Research On Voltage Collapse And Prective Approach In Electricity Market Considering Load Characterstic

In this dissertation, based on load characteristic and its effect on voltage collapse, theapproach to coordinate economic profit with voltage collapse margin in electricitymarket is studied. The quantitive assessment methods on market participators'contributions to multi-objective are proposed. The main contents are expatiated asfollows:An OPF based voltage collapse critical point algorithm considering the characteristicand increasing uncertainty of load is proposed. By fuzzifying load increase based onexpected value of the maximum and minimum of node load forecast, the uncertaintyattribute of load increase is described. Then according to different system securityrequirements, the voltage collapse critical point algorithm is proposed in two differentways. One considers critical point static security constraint;the effects of loadcharacteristic, generator reactive power reserve and SVC compensation on voltagecollapse are discussed. The other considers both of current and critical point staticsecurity constraints;an index to the effect of node inject power to critical point isdefined. These two algorithms can determine each load increasing bound of voltagecollapse prevention.The effects of physical and economic features of market participators on voltagecollapse margin are analyzed. The contribution of crowd effect of load on voltagecollapse margin is analyzed by Continual Power Flow (CPF) simulation. Furthermore,the contributions of main physical and economic features of market participators tovoltage collapse margin are analyzed by dynamic simulation. A WAMS based on-linevoltage collapse index to generator reactive power reserve (VCIG)and transmissionline transfer capacity is proposed.Based on load increase bound of the voltage collapse critical point algorithm, an OPFbased transaction scheduling considering load characteristic is proposed;and aquantitive approach to assess the voltage collapse margin of the scheduling and thecontributions of market participators is presented. A sensitivity index is defined totransaction-specifically describe the effect of load level, price and characteristic oneconomic profit quantitively. By modal analysis of reduced power flow Jacobian matrixof optimal transaction, an approach to quantitively assess the voltage collapse marginof specific transaction scheduling and the contributions of market participators areproposed simultaneously.Furthermore, taking multi-attributes on economy, security and environment protectionof transaction scheduling and pricing into account, two kinds of OPF basedmulti-objective transaction scheduling and pricing methods with consideration of loadcharacteristic and voltage collapse prevention under different security constraints areproposed. One is a multi-objective transaction model based on load bidding bound of thevoltage collapse critical point algortihm. The multi-objective transaction functionconsists of economy, environment protection and minimum real power losses. A conceptof Generalized Location Marginal Price (GLMP) to assess the contributions of generatorcompanies to the multi-objective quantitively is defined by KKT condition. The voltagecollapse margin and the contributions of market participators can also be quantitivelyassessed through singular value analysis of power flow Jacobian matrix ofmulti-objective optimal solution. The other is multi-objective transaction model thatmaximizes voltage collapse margin and economic profit synthetically under staticsecurity constraints of current and critical operation points. Location MarginalSecurity Price (LMSP) is defined with consideration of load characteristic and voltagecollapse prevention to assess the contributions of nodes to economic profit and voltagecollapse margin quantitively under specific transaction.