Sensor-Based Cables for Underground Reliability of Electricity Infrastructures (SECURE) takes aim at a fundamental problem: utilities rely on miles of aging underground cables to distribute electricity, with no cost-effective way of telling which are in danger of failing.
The scale of the problem is vast — PG&E alone maintains 75,000 miles of high-voltage cable. An interdisciplinary team at UC Berkeley is investigating the causes of cable failure and developing an intelligent, economical sensor-based system for spotting early-stage problems, allowing utilities to fix or replace cables before major damage and widespread outages occur.
One precursor to cable failure is a phenomenon known as “treeing.” Electrical trees are hollow channels that spread quickly through cable insulation in a path that looks like the branches of a tree, developing over hours or weeks. They are a direct cause of arcing, flashover, and ultimately failure. Water trees are similar; these water-filled tubes can propagate for years, permeating the entire layer of insulation and weakening its dielectric properties. An electrical surge can convert them into electrical trees, leading to cable failure.
The SECURE project is exploring the science behind such cable deterioration, identifying measurable predictors of failure, and employing MEMS, energy scavenging, and wireless sensing technologies to discover, evaluate, and prevent cable degradation.