System and method for controlling a variable speed drive of a compressor motor
AssigneeJohnson Controls Technology Company
InventorPaul Nemit, JR.
Life of this patent
Estimating the term…
Abstract
A variable speed drive (VSD) can be used to vary the voltage-to-frequency ratio (V/f) supplied to a compressor motor of a heating, ventilation, air conditioning or refrigeration (HVAC&R) system to make the motor stronger or weaker to compensate for varying conditions in the HVAC&R system. The VSD and corresponding control system or algorithm can monitor an operating parameter of the HVAC&R system, such as the kW absorbed by the motor, and then raise or lower the V/f of the VSD to obtain the lowest possible power consumption from the motor.
Claims17
A system comprising:
- a compressor, a condenser, an expansion device and an evaporator connected in a closed refrigerant circuit;
- a motor connected to the compressor to power the compressor;
- a variable speed drive connected to the motor to power the motor, the variable speed drive being operable to provide a variable voltage to the motor and a variable frequency to the motor;
- a control panel to control operation of the variable speed drive and one or more components of the system;
- a sensor to measure an operational parameter of the system, the sensor being operable to communicate the measured operational parameter to the control panel;
- and
- the control panel being operable to execute a control algorithm to determine a voltage-to-frequency ratio to be output by the variable speed drive using the measured operational parameter, wherein the voltage-to-frequency ratio varies based on the measured operational parameter.
A method for controlling a variable speed drive, the method comprising:
- measuring an operational parameter of an HVAC&R system;
- determining a voltage-to-frequency ratio to be output by a variable speed drive using the measured operational parameter, the variable speed drive powering a compressor motor of the HVAC&R system;
- generating control instructions for the variable speed drive based on the determined voltage-to-frequency ratio;
- and
- adjusting the output voltage-to-frequency ratio provided by the variable speed drive to the compressor motor with the generated control instructions.
Dependencies are inferred from the claim text.