动态电力系统四.ppt

1、动态电力系统Chap.7 Power System LoadslProblem:Why Load modeling is always based on a considerable amount of simplification?7.1 Basic Load-Modeling Concepts lProblem:What is the concept of composite load?Loads are usually represented at what system level?for angular stability or for voltage stability)7.1.1

2、 Static load models l幂次式负荷模型：当幂为0，1，2时的特殊性For composite system loads,exponent of active load:0.5-1.8reactive load:1.5-6,1.it varies as a nonlinear function of voltage 2.at higher voltage,?Problem:In the absence of specific information,what is the most accepted static load model?l多项式负荷模型:ZIP model Ho

3、w to take into account of the frequency dependency of load characteristics?What are the typical parameter for Kpf(0,3.0)and Kqf(-2.0,0)?How to get the variation of a bus frequency in simulation?How to make comprehensive static model?Is the static load realistic at low voltage?What practice is applie

4、d to deal with this problem?7.1.2 Dynamic Load ModelslProblem:Why dynamic load model is needed?When static and dynamic load models are used?What kinds of dynamic loads there are?(a).(b).(c).(d)7.2 Modeling of induction Motors7.3 Synchronous Motor Model7.4.1 measurement-based approach lsteady-state l

5、oad-voltage characteristicsProblem:At what voltage level?How to get voltage change?What parameters are interested lsteady-state load-frequency characteristicsProblem:How to get frequency change?How to separate the influence of voltage change?lDynamic load-voltage characteristics What is the basic ap

6、proach?7.4.2 Component-based approachBase on a structure:Bus load Load class mix Load components Component characteristics Chap.8 Excitation SystemlProblem:What is its basic function?What is its main control function?8.1Excitation sys.requirementslGenerator considerationsBasic function:continuous ca

7、pabilityEmergency function:short-term capabilitylPower system considerations Functions:voltage controlTransient stability controlSmall-signal control lExcitation requirementsMeet response criteriaProvide limiting and protective functions Meet specific requirement for operation flexibilityMeet the de

8、sired reliability and availability8.2 Elements of Excitation Sys.lExciter:provide DC powerlRegulator:process and amplify input signallTerminal voltage transducer and load compensation:lPSSlLimiter and protective circuits:8.3 Types lBroad types of excitation systemDCACStatic 8.4.1 Dynamic Performance

9、 MeasureslCeiling voltagelCeiling currentlVoltage time response l8.4.2 Small-signal performance MeasureslTime response lFrequency response 8.5 Control and protective functionsl8.5.1 Reguratorsl8.5.2 Stabilizing Circuitsl8.5.3 PSSl8.5.4 Load compensationl8.5.5 Under-excitation limiterl8.5.6 Over-excitation limiterl8.5.7 Volts-per-Herts Limiter and protectionl8.5.8 Field-shorting Circuits8.6 Modeling of Excitation Systemsl8.6.1 Per unit systeml8.6.2 Modeling of components l8.6.3 Modeling of complete excitation system l8.6.4 Field Testing