Monitoring system for grounding apparatus

• US 10,371,726 B2
• Filed: 01/10/2017
• Issued: 08/06/2019
• Est. Priority Date: 01/11/2016
• Status: Active Grant

• Current Assignee: Cutsforth Incorporated
• Original Assignee: Cutsforth Incorporated
• Inventors: Jahnke, David A., Cutsforth, Robert S., Cutsforth, Dustin L.
• Primary Examiner(s): Rivera Vargas, Manuel A
• Application Number:
  US15/402,455
• Publication Number:
  US 20170199232A1
• Time in Patent Office: 938 Days
• CPC Class Codes: G01R 19/25 using digital measurement techniques
• CPC Class Codes: G01R 19/2509 Details concerning sampling, digitizing or waveform capturing
• CPC Class Codes: G01R 31/343 in operation
• CPC Class Codes: G01R 31/52 Testing for short-circuits, leakage current or ground faults
• CPC Class Codes: G05B 23/0235 based on a comparison with predetermined threshold or range, e.g. "classical methods", carried out during normal operation; threshold adaptation or choice; when or how to compare with the threshold
• CPC Class Codes: H02K 11/40 Structural association with grounding devices

Abstract

A shaft grounding and monitoring system may include a grounding member slidingly engageable with a rotating shaft. An electrical sensor may be configured to be coupled with the grounding member in order to detect an electrical parameter that provides an indication of electricity flowing from the rotating shaft to ground through the grounding member. A processor may be operably coupled with the electrical sensor and may receive and analyze data from the electrical sensor. The processor may be configured to periodically analyze the data representing the electrical parameter from the electrical sensor at a sampling rate and for a sampling period that is related to a rotation speed of the rotating shaft. A memory may be operably coupled with the processor and may be configured to store data processed by the processor that is representative of the data provided by the electrical sensor.

Claims

1. A shaft grounding and monitoring system for a device having a rotating shaft, the shaft grounding and monitoring system comprising:

a grounding member configured to make sliding electrical contact with the rotating shaft, the grounding member configured to be connected to ground;

an electrical sensor configured to sense an electrical parameter that provides an indication of electricity flowing through the grounding member,

a processor operably coupled with the electrical sensor, the processor configured to receive and analyze data from the electrical sensor representing the electrical parameter;

the processor is further configured to periodically analyze the data representing the electrical parameter from the electrical sensor for a sampling period and to not analyze the data representing the electrical parameter for a period of time immediately after the sampling period, where the sampling period is related to a rotation speed of the rotating shaft; and

a memory operably coupled with the processor and configured to store data processed by the processor that is representative of the data provided by the electrical sensor.

2. The shaft grounding and monitoring system of claim 1, wherein the electrical sensor comprises an electrical current sensor or an electrical voltage sensor.

3. The shaft grounding and monitoring system of claim 1, wherein the electrical sensor detects the electrical parameter at a sampling rate that provides enough data points per second to capture any anomalous or threshold condition that may be occurring in the device.

4. The shaft grounding and monitoring system of claim 1, wherein the sampling period is equal to or greater than one complete revolution of the rotating shaft.

5. The shaft grounding and monitoring system of claim 1, wherein the period of time immediately after the sampling period in which the processor does not analyze the data representing the electrical parameter is longer than the sampling period in which the processor analyzes the data representing the electrical parameter.

6. The shaft grounding and monitoring system of claim 1, wherein the processor is configured to analyze the data representing the electrical parameter from the electrical sensor for a sampling period ranging from 0.01 seconds per each second to 0.5 seconds per each second, and the processor is configured to not analyze the data representing the electrical parameter from the electrical sensor for a subsequent time period ranging from 0.5 seconds per each second to 0.99 seconds per each second.

7. The shaft grounding and monitoring system of claim 1, wherein the processor is configured to analyze the data representing the electrical parameter from the electrical sensor for a sampling period ranging from 0.05 seconds per each second to 0.25 seconds per each second, and the processor is configured to not analyze the data representing the electrical parameter from the electrical sensor for a subsequent time period ranging from 0.75 seconds per each second to 0.95 seconds per each second.

