Reliability and sensitivity analysis of loop-designed security and stability control system in interconnected power systems

Security and stability control system(SSCS)in power systems involves collecting information and sending the decision from/to control stations at different layers;the tree structure of the SSCS requires more levels.Failure of a station or channel can cause all the execution stations(EXs)to be out of control.The randomness of the controllable capacity of the EXs increases the difficulty of the reliability evaluation of the SSCS.In this study,the loop designed SSCS and reliability analysis are examined for the interconnected systems.The uncertainty analysis of the controllable capacity based on the evidence theory for the SSCS is proposed.The bidirectional and loop channels are introduced to reduce the layers and stations of the existing SSCS with tree configuration.The reliability evaluation and sensitivity analysis are proposed to quantify the controllability and vulnerable components for the SSCS in different configurations.By aiming at the randomness of the controllable capacity of the EXs,the uncertainty analysis of the controllable capacity of the SSCS based on the evidence theory is proposed to quantify the probability of the SSCS for balancing the active power deficiency of the grid.

Analysis and Recommendations for the Adaptability of China’s Power System Security and Stability Relevant Standards

In developing power grids,setting standards is critical to its success.The development of China’s power industry has proposed new requirements for power systems to ensure secure and stable operations.The principal standards for the security and stability of China’s current power systems are analyzed in terms of operational control,generator-grid coordination and simulation.The shortcomings are pointed out and the directions of future development are discussed.In the end,the study highlighted the following key areas that require further research and improvement:the evaluation criteria of power system security and stability should be improved to ensure the secure and stable operation of China’s power systems;the operational control standards should be constantly enhanced to increase the reliability and flexibility of operational control strategies;generatorgrid coordination standards should be upgraded to improve the coordination between the generator control protection system and the grid;and the simulation methodology should be standardized in future power system security and stability research.

Research on the emergency response mechanism of emergencies in student management in private colleges and universities

With the advancement of the popularization of higher education in China,the development of private higher education institutions has been rapid and dynamic.However,various unexpected events have become increasingly frequent,bringing negative impacts to schools and even threatening their survival and development.Therefore,ensuring the harmonious and stable development of private higher education institutions and improving their emergency management mechanisms for unexpected events is an urgent task.This paper analyzes the relevant issues and causes regarding the management of unexpected events in private higher education institutions from six aspects:emergency awareness,organizational structure,plan formulation,training and drills,supervision and evaluation,and post-incident handling and accountability.Based on these analyses,the paper further proposes corresponding strategies from three levels:prevention,response,and recovery,aiming to provide theoretical references of value for enhancing the governance system and capacity of private higher education institutions in managing unexpected events.

Identification of critical nodes for cascade faults of grids based on electrical PageRank

In this paper,the electrical PageRank method is proposed to identify the critical nodes in a power grid considering cascading faults as well as directional weighting.This method can rapidly and accurately focus on the critical nodes in the power system.First,the proposed method simulates the scenario in a grid after a node is attacked by cascading faults.The load loss of the grid is calculated.Second,the electrical PageRank algorithm is proposed.The nodal importance of a grid is determined by considering cascading faults as well as directional weights.The electrical PageRank values of the system nodes are obtained based on the proposed electrical PageRank algorithm and ranked to identify the critical nodes in a grid.Finally,the effectiveness of the proposed method is verified using the IEEE39 node system.The proposed method is highly effective in preventing the occurrence of cascading faults in power systems.

Characteristic Analysis of UHVAC/DC Hybrid Power Grids and Construction of Power System Protection

Strong DC coupling with weak AC and large-scale renewable energy integration are the two significant characteristics of ultra-high-voltage AC/DC(UHVAC/DC)hybrid power grids in China.Strong coupling between AC and DC grids and the different integration performance of renewable energy sources have profoundly changed the stability characteristics of the power system.The traditional stability control system is inadequate for the stability control of UHVAC/DC power grids.This paper analyzes the requirements for constructing an integrated defense system in a UHVAC/DC hybrid power grid(i.e.power system protection).The definition,connotation,and designing principles of power system protection are put forward.The relationship between the power system protection and the traditional three-defense lines is investigated.The design principles,general hardware structure and main functions of a power system protection are presented.Key problems and technologies are specified in the construction of the power system protection.