Proactive arc management of a plasma load

• US 8,552,665 B2
• Filed: 08/20/2010
• Issued: 10/08/2013
• Est. Priority Date: 08/20/2010
• Status: Active Grant

• Current Assignee: AES Global Holdings Pte Ltd. (Advanced Energy Industries, Inc. (China))
• Original Assignee: Advanced Energy Industries Incorporated
• Inventors: Larson, Skip B., Walde, Hendrik, McDonald, R. Mike, Nauman, Kenneth E. Jr.
• Primary Examiner(s): Owens, Douglas W
• Assistant Examiner(s): Chen, Jianzi
• Application Number:
  US12/859,998
• Publication Number:
  US 20120043890A1
• Time in Patent Office: 1,145 Days
• Field of Search: 315/119, 315/291, 315/297, 315/299, 315/306, 315/307, 315/308, 315/312, 315/326
• US Class Current: 315/308
• CPC Class Codes: H01J 37/32944 Arc detection
• CPC Class Codes: H05H 1/46 using applied electromagnetic fields, e.g. high frequency or microwave energy H05H1/26 takes precedence
• CPC Class Codes: H05H 2242/22 DC, AC or pulsed generators
• CPC Class Codes: H05H 2242/24 Radiofrequency or microwave generators

Abstract

Proactive arc management systems and methods are disclosed. In many implementations, proactive arc management is accomplished by executing an arc handling routine in response to an actual arc occurring in the plasma load and in response to proactive arc handling requests in a sampling interval. The number of proactive arc handling requests in a sampling interval is a function of a proactive arc management count that in turn is a function of actual number of arcs in a preceding sampling interval. Accordingly during a present sampling interval proactive arc management executes arc handling for actual arcs in the present sampling interval and for each count in a proactive arc management count updated as a function of the number of arcs in the immediately preceding sampling interval.

Claims

1. A proactive arc management module in a power supply having a power module providing power to a plasma load through arc management hardware, and a digital power monitor module monitoring the present voltage and current supplied to the plasma load, said proactive arc management module comprising:

arc detect module comparing a present voltage supplied to the plasma load to a preset voltage threshold and comparing present current supplied to the plasma load to a preset current threshold and generating an actual arc handling request when comparison of the present voltage or present current to the voltage threshold and current threshold, respectively, indicates an arc is occurring in the plasma load;

proactive arc management adjust module responsive to actual arc handling requests from the arc detect module and providing a proactive arc management count as a function of the actual arc handling requests received during a sampling interval; and

arc management control module responsive to the proactive arc management count and to actual arc handling requests to control the arc management hardware to execute an arc handling routine for each proactive count and each actual arc so that arcs in the plasma load are reduced to a minimum while the plasma load operates at maximum efficiency.

2. The proactive arc management module of claim 1 wherein said proactive arc management adjust module comprises:

a counting module responsive to the arc detect module and counting arcs occurring in the plasma load during a sampling interval to provide an actual arc count for the present sampling interval;

index module for setting an index value; and

update module responsive to a preset arc management count, the actual arc count and the index value and updating the proactive arc management count as a function of the preset arc management count, the actual arc count and the index value to provide the proactive arc management count for the next sampling interval.

3. The proactive arc management module of claim 2 wherein the arc management control module comprises:

apply module responsive to the proactive arc management count and sending a proactive arc handling request for each count in the proactive arc management count and distributes the proactive arc handling requests over the sampling interval; and

execute module responsive to actual arc handling requests from the arc detect module and responsive to proactive arc handling requests from the apply module and controlling the arc management hardware to execute each arc handling request whether proactive or actual.

4. The proactive arc management module of claim 2 wherein the index module sets the index value as a percentage of the actual arc count.

5. The proactive arc management module of claim 2 wherein the index module sets the index value to a preset index value.

6. The proactive arc management module of claim 2 wherein the update module updates the proactive arc management count by summing the preset arc management count, the actual arc count and the index value.

