This paper deals with simulation of multilevel inverter based DVR. The DVR circuit produces high quality voltage since it uses a nine level inverter. This DVR gives better solution to the voltage sag problem by injecting a voltage with reduced harmonics. DVR controls the voltage applied to the load by injecting voltage of proper amplitude and phase angle. Thus DVR is responsible for restoring q...

This paper presents a novel control strategy of a threephase four-wire Unified Power Quality (UPQC) for an improvement in power quality. The UPQC is realized by integration of series and shunt active power filters (APFs) sharing a common dc bus capacitor. The shunt APF is realized using a thee-phase, four leg voltage source inverter (VSI) and the series APF is realized using a three-phase, thre...

Voltage sags are normally described by magnitude variation and duration. In addition to these quantities, sags are also characterized by unbalance (asymmetry), nonsinusoidal waveshapes, and phase angle shift (phase jump). These factors are important for determining the behavior of ac motor drives during sags. Voltage unbalance and phase angle shifts cause large unbalanced source currents to, ex...

Purpose. This article proposes a new control strategy for Dynamic Voltage Restorer (DVR) in utility grid distribution system. The proposed DVR using PI tuned fuzzy logic scheme is based on replacement of conventional and voltage sag compensation system network. novelty the work consists presenting an enhanced algorithm to efficiently dynamic restorer when suddenly occurred. Methods. which provi...

This thesis focuses on controller design and analysis for induction motor (IM) drives, flux control for electrically excited synchronous motors with damper windings (EESMs), and to enhance voltage sag ride-through ability and analysis for a wind turbine application with a full-power grid-connected active rectifier. The goal is to be able to use the existing equipment, without altering the hardw...

One of the most concerning disturbances affecting power quality are voltage sags. Their major source are short-circuits on the utility lines. Faults many kilometres from the disturbed process will generate a momentary voltage sag in the electrical environment to the end user. A reduction of the short-circuit current magnitude may lead to a substantial power quality improvement because the major...

This paper introduces a new concept of optimal utilization of a unified power quality conditioner (UPQC). The series inverter of UPQC is controlled to perform simultaneous 1) voltage sag/swell compensation and 2) load reactive power sharing with the shunt inverter. The active power control approach is used to compensate voltage sag/swell and is integrated with theory of power angle control (PAC...