Slashdot Mirror

← Back to Stories (view on slashdot.org)

Superconducting Cables To Carry Power In Detroit

Posted by timothy on from the but-what-kernel-do-they-run? dept.

bewert writes: "Check out [this Knight-Ridder wire story.] This could change electricity distribution economics as we know it. A project is under way to replace 9 major copper power distribution cables with 3 smaller ones made from a high-temperature superconducting material called BSCCO (pronounced bisco). Pretty interesting technology, and one that could have huge implications for reduction of transmission power losses and the need for more generation." Not to mention that it means a 25-fold reduction in the weight of the cables used to carry electricity for a large chunk of Detroit.

1 of 161 comments (clear)

  1. corrections to the engineering of power cables by Anonymous Coward · · Score: 5

    Yikes, let's clean this engineering up.

    1. One of the main reasons for using the HTS cables is space. Detroit Edison needs to increase the current carrying capability at the station, and using the HTS means they get more capacity with the same underground conduit, so they don't have to excavate to improve the circuit. big savings. Plus, the smaller diameter and weight make it easier to pull the cable through the conduit, and eliminates the need for splices in the cable due to maximum pull weights. Bad splices are a common cause of failure in underground cables. Of course, if you are ComEd in Chicago, you just ignore that until the city goes dark...

    2. Cables have higher capacitance than overhead transmission lines, because the conductor is closer to the ground potential. It also has lower inductance for the same reason. There is no external electric field. The sheath is at ground potential, so the field is between the conductor and the sheath.

    3. Long distance cables are typically DC because in high voltage AC cables the voltage increases at the sending end due to the high capacitance of the line. That's why underground AC networks have shunt reactors, to keep the voltage down.
    Although inductance does reduce the maximum power transfer in a circuit, it's due to its affect on voltage.

    4. Although the lossless characteristics of HTS are important, that doesn't by itself make the economics attractive. Avoiding construction costs and pushing more power through the same rights of way due to higher current density is the niche that HTS is currently filling.

    Elvis, the power engineer-nerd.