1. 动态电力系统 张 毅 威 ywzhang@mail.eea.tsinghua.edu.cn ywzhang@mail.eea.tsinghua.edu.cn 西主楼 III-210 电话 62794698 Ftp ： 166.111.60.30

2. Chap. 7 Power System Loads Problem: – Why Load modeling is always based on a considerable amount of simplification?

3. 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)

4. 7.1.1 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: 0.5-1.8 reactive 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 ?

5. 多项式负荷模型 : ZIP 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 practice is applied to deal with this problem?

6. 7.1.2 Dynamic Load Models Problem: – 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. 7.2 Modeling of induction Motors

8. 7.3 Synchronous Motor Model

9. 7.4.1 measurement-based approach steady-state load-voltage characteristics – Problem : At what voltage level? How to get voltage change? What parameters are interested steady-state load-frequency characteristics – Problem : How to get frequency change? How to separate the influence of voltage change?

10. Dynamic load-voltage characteristics – What is the basic approach ?

11. 7.4.2 Component-based approach Base on a structure: Bus load Load class mix Load components Component characteristics

12. Chap.8 Excitation System Problem: – What is its basic function? – What is its main control function?

13. 8.1Excitation sys. requirements Generator considerations – Basic function : continuous capability – Emergency function: short-term capability Power system considerations Functions : – voltage control – Transient stability control – Small-signal control

14. Excitation requirements – Meet response criteria – Provide limiting and protective functions – Meet specific requirement for operation flexibility – Meet the desired reliability and availability

15. 8.2 Elements of Excitation Sys. Exciter: provide DC power Regulator: process and amplify input signal Terminal voltage transducer and load compensation: PSS Limiter and protective circuits:

16. 8.3 Types Broad types of excitation system – DC – AC – Static

17. 8.4.1 Dynamic Performance Measures Ceiling voltage Ceiling current Voltage time response …

18. 8.4.2 Small-signal performance Measures Time response Frequency response

19. 8.5 Control and protective functions 8.5.1 Regurators 8.5.2 Stabilizing Circuits 8.5.3 PSS 8.5.4 Load compensation 8.5.5 Under-excitation limiter 8.5.6 Over-excitation limiter 8.5.7 Volts-per-Herts Limiter and protection 8.5.8 Field-shorting Circuits

20. 8.6 Modeling of Excitation Systems 8.6.1 Per unit system 8.6.2 Modeling of components 8.6.3 Modeling of complete excitation system 8.6.4 Field Testing