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Zhu X.,North China Electrical Power University | Liu W.,North China Electrical Power University | Zhang J.,North China Electrical Power University | Wu X.,Anhui Electrical Power Dispatching and Communication Center | And 2 more authors.
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2014

To improve the fitting degree between analysis results and actual situation, the idea of dynamic power flow was introduced into probabilistic load flow (PLF) analysis to research the model and algorithm of PLF considering frequency modulation. Based on processes of frequency response in real system, the analytical model of dynamic unbalance power distribution was established by use of piecewise functions. And the model was combined with traditional PLF model to establish the model of PLF considering frequency modulation. The proposed PLF model was modified according to the impact of insufficient frequency modulation on unbalance power distribution. To ensure the practicality of the model solution, a hybrid method was proposed, which is simple and easy to realize. Compared with conventional analytical method, the proposed method has more powerful capacity of random processing. Compared with conventional simulation method, the solving speed can be greatly improved while keeping higher calculation accuracy. The effectiveness of the proposed model and method was verified via IEEE 24 bus system tests. © 2014 Chin. Soc. for Elec. Eng.. Source


Wang Z.-F.,Anhui Electrical Power Dispatching and Communication Center
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2012

Based on SCADA/EMS system, power load measurement and on-line power network loss compute can be realized. Power load measurement, power load ratio and capacity-load ratio of power network equipment can be calculated and stated every five minutes. Power load ratio and operation state of power network equipment can be reflected by the year or month calculated and statistical result of those indexes. On-line power network loss compute can be realized every five minutes. Based on on-line power network loss compute, power network loss quantity can be got to revise power network loss quantity by electrical energy gather system. It is indicated that helpful guidance can be provided for power system manager through practical operation and application. Source


Wang Z.-F.,Anhui Electrical Power Dispatching and Communication Center
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2010

At first the basic function of dynamic monitoring preventive alarm and auxiliary decision system which is widely used at present time in China is introduced. The simulation analysis from off-line to on-line is realized. Then, it indicates that dynamic monitoring preventive alarm and auxiliary decision system can be extended to online parameter identification of power system through dynamical data of PMU. Also, it can be extended to preventive plan of power network operating mode. The preventive plan rationality of power network mode can be improved. The conception of off-line limit load power cover will be updated to the conception on-line limit load power cover. So transmission capability can be appropriately improved. The method which is used in the first frequency modulation can be mended by PMU. Finally, the function which can be used in economy operation is discussed. Source


Xie D.-W.,Anhui Electrical Power Dispatching and Communication Center | Liu Y.-J.,Nanjing University of Information Science and Technology | Li B.-J.,State Grid Electric Power Research Institute of China
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2010

The technical status of power grid dynamic security and stability pre-warning system is introduced. The problems of pre-warning accuracy is analyzed, including that power flow simulation is not accurate, expected fault set is incomplete, fault in substations is difficult to simulate, the state of protective relay and safety automatic device are difficult to identify, and the accuracy of online calculation parameters is difficult to verify. The factors possibly affecting the pre-warning accuracy are analyzed. The general idea of improving pre-warning accuracy is proposed, and the relevant objectives, implementation methods and applications are described specifically. Source


Lei T.,Anhui Electrical Power Dispatching and Communication Center | Huang T.,Anhui Electrical Power Dispatching and Communication Center | Li B.,Anhui Electrical Power Dispatching and Communication Center | Tang J.,Anhui University
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2010

The implementation and application of a time synchronization monitoring and analysis system are described. A time analysis synchronization technical framework architecture based on three-layer, real-time monitoring, real-time analysis and comprehensive application is presented. Some implementing methods are presented, which mainly include error control based on the autoregressive integrated moving average (ARIMA) model, global time consistency analysis, self-running precision analysis, correlation analysis of error diagnosis, and NTP timestamp-based performance monitoring. Engineering implementation of the system is dealt with, and system applications including clock state maintenance analysis, time error intelligent diagnosis and system performance and load analysis are discussed. © 2010 State Grid Electric Power Research Institute Press. Source

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