Operation Risk Assessment And Counter-measures Research Of Regional Power Grid In Maintenance State

Electrical equipment maintenance is an important work for the daily operation of thepower supply enterprise. The redundancy of the electrical equipment decreases during themaintenance, which leads to increasing the operational risk of the power grid and making thesafety and reliability of power system confront more challenge. The research on the approachfor operational risk assessment of original power grid during maintenance is not only helpful foraccurately indentifying the influence of the equipment maintenance but also meaningful todevelop countermeasures so as to reduce the operational risk of power grid. Achieving thetargets some work has done as fellow:An operational risk index system of regional power grid was defined according to the riskcharacteristics of the original power grid in state of maintenance. From the view of busvoltage-loss and branch overload, this risk index consist of system index and area index. Themethod for operational risk assessment of original power grid during maintenance was presented.Contingency enumeration method is employed to determine the system fault state, then the faultprobability taking weather factor and load rate factor into account was calculated. The approachof calculating the severity of risk used various analysis method, such as islanding detection baseon topology analysis, the action analysis of busbar automatic transfer switch(BATS), the loadflow calculation method, sensitivity analysis of N-1outage power flow calculation method, whichmake the risk assessment results more efficient and accurate. The assessment of operational riskassessment of original power grid during maintenance achieved after the calculation of probabilityand severity has finished. The fault sets are reduced by locating the area influenced bymaintenance so as to reduce system state and computing scale, which could improve theefficiency of assessment.To identify the risk of system and find out the reason, the risk of original power grid duringmaintenance should be assessed. The assessment result will be applied to grasp the law of theeffect of the maintenance, which can help the operator to take some control measures to deal withthe risk. So comparison method of load transfer schemes based on risk analysis was described and the control measures of eliminating equipment overloading were proposed, they will providedecision support to reduce the risk.Finally, a risk assessment and decision support system has been developed, applied to originalpower grid. The system can show accurate assessment result and the control measures efficiently,so as to provide reliable decision supports for the operator.