Time filter

Source Type

Li X.-N.,China Electric Power Research Institute | Li T.,China Electric Power Research Institute | Lu P.-F.,National Electrical Power Dispatching and Communication Center | Zeng N.-C.,China Electric Power Research Institute
Gaodianya Jishu/High Voltage Engineering | Year: 2011

The entrance/exit of converter in on-line way is a new technology based on the series connection configuration of two 12-pulse converters in ±800 kV UHV DC links. According to system commissioning tests of this project, taking a second converter in operation(converter entry)and taking the first converter out of operation(converter exit), we researched strategies for protecting converter and exiting. In joint control model, the converter entrance/exit in the rectifier and the inverter station should be automatically accomplished by sequential actions; however, in separate control, the operator coordination with the other stations must be performed via telephone. At converter entry, the converter in the rectifier should first be started, but at converter exit, the converter in the inverter should first be exited with the exception of protection actions. The results can provide technical reference for UHVDC system operation and maintenance.


Luo X.,Electrical Reliability Council of Texas Inc. | Ma K.,National Electrical Power Dispatching and Communication Center
Dianwang Jishu/Power System Technology | Year: 2011

ERCOT region has witnessed the booming of wind generation development in recent years and leads the U. S. with the most installed wind generation capacity. ERCOT has gained rich experience in operations of wind generation. This paper introduces wind power forecast, and day-ahead and real-time operations of wind generation in ERCOT nodal power market. ERCOT's emergency operations in wind related events are also presented. The paper is concluded with a summary of ERCOT's experience that can be learned to improve operations of wind generation in China.


Lin Y.,Tsinghua University | Sun H.,Tsinghua University | Wu W.,Tsinghua University | Yu J.,National Electrical Power Dispatching and Communication Center | Zhang B.,Tsinghua University
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2012

Formulation of day-ahead operation schedule for large-scale power grid requires security validation, including static security, dynamic and transient stability. It is an important and basic task for day-ahead security validation to generate an AC power flow that satisfies the demand of the schedule. A new method of generating the day-ahead schedule power flow is proposed, which consists in dividing the problem into two subproblems-the active subproblem and the reactive subproblem. The inconsistency of various kinds of schedule data is coordinated by solving the active subproblem, while a rational voltage distribution is achieved by solving the reactive subproblem. Both of the two problems are formulated as optimization models with constraints satisfied and are solved with an interior point algorithm. Numerical test results on the testing system and real power systems show that the method is capable of providing rational day-ahead schedule power flow. © 2012 State Grid Electric Power Research Institute Press.


Pei Z.,National Electrical Power Dispatching and Communication Center | Wu Y.,Huazhong University of Science and Technology | Ji C.,North China Electrical Power University | Li G.,State Grid Electric Power Research Institute of China
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2010

The distribution of hydropower stations in China and its hydro and water regulation characteristics are studied in the paper. The dispatch model for joint optimal dispatch of some large-scale hydroelectric power station group between southwest China & Central China is established. The dispatch problem of cross-regional hydropower station group may divide into several smaller tasks, then overall coordination can be made with reservoir operation experience. The analysis results show that hydropower generation optimal dispatch can not only increase the hydropower generation capacity, and but also can improve the guaranteed output of hydropower station group. The hydropower generation dispatch is of great significance for implementation of national strategy of transmitting power from west to east, optimizing resource allocation and achieving sustainable development. © 2010 State Grid Electric Power Research Institute Press.


Liang Z.,National Electrical Power Dispatching and Communication Center | Ge R.,National Electrical Power Dispatching and Communication Center | Dong Y.,National Electrical Power Dispatching and Communication Center | Chen G.,National Electrical Power Dispatching and Communication Center
Dianwang Jishu/Power System Technology | Year: 2013

The occurrence and expansion of large-scale blackouts occurred on July 30 and 31, 2012 respectively in India Power Grid and the restoration of the power grid from the blackouts as well as the analysis on the reason causing the large-scale blackouts are presented. On the basis of summing up the lessons from the large-scale blackouts occurred in India, the main large-scale blackouts occurred in foreign countries in recent years are retrospected and the common character of these blackouts and differences among them are summarized. Finally, based on China's power grid operation and management and actual conditions of interconnected interregional power grids in China, the lessons to be learnt from large-scale blackouts occurred abroad for China's power grid dispatch and operation are listed.


Feng C.-Y.,National Electrical Power Dispatching and Communication Center | Feng C.-Y.,Xi'an Jiaotong University | Wang X.-F.,Xi'an Jiaotong University
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2011

Unit maintenance scheduling (UMS) is important to reduce the unit failure rate and guarantee the system reliability. The deregulation of power industry creates the independent market entities with different objectives, including the self-interested power producers for maximizing their potential payoffs and the independent system operator (ISO) for ensuring the system reliability. Therefore, UMS should also be determined to achieve a balance between the producers' benefits and the system reliability, which is different from the traditional system-centralized mechanism. Based on the current research, this paper mainly discusses the impacts of market environment on the UMS from several aspects, which contain the schedule mode, the related uncertainty factors, the assessment criterion, the producers' UMS model and the ISO's coordination strategy, and the model's solving algorithm. Furthermore, some challenges that may be faced in the future study are also presented.


