On The Strategy Optimization Of Busbar Automatic Transfer Switch In Auxiliary Power System Of Large Power Station Using Wide Area Control

The operation mode of auxiliary power system in power station is flexible,especially for large power stations.Due to the large difference in the operation modes of the power generation system during the maintenance period and the full generation period,the operation modes of the auxiliary power system differ accordingly.This makes the design of Busbar Automatic Transfer Switch(BATS)in auxiliary power system face many challenges: it needs to adapt to the flexible operation mode of the system to ensure the reliability of the system in small modes.At present,most power stations adopt local configuration of Busbar Automatic Transfer Switch(BATS),which only considered switching reactions between adjacent buses.For buses in a longer distance,even if a tie line exists between two bus sections,artificial operation is adopted to restore power supply so far.Current BATS fails to make full use of the redundant configuration of the primary system in the power station,and is even far away from the promotion of intelligent mode and information sharing technology in the current power system.To address this:Firstly,this paper analyzes the problems existing in traditional BATS in auxiliary power system and demonstrates the necessity of regional control strategy.In addition,the function configuration and demand analysis of the new mode of BATS are built up and proceeded in detail.Combined with the characteristics of the auxiliary power wiring in large power stations,the control modes of BATS based on regional information is constructed.A potential combination of regional BATS and auxiliary power protection is proposed.The compatibility between the regional and the station BATS is analyzed,and various adaptive solutions are proposed.In addition,an identification method based on on-line verification is raised,which could make BATS adapt to the information distortion and modify the error information adaptively.Based on the above investigation,this paper also studied the construction of general regional BATS in auxiliary power and makes it adapts to the primary system well,which breaks through the limitations of station area and makes a good advantages of information sharing.Secondly,the actual auxiliary power system is abstracted and simplified,and the data structure is constructed.Analyzing the characteristics of the auxiliary power system,a matrix method suitable for the topological analysis of the auxiliary power system network is proposed.This method can identify the power loss area,analyze the network connectivity,search the recovery path of the auxiliary power system,and further build a model for power flow calculation in the auxiliary power system,which was complex under differed operation modes before.It provides theoretical basis and data support for the safety and stability analysis of auxiliary power system after automatic switching.Finally,an algorithm model based on heuristic search algorithm is proposed,and an automatic generation system of BATS based on safety stability and topology constraints is constructed by MATLAB simulation.When the bus lose voltage due to certain system fault,the auto-generation system could create multiple solutions based on reliability and economy and chose the optimal reactions to achieve the fast self-healing of auxiliary power system.The strategy generation method can improve the reliability of the auxiliary power system and make it more adaptive.It can also fully integrate and utilize the equipment resources of the whole plant,reduce the investment in the primary equipment of the new and expansion projects,greatly reduce the operation and maintenance cost and workload,and provide ideas for the realization of the intelligent power station.