MOTOR CURRENT BASED AIR CIRCUIT OBSTRUCTION DETECTION

• US 20100148748A1
• Filed: 12/17/2008
• Published: 06/17/2010
• Est. Priority Date: 12/17/2008
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Bharadwaj, Raj Mohan, Lazarovich, David
• Granted Patent: US 8,125,230 B2
• Time in Patent Office: Days
• US Class Current: 324/71.100
• CPC Class Codes: F24F 11/30 for purposes related to the operation of the system, e.g. for safety or monitoring
• CPC Class Codes: F24F 11/32 Responding to malfunctions or emergencies
• CPC Class Codes: F24F 11/38 Failure diagnosis
• CPC Class Codes: F24F 11/64 using pre-stored data

Abstract

A method for determining an obstruction in an air circuit, the air circuit having a fan and a motor that drives the fan, includes the steps of obtaining a load current of a motor coupled to the air circuit, comparing the load current to a predetermined value, and determining the obstruction using the load current and the predetermined value.

Claims

1. A method for determining an obstruction in an air circuit, the air circuit comprising a fan and a motor that drives the fan, for an environmental control unit, the method comprising the steps of:

obtaining a load current of the motor;

comparing the load current to a predetermined value; and

determining the obstruction using the load current and the predetermined value.

2. The method of claim 1, wherein the step of comparing the load current to a predetermined value comprises the step of:

comparing the load current to a plurality of values, each of the plurality of values comprising a measure of load current of a corresponding one of a plurality of models;

selecting one of the models, based at least in part on the comparison of the load current to the plurality of values;

obtaining a measure of obstruction from the selected one of the models; and

determining the obstruction using the measure of obstruction.

3. The method of claim 2, further comprising the step:

determining a state of the motor;

wherein the step of comparing the load current to the plurality of values comprises the steps of;

comparing the load current to a first plurality of values if the motor is in a steady state, each of the first plurality of values comprising a measure of load current of a corresponding one of a first plurality of models representing steady state operation of the motor; and

comparing the load current to a second plurality of values if the motor is in a transient state, each of the second plurality of values comprising a measure of load current of a corresponding one of a second plurality of models representing transient state operation of the motor.

4. The method of claim 3, further comprising the steps of:

generating the first plurality of models using steady state motor data; and

generating the second plurality of models using transient state motor data.

5. The method of claim 1, wherein the step of determining the obstruction comprises the step of:

determining a percentage obstruction of the air circuit using the load current and the predetermined value.

6. The method of claim 1, wherein the step of determining the obstruction comprises the step of:

determining a distance between the obstruction of the air circuit and the fan, using the load current and the predetermined value.

7. A program product for determining an obstruction in an air circuit for an environmental control unit, the program product comprising:

a program configured to at least facilitate;

obtaining a load current of a motor coupled to the air circuit;

comparing the load current to a predetermined value; and

determining the obstruction using the load current and the predetermined value; and

a computer readable signal bearing media bearing the program.

8. The program product of claim 7, wherein the program is further configured to at least facilitate:

comparing the load current to a plurality of values, each of the plurality of values comprising a measure of load current of a corresponding one of a plurality of models;

selecting one of the models, based at least in part on the comparison of the load current to the plurality of values;

obtaining a measure of obstruction from the selected one of the models; and

determining the obstruction using the measure of obstruction.

9. The program product of claim 8, wherein the program is further configured to at least facilitate:

determining a state of the motor;

comparing the load current to a first plurality of values if the motor is in a steady state, each of the first plurality of values comprising a measure of load current of a corresponding one of a first plurality of models representing steady state operation of the motor; and

comparing the load current to a second plurality of values if the motor is in a transient state, each of the second plurality of values comprising a measure of load current of a corresponding one of a second plurality of models representing transient state operation of the motor.

10. The method of claim 9, wherein the program is further configured to at least facilitate:

generating the first plurality of models using steady state motor data; and

generating the second plurality of models using transient state motor data.

11. The program product of claim 7, wherein the program is further configured to at least facilitate determining a percentage obstruction of the air circuit, a distance between the obstruction of the air circuit and the fan, or both, using the load current and the predetermined value.

12. A system for determining an obstruction in an air circuit for an environmental control unit, the system comprising:

a sensor configured to at least facilitate obtaining a load current of a motor coupled to the air circuit; and

a processor coupled to the sensor, the processor configured to at least facilitate;

comparing the load current to a predetermined value; and

determining the obstruction using the load current and the predetermined value.

13. The system of claim 12, wherein the processor is further configured to at least facilitate:

comparing the load current to a plurality of values, each of the plurality of values comprising a measure of load current of a corresponding one of a plurality of models;

selecting one of the models, based at least in part on the comparison of the load current to the plurality of values;

obtaining a measure of obstruction from the selected one of the models; and

determining the obstruction using the measure of obstruction.

14. The system of claim 13, wherein the processor is further configured to at least facilitate:

determining a state of the motor;

comparing the load current to a first plurality of values if the motor is in a steady state, each of the first plurality of values comprising a measure of load current of a corresponding one of a first plurality of models representing steady state operation of the motor; and

comparing the load current to a second plurality of values if the motor is in a transient state, each of the second plurality of values comprising a measure of load current of a corresponding one of a second plurality of models representing transient state operation of the motor.

15. The system of claim 14, wherein the processor is further configured to at least facilitate:

generating the first plurality of models using steady state motor data; and

generating the second plurality of models using transient state motor data.

16. The system of claim 12, wherein the processor is further configured to at least facilitate:

determining a percentage obstruction of the air circuit, a distance between the obstruction of the air circuit and the fan, or both, using the load current and the predetermined value.

17. The system of claim 12, wherein the processor is part of an environmental control system of an aircraft.

18. The system of claim 12, wherein the processor is part of a load protection and control unit (ELCU) of an aircraft.

19. The system of claim 12, wherein the processor is part of an integrated modular avionic unit (IMA) of an aircraft.

20. The system of claim 12, wherein the processor is part of a solid state power controller (SSPC) of an aircraft.