Research On The Key Problems Of Relay Protection Configuration And Setting Calculation For Generator And Transformer In Pumped Storage Power Station

Pumped storage power station has many important functions,such as peak shaving and valley filling,frequency modulation and phase modulation,accident reserve and so on.It plays an irreplaceable role in ensuring the safe and stable operation of power grid.The construction of pumped storage power stations in China has entered a peak period,and more and more power plants will be put into operation.During the operation and maintenance of pumped storage power stations in recent years,many problems have been exposed,especially in the configuration and setting calculation of generator-transformer protection,which need to be analyzed and improved in detail.This paper first briefly introduces the working principle of pumped storage power station;through some examples,introduces the role of pumped storage power station in the power grid;analyzes the problems faced by pumped storage power stations,and points out that the existence of these problems affects the pumped storage power station.The operational reliability of group protection has higher requirements,and corresponding improvement strategies need to be proposed.This paper analyzes the general configuration of generator-transformer protection in pumped storage power station,analyzes several relay protection tripping events in detail,points out the problems existing in the functional configuration of relay protection,puts forward suggestions for improving the protection configuration of generator-transformer protection and clarifies the generator-transformer protection of pumped storage power station.Typical configuration and outlet mode of protection,especially the necessity of rotor grounding protection and zero-sequence voltage protection on low-voltage side of main transformer are analyzed,which corresponds to the typical configuration of generator-transformer protection,and other issues needing attention in the configuration of transformer protection are expounded in detail.In this paper,the technical standards for setting calculation of generator-transformer protection in pumped storage power stations are analyzed,and the existing problems in setting calculation are pointed out.A typical case of low frequency overcurrent protection setting is analyzed,and the setting method is clarified.This paper also analyzes the setting and coordination of zero sequence voltage protection of generator stator and zero sequence voltage protection of low voltage side of main transformer,and gives the concrete coordination principle.In addition,for a long time in the transformer non-electric protection setting lack of basis,through the collection and collation of relevant literature and combined with the actual situation,given the specific setting standards.