The document discusses different types of leakage flux that occur in rotating electrical machines. It describes leakage flux as any magnetic flux that does not contribute to the useful power transfer in the machine. Several types of leakage flux are covered, including pole leakage flux, slot leakage flux, tooth-tip leakage flux, zig-zag leakage flux, overhang leakage flux, and rotor bar leakage flux. The document emphasizes that minimizing leakage fluxes is important for optimal machine design and performance.

1. LEAKAGE FLUX IN ROTATING
MACHINE
Kongunadu College of Engineering & Technology LEAKAGE FLUX IN ROTATING MACHINE 1
Content:
 Introduction to leakage flux.
 Different types of leakage flux and steps to minimize the leakage
fluxes.
 References

2. INTRODUCTION
• In machines, there are 2 parts to which
leakage fluxes
• i) Main Poles ii) Armature flux
• Flux linkages in main pole- D.C motor- stator
• Synchronous machines- rotor
• Flux is generated by main poles entering the
armature passing through the airgap is called
useful flux
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3. POLE LEAKAGE FLUX
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4. LEAKAGE FLUX IN ARMATURE
• Armature carries the distributed winding and
its slotted hence the airgap is not uniform.
• Many types of leakage fluxes associated with
an armature.
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5. SLOT LEAKAGE
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6. SLOT LEAKAGE
• Leakage flux associated with stator and rotor
conductors flowing across the slots having
path from tooth to tooth.
• Flux path is perpendicular to path of the main
flux
• Leakage depends on the shape of the slot
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7. Tooth-tip leakage
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8. Tooth-tip leakage
• Leakage flux flows from tip of the one tooth to
the adjacent tooth tip, surrounding all the
conductors.
• This type of flux more in machines where
airgap is larger.
• Airgap is very narrow hence tooth-tip flux is
low. eg. Induction machine
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9. ZIG-ZAG LEAKAGE
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10. ZIG-ZAG LEAKAGE
• Wound rotor machines, both stator and rotor
are slotted for accommodating the windings.
• Flux takes path which alternates between
stator teeth and rotor teeth.
• This path zig-zag in nature.
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11. Over hang leakage
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12. Over hang leakage
• Design the stator and rotor windings, the end
conductors are necessary.
• Flux associated with end conductors is
overhang leakage flux.
• No overhang- SQIM
Kongunadu College of Engineering &
Technology
LEAKAGE FLUX IN ROTATING MACHINE
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13. Rotor bar leakage
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14. Rotor bar leakage
• Leakage flux exists across the rotor bar circuit.
• Contributes to decide the starting
performance of the machine.
• Mainly responsible for leakage reactance
• A.C machines affects steady state and starting
performance must be considered at the time
of designing the machine.
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15. Conclusion:
The different types of leakage flux is explained in detail with suitable
diagrams.
References:
1. P. C. Sen., ‘Principles of Electrical Machines and Power Electronics’, John Wiley &
Sons, 1997.
2. Deshpande M. V., “Electrical Machines” PHI Learning Pvt. Ltd., New Delhi, 2011.
3. P.S. Bimbhra, ‘Electrical Machinery’, Khanna Publishers, 2003.
4. S.Sarma & K.Pathak “Electric Machines”, Cengage Learning India (P) Ltd., Delhi,
2011.
5. U.A.Bakshi&M.N.Bakshi “Electric Machines-I”,Technical publications,2015.
6. Other Web Sources
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