structural components. This complex process is difficult to model in vitro, while in vivo mouse models differ substantially from humans with regards to cardiac electrophysiology. Thus, there is a need for alternative disease models in cardiac arrhythmia research. The zebrafish heart shows remarkable similarity to humans in its electrocardiogram and action potential (AP) morphology. Due to the optical translucency of zebrafish larvae, it is possible visualize the cardiac calcium and voltage dynamics across their entire hearts in vivo by use of genetically encoded calcium and voltage indicators (GECI and GEVI). We combined the fast kinetics of a next generation voltage reporter (Ace2N-mNeon) with a spectrally compatible calcium sensor (R-GECO) to create a sensitive high throughput method for in vivo characterization of the cardiac AP. Methods Ace2N-mNeon and R-GECO were expressed under control of a myocardial specific promoter via the Tol2kit system. The effect of sensor expression on normal physiology was assessed by patch clamp experiments. Fluorescence recordings were obtained with a Leica SP8 DLS microscope and a custom-built light sheet microscope. Our zebrafish sensor line was validated by experiments with quinidine drug exposure, as well as a novel model for long QT syndrome (LQTS) with a knock-in (KI) mutation in the cacna1c gene. Results Sensor expression did not significantly alter cardiac electrophysiology. The tg(myl7:Ace2N-mNeon/R-GECO) line demonstrated alterations in the heart rate, depolarization and repolarization induced by quinidine exposure. We observed a significantly prolonged ventricular repolarization in the LQTS KI line. Three-dimensional optical maps of AP characteristics across the entire zebrafish heart exhibited the physiological characteristics of the zebrafish cardiac electrophysiology, with activation initiated at the atrial venous pole and propagated towards the ventricular outflow tract, prolonged repolarization in the ventricles compared to the atria and slowed depolarization in the atrio-ventricular canal. Conclusion By expressing Ace2N-mNeon and R-GECO in the zebrafish heart, we were able to accurately detect drug- and mutation induced alterations in the cardiac AP, as well as AP characteristics across the entire heart, without compromising normal cardiac electrophysiology. Our transgenic line will provide a promising assay for future studies of cardiac arrhythmia.

Real-time analysis of voltage and frequency regulation of self-excited induction generator based micro hydro plant using generalized impedance controller

– The self-excited induction generator (SEIG) is well accepted for application in micro hydropower plants. However, in the edge-of-grid application it exhibits a limitation in its capacity to sustain the desired terminal voltage along with the frequency of variations in the prime mover's speed and load. Terminal voltage and frequency regulation are significant concerns for such schemes, and many such techniques are available to regulate the same. This paper presents a closed-loop control technique based on a generalized impedance controller (GIC) responsible for the impedance-controlled functioning of the pulse width variation voltage source converter (PWM-VSC) to regulate frequency and terminal voltage of machine with various loading conditions. A coupling transformer is connected between GIC and SEIG, and the ratings of GIC and transformer should be the same as SEIG, as GIC must compensate for the entire SEIG output. Three phase, 2.2 kW, 415 V, 4.8 A, 50 Hz SEIG, and a three IGBT-based voltage-sourced inverter with coupling transformer, are modelled in MATLAB environment. SEIG frequency and voltage effects in response to the GIC modulation index and phase angle are investigated in the real-time environment using the OPAL-RT (ver. OP4510) environment. The voltage and frequency are controlled using the proposed SEIG-GIC scheme, and the simulation results achieved from MATLAB/Simulink were validated with real-time observations.

Direct calibration of a true-rms ac voltmeter against a He-free pulsed Josephson standard

Starting from 2019 a new central role is played by quantum standards, owing to the redefined SI, where electrical units are directly linked to the fundamental constants e (elementary charge) and h (Planck constant). Thus, metrologists are nowadays trying to extend the astonishing accuracy attainable in dc measurements to ac and beyond, moving towards calibrations aiming quantum ac voltage generation. Programmable Josephson Voltage Standards are nowadays capable of fulfilling primary metrology requirements only for stepwise-approximated voltage signals up to few hundreds Hz. Pulsed Josephson standards are instead capable of generating arbitrary waveforms at higher frequencies, so are generally called Josephson Arbitrary Waveform Standards (JAWS). Despite of the lower attainable voltage, JAWS are very promising and are the subject of intense research activity. In particular, the capability of generating high spectral purity signals allows high accuracy measurements especially at the low voltage levels (<100mV rms), which are challenging to be performed by the traditional ac-dc transfer difference using thermal converters. We report in the following about our setup for quantum-based calibrations of a true-rms ac voltmeter with low uncertainty, first results obtained and unsolved issues.

A new single switch universal supply voltage DC-DC converter for PV systems with MGWM-AFLC MPPT controller.