8. The shaft grounding and monitoring system of claim 1, wherein the processor is configured to analyze the data representing the electrical parameter from the electrical sensor for a sampling period of 0.1 seconds per each second, and the processor is configured to not analyze the data representing the electrical parameter from the electrical sensor for a subsequent time period of 0.9 seconds per each second.

9. A monitoring system for a device having a rotating shaft and a grounding member positioned in electrical contact with the rotating shaft, the monitoring system comprising:

a current sensor configured to sense an electrical current flowing through the grounding member, the current sensor configured to sample at a first sampling rate for a first time interval;

a voltage sensor configured to sense an electrical voltage in the rotating shaft, the voltage sensor configured to periodically sample at a second sampling rate for a second time interval, wherein the second sampling rate is higher than the first sampling rate and the first time interval is longer than the second time interval and overlapping with the second time interval;

a processor operably coupled with the current sensor and with the voltage sensor and configured to receive data indicative of electrical current sensed by the current sensor and data indicative of electrical voltage sensed by the voltage sensor;

the processor configured to analyze the data from the current sensor and the data from the voltage sensor; and

a memory operably coupled with the processor and configured to store information representative of the data from the current sensor and the data from the voltage sensor.

10. The monitoring system of claim 9, wherein the first sampling rate is about 100 kHz or greater.

11. The monitoring system of claim 9, wherein the voltage sensor is configured to sample for about two-hundredths to about one-tenth of each second.

12. The monitoring system of claim 9, wherein the second sampling rate is about 20 MHz or more when sampling.

13. The monitoring system of claim 9, wherein the processor is further configured to analyze a snapshot of data from the current sensor during a sampling period in order to identify a potential anomalous or threshold condition.

14. The monitoring system of claim 13, wherein if the processor does not identify a potential anomalous or threshold condition from the snapshot of data from the current sensor, the processor is further configured to store one or more values representative of the snapshot of data from the current sensor to memory.

15. The monitoring system of claim 9, wherein if the processor does identify a potential anomalous or threshold condition from the snapshot of data from the current sensor, the processor is further configured to store one or more values representative of the snapshot of data from the current sensor to memory and to analyze a temporally aligned snapshot of data from the voltage sensor in order to provide additional information regarding the potential anomalous or threshold condition.

16. A shaft grounding and monitoring system for a device having a rotating shaft, the shaft grounding and monitoring system comprising:

a grounding member configured to slidingly contact the rotating shaft and make electrical contact with the rotating shaft, the grounding member configured to be connected to ground;

an isolated contact member configured to slidingly contact the rotating shaft, the isolated contact member electrically isolated from ground; and

the monitoring system of claim 9;

wherein the current sensor is coupled with the grounding member in order to sense an electrical current flowing from the rotating shaft to ground through the grounding member and the voltage sensor is coupled with the isolated contact member in order to sense an electrical voltage in the shaft.

17. A method of monitoring a rotating conductive shaft in a device including a grounding apparatus, the method comprising:

receiving data at a first sampling rate during a first sampling period from a current sensor that is operably coupled with the grounding apparatus;

periodically receiving data at a second sampling rate during a second sampling period from a voltage sensor configured to sense a voltage within the rotating shaft, the second sampling rate being higher than the first sampling rate;

analyzing a snapshot of data from the current sensor to identify a potential anomalous or threshold condition; and

if a potential anomalous or threshold condition is seen in the snapshot of data from the current sensor, analyzing a snapshot of data from the voltage sensor;

wherein the snapshot of data from the voltage sensor that is analyzed at least partially temporally aligns with the snapshot of data from the current sensor that was analyzed.

18. The method of claim 17, wherein if a potential anomalous or threshold condition is seen in the snapshot of data from the current sensor, storing the snapshot of data from the current sensor for future analysis.

19. The method of claim 17, wherein if a potential anomalous or threshold condition is not seen in the snapshot of data from the current sensor, storing representative information pertaining to the snapshot of data from the current sensor to memory.

20. The method of claim 17, wherein the first sampling period at least partially temporally overlaps the second sampling period.