Metering system for measuring parameters of high AC electric energy flowing in an electric conductor

• US 4,578,639 A
• Filed: 03/02/1984
• Issued: 03/25/1986
• Est. Priority Date: 03/02/1984
• Status: Expired due to Fees

• Current Assignee: ABB Power T&D Limited (ABB Limited)
• Original Assignee: Westinghouse Electric Company LLC (Brookfield Asset Management Incorporated)
• Inventors: Miller, Robert C.
• Primary Examiner(s): Levy, Stewart J.
• Assistant Examiner(s): Baker, Stephen M.
• Application Number:
  US06/585,483
• Time in Patent Office: 753 Days
• Field of Search: 324/96, 324/126, 324/142, 324/72, 332/7.51, 356/368, 350/374
• US Class Current: 324/96
• CPC Class Codes: G01R 15/246 based on the Faraday, i.e. linear magneto-optic, effect
• CPC Class Codes: G01R 21/00 Arrangements for measuring electric power or power factor G01R7/12 takes precedence

Abstract

Metering system for measuring parameters of high AC electric energy flowing in an electric conductor and characterized by separate current sensor means for generating separate polarized light outputs representative of voltage end current passing through a conductor, separate electronic means for receiving and transforming the voltage and current outputs into power, voltage, and current signals.

Claims

1. A metering system for measuring the parameters of high voltage AC electric energy flowing in an electric conductor, comprising:

(a) a magneto-optical material disposed to enclose a current-carrying conductor;

(b) polarizing means for inputting polarized light into the magneto-optical material;

(c) analyzer means for converting the light from the polarizing means to an optical signal of varying intensity in response to the rotation produced in said material;

(d) means including fiber optic and detector means with associated electronic circuitry for providing a first electrical voltage output that is proportional to the current flowing in the conductor;

(e) circuit means including series-connected capacitors extending from the electric conductor to ground and means for providing electrical voltage output which is proportional to electrical current flowing to and from the capacitors generating a second voltage output which is proportional to the rate of change of line voltage with respect to time;

(f) electronic means for receiving input signals including the first voltage output and the second voltage output which signals are converted to produce an output pulse representative of a quantitized amount of electric energy carried by the conductor;

(g) means for receiving the second voltage output from the circuit means and converting it into third voltage outputs;

(h) a first signal conditioner responsive to the third voltage outputs for converting them into conditioned voltage signals; and

(i) a second signal conditioner responsive to the first voltage output for converting it into conditioned current signals.

2. The system of claim 1 in which the signal conditioners are analog-digital converters.

3. The system of claim 2 in which fiber optic data links transmit optical signals from the electronic means including the analog-digital converters to provide a binary coded current signal which is transmitted through a data link receiver and a signal conditioner to meter means for displaying line current.

4. The system of claim 2 in which the electronic means comprises a solid-state watthour meter.

5. The system of claim 2 in which data link receiving and signal conditioning and meter means are optically connected through fiber optic cable to the electronic means including signal conditioners for converting the output pulse, the conditioned voltage signals, and the conditioned current signals into displayed quantities, and so as to provide analog signals for use in line protection relays.

6. The system of claim 5 in which the fiber optic cable comprises electrically insulating optic data links between the current-carrying conductor and the associated components.

7. The system of claim 2 in which the fiber optic data link transmit optical signals from the analog-digital converter through a data link receiver and a signal conditioner to meter means for displaying line voltage.

8. The system of claim 1 in which the output pulse is transmitted optically through a data link receiver and a signal conditioner to meter means for displaying energy parameters.