Materials characterization cell for polarization spectrum and streaming electrification measurements

• US 5,804,974 A
• Filed: 05/21/1997
• Issued: 09/08/1998
• Est. Priority Date: 06/07/1995
• Status: Expired due to Fees

• Current Assignee: ABB Incorporated (ABB Limited)
• Original Assignee: ABB Power T&D Co Inc (ABB Limited)
• Inventors: Frimpong, George K., Brubaker, Michael A.
• Primary Examiner(s): BROWN, GLENN WARNER
• Application Number:
  US08/859,749
• Time in Patent Office: 475 Days
• Field of Search: 324/425, 324/439, 324/450, 324/693, 324/698, 324/701, 324/707, 324/71.1, 324/76.19, 324/547, 324/551, 324/553
• US Class Current: 324/553
• CPC Class Codes: G01N 27/221 by investigating the dielectric properties using microwaves G01N22/00; measuring loss factors or dielectric constants per se G01R27/26
• CPC Class Codes: G01N 27/226 Construction of measuring vessels; Electrodes therefor
• CPC Class Codes: G01N 27/60 by investigating electrostatic variables , e.g. electrographic flaw testing G01N27/007 takes precedence
• CPC Class Codes: G01N 27/605 for determining moisture content, e.g. humidity

Abstract

A materials characterization test cell is disclosed. The test cell includes a housing including spacers for supporting sample insulation materials, and a channel disposed in the housing to permit the passage of oil through the housing. A pair of electrodes is provided to provide a mechanism for making polarization spectrum and/or streaming electrification measurements.

Claims

1. A materials characterization system, comprising:

(a) a materials characterization cell;

(b) a polarization spectrum analyzer coupled to said materials characterization cell; and

(c) means for providing a controlled flow of oil through said materials characterization cell.

2. A materials characterization system as recited in claim 1, wherein said materials characterization cell comprises a housing;

a channel disposed in said housing, said channel permitting the passage of oil through said housing;

a first sample of insulation material disposed in said housing adjacent to said channel; and

a first electrode disposed in said housing adjacent to said first sample.

3. A materials characterization system as recited in claim 2, wherein said materials characterization cell further comprises a second sample of said insulation material, said second sample being disposed in said housing adjacent to said channel and opposite said first sample;

and a second electrode disposed in said housing adjacent to said second sample.

4. A method for obtaining a polarization spectrum of a sample of insulation material for use in an oil filled transformer, said polarization spectrum being indicative of the age and moisture content of said sample, comprising the steps of:

(a) disposing said sample in a materials characterization cell;

(b) coupling a polarization spectrum analyzer to said materials characterization cell; and

(c) obtaining said spectrum with said analyzer.

5. A method as recited in claim 4, wherein said materials characterization cell comprises a housing;

a channel disposed in said housing, said channel permitting the passage of oil through said housing;

said sample of insulation material disposed in said housing adjacent to said channel; and

a first electrode disposed in said housing adjacent to said sample.

6. A method as recited in claim 5, wherein said materials characterization cell further comprises a second sample of said insulation material, said second sample being disposed in said housing adjacent to said channel;

and a second electrode disposed in said housing adjacent to said second sample.

7. A method for determining the charging tendency of a combination of liquid and solid insulation materials, comprising the steps of:

(a) disposing a sample of a solid insulation material in a materials characterization cell;

(b) passing a dielectric liquid through said materials characterization cell;

(c) measuring a streaming current associated with said dielectric liquid with a meter coupled to said materials characterization cell; and

(d) determining the charging tendency on the basis of the flow rate of the liquid dielectric and the measured streaming current.

8. A method as recited in claim 7, wherein said materials characterization cell comprises a housing;

a channel disposed in said housing, said channel permitting the passage of said liquid dielectric through said housing;

said sample of insulation material disposed in said housing adjacent to said channel; and

a first electrode disposed in said housing adjacent to said sample.

9. A method as recited in claim 8, wherein said materials characterization cell further comprises a second sample of said insulation material, said second sample being disposed in said housing adjacent to said channel;

and a second electrode disposed in said housing adjacent to said second sample.