Power-System-Loadsppt课件教学教程VIP

1、动态电力系统Chap. 7 Power System LoadsProblem:Why Load modeling is always based on a considerable amount of simplification?7.1 Basic Load-Modeling Concepts Problem: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 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 ? 多项式负荷模型: ZIP

3、 model How 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 pra

4、ctice is applied to deal with this problem? 7.1.2 Dynamic Load ModelsProblem: 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 appro

5、ach steady-state load-voltage characteristicsProblem : At what voltage level? How to get voltage change? What parameters are interested steady-state load-frequency characteristicsProblem : How to get frequency change? How to separate the influence of voltage change?Dynamic load-voltage characteristi

6、cs What is the basic approach ? 7.4.2 Component-based approachBase on a structure: Bus load Load class mix Load components Component characteristics Chap.8 Excitation SystemProblem:What is its basic function?What is its main control function?8.1Excitation sys. requirementsGenerator considerationsBas

7、ic function : continuous capabilityEmergency function: short-term capabilityPower system considerations Functions : voltage controlTransient stability controlSmall-signal control Excitation requirementsMeet response criteriaProvide limiting and protective functions Meet specific requirement for oper

8、ation flexibilityMeet the desired reliability and availability8.2 Elements of Excitation Sys.Exciter: provide DC powerRegulator: process and amplify input signalTerminal voltage transducer and load compensation:PSSLimiter and protective circuits:8.3 Types Broad types of excitation systemDCACStatic 8

9、.4.1 Dynamic Performance MeasuresCeiling voltageCeiling currentVoltage time response 8.4.2 Small-signal performance MeasuresTime response Frequency response 8.5 Control and protective functions8.5.1 Regurators8.5.2 Stabilizing Circuits8.5.3 PSS8.5.4 Load compensation8.5.5 Under-excitation limiter8.5.6 Over-excitation limiter8.5.7 Volts-per-Herts Limiter and protection8.5.8 Field-shorting Circuits8