Hu W.,Tsinghua University | Wang S.,Tsinghua University | Xu F.,Tsinghua University | Zhang W.,National Electrical Power Dispatching and Communication Center | Zhou J.,National Electrical Power Dispatching and Communication Center
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2011

There exist negative effects between the control commands and control targets of the automatic generation control (AGC) and automatic voltage control (AVC) system, which is apt to result in such problems as system security and overshoot. By adopting the decomposition-coordination method between active frequency and reactive voltage based on time dimension, a coordinated automatic control system of AGC and AVC based on hierarchical control is built. The design scheme of each control layer is also given. The upper controller optimizes and coordinates active and reactive power, and provides economical, safe, and optimal reference setting trajectory. The lower controller improves the control strategy of AGC in advance thus realizing comprehensive energy saving. And a study of the AGC effects to be exerted on voltage control is made. By means of the corresponding reactive voltage control command, optimal coordinated control of the economy and security of the power system are realized, enabling the system to operate in the multi-objective sub-optimal region. Meanwhile, the AGC and AVC commands should be checked and revised by employing the staggered iteration concept to obtain the comprehensive coordination command and minimize the negative effects of the two on each other. The effectiveness of the control system, strategy and method proposed is proved by computer simulation results. © 2011 State Grid Electric Power Research Institute Press.


Xin Y.,National Electrical Power Dispatching and Communication Center
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2010

The situation analysis on power grid large disturbance in recent years by CIGRE'2010 study committee (SC) C2 is presented. The key technology subjects are reviewed, including dynamic security assessment, wide area measurement system (WAMS), security criterions and key indices, as well as control center coordination. At last, preferential key technology subjects of SC C2 for the year of 2012 are listed. © State Grid Electric Power Research Institute Press.


Liu Y.,National Electrical Power Dispatching and Communication Center | Shu Z.,National Electrical Power Dispatching and Communication Center | Cheng X.,National Electrical Power Dispatching and Communication Center | Zhang S.,National Electrical Power Dispatching and Communication Center
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2011

On February 4, 2011, a blackout occurred in Northeast of Brazil. The process of blackout is introduced and analyzed. An error of an electronic component in the relay equipment aroused the false action of the breaker failure protection in the substation Luiz Gonzaga and resulted in the blackout finally. With reference to the blackout incident in Brazil, the deficiency of the breaker failure logic adopted in Brazil power grid is analyzed, and the standard breaker failure logic developed by State Grid Corporation of China is also analyzed. The analysis results reveal that the standard logic can avoid the occurring of similar incidents. © 2011 State Grid Electric Power Research Institute Press.


Li X.,Beijing Jiaotong University | Lu P.,National Electrical Power Dispatching and Communication Center | Yang P.,China Electric Power Research Institute | Wan X.,National Electrical Power Dispatching and Communication Center | And 2 more authors.
Dianwang Jishu/Power System Technology | Year: 2012

The double circuit ±500kV DC transmission lines from Tuanlin to Fengjing and the double circuit ±500kV DC transmission lines from Gezhouba to Shanghai are erected on the same tower and it is the first engineering project applying multi-circuit HVDC transmission lines on the same tower in the world. There is electromagnetic coupling among transmission lines on the same tower, however the coupling among polar conductors will not bring serious affect on steady-state operation of HVDC power system, and only under the condition of grounding fault occurred in one of HVDC circuits the transient component caused by the fault may affect on other polar conductors in the normal operation due to electromagnetic coupling and unbalance of line parameters. For this reason, firstly during the commissioning of HVDC transmission line from Tuanlin to Fengjing the influences of fault occurred in one polar conductor of HVDC transmission lines from Tuanlin to Fengjing and missing single-pulse test on HVDC transmission lines erected on the same tower are analyzed; secondly, a model of double circuit HVDC transmission lines on the same tower is built by EMTDC, and on the basis of reappearing fault occurred in HVDC transmission line and missing pulse test the reason of commutation failure in healthy pole of HVDC transmission lines from Tuanlin to Fengjing caused by fault occurred in polar conductor of another circuit of these transmission lines as well as the reason of commutation failure in HVDC transmission line from Gezhouba to Shanghai caused by missing pulse occurred in HVDC transmission line from Tuanlin to Fengjing are analyzed in depth.

Loading National Electrical Power Dispatching and Communication Center collaborators
Loading National Electrical Power Dispatching and Communication Center collaborators