Transient Stability Analysis Of Zhejiang Power Grid With HVDC Link

This paper describes the study of the Zhejiang power grid stability effected by the UHVDC transmission lines from Xiluodu to Jinghua which is the Jinshajiang project. The main work is as follows:In chapter 1, the characteristics of HVDC transmission technology and the present situation of the power system development in China are discussed, and some widely used softwares which are used for electromechanical transient simulation are introduced.In chapter 2, the mathematical models for electromechanical transient simulation of AC/DC power systems are studied. According to whether considering the inductive transient processes in DC transmission line and the dynamic characteristics of the high frequency DC controller or not, the HVDC models can be classified into two kinds: HVDC response model and HVDC detail model. Also, the models for excitation systems, the turbines and governing systems, load are studied. Based on those, the suitable models can be selected for the transient stability analysis of large-scale AD/DC power systems such as Zhejiang power grid.Chapter 3 introduces a very powerful software which used for electromechanical transient simulation, the BPA program. Then the modules used in normal simulations, i.e. the load flow module, dynamic simulation module, diagram plotting module and short-circuit current calculation module.Chapter 4 uses the programmed computing and simulation of BPA to analyze the transient stability of Zhejiang power grid for the year of 2018. The modeling methods and computing principles on BPA program are presented. The stability of Zhejiang power grid under AC disturbances and DC disturbances are discussed and some important conclusions are drawn.Chapter 5 introduces the characteristics and the progress of reliability assessment of TPLAN which is a computer software package for transmission reliability assessment and the reliability of Zhejiang power grid which is an AC/DC system is analyzed using TPLAN.