Method and systems for diagnosing an engine

• US 10,345,195 B2
• Filed: 03/07/2016
• Issued: 07/09/2019
• Est. Priority Date: 03/07/2016
• Status: Active Grant

• Current Assignee: Transportation IP Holdings, LLC (Westinghouse Air Brake Technologies Corporation)
• Original Assignee: GE Global Sourcing LLC (Westinghouse Air Brake Technologies Corporation)
• Inventors: Das, Subhas Chandra, Kumar, Ajith Kuttannair, Chandrasekaran, Shankar, Mukherjee, Rupam
• Primary Examiner(s): Black, Thomas G
• Assistant Examiner(s): Li, Ce Li
• Application Number:
  US15/063,043
• Publication Number:
  US 20170254726A1
• Time in Patent Office: 1,219 Days
• CPC Class Codes: B60L 50/10 using propulsion power supplied by engine-driven generators, e.g. generators driven by combustion engines
• CPC Class Codes: F02B 63/047 Movable engine-generator combinations on wheels
• CPC Class Codes: F02D 2041/288 for performing a transformation into the frequency domain, e.g. Fourier transformation
• CPC Class Codes: F02D 2200/1002 Output torque
• CPC Class Codes: F02D 2200/101 Engine speed
• CPC Class Codes: F02D 29/02 peculiar to engines driving vehicles; peculiar to engines driving variable pitch propellers
• CPC Class Codes: F02D 29/06 peculiar to engines driving electric generators
• CPC Class Codes: F02D 41/0085 Balancing of cylinder outputs, e.g. speed, torque or air-fuel ratio
• CPC Class Codes: F02D 41/0097 using means for generating speed signals
• CPC Class Codes: F02D 41/1498 measuring engine roughness
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: G01M 15/11 by detecting misfire
• CPC Class Codes: G01M 15/12 by monitoring vibrations
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A system includes a generator coupled to an engine and configured to generate electricity from rotational movement of a shaft of the engine, a sensor configured to measure one or more of a parameter of generator output, engine speed, or engine shaft torque, and a controller configured to detect engine imbalance based on a frequency content of a signal output from the sensor in response to a contribution to the frequency content from another component of the system being less than a threshold value.

Claims

1. A system, comprising:

a generator coupled to an engine and configured to generate electricity from rotational movement of a shaft of the engine;

one or more traction motors driven by the generator through a rectifier that produces a DC link voltage to one or more inverters;

a sensor configured to measure the DC link voltage; and

a controller configured to;

detect engine imbalance based on a frequency content of a signal output from the sensor in response to a contribution to the frequency content from the one or more inverters being less than a threshold value, including determining an inverter frequency of each inverter and, if the inverter frequency is within a threshold range of an engine rotational frequency, indicating the contribution is above the threshold value.

2. The system of claim 1, wherein the controller is configured to, in response to the contribution being above the threshold value, delay the detection of the engine imbalance until the contribution is less than the threshold value.

3. The system of claim 1, wherein to detect engine imbalance, the controller is configured to compare a magnitude of a selected frequency of the frequency content to a first threshold magnitude and indicate engine imbalance if the magnitude exceeds the first threshold magnitude.

4. The system of claim 3, wherein the controller is configured to, in response to the contribution being above the threshold, adjust the detection of the engine imbalance by comparing the magnitude of the selected frequency to a second threshold magnitude, higher than the first threshold magnitude, and indicate imbalance when the magnitude exceeds the second threshold magnitude.

5. The system of claim 1, wherein to determine if the contribution to the frequency content by the one or more inverters is greater than the threshold value, the controller is configured to:

identify one or more sidebands of a selected frequency of the frequency content; and

if a magnitude of a sum of the one or more sidebands exceeds a threshold magnitude, indicate the one or more inverters are contributing to the frequency content.

6. The system of claim 1, wherein the controller is further configured to detect engine imbalance based on the frequency content of the signal output from the sensor in response to a contribution to the frequency content from a change in engine operation being less than the threshold value.

7. The system of claim 1, wherein the controller is configured to, responsive to detecting engine imbalance, adjust one or more engine operating parameters.

8. A method for a vehicle system, comprising:

determining a frequency content of a signal output from a sensor configured to measure a parameter of a generator coupled to an engine of the vehicle system;

identifying whether a contribution to the determined frequency content by one or more vehicle system components at one or more selected frequencies is greater than a threshold;

when the contribution is not greater than the threshold, detecting engine imbalance based on the one or more selected frequencies of the determined frequency content, and adjusting an engine operating parameter in response to the detected engine imbalance; and

when the contribution is greater than the threshold, adjusting the detecting of the engine imbalance based on the one or more selected frequencies of the determined frequency content.

9. The method of claim 8, wherein adjusting the detecting of the engine imbalance based on the determined frequency content comprises delaying the detecting of the engine imbalance until the contribution is not greater than the threshold, and wherein the one or more vehicle system components comprise one or more of an inverter, an alternator, or a generator auxiliary load.

10. The method of claim 8, wherein detecting engine imbalance based on the determined frequency content comprises comparing a magnitude of the one or more selected frequencies of the frequency content to a first threshold magnitude and indicating engine imbalance if the magnitude exceeds the first threshold magnitude.

11. The method of claim 10, wherein adjusting the detecting of the engine imbalance based on the determined frequency content comprises adjusting the first threshold magnitude to a second, higher threshold magnitude.

12. The method of claim 8, wherein the one or more vehicle system components comprise an inverter, and wherein identifying whether the contribution to the determined frequency content by the one or more vehicle system components at the one or more selected frequencies is greater than the threshold includes identifying whether a frequency of the inverter is within a threshold range of an engine frequency.

13. A system, comprising:

an engine having a plurality of cylinders;

a generator coupled to the engine and configured to generate electricity from rotational movement of a shaft of the engine;

one or more traction motors driven by the generator through a rectifier that produces a DC link voltage to one or more inverters;

a sensor configured to measure the DC link voltage; and

a controller configured to;

identify one or more sidebands of a selected frequency of frequency content of a signal output by the sensor;

when a first magnitude of a sum of the one or more sidebands exceeds a first threshold magnitude, indicate the one or more inverters are contributing to the frequency content of the signal output by the sensor; and

when the first magnitude does not exceed the first threshold magnitude, indicate engine imbalance based on a second magnitude of the selected frequency exceeding a second threshold magnitude.

14. The system of claim 13, wherein the controller is configured to, responsive to indicating the one or more inverters are contributing to the frequency content, delay the indication of engine imbalance until the first magnitude drops below the first threshold magnitude.

15. The system of claim 13, wherein the controller is configured to, responsive to indicating engine imbalance, adjust one or more engine operating parameters.