7. A method for proactively managing power supplied to a plasma load to minimize the occurrence of arcs in the plasma load, said method comprises:

detecting an arc in the plasma load and sending an actual arc handling request when an arc in the plasma load is detected;

counting actual arc handling requests during a sampling interval to provide an actual arc count;

updating a proactive arc management count as a function of the actual arc count; and

controlling the arc management hardware to execute an-arc handling routine to extinguish the arc in the plasma load in response to an actual arc handling request, and to discharge built-up charge in the plasma load in response to a proactive arc handling request for each count in the proactive arc management count.

8. The method of claim 7 wherein said updating comprises:

setting the index value as a function of the actual arc count; and

summing the preset arc management count, the actual arc count and the index value to update the proactive arc management count.

9. The method of claim 8 wherein said setting sets the index value as a percentage of the actual arc count.

10. The method of claim 8 wherein said setting sets the index value to a preset index value.

11. The method of claim 8 wherein said updating comprises:

detecting whether the actual arc count during the present sampling interval is zero; and

when the actual arc count is zero, bypassing said setting and said updating to proceeding directly to said controlling so that the proactive arc management count provided said controlling in the next sampling interval is the same as the proactive arc management count provided during the present sampling interval.

12. The method of claim 11 wherein said controlling comprises:

distributing the counts of the proactive arc management count over the sampling interval to provide proactive arc handling requests distributed over the sampling interval; and

executing an arc handling routine for each proactive arc handling request and for each actual arc handling request.

13. The method of claim 12 wherein said distributing comprises:

dividing the sampling interval by the proactive arc management count to split the sampling interval into subintervals; and

providing a proactive arc handling request at the end of each subinterval.

14. A computer program product readable by a computing system in a power supply providing power to a plasma load and encoding a computer program of instructions for executing a computer process for proactive arc management of the power supply and plasma load, said computer process comprises:

comparing a voltage value and a current value to a voltage threshold and a current threshold, respectively, to detect an arc in the plasma load;

generating an actual arc handling request when an arc in the plasma load is detected;

counting actual arc handling requests during a present sampling interval (T_M) to generate an actual arc count (C_A) for the present sampling interval (T_M);

updating a proactive arc management count (C_AM) as function of a preset arc-management count (C_AM-PRESET), the actual arc count (C_A) for the present sampling interval am), and an index value (N) equal to a function of the actual arc count (C_A); and

controlling arc management hardware to execute an-arc handling routine during the next sampling interval (T_M+1) in response to an actual arc handling request occurring during next sampling interval (T_M+1) and in response to the proactive arc management count (C_AM) from present sampling interval (T_M), the arc handling routine discharges accumulated charge in the plasma load when executed.

15. The computer process of the computer program product of claim 14 further comprises:

detecting whether the actual arc count (C_A) for the present sampling interval (T_m) is zero;

when the actual arc count (C_A) for the present sampling interval (T_M) is not equal to zero passing the computer process flow to said updating; and

when the actual arc count for the present sampling interval (T_M) is zero, passing the computer process flow directly to said controlling so that the proactive arc management count (C_AM) provided said controlling in the next sampling interval (T_M+1) is the same as the proactive arc management count provided during the present sampling interval (T_M).

16. The computer process of the computer program product of claim 15 wherein said updating comprises:

setting index value (N) equal to a function of the actual arc count (C_A); and

summing the preset arc management count (C_AM-PRESET) plus the actual arc count (C_A) plus the index value (N) to update the proactive arc management count (C_AM) for the next sampling interval (T_M+1).

17. The computer process of the computer program product of claim 16 wherein said setting sets (N) equal to a percentage of actual arc count (C_A).

18. The computer process of the computer program product of claim 16 wherein said setting sets (N) equal to a selected one of a plurality of preset index values (N_P) where the selected index value depends upon the actual arc count (C_A).

19. The computer process of the computer program product of claim 15 wherein said controlling comprises:

distributing the counts of the proactive arc management count (C_AM) over the present sampling interval (T_M) to provide proactive arc handling requests distributed over the sampling interval; and

executing an arc handling routine for each proactive arc handling request and for each actual arc handling request.

20. The computer process of the computer program product of claim 19 wherein said distributing comprises:

dividing a preset duration (T_P) of the sampling interval by the proactive arc management count (C_AM), i.e. (T_P/C_AM), to split the sampling interval into subintervals; and

providing a proactive arc handling request during each subinterval.