Mechanical Testing and Evaluation of Braced Line Post Assemblies - - PowerPoint PPT Presentation

SEPTEMBER 5 - 7, 2018

Mechanical Testing and Evaluation of Braced Line Post Assemblies Composed

• f Non-Ceramic Insulators
• R. A. Bernstorf

Hubbell Power Systems

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Braced Line Post Family

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Calculation Template

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Buckling Loads and Equations

• ΣFx = Pc*cos(α) – ST*cos(β) = 0
• ΣFy = Pc*sin(α) + ST*sin(β) – V = 0
• Pivoting Horizontal V:

– Buckling Load = π2*E*I/(1.03*L2)

• Fixed Base Horizontal V:

– Buckling Load = π2*E*I/(1.02*L2)

• Braced Line Post:

– Buckling Load = π2*E*I/(1.33*L2)

SEPTEMBER 5 - 7, 2018

SEPTEMBER 5 - 7, 2018

SEPTEMBER 5 - 7, 2018

SEPTEMBER 5 - 7, 2018

2 4 6 8 10 12 14 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000 Longitudinal Deflection (in) Vertical Load (lb)

Braced Line Post - 230 kV

L = 98.5 inches α = 12⁰ β = 50⁰

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0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2000 4000 6000 8000 10000 12000 Deflection (in) Applied Vertical Load (lb)

230 kV Braced Line Post - Fixed Point Loading

L = 98.5 inches α = 12° β = 50°

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5 10 15 20 25 30 2000 4000 6000 8000 10000 12000 14000 Longitudinal Deflection (in.) Vertical Load (lb)

250 Braced Line Post - 345 kV

250 Loading

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0.2 0.4 0.6 0.8 1 1.2 1.4 2000 4000 6000 8000 10000 12000 14000 16000 18000 Longitudinal Deflection (in) Applied Vertical Load (lb)

345 kV Braced Line Post - Fixed Point Loading

L = 110 inches α = 12° β = 44°

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Series 300 BLP - 345 kV

Series 300 BLP

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SEPTEMBER 5 - 7, 2018

Conclusions

• There are no standards regarding BLP testing.
• Fixed point loading offers very high buckling strength.
• Free weight loading offers lower buckling strength.
• In the absence of standards, Utilities must assess their own

requirements.