Distribution network power line carrier communication system

• US 3,911,415 A
• Filed: 10/31/1974
• Issued: 10/07/1975
• Est. Priority Date: 12/18/1973
• Status: Expired due to Term

• Current Assignee: ABB Power T&D Co Inc (ABB Limited)
• Original Assignee: Ian A. Whyte
• Inventors: Whyte, Ian A.
• Primary Examiner(s): Habecker, Thomas B.
• Application Number:
  US05/519,702
• Time in Patent Office: 341 Days
• Field of Search: 340/31A
• US Class Current: 340/10.1
• CPC Class Codes: H02J 13/00007 using the power network as support for the transmission
• CPC Class Codes: H02J 13/00034 the elements or equipment being or involving an electric power substation
• CPC Class Codes: H04B 2203/5437 Wired telephone
• CPC Class Codes: H04B 2203/5466 using three phases conductors
• CPC Class Codes: H04B 3/36 Repeater circuits H04B3/58 takes precedence
• CPC Class Codes: H04B 3/54 Systems for transmission via power distribution lines
• CPC Class Codes: Y02E 60/00 Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• CPC Class Codes: Y04S 10/16 Electric power substations
• CPC Class Codes: Y04S 40/121 using the power network as support for the transmission

Abstract

A power line carrier communication system for linking individual power customers with a central station includes the power distribution network between a distribution substation and the customer locations. Frequency translating and signal reconditioning repeaters are connected to intermediate locations of the network to relay carrier signals at different frequencies. Customers are also linked to individual repeaters so as to be grouped into separate communication zones. Each repeater includes separate repeater channels for duplex operation in which two receiving and two transmitting carrier signals have separate and non-interfering frequencies. The repeaters maintain the carrier signals at usable signal to noise ratios when transmitted through extended power line distances having various attenuation and loading characteristics.

Claims

1. A power line communication system for transmitting communication signals over distribution network power line conductors connected between a distribution network substation and a plurality of electric power customers, comprising:

a first communication terminal including transmitter means and receiver means arranged for coupling to said power line conductors at said substation, said transmitter means being operative to transmit a first interrogation signal in a first frequency band modulated by binary logic information signals, repeater means including first and second channels, said first channel including first receiver means and first transmitter means, said second channel including second receiver means and second transmitter means, said first and second receiver means and said first and second transmitter means being arranged for coupling to said power line conductors, and a second communication terminal including transmitter means and receiver means arranged for coupling to said power line conductors at one of said plurality of electric power customers, said second communication terminal including decoding and encoding logic circuit means connected to said transmitter means and said receiver means, said first channel of the repeater means providing a second interrogation signal in response to said first interrogation signal which has the same binary logic information as the first interrogation signal but which is in a second frequency band, non-overlapping with said first frequency band, said receiver means of the second communication terminal, in response to a second interrogation signal, including means reconstructing the binary logic information signals of the second interrogation signal, and means applying the binary logic information signals to said decoding and encoding logic circuit means, said transmitter means of the second communication terminal including means operative to modulate binary logic information signals applied thereto from said decoding and encoding logic circuit means, and being further operative to provide a first response signal in a third frequency band which is non-lapping with the frequency band of the second interrogation signal, said second channel of the repeater means providing a second response signal in response to said first response signal which has the same binary logic information as the first response signal but which is in a fourth frequency band, non-overlapping with the third frequency band, said receiver means of the first communication terminal being operative to receive said second response signal.

2. The power line communication system of cLaim 1 wherein the first and second interrogation signals and the first and second response signals received and transmitted from the repeater means include frequency shift keyed modulated carrier signals having base band binary logic information signals, and wherein each of the first and second receiver means of the repeater means include slope detector means having a detecting element developing a detected signal variable between two voltage levels, and comparator amplifier means responsive to the two voltage levels of said detected signal for developing for two level logic signals corresponding to a reconditioned form of the base band binary logic information signals of the received carrier signal.

3. A distribution network power line carrier communication system for transmitting communication signals over power line conductors connected between a distribution network substation and a plurality of electric power customers, comprising:

first terminal means at the substation providing a first interrogation signal in a first frequency band, means for applying said first interrogation signal to the power line conductors, first repeater means remote from the substation including first receiver means for receiving said first interrogation signal from the power line conductors, said first repeater means including first transmitter means providing a second interrogation signal responsive to said first interrogation signal in a second frequency band which is non-overlapping with the first frequency band of said first interrogation signal, and means applying said second interrogation signal to the power line conductors.

4. The distribution network power line carrier communication system of claim 3 including:

second terminal means, said second terminal means including means for receiving the second interrogation signal, and means responding to at least certain of the second interrogation signals by providing a first response signal in a third frequency band which is non-overlapping with the second frequency band, means for applying said first response signal to the power line conductors, and means for receiving said first response signal from the power line conductors.

5. The distribution network power line carrier communication system of claim 4 wherein the means for receiving the first response signal includes second receiver means of the repeater means, and wherein the repeater means includes second transmitter means responsive to the first response signal providing a second response signal in a fourth frequency band which is non-overlapping with the third frequency band, means applying the second response signal to the power line conductors, and means for receiving said second response signal from the power line conductors.

6. The distribution network power line carrier communication system of claim 3 including distribution transformer means, and wherein the power line conductors include first power line conductors which extend from the substation to said distribution transformer means, and second power line conductors which extend from said distribution transformer means to certain of the electric power customers, the repeater means is located at said distribution transformer means, the first receiver means receives the first interrogation signal from the first power line conductors, and the first transmitter means applies the second interrogation signal to the second power line conductors.

