VSD control
AssigneeCarrier Corporation
InventorsSteven J. Holden, Vishnu M. Sishtla, Cornelius Holmes
Life of this patent
Estimating the term…
Abstract
A compressor is powered by a motor which is, in turn, powered by a variable speed drive (VSD). The switching frequency and voltage/frequency relationship of the VSD may be adjusted dynamically to maximize efficiency.
Claims19
A method for controlling a variable speed drive supplying pulse width modulated electric power of an output voltage and output frequency to a motor to drive a compressor, the method comprising:
- dynamically changing an inverter switching frequency in association with changing said output frequency;
- and
- within a first portion of an output frequency domain, operating the drive with a dynamically changing relationship of said output voltage to said output frequency.
A compressor system comprising:
- a compressor;
- a motor coupled to the compressor to drive the compressor and having a motor speed;
- a variable speed drive coupled to the motor to supply the motor with electric power having a voltage and a frequency;
- and
- a control means coupled to the variable speed drive and configured to operate the variable speed drive to supply said electric power so as to improve a combined efficiency of the motor and variable speed drive relative above a baseline efficiency associated with an essentially constant inverter switching frequency and an essentially constant ratio of said voltage to said frequency, wherein:
- the control means is configured to supply said electric power as pulse width modulated electric power via at least one of:
- dynamically changing an inverter switching frequency in association with changing the output frequency;
- and
- within a first portion of an output frequency domain, operating the drive with a dynamically changing relationship of said output voltage to said output frequency.
A method for remanufacturing a variable speed drive and motor combination or reengineering a configuration of said combination from a baseline condition to a second condition comprising:
- configuring a control hardware or software coupled to the variable speed drive to operate the variable speed drive to supply electric power having a voltage and a frequency so as to improve a combined efficiency of the motor and variable speed drive above a baseline condition efficiency associated with an essentially constant inverter switching frequency and an essentially constant ratio of said voltage to said frequency, wherein:
- the control means is configured to supply said electric power as pulse width modulated electric power via at least one of:
- dynamically changing an inverter switching frequency in association with changing the output frequency;
- and
- within a first portion of an output frequency domain, operating the drive with a dynamically changing relationship of said output voltage to said output frequency.
Dependencies are inferred from the claim text.