Systems and methods for controlling fan motors with variable frequency drives
AssigneeJohnson Controls Tyco IP Holdings LLP
InventorsHarold J. Dubensky, James K. Spitzer, Roderick Ray Sentz, Kevin R. Stockton
Life of this patent
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Abstract
A fan assembly is provided. The fan assembly includes a fan, a motor that is coupled to the fan, and a variable frequency drive (VFD) that is coupled to the motor. The motor includes a maximum rated speed that is greater than a maximum structural speed limit of the fan, and the VFD includes a current output limit configured to limit an operational speed of the motor to be less than or equal to the maximum structural speed limit of the fan.
Claims20
A heating, ventilation and/or air-conditioning (HVAC) system, comprising:
- a fan or air blower having a maximum structural speed limit;
- a motor having a maximum rated speed that exceeds the maximum structural speed limit;
- a variable frequency drive (VFD) coupled to the motor;
- and
- a controller configured to utilize operational settings indicative of the maximum structural speed limit to control operation of the VFD to limit an operational speed of the motor to be only less than or equal to the maximum structural speed limit by altering frequency, electrical potential, and/or current of electrical power supplied to the motor.
A fan or blower assembly, comprising:
- a fan or blower comprising a maximum structural speed limit;
- an alternating current (AC) induction motor comprising a maximum rated speed that is greater than the maximum structural speed limit;
- a variable frequency drive (VFD) coupled to the AC induction motor;
- and
- a controller configured to utilize one or more operational settings, including an indication of the maximum structural speed limit, to operate the VFD to maintain an operational speed of the AC induction motor to be only less than or equal to the maximum structural speed limit by altering frequency, electrical potential, and/or current of electrical power supplied to the motor during operation of the motor.
A computer-readable medium storing instructions which, when implemented by a processor, cause the processor to:
- determine at least one operational setting indicative of a maximum structural speed limit of a fan or blower assembly;
- determine electrical power settings to facilitate control of a motor based on the at least one operational setting, wherein the motor is configured to drive the fan or blower assembly, and the motor comprises a maximum rated speed that is greater than the maximum structural speed limit;
- and
- send a command to a variable frequency drive (VFD) to provide electricity with the electrical power settings to alter frequency, electrical potential, and/or current of electrical power supplied to the motor during operation of the motor and thereby maintain an operational speed of the motor to be only less than or equal to the maximum structural speed limit of the fan.
Dependencies are inferred from the claim text.