The objectives of this research performed on field-aged cable cross linked polyethylene cable samples, removed from service by DSTAR member utilities, were to:
- Evaluate the linkage between impulse duty and insulation degradation in field-aged cross linked polyethylene primary distribution cable.
- Determine if a recently developed partial discharge site detector can successfully assess cable insulation aging.
The objectives of the project were to: 1) investigate the impulse performance of semi-conductive (semi-con) jacketed cable when subjected to impulses from the overhead system, 2) assess the susceptibility of semi-con cable to induced neutral currents during ground strokes, and 3) quantify secondary surge currents caused by nearby ground strokes to the primary semi-con cable circuit.> Read More →
Field tests, augmented by simulation studies, were performed to:
- Characterize voltage transients generated by routine cable and capacitor switching operations.
- Compare the performance provided by different switching devices.
- Generate guidelines for switching practice and arrester application which can minimize switching surge overvoltages applied to underground distribution systems.
Based on extensive field tests, this research had the following objectives:
- Characterize ferroresonant behavior when grounded-wye padmount transformers are switched.
- Develop formulas for estimating ferroresonant overvoltage magnitude as a function of transformer and cable parameters.
- Provide detailed guidelines specifying the maximum cable length which can be switched with a given transformer without exceeding a critical overvoltage magnitude.