ABB Review Special Report - ABB - ABB Group

highly accurate system overview. Severalelectrical utilities have already deployedPMUs in their grids, mainly for manualdata acquisition and processing.A key feature of wide area monitoringsystems is the central acquisition ofdata from PMUs, enabling utilities toutilize phasor information wherever itis needed. PSG 850 provides the followingcustomized forms of data utilizationin support of utilities’ asset managementtargets.Monitoring of dynamic system behavior –stability assessmentAt present, power system operationtends to be based on static or quasi-dynamicinformation extracted from rmsmeasurements, mostly using SCADA systems.Phasor measurements at importantnodes help system operators gain adynamic view of the power system andinitiate any necessary stabilizing measuresin good time. Significant supportis provided by stability assessment algorithms,which are designed to take advantageof the phasor measurement information.This increases the efficiencyof power system operation and helps tomaintain security at the desired level.Monitoring of transmission corridors –congestion managementEnergy is often traded over the transmissioncorridors interconnecting thepower systems – an activity that addssignificantly to the cost, and thereforeprice, of energy in liberalized markets.However, the transmission capacity ofsuch corridors is often constrained bystabilityconcernsa 4 to 6 % increase in transmission capacityachieved by deploying a widearea monitoring system could help topostpone or even avoid major investmentsworth 10Phasor measurements at importantnodes help system operators gain adynamic view of the power systemand initiate any necessary stabilizingmeasures in good time.havingtheir origininuncertaintyabout theunderlyingsystemstatus. The traditional solution – toreinforce transmission path capacity byinstalling new lines – has the advantageof offering high availability, but alsothe substantial disadvantage that lineconstruction is time-consuming andrequires huge new investments.An alternative solution is to significantlyimprove asset utilization through widearea monitoring. This reduces uncertaintiesand, consequently, the operationalrisks. Under certain conditions, such aslower-than-assumed ambient temperatures,the dynamic capacity increase canbe significant. The smaller investmentmakes the ABB solutionfar more cost-effectivethan installing newlines. For example,to 100millionUSD.PSG 850is thereforealsoan importantdecision support tool for congestionmanagement and investment planning.Disturbance analysis and system extensionplanningThe continuous data storage functionalityprovided by PSG 850 is a veryvaluable source of information for theanalysis of incidents and disturbancesoccurring in the power system. Besidesimproving the efficiency of power systemanalyses, it helps to determine andeliminate the actual causes of such inci-34Special ReportABB Review