Solidifying Power Electronics [Historical]

More than one century ago, in 1902, American engineer Peter Cooper Hewitt (1861\u20131921) derived the mercury arc-rectifier, enclosed in a glass bulb, from his mercury-vapor lamp of the previous year. He devised its use for feeding dc motors from alternating currents. As the first rectifier for power uses (two years before Fleming\u2019s diode and four before De Forest\u2019s audion [1]), the mercury arc-rectifier marked the birth of power electronics

New column configurations for pressure swing batch distillation I. Feasibility Studies

The feasibility of the pressure swing distillation in different batch column configurations is investigated. The method is based on the assumption of maximal separation. Besides studying the well known batch configurations (rectifier, stripper, middle vessel column) we also suggest two novel configurations such as double column batch rectifier and double column batch stripper. We also study the alternate application of a rectifier and a stripper

Three phase boost rectifier design

An electric power can be converted from one form to another form by using power electronics devices. The function of power electronics circuits by using semiconductor devices as switch is modifying or controlling a voltage. The goal of power electronics circuits are to convert electrical energy from one form to another, from source to load with highest efficiency, high availability and high reliability with the lowest cost, smallest size and weight. The term rectification refers to the power circuit whose function is to alter the ac characteristic of the line electric power to produce a “rectified”ac power at the load side that contain the dc value In this project, a study has done for the two types of rectifier topology of alternating current to direct current voltage of a three-phase boost rectifier with pulse width modulation (PWM) and a threephase boost rectifier with active power filter (APF). Power factor, shape distortion and voltage can be increased as much as seen through two types of this topology if it is connected to the non-linear loads in power systems. Three phase rectifier with pulsewidth modulation (PWM) is one of controlled rectifier consist six pulses divides into two groups which are top group and bottom group. For top group, IGBT with its collector at the highest potential will conduct at one time. The other two will be reversed. Thus for bottom group, IGBT with the its emitter at the lowest potential will conduct. This project also observes the current, voltage waveform and the harmonics component when the active power filter (AFC) placed in series with non-linear load. Type of rectifier used is uncontrolled rectifier. In this work MATLAB/SIMULINK power system toolbox is used to simulate the system Results of simulations carried out, the advantages and disadvantages, the increase in voltage and waveform distortion for the system under consideration can be show

A Single-Stage LED Driver Based on ZCDS Class-E Current-Driven Rectifier as a PFC for Street-Lighting Applications

This paper presents a light-emitting diode (LED) driver for street-lighting applications that uses a resonant rectifier as a power-factor corrector (PFC). The PFC semistage is based on a zero-current and zero-derivative-switching (ZCDS) Class-E current-driven rectifier, and the LED driver semistage is based on a zero-voltage-switching (ZVS) Class-D LLC resonant converter that is integrated into a single-stage topology. To increase the conduction angle of the bridge-rectifier diodes current and to decrease the current harmonics that are injected in the utility line, the ZCDS Class-E rectifier is placed between the bridge-rectifier and a dc-link capacitor. The ZCDS Class-E rectifieris driven by a high-frequency current source, which is obtained from a square-wave output voltage of the ZVS Class-D LLC resonant converter using a matching network. Additionally, the proposed converter has a soft-switching characteristic that reduces switching losses and switching noise. A prototype for a 150-W LED street light has been developed and tested to evaluate the performance of the proposed approach. The proposed LED driver had a high efficiency (>91%), a high PF (>0.99), and a low total harmonic distortion (THD i <; 8%) under variation of the utility-line input voltage from 180 to 250 V rms . These experimental results demonstrate the feasibility of the proposed LED scheme

The simulation of a twelve pulse diode rectifier with saturable reactors

A twelve pulse diode rectifier with saturable reactors to allow a degree of phase control is simulated using mathematical software. First order differential equations are solved numerically to allow calculation of line current. Application of the fast Fourier transform to line current provides harmonic current magnitudes. Line current waveforms and harmonic magnitudes from the simulation agree with expected results. The simulation is to be used as part of a harmonic analysis of multiple parallel connected diode rectifier

Elastomeric microfluidic diode and rectifier work with Newtonian fluids

We report on two microfluidic elastomeric autoregulatory devices—a diode and a rectifier. They exhibit physically interesting and complex nonlinear behaviors (saturation, bias-dependent resistance, and rectification) with a Newtonian fluid. Due to their autoregulatory properties, they operate without active external control. As a result, they enable increased microfluidic device density and overall system miniaturization. The demonstrated diode and rectifier would also be useful components in future microfluidic logic circuitry

Entrainer selection for pressure swing batch distillation

The feasibility of the separation of binary homoazeotropes with pressure swing batch distillation by the application of an entrainer is studied. The feasibility studies are based on the assumption of maximal separation and on the analysis of batch distillation/stripping regions and the vessel path in the residue curve map of the ternary mixture. The following configurations are investigated: batch rectifier, batch stripper, double column batch rectifier and double column batch stripper. Rules for the selection of an entrainer are suggested