7. The distribution network power line carrier communication system of claim 6 including second terminal means for receiving the second interrogation signal from the second power line conductors and for applying a first response signal in a third frequency band, non-overlapping with the second frequency band, to the second power line conductors, and the repeater means includes second receiver means for receiving the first response signal from the second power line conductors, and second transmitter means providing a second response signaL responsive to the first response signal in a fourth frequency band, non-overlapping with the third frequency band, and means applying the second response signal to the first power line conductors.

8. The distribution network power line carrier communication system of claim 3 including means providing a first binary base band signal, with the first terminal means including modulator means which provides the first interrogation signal in response to said first binary base band signal.

9. The distribution network power line carrier communication system of claim 8 wherein the first receiver means includes means responsive to the first interrogation signal for reconstituting the first binary base band signal, and the first transmitter means includes modulator means responsive to the reconstituted binary base band signal for providing the second interrogation signal.

10. The distribution network power line carrier communication system of claim 9 wherein the first receiver means includes means for improving the waveform of the reconstituted first binary base band signal.

11. A distribution network power line carrier communication system for transmitting signals over power line conductors connected between a distribution network substation and a plurality of electric power customers, comprising:

means providing interrogation and response signals on the power line conductors in different, non-overlapping frequency bands, and repeater means coupled to the power line conductors including first receiver means for receiving an interrogation signal in a first of the frequency bands, and first transmitter means responsive to the interrogation signal received by said first receiver means for providing an interrogation signal on the power line conductors in a second of the frequency bands.

12. The distribution network power line communication system of claim 11 wherein the repeater means includes second receiver means for receiving a response signal in a third of the frequency bands, and second transmitter means responsive to the response signal received by said second receiver means for providing a response signal on the power line conductors in a fourth of the frequency bands.

13. The distribution network power line communication system of claim 12 wherein the repeater means includes switch means for selectively connecting each of the first and second receiver means to either of the first and second transmitter means.

14. A distribution network power line carrier communication system for transmitting communication signals over power line conductors connected between distribution network substations and a plurality of electric power customers, comprising:

first terminal means at a first substation in signal communication with the power line conductors of the first substation, said first terminal means including first transmitter means and said receiver means, said first transmitter means providing interrogation signals in a first frequency band, and second terminal means in signal communication with the power line conductors of the first substation at one of the electric power customers, said second terminal means including second receiver means and second transmitter means, said second receiver means being responsive to at least certain of said interrogation signals, said second transmitter means providing a response signal in a second frequency band, non-overlapping with said first frequency band, in response to said second receiver means, said first receiver means being responsive to response signals in said second frequency band.

15. The distribution network power line carrier communication system of claim 14 including:

repeater means in signal communication with the power line conductors, and third terminal means in signal communication with the power line conductors, at another of the electric power customers, said repeater means including third receiver means responsive to interrogation signals in the first frequency bAnd, and third transmitter means providing interrogation signals in a third frequency band, non-overlapping with the first and second frequency bands, in response to said third receiver means, said third terminal means including fourth receiver means responsive to at least certain of the interrogation signals in said third frequency band.

16. The distribution network power line carrier communication system of claim 15 wherein the third terminal means includes fourth transmitter means providing response signals in a fourth frequency band in response to the third receiver means, and wherein the repeater means includes fifth receiver means and fifth transmitter means, said fifth receiver means being responsive to response signals in said fourth frequency band, said fifth transmitter means providing response signals in the second frequency band in response to said fifth receiver means.

17. The distribution network power line carrier communication system of claim 14 including:

third terminal means at a second substation in signal communication with the power line conductors of the second substation, said third terminal means including third transmitter means and third receiver means, said third transmitter means providing interrogation signals in a third frequency band, non-overlapping with the first and second frequency bands, fourth terminal means in signal communication with the power line conductors of the second substation at one of the electric power customers, said fourth terminal means including fourth receiver means and fourth transmitter means, said fourth receiver means being responsive to at least certain of the interrogation signals in the third frequency band, said fourth transmitter means providing a response signal in a fourth frequency band, non-overlapping with the first, second and third frequency bands, in response to said fourth receiver means, said third receiver means being responsive to response signals in said fourth frequency band, switch means interconnecting the power line conductors of the first and second substations, and first and second repeater means in signal communication with the interconnected power line conductors of the first and second substations, said first repeater means including a first channel having fifth receiver means and fifth transmitter means, and a second channel having sixth receiver means and sixth transmitter means, said second repeater means including a first channel having seventh receiver means and seventh transmitter means, and a second channel having eighth receiver means and eighth transmitter means, the first channels of said first and second repeater means relaying interrogation signals from the first terminal means to the fourth terminal means, with said fifth receiver means being responsive to interrogation signals in the first frequency band, the fifth transmitter means providing interrogation signals in a fifth frequency band in response to said fifth receiver means, said seventh receiver means being responsive to interrogation signals in the fifth frequency band, and said seventh transmitter means providing interrogation signals in the third frequency band, the second channels of said first and second repeater means relaying response signals from the fourth terminal means to the first terminal means, with the eighth receiver means being responsive to response signals in the fourth frequency band, the eighth transmitter means providing response signals in a sixth frequency band, in response to said eighth receiver means, the sixth receiver means being responsive to response signals in the sixth frequency band, and the sixth transmitter means providing response signals in the second frequency band, in response to said sixth receiver means.