The Research Of Substation-Area Protection Device For New Generation Smart Substation

With the increasement of the power system's scale and importance in China,the requirements of the power system's reliability and stability become higher.Therefore,the defects of the traditional relay protection are more prominent,and more advanced relay protection schemes and better device performance are needed.As an important part of the hierarchical protection for the new generation of smart grid,the substation protection uses the multi-source information to meet the new requirements.This thesis elaborates the general design scheme of the substation protection device,including the function configuration and hardware architecture.Then,this thesis discusses the key technologies of the station protection device,including the multi-CPU platform technology based on high-speed bus,the implementation of multi-site communication and configuration of substation protection,the preprocessing data technology based on FPGA and the fiber-optic differential protection technology based on HSB bus.According to the abnormal data due to the abominable EMC enviroment,this thesis proposes a better algorithm to resolve the problem,based on the continuity characteristics of the sampling point in sine current.This algorithm has less computation and is more accurate,which can be used in other relay protection devices and enhance the reliability of the power system.What's more,from the point of view of operation and maintenance,this thesis proposes a method of automatic setting,which reduces manual operation and improves the reliability and flexibility of the device.Meanwhile,according to the typical design of substation in power system,the substation protection device based on SAC's EDP system is designed and completed from three aspects: hardware and software structure design of the platform,protection function's configuration and function migration's design.Finally,with using the RTDS real-time simulation system,this thesis establishes the simulation model based on the substation protection control system test specification.The simulation test containes follow items: busbar automatic transfer switch,simple bus protection function,breaker failure function,overload cutting,low-cycle load reduction,multi-faults and abnormal communication,etc.So far the substation protection device in this thesis has been successfully applied in a number of intelligent substations in China,and the operation situation shows the performance of the device is good enough to improve the stability of the power system.