Current harvesting transformer with protection from high currents
AssigneeSentient Energy, Inc.
InventorRonald S. Rumrill
Life of this patent
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Abstract
A power distribution monitoring system is provided that can include a number of features. The system can include a plurality of monitoring devices configured to attach to individual conductors on a power grid distribution network. In some embodiments, a monitoring device is disposed on each conductor of a three-phase network and utilizes a split-core transformer to harvest energy from the conductors. The monitoring devices can be configured to harvest energy from the AC power grid and saturate the magnetic core of the transformer in the event of a fault condition or when harvested power is not needed. Methods of installing and using the monitoring devices are also provided.
Claims18
A method of monitoring a power grid distribution network, comprising the steps of:
- harvesting energy from a conductor line of the power grid distribution network with a split-core transformer of a monitoring device installed on the conductor line;
- powering the monitoring device with the harvested energy;
- during normal conductor line conditions, creating a DC current in the split-core transformer with a half-wave control circuit of the monitoring device to saturate a magnetic core of the split-core transformer during positive half-cycles to limit harvested energy;
- and
- in the event of fault conditions on the conductor line, creating the DC current in the split-core transformer with a full-wave control circuit of the monitoring device to saturate the magnetic core of the split-core transformer during negative and positive half-cycles to prevent harvested energy.
A method of monitoring a power grid distribution network, comprising the steps of:
- harvesting energy from a conductor line of the power grid distribution network with a harvesting coil wound around a split-core transformer of a monitoring device installed on the conductor line;
- powering the monitoring device with the harvested energy;
- creating a DC current in the harvesting coil with a half-wave control circuit of the monitoring device to short the split-core transformer to limit harvested energy during positive half-cycles;
- and
- in the event of an abnormally high current on the conductor line, changing the half-wave control circuit to a full-wave control circuit and creating the DC current in the harvesting coil with the full-wave control circuit to short the split-core transformer to limit harvested energy during positive and negative half-cycles.
A power line monitoring device, comprising:
- a split-core current transformer comprising first and second core halves, the split-core transformer being configured to harvest energy from a conductor line of a power grid distribution network to power the power line monitoring device;
- secondary windings disposed around at least the first core half of the split-core transformer;
- and
- a control circuit electrically coupled to the secondary windings, the control circuit configured to create a DC current to short the secondary windings to limit harvested energy during positive half-cycles, and in the event of an abnormally high current on the conductor line, being configured to create the DC to short the secondary windings to limit harvested energy during positive and negative half-cycles.
Dependencies are inferred from the claim text.