The Research On Relay Protection Scheme Based On Electronic Mutual Inductor Of Hejia Transformer Substation

Smart power grid and strong power grid cannot develop without smart substation,and smart substation will be the development direction of future substation.The development of intelligent substation cannot be separated from electronic transformer,which is the basis of current signal and voltage signal detection on the primary side of intelligent substation and the data source of relay protection.Therefore,the safety and reliability of electronic transformer operation is the guarantee of the smooth operation of intelligent substation.As the first three-in-one intelligent substation in liaoning province,the construction and operation reliability and safety of chaoyang hejia 220 kV substation must be guaranteed.Electronic transformer,as the foundation of intelligent substation,is also a new technology.The reliability and safety of its application must be verified theoretically and practically.In this paper,the performance of electronic transformer is tested from the aspects of its structure,characteristics,laboratory test and real environment test.Compared with the traditional electromagnetic transformer,the electronic transformer has no magnetic saturation problem.At the same time,its measurement dynamic range is larger,the measurement result is more accurate,and effectively improves the sensitivity and reliability of relay protection.Firstly,this paper analyzes the relationship between the electronic transformer and the intelligent substation and the related technology.It confirms that the electronic mutual inductor is the foundation of the construction of Smart Substation.It compares and analyzes the traditional transformer and electronic transformer.It completes the analysis of the principle and classification of electronic transformer.The structure and characteristics of electronic transformer are discussed.Secondly,it studies the influence of electronic mutual inductor on relay protection.It completed the electronic transformer under laboratory conditions for application testing and application testing environment in ho.The field detection principle and method of electronic voltage transformer and electronic current transformer are discussed.The error adjustment method of electronic instrument transformer is analyzed.It realizes the error adjustment of electronic mutual inductor from two aspects of hardware and software.At the end of this paper,it presents the improvement of the relay protection scheme of intelligent substation based on electronic transformer.It according to the specific situation and outlet of the ho variable voltage respectively,electronic transformer configuration and line spacing of 220 kV and the parent of 66 kV level circuit is designed.The use of 220 kV bus card magnetic optical glass type electronic transformer.Rogowski coil type electronic transformer on 66 kV bus.It gives a detailed design sketch map.It analyzes the protection scheme of electronic transformer based on home design.It gives the circuit protection,transformer protection,high voltage shunt reactor protection and other implementation plans.Finally,the application of the electronic transformer in the Hejia 220 kV substation is carried out,and the field test data is analyzed.It is determined by testing that its indicators meet the requirements for use.Through the actual test,the problems that the electronic transformer needs to pay attention to in practical application are summarized.Including the influence of the quality of the boosting power supply on the error,the acquisition card and the merging unit configuration problem,the capacitor voltage division electronic voltage transformer error adjustment problem and the Rogowski coil principle electronic current transformer primary current access point selection problem.