Effect of Dynamic Voltage Restorer in Compensating forudVoltage Sag and Controlling Harmonics in a PowerudDistribution System using Fumman Industry as a CaseudStudy

摘要

Different power quality surveys done byudresearchers identify voltage sags as the most serious powerudquality problems for industrial customers. Voltage sag canudcause serious problems to electric loads that cannotudwithstand variation in voltage such as adjustable speeduddrives, process control equipment and computers. Thisudresearch work investigated the effect of Dynamic VoltageudRestorer (DVR) in compensating for voltage sag andudcontrolling harmonics in a power distribution system. A DVRudis a power electronic converter base device that is used toudregulate the voltage at the load terminals from various powerudquality problems like sag, swell unbalance etc in the supplyudvoltage. The mathematical equations representing voltage sagudand it compensation are presented. To implement the effectudof DVR on industrial load network, Fumman Industry wasudconsidered as a case study. The DVR was modeled byudbuilding the subsystem of each major component. Theudcomponents are injection transformer, fuzzy logic controller,udbattery and Pulse Width Modulation (PWM) inverter.udOptimization technique was used to determine theudappropriate battery size. Simulation was done without andudwith the DVR using Matlab/Simulink; under three anduddouble phase line-to-ground faults.Simulation results showedudthat the modeled DVR can work very well against balancedudand unbalanced voltage sag caused by fault in industrialuddistribution systemconsidering the harmonic limits.