Beam-Plasma Stabilizer for the New Type of Nuclear Power Energy Systems

In this paper the electrokinetic characteristics of helium low-voltage beam discharge plasma in operating conditions of a three-electrode device with a hot cathode are studied. A method and a device are proposed to ensure effective voltage stabilization in a range up to 110 V by controlling the electron velocity distribution function using the plasma channel external boundaries.

Ensuring an effective voltage regime in the electrical network when powering ships of the technical fleet and floating objects from the shore

The article deals with topical issues of reducing the asymmetry of linear voltages in the electrical networks of water transport enterprises. Asymmetric modes in the electrical network are researched, which defined the need for automated determination of conductive electromagnetic disturbance. A mathematical description of the occurrence process and strategy for determining the conductive low-frequency electromagnetic disturbance by the voltage asymmetry coefficient in the reverse sequence are presented. The parameters of this coefficient are described: mathematical expectation, standard deviation, probability of occurrence during the calculation period. A mathematical model is obtained that represents a conductive electromagnetic disturbance and explains the probability of its occurrence. A method of automated determination of conductive electromagnetic disturbance has been developed. A software product is presented (certificate of registration No. 2016661752), which allows processing the voltage coefficients obtained as a result of measurements in the reverse sequence. The conductive disturbance is determined for the purpose of suppression and ensuring electromagnetic compatibility. To ensure an effective mode by powering ships from the shore and to increase the efficiency of power transmission, a strategy for voltage symmetry in the electrical network is presented.

A novel AlGaN/GaN heterostructure field-effect transistor based on open-gate technology

In this study, a novel AlGaN/GaN heterostructure field-effect transistor based on open-gate technology was fabricated. Sample transistors of different structures and sizes were constructed. Through measurements, it was found that by changing the width of the opening, the threshold voltage of the device could be easily modulated across a larger range. The open-gate device had two working modes with different transconductance. When the gate-source voltage VGS ≤ − 4.5 V, only the open region was conductive, and a new working mechanism modulated the channel current. Corresponding theoretical analysis and calculations showed that its saturation mechanism was related to a virtual gate formed by electron injection onto the surface. Also, the gate-source voltage modulated the open channel current by changing the channel electron mobility through polarization Coulomb field scattering. When used as class-A voltage amplifiers, open-gate devices can achieve effective voltage amplification with very low power consumption.

Electroconvection near an ion-selective surface with Butler–Volmer kinetics

We study the effects of interfacial kinetics on the electro-hydrodynamics of ion transport near an ion-selective surface using a combination of linear stability analysis and numerical simulation. The finite kinetics of the electrolyte–electrode interface affects the ion transfer and electroconvection in many ways. On a surface of fixed topography, such as a metal surface of slow and stable ion deposition or covered by a polymer membrane, the finite kinetics reduces the current in one-dimensional ion diffusion/migration, increases the critical voltage for the onset of the electroconvective instability, changes the dynamics of the electroconvection and the overlimiting current, and enhances the lateral ion diffusion within the interfacial layer. The first three effects are indirectly caused by the reaction kinetics and can be characterized by an effective voltage difference across the liquid electrolyte. In comparison, the last effect is controlled by a direct interplay between kinetics and nonlinear electroconvection. Scaling laws for ion transport and features of electroconvection are proposed. We also analyse the linear stability of a surface which evolves under ion deposition and find that the finite kinetics decreases the growth rate of both electroconvective and morphological instabilities and therefore modifies the wavenumber of the most unstable mode.

Reactive Power Compensation and Power Factor Correction by using Static VAR Compensator (SVC)

In this paper, a reactive power compensation system using static VAR compensator is presented. To confine on system stability and reliability, the reactive power compensation is the fundamental way forflexible AC transmission systems (FACTS). The variations of reactive power have an effect on thegenerating units, lines, circuit breakers, transformers, relays, and isolators. It can also cause effective voltage sags and increase losses. In the proposed system, the lead time between voltage pulse and curren pulse is measured and fed to the interrupt pins of the microcontroller where the program takes over to bring the shunt capacitors to the circuit to get the reactive power compensated. Back-to-back SCRs interfaced through optical isolation from the microcontroller are used in parallel for controlling the capacitor.

IoT high-frequency electronic transformer with dimmable output voltage using PWM signals

This work presents the design, simulation, and implementation of a low-power electronic transformer, which output effective voltage can be controlled wirelessly through WIFI, via a user interface on a mobile phone. The methodology used in this project consists of 4 stages, a rectifier, an inverter, the inverter’s control system, and a ferrite reducer. The inverter has a full-bridge design and was implemented using MOSFET. The control system can vary the frequency and duty cycle of the output signals, by phase shifting the control signals, thus achieving the functionality of reducing the effective output voltage. Circuit design simulations were performed using PsPice Orcad. The implementation and the mathematical model of the built electronic transformer are carried out. The designed transformer operates with a maximum input voltage of 120 Vrms at 60 Hz at frequencies between 20 kHz and 30 kHz, which are controlled through the user interface; can reduce a 120 Vrms 60 Hz input signal to an effective voltage between 10 Vrms and 20 Vrms at a maximum power of 50 W. This project presents the feasibility of developing electronic transformers with variable output voltage, remotely controlled using IoT technology.

Analisis Perencanaan Jarak Celah Udara Pada Generator Axial

The generator uses a permanent magnet so it does not require initial excitation to generate a voltage. The generator design is axial flux type, uses ceramic type permanent magnet (NdFeB), uses two flanking stator rotors. For electricity use, the AC voltage is changed to DC voltage using a rectifier for charging the accumulator. The air gap in the axial generator is the distance between the rotor and the stator. The air gap is also a place for the transfer of the magnetic field through the coil on the stator to produce a magnetic flux value that affects the induced voltage in the coil. The faster the rotation, the greater the voltage generated. This axial generator that has been designed can produce a frequency of ± 50 Hz, an effective voltage of ± 22 V when the air gap is 2 mm, the frequency measurement has an error of 10-20 Hz and an error percentage of 5-10%, with the results of measuring the induced current that has a large the same voltage.