Simulation And Research On Secondary System Performance Of New Generation Smart Substation

As an important part of Cyber-Physical Power System（CPPS）,the coupling and interaction between energy and information flows in smart substation have become increasingly inseparable with the steady development of advanced sensing and communication technologies.Compared to traditional smart substation,the new generation smart substations places greater demands on the integration of secondary system equipment and the hierarchy of information.As the information flow in secondary system possesses the key functions of reflecting and regulating the energy flow in primary system,the performance of the communication network in secondary system greatly restricts the reliability of the new generation smart substation in the context of digital information transmission and sharing.Therefore,clarifying the interoperability logic of the secondary system network and analysing the correctness and real-time performance of information transmission are of great value and significance in optimising the overall substation operational performance.In this thesis,key issues in substation secondary system network such as device modeling,traffic analysis and delay optimising are addressed and research methods on the communication network performance of new generation smart substation are formed,combining the mathematical modeling ideas and simulation analysis methods.This thesis first clarifies the interoperability and structural modeling requirements of each intelligent electronic device（IED）in secondary system network,as well as the operational logic at each network level.Based on the original finite state machine,a general method which can be applied to IED simulation modeling is then formed.And a set of IED simulation models satisfying the IEC 61850 standard is constructed in the OPNET network simulation platform,which is conducive to the simulation analysis of smart substation.Secondly,the characteristics of message traffic in process level network are clarified and summarized,and a mathematical model of injected traffic is constructed for the characteristics of different IEDs in sending messages.With the traffic models of process and bay level devices,a performance evaluation method based on the process level network traffic is proposed to achieve the network traffic analysis of smart substation primary and secondary systems under different operating states,and the simulation methods constructed in chapter two are used for verification.Finally,considering the real-time performance of SV（Sampled Value）message cascade transmission under complex network situation,as well as the impact of bus voltage cascade transmission delay on the data aggregation of merging unit,methods to reduce and compensate for the impact of delay are proposed in terms of equipment connection topology and information processing decisions.A comparative analysis of the real-time performance and reliability of both hardware and software solutions is carried out,and the applicability of both solutions is summarized.