Search

With the continuous increase of wind power grid-connected scale, in order to sense the operational risk of large-scale wind power and grid-connected AC/DC hybrid system online, this paper proposes a method based on probabilistic power flow to calculate the cascading failure risk analysis method. Firstly, based on the sequential operation theory, the power system probabilistic load flow calculation model of large-scale wind power grid-connected is constructed, and then the accident chain probability risk index is constructed by combining the short-circuit ratio calculation and fault search selection of AC/DC hybrid system. Finally, the accident chain search process combining probability flow and short circuit ratio is constructed, and the actual calculation is carried out on the IEEE 39-node grid model and the actual operating conditions are simulated. The operational risk of the actual AC/DC hybrid system can be obtained, which is verified by the paper. effective methods of analysis and rationality of cascading failure risk, conclusions can contain large AC and DC-scale wind power hybrid system operation arrangements to provide guidance.

The continuous construction of power grid brings up sharp rise in the scale of cross-regional electricity transmission in China. This circumstance highlights the issue of power system risk and security management and control under a "strong DC and weak AC" system structure. With weak reusability and extensibility, the current online security and stability analysis software is not able to integrate and use existing data resources to conduct global analysis for the whole grid. Based on clustered and servitized dispatching and control platform utilizing unified grid data and model, this paper creates a framework of unified analysis system for power grid risk online early warning. The framework realizes unified analysis of grid risk online early warning with shared system data from the entire power grid. By servitizing business scenarios, application functions and the support platform, the system is capable of compositing various functional modules. The solution proposed in this paper solves the problem of independent calculation and enormous work load of stability analysis, and the lack of data sharing and interaction among different dispatching organizations.

In allusion to the problem which is hard to identify the structure of the system for the AGC, this paper propose a new controller which direct apply the fuzzy control on the procedure of AGC, and through the thorough research on the method of fuzzy control, the new controller use a method which combine the member-ship function and variable universe to optimize the new fuzzy controller, this method could lead the controller accommodate the change of the structure or parameter of power system and the change of operation mode. The simulation results attest to the new control method could enhance the robustness and adaptability of the control system, and enhance the control performance at the same time.