The present power generation government companies focus on Renewable Power Sources (RPS) because their features are zero carbon footprint, unlimited power source, fewer greenhouse pollutants, fewer output wastages, plus creatinga very healthy atmosphere. In this work, the sunlight source is utilized for the Photovoltaic (PV) standalone network. The merits of sunlight sources are very optimal human resources needed, unlimited natural sources, plus easy operation. However, the solar power resource is nonlinear fashion. As a result, the operating point of the sunlight network fluctuates concerning sunlight intensity. So, in this article, the Modified Grey Wolf Methodology with Adaptive Fuzzy Logic Controller (MGWM-AFLC) is introduced to maintain the operating point of the sunlight system at the global power point position of the PV array. This controller traces the MPP with very low fluctuations in the PV-produced voltage. The advantages of this proposed method arefewer sensing devices required, less difficulty in development, more useful for rapid changes inthe sunlight temperatures, simpler to realize operation, greater economic growth, plus highly useful for household applications. The sunlight set-up generation voltage is lowwhich is improved by introducing the new Wide Power Rating High Voltage DC-DC Boost Converter (WPRHVBC). The features of this WPRHV converter are low voltage strain on semiconductor devices, few passive elements are enough to develop the circuit, plus easy understanding.

Gas classification by an electronic‐nose prototype based on a single gas sensor with novel temperature modulation

AbstractAn electronic nose prototype based on the novel temperature‐modulation technique is developed, where the heater voltage changes its amplitude and frequency periodically. The system comprises a sensor analog front end and a digital processing part including a heater voltage generator and a sensor data transmitter, where the digital part was implemented by a field programmable gate array. The fabricated prototype successfully generated the modulated heater waveform and synchronously acquired sensor responses at a sampling rate of 10 kHz. Whereby, sensor responses to the test gases of volatile organic compounds were collected. Gas classification was achieved with an accuracy of 99.6% based on the data obtained by the prototype, demonstrating the promising properties of the prototype as a compact and highly precise electronic nose.

Analytical and Numerical Approach for Performance Evaluation of Thermoelectric Generator

Growing demands in energy requirement need more efficient methods to recover waste energy from various energy conversion systems, among them generator set (Genset) run by diesel engines in construction and mining areas are commonly used to generate electrical energy and usually these systems work at an efficiency of around 30-35 %. A large part of energy loss in these systems is resulted from heat carried away by coolant and exhaust gases. The energy lost in the form of heat in the exhaust can be harvested using various heat recovery methods like Thermoelectric Generators [TEG]. Thermoelectric generators are used to convert thermal energy into electrical energy governed by the principle of Seebeck effect. Present work draws attention towards external factors that influence the output voltage of thermoelectric generators attached to a stationary waste heat source like Gensets. Here thermoelectric generator units were modelled by attaching them to the exhaust manifold of pipe of a diesel Genset and were analyzed both analytically and numerically to obtain their dependence of output voltage on thermal conductivity of exhaust pipe material, where TEGs can be mounted. From the analysis of obtained report it was observed that efficiency of waste heat recovery improved on using higher thermal conductive materials. In this preliminary analysis, an increase in thermal conductivity of 20% has resulted in an increase in power output of 11%.

Improvement of the Transient Stability of Grid Connected Microgrids Including Inverter Based DGs Using DSTATCOM

Microgrids are becoming popular because they can meet the needs of people who want energy from natural sources and are using more and more energy. Itis important to emphasis on numerous safety and control features of a microgrid. During the change from following the grid to forming the grid, the instability of frequency and voltage due to control problems becomes the main concern. Then, the paper uses a method to control the frequency and voltage of power generators so they can share power efficiently. Furthermore, we are suggesting a way to handle situations when there is not enough control and to keep the system strong. We are proposing a method to prioritize and shed different parts of the system in three stages to help with this. The effectiveness of the method depends on how quickly the system reacts and is calculated based on the changing speed of the frequency. The process combines the battery capacity system and D-STATCOM in the microgrid to provide a reliable power supply to customers for a long time without sudden power cuts. We test the proposed procedures on a smaller version of an IEEE 13-bus microgrid using MATLAB. We recreate the time-domain to see if the procedures work well.

Nonlinear Energy Harvesting From a Base Excited Size-Dependent Flexoelectric Nanostructure with Off-Center Rigid Tip Mass Subjected to Axial Pulsating Excitation

This study explores the incorporation of flexoelectricity and size-dependence effects in electricity harvesting from a novel nanostructure. This nanostructure, featuring a cylindrical-shaped rigid tip mass, is stimulated at the base with axial pulsating excitation. Designed with a nanobeam material, the energy harvester accounts for structural nonlinearity, flexoelectricity, and the presence of an off-center rigid mass, operating under multiple excitations. The eigenanalysis is employed to delve into the dynamic characteristics of the system, providing engineers with insights to identify safe operating regions and operational constraints. Additionally, perturbation techniques are utilized to estimate steady-state voltage and power characteristics, with a focus on maximizing voltage and power generation. The study underscores the impact of size dependence on nanoscale design, flexoelectricity, asymmetric tip mass, and various excitation parameters within a constrained operating range. Analysis reveals how saddle-node and pitchfork bifurcations can disrupt energy harvesting performance and suggests strategies for mitigating these issues by adjusting operational parameters. Moreover, the study emphasizes the significant role of the off-center rigid tip mass in energy estimation compared to conventional microstructure-based energy harvesters. Analytical findings are rigorously validated against numerical results under different resonant scenarios, showcasing the accuracy of the analytical approach in capturing nonlinear sources and optimizing energy harvesting from nanostructures.

