Energy harvest split core design elements for ease of installation, high performance, and long term reliability
A power distribution monitoring system is provided that can include a number of features. The system can include a plurality of power line sensing devices configured to attach to individual conductors on a power grid distribution network. In some embodiments, the power line sensors can include a split-core transformer. In some embodiments, a power line sensing device is disposed on each conductor of a three-phase network. The sensing devices can be configured to measure and monitor, among other things, current and electric-field on the conductors. Methods of installing, sealing, and protecting the split-core transformers of the power line sensors are also discussed.
1. A power line sensing device, comprising:
a split-core transformer comprising a first core half and a second core half, the split-core
transformer configured to harvest energy from a power line conductor;
a clamping mechanism configured to join the first core half to the second core half around the power line conductor, the clamping mechanism further comprising:
a hard stop mechanism positioned along an exterior surface of the first core half; and
a screw that, when tightened, applies pressure across a diameter of the split-core transformer to clamp the first core half and the second core half together;
a spring coupled to the hard stop mechanism and configured to apply a force against the power line conductor to press the power line conductor against the split-core transformer, the spring spanning across the split-core transformer to a spring catch; and
electronics configured to receive energy harvested from the split-core transformer to power the power line sensing device.
2. The power line sensing device of claim 1 further comprising an opening in the screw configured to receive a lineman's hot-stick, wherein rotation of the hot-stick advances the screw into the second core half.
3. The power line sensing device of claim 1 further comprising a grip pad disposed on an interior of the split-core transformer, the grip pad configured to increase friction between the split-core transformer and the power line conductor.
4. The power line sensing device of claim 1 wherein the clamping mechanism comprises a band clamp configured to surround a perimeter of the split-core transformer.
5. The power line sensing device of claim 1 , comprising:
the first core half comprising a first core face and the second core half comprising a second core face, wherein the first core face is configured to mate with the second core face when the first core half is joined to the second core half; and
a first perimeter seal disposed along an entire length of the first core face of the first core half, and a second perimeter seal disposed along an entire length of the second core face of the second core half, the first and second perimeter seals configured to join together to seal the first and second core faces off from contaminants.
6. The power line sensing device of claim 5 wherein the first and second perimeter seals form an o-ring: seal around the first and second core faces.
7. The power line sensing device of claim 5 wherein the first and second perimeter seals encircle both an interior perimeter and an external perimeter of the first and second core faces.