Method for monitoring the load condition of an engine and corresponding device

• US 7,644,607 B2
• Filed: 10/10/2005
• Issued: 01/12/2010
• Est. Priority Date: 10/19/2004
• Status: Active Grant

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Michaelis, Gerd
• Primary Examiner(s): MCCALL, ERIC SCOTT
• Application Number:
  US11/665,825
• Publication Number:
  US 20090066485A1
• Time in Patent Office: 1,555 Days
• Field of Search: 731/141.3, 731/141.4, 731/141.5, 731/142.4, 731/142.5
• US Class Current: 73/114.13
• CPC Class Codes: H02P 29/02 Providing protection against overload without automatic interruption of supply protection against faults of stepper motors H02P8/36

Abstract

There is described a method for monitoring the load condition of a variable speed engine. Said method shows a determination of an actual speed and an actual load moment during operation. A warning signal is emitted when the actual load moment remains outside a monitoring range, predetermined depending on the speed, for the duration of a predetermined delayed reaction time.

Claims

1. A method for monitoring a load condition of a variable speed engine, comprising:

determining an actual speed of the variable speed engine during operation;

determining an actual load moment of the variable speed engine during operation;

emitting a first warning signal when the actual load moment lies outside a first monitoring range for a duration of a first predetermined delayed reaction time, wherein the first monitoring range is predetermined based upon a speed value; and

emitting a second warning signal when the actual load moment lies outside a second monitoring range for a duration of a second predetermined delayed reaction time, wherein the second monitoring range is predetermined based upon the speed value.

2. The method as claimed in claim 1, wherein a shape of a monitoring area is a circle around an average value of a frequency of a load histogram, wherein a radius of the circle is based upon the speed value.

3. The method as claimed in claim 1, wherein a shape of a monitoring area is a circle around an average value of a frequency of a load histogram, wherein a radius of the circle is based upon a load moment.

4. The method as claimed in claim 1, wherein the first monitoring range is included entirely in the second monitoring range, and wherein the first delayed reaction time exceeds the second delayed reaction time.

5. The method as claimed in claim 4, wherein a monitoring range is determined based upon a load histogram, wherein the load histogram is based upon the speed, and wherein the monitoring range is at least one of the first and second monitoring ranges.

6. The method as claimed in claim 5, wherein the size of the monitoring range is based upon a histogram height.

7. The method as claimed in claim 4, wherein a monitoring range is determined based upon a load histogram, wherein the monitoring range is an area enclosed by a outer contour form circles around classes of the load histogram, and wherein the monitoring range is at least one of the first and second monitoring ranges.

8. The method as claimed in claim 7, wherein a radius of the circles is based upon a height of the histogram.

9. The method as claimed in claim 7, wherein a radius of the circles is based upon the speed.

10. The method as claimed in claim 7, wherein a radius of the circles is based upon the load moment.

11. A system for monitoring a load condition of a variable speed engine, comprising:

a measuring device to determine an actual speed and an actual load moment;

a monitoring device emitting a warning signal when the load moment remains outside a predetermined monitoring range based upon the speed; and

a configuration device to determine the predetermined monitoring range during a configuration operation of the engine based upon a speed-dependent load histogram.

12. The method as claimed in claim 11, wherein a shape of the monitoring area is a circle around an average value of a frequency of the load histogram, wherein a radius of the circle is based upon a speed value.

13. The method as claimed in claim 11, wherein a shape of the monitoring area is a circle around an average value of a frequency of the load histogram, wherein a radius of the circle is based upon a load moment.

14. The method as claimed in claim 11, wherein a size of the monitoring range is based upon a histogram height.

15. The method as claimed in claim 11, wherein the monitoring range is an area, which is enclosed by a outer contour form circles around classes of the load histogram.