Studies on Cr (VI) removal by constructed wetland integrated microbial fuel cell: Effect of electrodes

Heavy metal contamination significantly threatens human health and the environment, even at low concentrations. Among these metals, hexavalent chromium (Cr (VI)), primarily originating from mining activities, stands out as a significant concern. The Constructed Wetland-Microbial Fuel Cell (CW-MFC) represents an engineered solution inspired by natural wetlands. This study presents a novel approach to utilizing cement-graphite (CG) electrodes in CW-MFC to reduce Cr (VI). In this study, Cr (VI) spiked synthetic wastewater (25 mg/L to 100 mg/L) was treated using CG-CW-MFC (Cement-Graphite) and G-CW-MFC (Graphite) systems, at a constant hydraulic retention time of 48 hours. The results indicated that both CG-CW-MFC and G-CW-MFC exhibited a removal efficiency of 99% for Cr (VI). COD removal rates for CG-CW-MFC and G-CW-MFC ranged from 89% to 94% and 82.5–91.35%, respectively. Meanwhile, CG-CW-MFC showed stable voltage generation at 100 mg/L of Cr (VI) (Average voltage 191.45 mV), while G-CW-MFC showed a steep reduction in voltage generation with an average voltage of 1.48 mV. Thus, the study concludes that, in contrast to the G-CW-MFC electrode, the CG electrode can generate voltage under highly hazardous conditions because of the porous structure of CG. The findings of this study highlight the potential of CG electrodes in CW-MFC systems designed to remediate wastewater contaminated with Cr (VI).

SCADA implementation in microhydro power plant control and monitoring systems of screw turbine type

Screw turbine-type micro-hydro power plants are still controlled manually by humans when there is a change in the electrical load on the generator output. If there is a change in the electrical load, the generator output voltage will change, thus affecting the rotation of the turbine being used. In this case, humans are needed to manually regulate the flow of water entering the turbine to maintain the stability of the generator output voltage by controlling the sluice gate. The water discharge entering the screw turbine will rotate the generator through a belt/gearbox pulley transmission, thus producing an electrical voltage at the generator output. To maintain the stability of the generator output voltage, it is necessary to control the water discharge entering the screw turbine. The expected goal of this research is to design a control system for a screw turbine type microhydro power plant to stabilize the generator output voltage and monitor the output of a screw turbine type generator using a SCADA (Supervisory Control, and Data Aquisition) system. The method used is the research and development method, namely the system design stage based on secondary data that has been collected, where the system design includes hardware design and software design, followed by making hardware such as control panels and devices. Software, which includes display design and leader diagrams and testing, is carried out by testing the system on software, hardware, and overall system testing. From the results of the discussion and analysis, the screw turbine type microhydro power plant control design system was created, a load control system consisting of 6 groups and sluice gate opening control that uses an ultrasonic sensor to determine the water level. With the results of controlling the sluice gate at a door opening of 30 mm, the generator voltage is 18.42 Volts DC, DC current is 0.0 Ampere at a load of 0 watts, when the load is 30 watts the generator voltage decreases by 18.40 volts, current is 1.37 Ampere. Through the on-line monitoring system, electrical parameters are obtained which are displayed on the SCADA system by looking in real-time at the history of DC voltage and DC current, DC power, and DC energy generated by the screw turbine-type DC generator. The voltage read is 18. 57 volts, current 1.37 Amperes, DC electrical power is 25.4 watts with a DC light load of 30 watts.

Updates on Impact Ionisation Triggering of Thyristors

High voltage (HV) generators are used in multiple industrial and scientific facilities. Recent publications have demonstrated that triggering industrial thyristors (relatively slow switching devices) in overvoltage mode, also called impact ionization mode, significantly enhances their dU/dt and dI/dt characteristics. This novel triggering methodology necessitates the application of substantial overvoltage between the thyristor’s anode and cathode, delivered with a swift slew rate exceeding 1 kV/ns. The adoption of compact pulse generators constructed from commercially available off-the-shelf components (COTS) opens up avenues for deploying this technology across various domains, including the implementation of high-speed kicker generators in particle accelerators. In our methodology, we employed commercially available high-voltage SiC MOSFETs along with a custom-designed fast gate driver. This driver was conceptualized based on the recent development of gate boosting techniques, featuring a driving voltage exceeding 600 V. The gate driver for these MOSFETs comprises three key components: a level-shifter with NMOS and PMOS transistors, a compact Marx generator with two avalanche transistors, and a GaN HEMT in a high input and low output impedance configuration. The proposed gate-boosting driver achieves a slew rate exceeding 1 kV/ns for the driving pulse. Furthermore, we demonstrate that with this driver, a 1.7 kV rated SiC MOSFET can produce an output pulse of 1.45 kV and a maximum slew rate of ≈2.5 kV/ns. This gate-boosting driver aims to minimize commutation times, achieves a slew rate of over 1 kV/ns, and handle higher loads, making it ideal for impact ionization triggering of industrial thyristors.