POWER QUALITY ANALYSIS WITH CUSTOM POWER DEVICES

Abstract

Power quality relates to non-standard voltage, current or frequency deviation that results in failure or maloperation of end user equipment. Power quality problems such as voltage sag, swell and harmonics are highly undesirable for loads especially in industries; it is a challenging task to correct the power quality problems so that the desired load voltage magnitude can be maintained during the disturbances. In this thesis, Custom Power Devices is chosen to solve the power quality problems. Custom power technology is an emerging field for power quality problems and enhancing the power system reliability. Custom power devices are used to solve many types of active and reactive power problems at distribution level. In this work the effect of custom power devices will be studied in relation to prominent power quality problems such as voltage sag and harmonics. There are various methods for solving the voltage sag problems; amongst these custom power devices are most current and promising. Thesis describes the models of D-STATCOM (Distribution Static Compensator) in connection with the wind turbine generator network and different loading conditions in distribution system, DVR (Dynamic Voltage Restorer) and SSTS (Solid State Transfer Switch) operating in fault conditions. A PWM based control Scheme has implemented for controlling the electronic valves in the multilevel voltage source converters used with the D-STATCOM and DVR. For the elimination of voltage and current harmonics due to non-linear loads, simulation of APF (Active Power Filters) is carried out.