Methods and systems for envelope and efficiency control in an electric motor

摘要

An air moving system including an electric motor, a load coupled to the electric motor, and a motor drive controller coupled to the electric motor is provided. A DC voltage generated from an AC input voltage provided to the electric motor tends towards zero at about twice a frequency of the AC input voltage. The motor drive controller includes an adjustment control module configured to receive a measurement of an instantaneous motor current value for the electric motor, determine a flux component value based on the instantaneous motor current value, and determine, based at least in part on the flux component value and a flux component demand value, an adjusted flux component demand value that causes the motor drive controller to adjust an operation such that an average flux component value based on the flux component value is substantially similar to the flux component demand value.

主权项

1. An electric motor drive controller configured to be coupled to an electric motor, said electric motor drive controller comprising:
a rectifier configured to convert an AC input voltage having a frequency to a DC voltage, wherein the DC voltage tends towards zero at about twice the frequency of the AC input voltage; a DC link electrically coupled to said rectifier; an inverter electrically coupled to said DC link and configured to generate a three phase pulse width modulated (PWM) voltage to drive the electric motor; and an adjustment control module configured to:
receive a measurement of an instantaneous motor current value from a current sensor coupled to the electric motor at one or more multiples of the frequency of the AC input voltage;determine a flux component value based on the measurement of the instantaneous motor current value at one or more multiples of the frequency of the AC input voltage;determine an average flux component value by filtering the flux component value at one or more multiples of the frequency of the AC input voltage;receive a flux component demand value from a current command generator;determine an adjusted flux component demand value at one or more multiples of the frequency of the AC input voltage based on the determined average flux component value and the received flux component demand value, wherein the adjusted flux component demand value causes said motor drive controller to adjust an operation such that a difference between the average flux component value and the flux component demand value is within a first predetermined threshold; andreduce, by a torque compensator, a torque component demand value as the DC voltage tends towards zero to enable the adjusted flux component demand value to maintain the difference between the average flux component value and the flux component demand value within the first predetermined threshold, the DC voltage measured by a voltage sensor coupled to an output of said rectifier.