Improvement Of GIS Loop Resistance Testing Device And Its Application In The Field

With the rapid development of electric power system,high voltage and large capacity are conductive connecting piece is widely used,the most typical GIS system of the conducting rod,high voltage circuit breaker and isolating switch.Conductive connection is the key to the electrical connection in the power syst em,which directly affects the reliability of power supply,and its importance is self-evident.Therefore,it is of great significance to ensure the normal operation of conductive connection parts in the security and reliability of power network.In recent years,although the manufacturing materials and processes of GIS conductive connectors have been greatly improved,but in the actual installation process of GIS,due to the depth of the internal conductive rod insertion is not enough,resulting in the fai lure of the equipment.In addition,the oxide film and burr generated on the contact surface,the pressure between the switch contact is insufficient,and it is also an important cause of the power grid accident.The above failures can be summed up as a co mmon feature,that is,the conductive connection piece of the conductive circuit resistance is too large.The circuit resistance of the GIS conductive connection piece is composed of the contact resistance of the connecting piece and the resistance of the connecting wire.As the contact resistance is far greater than the connection line resistance,therefore,the resistance of the conductive circuit is mainly determined by the contact resistance.At present in the project,the measurement of the contact re sistance is basically the use of DC voltage drop method,by switching circuit,etc.the 220 V voltage source is converted to 100 A to 600 A constant current source,used to do the measurement of current.Because the current is small,it is not enough to expos e the defect of the contact,which can not reflect the contact condition of the contact.This paper in view of the existing DC voltage drop method can not completely exposed contact defects,in GIS research is electrically connected to the conductive loop resistance based on the proposed to super capacitor as the core,improve the existing loop resistance testing device,impulse current source contact measuring contact resistance to closer to the actual working situation,than the ordinary direct to reaction contact the actual contact state,exposed defects in DC measurements could be exposed,in GIS conductive connector fault reason,achieve a purpose,planned,targeted to GIS for modification and operation maintenance,improve the reliability of GIS device and power system operation.