Research On Busbar Protection For Chezhoushan Substation

Busbar protection is an important protection of power system,it plays a very critical role in the safety and reliability of the power grid.When busbar internal short circuit,reliable and rapidly remove the busbar fault,which can effectively improve the stability of the system,reduce the impact range of fault.Our conventional busbar protection is divided into high,medium and low impedance type busbar protection,PMH-150(RADSS/S)in the impedance type busbar differential protection,it uses the ratio braking characteristic current differential protection scheme,its rapid and sensitive characteristics to become the representative of the medium impedance busbar protection,in the past period of time is widely used in the power grid.But it has the wiring complex,debugging trouble,the operation and maintenance difficulty,the relay characteristic discrete value big malpractice and the shortcoming,give the regional power grid to bring hidden dangers.Therefore,carry on the thorough analysis research to this type of bus protection,and then carries on the upgrading and transformation has practical value.This paper studied the medium impedance type and microcomputer type in two generations of busbar protection device characteristics,the key analyses the PMH-150(RADSS/S)as representative of medium impedance protection of operation characteristics and work defects.On this basis,combining the characteristics of Chezhoushan substation,it has been studied that problem and coping methods that need to be considered of new busbar protection,designed the new bus protection configuration scheme,according to the configuration of the protection of the busbar selection and upgrading reform;the principle of setting calculation of new busbar protection is studied,and the setting calculation of the protection device is carried out.New bus protection exist in the actual operation "when voltage switching abnormal cases,charging an empty bus will tripping operation accidentally run bus" problem.In order to solve this problem this paper proposed that external charging protection device of charging the protection linking piece,add to " busbar connection current is not included in the small range of differential procedures" of Logic circuits as the improved scheme,and in the device to achieve.Verified by practical,the proposed scheme effectively prevents the new bus protection misoperation.