Architecture Design And Integration Of System Protection Strategy Assessment Software For AC/DC Hybrid Power Systems

Due to the reverse distribution of power resources and load demand in geographical location,China has implemented the West-to-East Power Transmission Project.Considering the advantages of DC transmission in long-distance and large capacity transmission,DC transmission has become the main form of power transmission between the West and the East.With the access of new energy power generation and flexible load,and the formation of strong AC / DC coupling at the sending and receiving ends,the uncertainty of power grid operation mode is gradually increasing.DC locking faults are easy to occur in the operation of DC transmission system,which lead to global risk.In this case,coordinated check of three defense lines and system protection is necessary,so as to propose a reasonable stability control strategy according to the actual operation mode of power grid.In this paper,the architecture of system protection and the control strategy in AC /DC hybrid power grid are studied,based on the above research,the software of “Three Defense Lines and System Protection Collaborative Assessment” for AC / DC hybrid power grid system protection assessment is developed.It can make the assessment analysis and aided decision for various DC locking faults,which may occur in AC / DC hybrid power grid.The main research contents of this paper are as follows :First,an optimization method of system protection strategy considering multi resource coordinated control is proposed.According to the architecture of system protection and strategy,the model for the DC locking scenarios that may occur in the power grid are constructed.According to the particle swarm optimization algorithm,the control strategy are optimized by optimizing multi-DC emergency control,load shedding at the receiving end,pump shedding and other measures.Finally,the effectiveness of the algorithm is verified by the analysis of power grid examples.Second,the application modules and middleware interface of the system protection strategy assessment software are developed.Through the development of software modules and the interface,the software can make human-computer interaction and assess the system protection strategy,which can help make aided decision when DC blocking faults occurs.Finally,the system protection strategy assessment software is developed based on the new generation control platform developed by the State Grid.The software uses the actual Northwest-East China asynchronous interconnected power grid model to carry out field deployment and trial operation in the analysis and decision center.The software can analyze the system protection strategy for the possible DC locking scenarios in the actual power system,and put forward the corresponding aided decision strategy,so as to provide reference for dispatchers.