Research On Power System Simulation Model Segmentation And Interface Algorithm

With the widespread interconnection of power grids across large areas,the interconnection of distributed generators,the popularization of HVDC transmission,and the power electronic equipments are continuously put in.Modern power systems are not only bigger in scale,but also exponentially increasing in complexity,which brings great challenges to the real-time simulation of power systems.In order to realize the real-time simulation of electromagnetic transient in power system,taking power systems with various topological structures as examples,this paper studies the selection of interface algorithm and the optimization of interface algorithm.The specific work is as follows:Firstly,the calculation method of electromagnetic transient simulation model is introduced,including the calculation method of electromagnetic transient network and numerical integration algorithm.The numerical calculation model of electromagnetic transient of AC components and converters is introduced,and the execution time sequence of serial and parallel calculation of power system segment model is introduced.Secondly,presents the calculation principles of transmission line model method,state-space nodal method and ideal transformer model method in the application of power system.The calculation steps of each interface algorithm are explained,and the advantages and disadvantages of each interface algorithm are analyzed.Then,the ideal transformer model method is selected as the model segmentation interface algorithms of power system,but the model segmentation delay affects the stability of ITM algorithm,which brings great difficulties to the application of ITM algorithm in power system.In view of this phenomenon,the stability criterion of ITM algorithm with various topologies and various interface forms is proposed,which are verified by simulation.Through summarizing the stability criterion of ITM algorithm,it is concluded that it is impossible to select suitable interface types for complex systems by using stability criterion.Therefore,several improvement measures for improving stability are discussed,and an improvement measure suitable for AC network is proposed.Finally,the ITM algorithm is applied to HVDC transmission system,large power system and hinge substation.To deal with the large power system numerical instability problem possibly caused by model segmentation delay,a method of error compensation for serial and parallel real-time simulation using dq transformation to reconstruct the signal is proposed,and proposed to use the hybrid integral method to solve the numerical instability problem of segmentation model of the hinge substation.The dynamic behavior of the segmenting model and the original integral model under various conditions is compared,and the offline simulation time of the original model,the serial model and the parallel model are compared.The results show the correctness of the interface algorithm and the effectiveness of the improvement measures.