Novel UPQC use power acceptability curve in voltage disturbance detection intended for losses reduction

Unified power quality conditioner is a powerful tool to settle the power quality problems. In reason of power devices technology promotion and their cost reduction, it is predicable that UPQC will attain wide spread usage. Therefore its lifetime and efficiency would become important issues. In this paper a control system is developed that devolves compensation of short duration and shallow depth voltage disturbances to shunt section. Since increasing of nominal VA of shunt section is not desired, control system uses a ITIC like curve to classification of voltage disturbances and entrusting voltage compensation to shunt section, in order to assuring of safe operation of load. Since a great many of voltage disturbances occur in power systems are tolerable to loads, this method reduces the operational losses of the UPQC considerably and has ameliorating effect on DC link voltage, furthermore obviates requirement of series section to very fast protection. The proposed system simulated by PSCAD/EMTDC
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and results discussed.