The knowledge of the cable and damping devices mechanical properties is essential to correctly estimate, dynamic response of overhead transmission lines to wind excitation through numerical models. In particular, conductor self-damping together with damper and spacer dynamic stiffnessand damping properties are assessed through laboratory tests and are used in numerical models both to evaluate the conductor + damping devices dynamic performance and to optimize the damping devices design. The laboratory allows both customized tests and standard tests carried out according to the main International Standards.

INSTRUMENTS & FACILITIES

• 50m long laboratory span
• Programmable Logic Control (PLC)
• Gearing Watson electro-dynamical shaker + amplifier (V617/DSA4-8k)
• Unholtz&Dickie electro-dynamical shaker + amplifier (SA15-S452)
• B&K 1050 controller
• Electromechanical actuator UNIMEC TP7010 MBD with electrical motor 7.5kW 750rpm (conductor tensile load control)
• N. 5 current suppliers TDK Lambda GEN25-400-3P400 (50kW total power) (conductor heating thermal tests)
• Load cell U10M/250kN + HBM Scout 55 (conductor tensile load measurement)
• Kistler 30 kN piezoelectric load cells
• Piezo-accelerometers B&K 4508 with power amplifiers PCB 480E09
• Strain gauges and conditioning modules
• Laser transducers and other displacement transducers
• Temperature sensors
• Various sizes hydraulic actuators and load cells + MTS Flex Test Digital Controllers

CERTIFICATIONS

• Test “Stockbridge Type Dampers Dynamic Characterisation” (ISO9001:2008 certification)
• Test “Stockbridge Type Dampers Effectiveness Test” (ISO9001:2008 certification)

ACTIVITIES

Cable Self-Damping Test

• Decay Method
• Power Method
• Inverse Standing Wave Ratio

Spacer-Dampers Dynamic Characterization

• Stiffness and damping properties
• Stiffness and damping properties at high and low temperature
• Aeolian vibrations and sub-span oscillations fatigue tests
• Simulated short circuit test
• Slip test

Stockbridge Dampers Dynamic Performances

• Damper characteristic curve (Mechanical impedance/Dynamic stiffness with Imposed constant speed or constant displacement)
• Damper effectiveness test

Cable + Suspension Clamp Fatigue Test High Temperature Conductors Thermal Tests

• Linear coefficient of thermal expansion
• Sag curve/knee-point temperature