A New Two Switched-Impedance Network for High Ratio Quasi-Z-Source Inverter

The increasing demand and widespread of renewable energy inherently compel the development of power electronics converter as an interface between consumers and the energy source/s. This paper presents a new two switched-impedance networks qZSI converter called High Ratio Two Switched-impedance quasi-Z-Source Inverter (HR2SZ-qZSI). Compared with the previous topology, this proposed HR2SZ-qZSI topology can achieve higher voltage gain with lower shoot-through duty ratio, and a higher boost factor. This paper also discusses comparative analysis between the previous topology and the proposed HR2SZ-qZSI topology. Furthermore, the simulation and experimental data are presented to prove the theoretical analysis of the proposed HR2SZ-qZSI topology. Despite the additional components needed, it accentuates that this proposed converter retains all features of qZSI: common ground point between the dc source and converter and smooth input current operation. Furthermore, almost all the devices rating including capacitor and diode voltage, and inductor current ripple are lower than the preceding relevant two switched-impedance qZSI family. Accordingly, this proposed HR2SZ-qZSI clearly a good power conditioning alternative for renewable generation system.

Analysis Design and Simulation of an Axially partitioned Dielectric loaded Bi frequency MILO

In this paper, a bi-frequency magnetically insulated line oscillator (MILO) was proposed and designed. The bi-frequency MILO proposed has two axially partitioned slow-wave interaction structures (SWS) and the second SWS is dielectric-loaded to create the frequency shift in the resonant frequency. The conventional MILO device design methodology was followed along with two SWSs separated by a segregation cavity. The dispersion relation of the dielectric-loaded SWS was calculated using an equivalent circuit approach. Furthermore, the cold analysis was carried out to find the energy stored in the different SWSs to validate the device oscillation frequency. The beam wave interaction behaviour and device RF output performance were investigated through 3D PIC (Particle-in-cell) simulation for typical diode voltage of 550 kV, and current 48 kA, respectively. Simulation results illustrate that the proposed MILO generates RF peak power of ~3.5 GW at frequencies 3.62 GHz and 3.72 GHz. The conversion efficiency of the device was ~13.25%.

Волновые эффекты в коаксиальном тракте при субнаносекундном переключении высоковольтного диода в режиме задержанного ударно-ионизационного пробоя

Theoretical analysis of wave processes in the coaxial line during subnanosecond switching of high-voltage pulse sharpening diode is presented. The relations between amplitudes of the incident, reflected and transmitted waves and experimentally measured voltages as well as between these voltages and triggering generator pulse are established. The effect of the diode voltage doubling before switching is calculated. On the basis of the obtained relations and experimental data the time dependence of the sharpening diode reflection coefficient is determined and the wave dynamics in the coaxial line during avalanche switching are reconstructed.

Comparison of collective accelaration of protons and deuterons in Luce diode with a polyethylene anode

Collective acceleration of protons and deuterons is compared in the same geometry of a Luce diode with a polyethylene anode at an accelerating diode voltage of 250 kV, current and pulse duration of relativistic electrons up to 30 kA and 90 ns, respectively. The accelerated ions were intercepted by B4C, BN, and AlN plates, in which analytical radionuclides were produced according to nuclear reactions 10B( p , α)7Be, 12C( p, γ)13N, 10B( d , n )11C, 12C( d , n )13N, 14N( d , n )15O and 27Al( d , p )28Al. The ion energy was determined according to the ratios of activity of the analytical radionuclides, while the number of accelerated ions was calculated from the number of induced nuclei of the radionuclides. It was found that the velocities of the main group of protons and deuterons were the same within the measurement error, and the average number of ions accelerated in one pulse was, on average, 3 times higher when protons were accelerated.

Angular Divergence of Electrons in Generating Two Ribbon Beams in a Single Accelerating Diode (Simulation, Experiment)

The paper presents the results of numerical simulation and experimental studies of the generation of two ribbon beams in an accelerating diode with magnetic insulation at a diode voltage of ~ 0.7 MeV and a current of 10 kA in it. Model-ing is implemented using the Particle CST Studio package. The experiments were conducted on the U-3 accelerator of the ELMI installation. In calculations with three-dimensional geometry corresponding to the experiments, the distribu-tion of electron velocities over the pitch angle at the exit of the beams from the diode under the conditions of an inho-mogeneous magnetic field with an induction of about 1 T was obtained. These calculated data were confirmed in an experiment in which, using a sensor with seven recording channels, a distribution function of the velocity of electrons with a characteristic width at half maximum of 0.03 rad was obtained. Using the GEANT4 software package in processing measurement results with this sensor gives confidence in the correctness of the obtained distribution function.

Modelling of High Frequency SIC MESFET for Optical Sensing Applications

The analysis and design of fabricated optical GaAs high frequency MESFET model was improved and also majority carrier concentration doping is improved in un flatted channel region. This result was proved with component of photo sensors. The diode voltage is produced at the metal semi conductor rectifying contact and its blocks current flow in one polarity of voltage. The Laplace’s equation is used to solve problematically under the absence of light in a place and interpretation state. This paper main intention is to develop the MESFET using the finite differences method and solve the under illumination. The simulation responses main improvement is bunch of charge particles in optical device, the channel charge particles are varied at various operating voltages and light and also the simulation result was plotted in X and Y direction respect of electric field. In here the simulated and plotted results was analyzed the optical component is purely affected with intensity of illumination.

Performance of 4H-SiC Bipolar Diodes as Temperature Sensor at Low Temperatures

In this paper we report on the performance of 4H-SiC bipolar diodes as temperature sensors far beyond 273K. The sensor is measured from 150K to 445K covering a temperature range of 295K. In this operating temperature range, the sensor characteristic VD-T is highly linear and it is dominated by the typical dependence of the p-i-n diode voltage on the temperature. The sensor sensitivity is -4.48mV/K for a diode current of 2nA with a maximum error of 4.3K across the full temperature range. Although 4H-SiC p-i-n are mainly focused on very high temperature applications, our analysis on the performance of bipolar diodes at low temperatures highlights its feasibility as temperature sensor for aerospace and high altitude applications where cryogenic temperatures are achieved.