Voltage-Sourced Converter (VSC) is the main component in a VSC-based High Voltage Direct Current (HVDC) system. In addition to the characteristic harmonics, the inter-harmonics could be originated from the characteristic of each converter working at different modulation frequencies, or from a distorting frequency on one or both ac (or dc) systems. The space vector representation of VSC’s switch...

This project presents reactive power compensation in a distribution power system. DSTATCOM (distribution static compensator) is a reactive power compensator for power quality improvement in a three phase four wire distribution system. A voltage source converter (VSC) based DSTATCOM with a zig-zag transformer is used for the compensation of reactive power for voltage regulation along with load b...

Three-phase voltage source converters (VSC) are commonly used to convert ac power from a three-phase grid to a regulated dc voltage with unity input power factor. The control of the VSC is normally achieved by an outer voltage feedback loop and a sinusoidal pulse-widthmodulated (SPWM) inner current loop. However, the nonideal power grid and the presence of other interacting loads give rise to n...

The traditional HVDC plays an important role in the development of power grid. But the traditional HVDC cannot supply power either to entirely passive AC network or to weak AC system. In fact, an entirely passive AC network can be effectively powered through VSC-HVDC. However, the cost of investment in VSC-HVDC is amazingly high due to the limitation of power electronics technology. Based on CS...

We proposed voltage-sourced converter (VSC) with Pulse-width modulation (PWM) provides a faster control that is required for flicker mitigation purpose. The voltage regulation in the distribution feeder is improved by installing a shunt compensator. The proposed DSTATCOM is modeled and its performance is simulated and verified for power factor correction and voltage regulation along with neutra...

A novel isolated ac/dc converter topology incorporates a voltage source converter (VSC) with capacitive snubbers and a cycloconverter, connected by a medium frequency transformer. The concept offers the possibility of bilateral power flow as well as three-level pulse width modulation on the ac side. It is shown that by alternately commutating the VSC and the cycloconverter it is possible to ach...

Three-Phase four-wire distribution systems are facing severe power quality problems such as poor voltage regulation, high reactive power and harmonics current burden, load unbalancing, excessive neutral current, etc.This creates excessive neutral current both of fundamental and harmonic frequency and the neutral conductor gets overloaded. By integrating phase shifting into an extremely low zero...

The assessment of plumage and integument condition in laying hens provides useful information about the occurrence of feather pecking and cannibalism. Although feather loss and skin injuries can result from mechanical abrasion or clinical diseases, they are valid animal-based indicators for behavioural disorders. This particularly applies to damage on the back and tail region of the hens. The a...

PURPOSE The aim of the study was to determine the longitudinal effect of an oral hygiene program on oral levels of volatile sulfur compounds (VSC). MATERIALS AND METHODS The study subjects were randomly selected from patients attending a student course in operative dentistry and from staff members of our dental clinic. The test group (n = 30) received an oral hygiene training including profes...

Volatile sulfur compounds such as methanethiol, dimethyl disulfide, dimethyl trisulfide, and hydrogen sulfide constitute an important fraction of Cheddar cheese flavor. These compounds are products of the catabolism of methionine and cysteine by bacteria in the cheese matrix. The objectives of this study were to examine the levels and types of volatile sulfur compounds produced from methionine ...