Optimization Scheme Of Substation Area Control And Protection System For Intelligent Substation

The trend of world's electricity development is the intelligent power grid.Developing smart grid has been the worldwide consensus.At the same time,smart grid construction puts forward higher requirements on power system relay protection.Studying substation area protection has important theoretical and practical significance to adapt to the smart grid development,improve the performance of protection and control system to ensure the safe and reliable operation of power grid.The main research work is as follows:The paper analysis of the structure of intelligent substation.Intelligent substation based on 1EC61850 standard is divided into process layer,spacer layer and station control layer.Using the process layer network and station control layer network which are two independent subnet realize communications within the station.Study the structure of the substation area protection of the existing intelligent station.The functions of the device are divided into redundant protection class,optimized backup protection class,security automatic control class and wide area control class based on different voltage level function positioning.The relationship and coordination of the station protection and the existing intelligent substation area protection system are also studied.The principle of station domain protection based on the current process variable is studied.The differential zone is divided into the boundary differential zone and the element differential zone,and a new differential priority sorting method is introduced to achieve the fast and accurate fault location for the faulty components.Based on the advantages of all station information sharing in intelligent substation,an optimization scheme for circuit breaker failure protection is proposed.First,the action logic of failure protection,the compound voltage atresia condition of the circuit breaker failure protection and the entry condition are analyzed.Two current transformers are configured to detect the flow of a circuit breaker.And the redundancy current of the bus is used to check the current.The original compound voltage closedown condition is added by using the reclosure test without pressure device to detect whether the line has pressure or not.Finally,the effectiveness of the proposed scheme is verified by simulation experiments.Based on the advantages of all station information sharing in intelligent substation,an optimization scheme for substation-area automatic bus transfer is proposed.The charging conditions,discharge conditions,the function configuration of infeed automatic bus transfer device and the function configuration of section automatic bus transfer device are analyzed.A basic method based on substation area information to improve the performance of automatic bus transfer is proposed,and the automatic bus transfer strategy of adaptive stability control system is focused on.The open principle of the automatic bus transfer device based on the change of the bus voltage and the open principle of the automatic bus transfer device based on the feed back current of the line load are proposed.It also proposes a automatic bus transfer switching overloading strategy,a automatic bus transfer strategy with distributed power supply access and a substation-area automatic bus transfer strategy with unconfigured bus protection.The correctness of the proposed method is verified by simulation analysis.Based on the platform of the Institute of relay protection of China Academy of electric power science and research,the type approval test of the current operation substation area control and protection system is carried out.All testing items including structural appearance inspection,protection function test,climate environmental impact test,mechanical environmental impact test and electromagnetic compatibility test were completed.Through the test verification,some problems and shortcomings existed in the existing station area protection devices were found,and the existing problems were analyzed and the solutions were put forward.