Li Bijun

Effects of fault current limiter on the safety and stability of power grid and its application: A research review

In this paper, basic principles, advantages and disadvantages, development and applications of different types of fault current limiter (FCL) are described. Effects on safety and stability of power grid and optimization configuration are also expounded with the application of FCL in aspects of relay protection, reclosure, transient power angle and voltage stability. In addition, several key problems of FCL engineering application are summarized. The development trends of FCL research and application are also proposed. It points out that FCL will play a unique role in fields such as improving the transmission capacity of DC Receiving-side, reducing the risk of commutation failure, improving power quality, enhancing large-scale new energy integration capability and so on. Due to the limitation of technical and economic constraints, economical FCL based on the normal electric equipment is still the first choice for application at present. However, with the increasing maturity of large-capacity and high-voltage self-turn-off power electronic devices, solid-state current limiter based on power electronic technology will become the research and application hotspot in the future.

Oriented Engineering Application for Voltage Security Analysis of Power Systems

This paper deals with oriented engineering application of voltage security analysis of large-scale power systems, including engineering criterion of voltage security, principal objective, and systematic procedure of voltage security assessment. A systematic approach to voltage security assessment is presented in this paper. Example of Yunnan grid voltage security analysis using systematic voltage security analysis method is presented

Parameters optimization of excitation system based on extended Heffron-Philips model

Control mode and control parameters of the excitation system play an important role in the security and stability operation of generator and even power grid. It is shown in some generator oscillation accidents without system fault in industrial enterprises that there have exciter stability problems in industrial power plants. In this paper, an extended Heffron-Philips model considering Var and power factor excitation system was established to analyze such the excitation system stability problem. And then with the system characteristics matrix system characteristics root will be carried out to study the principle factors on excitation system stability. A parameter optimal method for excitation system considering local power system small signal stability was proposed based on system root locus. The mechanism of abnormal oscillation without system fault occurred in actual industrial power grid was analyzed and the excitation control parameter was redesigned using the proposed method, which was verified by simulation results.