Study On The Strategy Of 10kV Standby Automatic Switching Under The Influence Of Small Power Supply

With the rapid development of economy,the demand of power supply reliability is higher and higher.As an important guarantee of power supply reliability,relay protection plays an important role in the safe and stable operation of power system.Generally,the current operation status and the long-term development of the substation need to be considered in the design of relay protection.However,due to the rapid development of the current distribution network,especially the access of various small power sources,most of the current 110 kV substation relay protection in operation is difficult to adapt to the current situation,so it is impossible to give full play to its value.Therefore,in this paper,the configuration of 110 kV substation relay protection device and the adverse effect of small power supply on substation relay protection are studied in depth,and the intelligent backup self switch solution based on real-time power judgment is proposed,and the protection strategy of intelligent backup self switch is simulated and analyzed,which proves the effectiveness and reliability of the intelligent backup self switch proposed in this paper.Firstly,it introduces the background and significance of the research,the current situation and problems of the research at home and abroad,which lays the foundation for the follow-up research.This paper introduces the related theory of standby automatic switching,mainly including the brief introduction of standby automatic switching device,basic requirements of standby automatic switching,classification of standby automatic switching,operation conditions of standby automatic switching,configuration of standby automatic switching in 110 kV typical substation.This paper analyzes the characteristics of small-scale water conservancy power plants,solar power plants,wind power plants and garbage power plants,presents the protection configuration of typical 110 kV substation,and analyzes the impact of small power supply access on 10 kV standby automatic switching,110 kV incoming power side protection and 10 kV outgoing line protection of 110 kV substation.Based on the current main functions and logic of 10 kV standby automatic switching,a new strategy of 10 kV standby automatic switching is proposed.This paper analyzes the new strategy of 10 kV standby automatic switching,which not only solves the adverse effects of small power supply on 10 kV standby automatic switching itself,but also solves the adverse effects on 110 kV incoming line power side protection.According to the function analysis of the new strategy of 10 kV standby automatic switching,the standby automatic switching is divided into several modules,and the design of main modules such as TV disconnectionmonitoring,small power supply of joint tripping,bus voltage loss trip main transformer switch,over-current protection,charging protection,standby automatic switching and charging is given.This paper discusses the action strategy of 10 kV standby automatic switching,and gives the action flow chart.This paper introduces the electromagnetic transient simulation software PSCAD briefly,and builds the relevant model to simulate and analyze the impact of small power supply on 10 kV standby automatic switching,the impact on 110 kV incoming line power side protection,and the application effect of the new strategy of the standby automatic switching,to verify the effectiveness and practicability of the standby automatic switching proposed in this paper.