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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.


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.


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.


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..


Wang Z.,Anhui Electrical Power Dispatching and Communication Center | Chen S.,Anhui Electrical Power Dispatching and Communication Center
Dianli Zidonghua Shebei/Electric Power Automation Equipment | Year: 2010

It is proposed that: apply the on-line stability calculation function of the real-time dynamic power network monitoring system to carry out the static state security analysis and transient stability calculation of power grid based on the data of SCADA/EMS, PMU, stability control equipment, bus load forecast, generation plan, operational order management and protection system, and then properly schedule its operating mode according to the calculated results and assistant strategy to improve its operational security and stability. As the heat stability limit after accident is overloaded stability, the power supply will be limited in 30 minutes after accident if there is no efficient countermeasures. To improve the power supply reliability, it is also pointed out that, the power supply ability after accident must be taken into account in the operating mode scheduling.


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.


Wang Y.-H.,Auhui Technical Colege of Water Resources and Hydroelectric Power | Wang Z.-F.,Anhui Electrical Power Dispatching and Communication Center | Ge F.,Anhui Electrical Power Dispatching and Communication Center
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2010

Not only is electrical power transported to import power network but also electrical power is offered for area need. So the configuration of export network is very important. At first, this paper points out that the voltage grade and the generator connection mode which is connected into power system must be thought over. Then, it indicates that the connection mode of export network can't be compact united. Finally, the connection mode between export network and import network is discussed. It indicates that in order to improve power system transmission capability, electrical distance must be reduced. Also, it points out the lower voltage power system programming must be taken into account when the high voltage power system programming is made.

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