US5202951A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mass flow rate control system and method
Assignee: HVAC MODULATION TECHNOLOGIES LLC
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Filing: 1991-06-05
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Granted: 1993-04-13
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Expires: 2011-06-05
Abstract
Abstract A system and method of controlling an electronically commutated motor (ECM) driving a blower to maintain the mass flow rate of the blower at a desired value. A microprocessor-based controller unit derives a motor control signal from just two inputs, namely the desired mass flow rate and a speed feedback signal representing the actual shaft speed of the ECM.
Inventors
- 👤 Edward F. Doyle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:02
CPC Classifications
G; G05; G05D; G05D7/00; G05D7/06; G05D7/0617; G05D7/0629; G05D7/0676; Y; Y10; Y10S; Y10S388/00; Y10S388/923; Y10S388/93
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
146 words
A system for controlling the mass flow rate of a blower which is drivably connected to an electronically commutated motor (ECM), the system comprising: means for generating a mass flow rate signal representing the desired mass flow rate of the blower, means for generating a speed feedback signal representing the actual shaft speed of the ECM, controller means for generating a motor control signal for supply to the ECM to control the torque output thereof, said controller means including a first input terminal for receiving said mass flow rate signal and a second input terminal for receiving said speed feedback signal, and said controller means operable to adjust said motor control signal as a function of said speed feedback signal and said mass flow rate signal to maintain the actual mass flow rate at a desired value which is represented by said mass flow rate signal.
Claim 2
Independent Claim
146 words
A system for controlling the mass flow rate of a blower which is drivably connected to an electronically commutated motor (ECM), the system comprising: means for generating a mass flow rate signal representing the desired mass flow rate of the blower, means for generating a speed feedback signal representing the actual shaft speed of the ECM, controller means for generating a motor control signal for supply to the ECM to control the torque output thereof, said controller means including a first input terminal for receiving said mass flow rate signal and a second input terminal for receiving said speed feedback signal, and said controller means operable to adjust said motor control signal as a function of said speed feedback signal and said mass flow rate signal to maintain the actual mass flow rate at a desired value which is represented by said mass flow rate signal.
Claim 3
Dependent Claim
51 words
The system of claim 1, wherein said controller means is operable to calculate a representation (D) of said motor control signal from said mass flow rate signal (W) and said speed feedback signal (N) according to the equation D=D.sub.0 +AN+BWN, where D 0 , A, and B are predetermined, positive constants.
Claim 4
Dependent Claim
25 words
The system of claim 2, wherein the controller means includes a microprocessor to perform the calculation of said representation (D) of the motor control signal.
Claim 5
Dependent Claim
20 words
The system of claim 2, further comprising non-volatile memory means for memorizing the constants D 0 , A, and B.
Claim 6
Dependent Claim
57 words
The system of claim 2, wherein the controller means comprises a duty cycle generator to convert said representation of the motor control signal into a pulse width modulated motor control signal for transmittal to the ECM, the duty cycle of said pulse width modulated motor control signal being determined by said representation of the motor control signal.
Claim 7
Dependent Claim
12 words
The system of claim 5, wherein said controller means includes a microprocessor.
Claim 8
Dependent Claim
42 words
The system of claim 1, wherein the blower is connected to a forced air heating system to provide supply air to said forced air heating system at said desired mass flow rate regardless of changes in the resistance of the heating system.
Claim 9
Independent Claim
127 words
A method of controlling an electronically commutated motor (ECM) driving a blower, so as to maintain the mass flow rate of the blower at a desired value, the method comprising the steps of: setting said desired value of the mass flow rate and generating an electrical mass flow rate signal indicative thereof, measuring the shaft speed of the ECM and generating an electrical speed feedback signal indicative thereof, determining from said mass flow rate signal and said speed feedback signal a motor control signal for controlling the torque output of the ECM, and adjusting the motor control signal in response to changing values of said mass flow rate signal and said speed feedback signal to maintain the desired mass flow rate corresponding to mass flow rate signal.
Claim 10
Independent Claim
127 words
A method of controlling an electronically commutated motor (ECM) driving a blower, so as to maintain the mass flow rate of the blower at a desired value, the method comprising the steps of: setting said desired value of the mass flow rate and generating an electrical mass flow rate signal indicative thereof, measuring the shaft speed of the ECM and generating an electrical speed feedback signal indicative thereof, determining from said mass flow rate signal and said speed feedback signal a motor control signal for controlling the torque output of the ECM, and adjusting the motor control signal in response to changing values of said mass flow rate signal and said speed feedback signal to maintain the desired mass flow rate corresponding to mass flow rate signal.
Claim 11
Dependent Claim
61 words
The method of claim 8 comprising the step of calculating a representation (D) of said motor control signal from said mass flow rate signal (W) and said speed feedback signal (N) according to the equation D=D.sub.0 +AN+BWN, where D 0 , A, and B are predetermined constants, and thereafter determining the actual motor control signal in response to said representation (D).
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-04-12 | 1996-10-12 | 1997-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-04-12 | 2000-10-12 | 2001-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-04-12 | 2004-10-12 | 2005-04-13 | $7700.00 | Window Closed / Lapsed |