Apparatus and method for arc detection

• US 6,736,944 B2
• Filed: 04/12/2002
• Issued: 05/18/2004
• Est. Priority Date: 04/12/2002
• Status: Active Grant

• Current Assignee: Schneider Automation Incorporated (Schneider Electric SE)
• Original Assignee: Schneider Automation Incorporated (Schneider Electric SE)
• Inventors: Buda, Paul R.
• Primary Examiner(s): VERSTEEG, STEVEN H
• Application Number:
  US10/121,445
• Publication Number:
  US 20030205460A1
• Time in Patent Office: 767 Days
• Field of Search: 204/192.13, 204/192.33, 204/192.38, 204/298.03, 204/298.41
• US Class Current: 204/192.13
• CPC Class Codes: H01J 2237/0206 Extinguishing, preventing or controlling unwanted discharges
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge

Abstract

An apparatus and technique are provided for generating a plasma using a power supply circuit and arc detection arrangement. The power supply circuit has a cathode enclosed in a chamber, and is adapted to generate a power-related parameter. The arc detection arrangement is communicatively coupled to the power supply circuit and adapted to assess the severity of arcing in the chamber by comparing the power-related parameter to at least one threshold. According to various implementations, arc occurrences, arcing duration, intensity and/or energy are measured responsive to comparing the power-related parameter to the at least one threshold. According to further implementations, the above-mentioned measured quantities are accumulated and/or further processed.

Claims

1. A plasma generation apparatus, comprising:

a power supply circuit having a cathode enclosed in a chamber, and adapted to generate a power-related parameter; and

an arc detection arrangement communicatively coupled to the power supply circuit and adapted to assess the severity of arcing in the chamber by comparing the power-related parameter to at least one threshold and further adapted to measure arcing duration responsive to comparing the power-related parameter to the at least one threshold wherein the arc detection arrangement includes a clock providing a clock signal having a fixed period and a digital counting arrangement adapted to count clock signal periods responsive to comparing the power-related parameter to at least one threshold.

2. A plasma generation apparatus, comprising:

a power supply circuit having a cathode enclosed in a chamber, and adapted to generate a power-related parameter; and

an arc detection arrangement communicatively coupled to the power supply circuit and adapted to assess the severity of arcing in the chamber by comparing the power-related parameter to at least one threshold and further adapted to measure cumulative arcing duration responsive to comparing the power-related parameter to at least one threshold and wherein the arc detection arrangement includes a clock providing a clock signal having a fixed period and a digital counting arrangement adapted to accumulate a count of clock signal periods responsive to comparing the power-related parameter to at least one threshold.

3. A plasma generation apparatus, comprising:

a power supply circuit having a cathode enclosed in a chamber, and adapted to generate a power-related parameter; and

an arc detection arrangement communicatively coupled to the power supply circuit and adapted to assess the severity of arcing in the chamber by comparing the power-related parameter to at least one threshold and further adapted to estimate arcing energy as a function of the power-related parameter integrated over a time interval responsive to comparing the power-related parameter to the at least one threshold.

4. A plasma generation apparatus, comprising:

a power supply circuit having a cathode enclosed in a chamber, and adapted to generate a power-related parameter; and

an arc detection arrangement communicatively coupled to the power supply circuit and adapted to assess the severity of arcing in the chamber by comparing the power-related parameter to at least one threshold and further adapted to approximate an area bounded by a function of the power-related parameter versus time and at least one threshold.

5. A plasma generation apparatus, comprising:

a power supply circuit having a cathode enclosed in a chamber, and adapted to generate a power-related parameter; and

an arc detection arrangement communicatively coupled to the power supply circuit and adapted to assess the severity of arcing in the chamber by comparing the power-related parameter to at least one threshold wherein at least one threshold is programmable via a logic arrangement coupled to the arc detection arrangement and wherein at least one programmable threshold is hysteretic.

6. A plasma generation apparatus, comprising:

a power supply circuit having a cathode enclosed in a chamber, and adapted to generate a power-related parameter; and

an arc detection arrangement communicatively coupled to the power supply circuit and adapted to assess the severity of arcing in the chamber by comparing the power-related parameter to at least one threshold and at least one threshold is hysteretic.

7. A plasma generation apparatus, comprising:

a power supply circuit having a cathode enclosed in a chamber, and adapted to generate a power-related parameter; and

an arc detection arrangement communicatively coupled to the power supply circuit and adapted to assess the severity of arcing in the chamber by comparing the power-related parameter to at least one threshold and wherein the arc detection arrangement includes a power-related parameter band-limiting filter.

8. A method for assessing arcing severity in a plasma generation chamber, comprising:

timing an arc duration responsive to comparing a power-related parameter to at least one arc intensity threshold; and

adding the arc duration to an accumulated arcing duration.

9. The method of claim 8, wherein at least one arc intensity threshold is hysteretic.

10. The method of claim 8, further comprising counting arc occurrences.

11. The method of claim 8, further comprising assessing arc severity as a function of arc intensity and arc duration.

12. The method of claim 8, further comprising assessing arc intensity as a function of the product of arc intensity and arc duration.

13. The method of claim 8, further comprising;

measuring the power-related parameter during non-arcing plasma generation; and

automatically adjusting the at least one arc intensity threshold responsive to the measuring the power-related parameter during non-arcing plasma generation.

14. A method to assess arcing severity in a plasma generation chamber, comprising:

determining arc intensity by comparing a power-related parameter to at least one arc intensity threshold;

timing an arc duration responsive to comparing the power-related parameter to the at least one arc intensity threshold;

computing arc energy as a function of arc intensity and arc duration; and

adding the arc energy to an accumulated arcing energy.

15. The method of claim 14, further including counting arc occurrences responsive to comparing the power-related parameter to the at least one arc intensity threshold.

16. The method of claim 15, further including:

transmitting information representative of arcing to a computing arrangement on command via a shared data path, the information being one selected from a group that includes quantity of arc occurrences and accumulated arcing duration.

17. The method of claim 14, wherein at least one arc intensity threshold is hysteretic.

18. The method of claim 14, further including:

measuring the power-related parameter'"'"'s nominal value during non-arcing plasma generation; and

automatically programming the at least one arc intensity threshold responsive to the power-related parameter'"'"'s nominal value.

19. The method of claim 14, further comprising:

forming the power-related parameter as a digital representation of plasma generation chamber operating characteristics.

20. The method of claim 14, wherein the power-related parameter is a function of plasma generation chamber voltage.

21. The method of claim 14, further comprising:

communicating the quantity of arcs and the accumulated arcing duration to a computing arrangement a common data path.