Apparatus and method for harvesting power from an overhead transmission conductor

• US 9,214,827 B2
• Filed: 02/21/2013
• Issued: 12/15/2015
• Est. Priority Date: 02/22/2012
• Status: Active Grant

• Current Assignee: Electric Power Research Institute Incorporated
• Original Assignee: Electric Power Research Institute Incorporated
• Inventors: Phillips, Andrew John, Engelbecht, Chris, Engdahl, Eric
• Primary Examiner(s): Whitmore, Stacy
• Application Number:
  US13/773,131
• Publication Number:
  US 20130214736A1
• Time in Patent Office: 1,027 Days
• Field of Search: 320/107, 320/109, 320/113
• US Class Current: 1/1
• CPC Class Codes: H02J 11/00 Circuit arrangements for providing service supply to auxiliaries of stations in which electric power is generated, distributed or converted
• CPC Class Codes: H02J 50/001 Energy harvesting or scavenging
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/402 the two or more transmitting or the two or more receiving devices being integrated in the same unit, e.g. power mats with several coils or antennas with several sub-antennas
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0042 characterised by the mechanical construction
• CPC Class Codes: H02J 7/0044 specially adapted for holding portable devices containing batteries H02J7/0045 takes precedence
• CPC Class Codes: H02J 7/0045 concerning the insertion or the connection of the batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/167 Systems integrating technologies related to power network operation and communication or information technologies for supporting the interoperability of electric or hybrid vehicles, i.e. smartgrids as interface for battery charging of electric vehicles [EV] or hybrid vehicles [HEV]

Abstract

An apparatus and method of harvesting power for charging batteries of a robot traversing an overhead transmission conductor is disclosed. The apparatus is adapted to harvest power from the overhead transmission conductor and provide a DC voltage for charging a battery and includes a first shield wire bonded to a structure that is grounded to the earth, a second shield wire isolated from the structure, and a charging station. The first shield wire, second shield wire, structure, and earth form a loop into which induced currents flow. The charging station is electrically connected to the second shield wire and adapted to convert induced currents flowing along the second shield wire into a DC voltage for charging a battery of the charging station.

Claims

1. An apparatus adapted to harvest power from an overhead transmission conductor that is supported by a plurality of spaced-apart structures that are grounded to the earth, and to provide a DC voltage for charging a battery, comprising:

(a) a first shield wire extending between and electrically bonded to the structures;

(b) a second shield wire extending between and electrically isolated from the structures, wherein the first shield wire, second shield wire, structure, and earth form a loop into which induced currents flow in response to AC current flowing in the overhead transmission conductor; and

(c) a charging station electrically connected to the second shield wire and adapted to convert induced currents flowing along the second shield wire into a DC voltage for charging a battery of the charging station.

2. The apparatus according to claim 1, wherein the second shield wire is terminated at opposing ends by a capacitor to create an insulated charging section.

3. The apparatus according to claim 1, wherein the battery of the charging station includes a first terminal bonded to the structure and a second terminal of the battery bonded to the second shield wire.

4. The apparatus according to claim 3, wherein the charging station includes:

(a) a 60 Hz blocking filter positioned between the battery and the structure to prevent 60 Hz currents from flowing into the battery of the charging station; and

(b) a current transformer and associated power electronics to electrically connect the charging station to the second shield wire and extract the induced currents flowing through the second shield wire and charge the battery.

5. The apparatus according to claim 2, wherein the charging station is used to charge batteries of an inspection device positioned along the charging section of the second shield wire.

6. The apparatus according to claim 5, wherein the battery of the charging station energizes the charging section of the second shield wire with a DC voltage, thereby creating a DC offset along the charging section for use in charging batteries of the inspection device.

7. The apparatus according to claim 4, wherein the charging station further includes a diode positioned between the battery and the 60 Hz blocking filter to prevent the charging station from charging another charging station positioned on the second shield wire.

8. A method of harvesting power from an overhead transmission conductor that is supported by a plurality of spaced-apart structures that are grounded to the earth, comprising the steps of:

(a) providing an apparatus adapted to harvest power from the overhead transmission conductor, having;

(i) a first shield wire extending between and electrically bonded to the structures;

(ii) a second shield wire extending between and electrically isolated from the structures; and

(iii) a charging station electrically connected to the second shield wire;

(b) forming an induced current loop using the first shield wire, second shield wire, grounded structure, and earth to allow induced currents created by a magnetic field generated by AC current flowing in the overhead transmission conductor to flow therein; and

(c) using the charging station to convert the induced currents flowing through the second shield wire into a DC voltage for charging a battery of the charging station.

9. The method according to claim 8, wherein the apparatus further includes capacitors positioned at opposing ends of the second shield wire to create an insulated charging section.

10. The method according to claim 8, further including the step of electrically connecting a first terminal of the battery to the structure and a second terminal of the battery to the second shield wire.

11. A method of harvesting power from an overhead transmission conductor that is supported by a plurality of spaced-apart structures that are grounded to the earth, and using the harvested power to charge a battery of an inspection device, comprising the steps of:

(a) providing an apparatus adapted to harvest power from the overhead transmission conductor, having;

(i) a first shield wire extending between and electrically bonded to the structures;

(ii) a second shield wire extending between and electrically isolated from the structures; and

(iii) a charging station electrically connected to the second shield wire;

(b) forming an induced current loop using the first shield wire, second shield wire, grounded structures, and earth to allow induced currents created by a magnetic field generated by AC current flowing in the overhead transmission conductor to flow therein;

(c) using the charging station to convert the induced currents flowing through the second shield wire into a DC voltage for charging a battery of the charging station; and

(d) using the battery of the charging station to energize the second shield wire with a DC voltage for charging the battery of the inspection device.

12. The method according to claim 11, wherein the inspection device is a robot positioned on the second shield wire.

13. The method according to claim 11, further including the step of electrically connecting a first terminal of the battery of the charging station to a first one of the structures and a second terminal of the battery of the charging station to the second shield wire.

14. The method according to claim 11, further including the step of electrically connecting a first terminal of the battery of the inspection device to a second one of the structures and a second terminal of the battery of the inspection device to the second shield wire.

15. The method according to claim 11, wherein the inspection device further includes a DC converter to convert the DC voltage on the second shield wire at the inspection device to a pre-determined charging voltage for charging the battery of the inspection device.

16. The method according to claim 11, wherein the apparatus further includes capacitors positioned at opposing ends of the second shield wire to create an insulated charging section, and wherein the inspection device is positioned on the second shield wire within the charging section.