Vacuum circuit breaker’s solenoid force evaluation

29/12/2009

Deliverable 1

• Report on the compliance of the brand new trip coil and close coil to specification and their safety factors as derived from the laboratory experiments

EPE Switchgear -11 & 33KVClosing and Opening Coil

32 mm

Pull gauge

coilStopper block

Plunger

Trip hook/strike

16Kgf

232

2)(3.5)29(2(2205)7104 3.5A)F(32mm

2x

2Ai2Noμi)F(x,

EPE solenoid Force and Stroke EPE solenoid Force and Stroke RelationshipRelationship!!

μo is the Permeability of free spaceN is the number of coil turnsA is the effective cross sectionali is the max current x is the stroke length of the plunger

N.B. Data sheet of the coil attached in appendix

! A. E. Fitzgerald, Electric Machinery: The process, devices and systems of electromechanical energy conversion, McGraw Hill 1971

7.5Kgf

28

2)(3.5)23(2(350)7104 3.5A)F(8mm

2x

2Ai2Noμi)F(x,

ETAH solenoid Force and Stroke ETAH solenoid Force and Stroke RelationshipRelationship!!

μo is the Permeability of free spaceN is the number of coil turnsA is the effective cross sectionali is the max current x is the stroke length of the plunger

N.B. Data sheet of the coil attached in appendix

! A. E. Fitzgerald, Electric Machinery: The process, devices and systems of electromechanical energy conversion, McGraw Hill 1971

Stroke length (x) mm

Forc

e in

Kgf

EPE Solenoid Force & Amps vs Plunger positionEPE Solenoid Force & Amps vs Plunger position

Forc

e in

Kgf

TAMC) (ETAH) Solenoid Force & Amps vs Plunger positionTAMC) (ETAH) Solenoid Force & Amps vs Plunger position

Stroke length (x) mm

Photo Gallery

New Solenoid testing

Appendix – Solenoid Data Sheet