Multi-level programming of motor for a ventilation system
First Claim
1. A method of operating a ventilation system, the method comprising:
- providing a user interface of the ventilation system, which comprises an electric motor having predetermined values of rated electric current and rated rotational speed, the user interface being configured to receive a user'"'"'s input for operating the electric motor;
receiving a desired level of airflow rate through the user interface, wherein the desired level represents a first fraction of a maximum hypothetical airflow rate, the maximum hypothetical airflow rate being computed as the product of the predetermined values of rated electric current and rated rotational speed;
obtaining a target value corresponding to the desired level of airflow for a feedback control of the electric motor;
monitoring electric current and rotational speed of the electric motor while running the electric motor; and
conducting the feedback control of the electric motor such that the product of the monitored electric current and rotational speed stays within proximity of the target value.
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Accused Products
Abstract
A method of constant airflow control for a ventilation system is disclosed. The method includes various controls to accomplish a substantially constant airflow rate over a significant change of the static pressure in a ventilation duct. One control is a constant I·RPM control, which is primarily used in a low static pressure range. Another control is a constant RPM control, which is primarily used in a high static pressure range. These controls requires neither a static pressure sensor nor an airflow rate sensor to accomplish substantially constant airflow rate while static pressure changes. This is because these controls use only intrinsic control variables which are electric current and rotational speed of the motor. Also, the method improves the accuracy of the control by correcting certain deviations that are caused by the motor'"'"'s current-RPM characteristics. To compensate the deviation, the method adopts a test operation in a minimum static pressure condition. Also disclosed is an apparatus for conducting these control methods.
154 Citations
13 Claims
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1. A method of operating a ventilation system, the method comprising:
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providing a user interface of the ventilation system, which comprises an electric motor having predetermined values of rated electric current and rated rotational speed, the user interface being configured to receive a user'"'"'s input for operating the electric motor; receiving a desired level of airflow rate through the user interface, wherein the desired level represents a first fraction of a maximum hypothetical airflow rate, the maximum hypothetical airflow rate being computed as the product of the predetermined values of rated electric current and rated rotational speed; obtaining a target value corresponding to the desired level of airflow for a feedback control of the electric motor; monitoring electric current and rotational speed of the electric motor while running the electric motor; and conducting the feedback control of the electric motor such that the product of the monitored electric current and rotational speed stays within proximity of the target value. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method of operating a ventilation system, the method comprising:
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providing a user interface of the ventilation system, which comprises an electric motor having predetermined values of rated electric current and rated rotational speed, the user interface being configured to receive a user'"'"'s input for operating the electric motor; receiving a desired level of airflow rate through the user interface, wherein the desired level represents a first fraction of a maximum hypothetical airflow rate, the maximum hypothetical airflow rate being computed as the product of the predetermined values of rated electric current and rated rotational speed; obtaining a target value corresponding to the desired level of airflow for a feedback control of the electric motor; and monitoring electric current and rotational speed of the electric motor while running the electric motor; conducting the feedback control of the electric motor such that the product of the monitored electric current and rotational speed stays within proximity of the target value; receiving a desired level of a rotational speed through the user interface; and obtaining a target rotational speed corresponding to the desired level for another feedback control. - View Dependent Claims (8, 9, 10, 11, 12, 13)
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Specification