US 10,483,902 B1 · System and method for reducing current harmonic distortion in a motor controller

Abstract

A current regulator for a motor controller reduces distortion of the current output to a motor. Feedback signals corresponding to the current present on the motor are transformed into a fundamental and a harmonic reference frame. Notch filters in each reference frame attenuate components of the current feedback signal from the other reference frame. Current regulators in each reference frame receive the filtered current feedback signal in the corresponding reference frame and generate an output signal that is used to regulate the output current to the motor to the desired level of current in the corresponding reference frame. The output signal from the regulator in the harmonic reference frame is transformed to the fundamental reference frame, and the output of the two regulators are combined in a common reference frame to generate a reference signal corresponding to the required voltage output to the motor to achieve desired operation.

Claims20

Dependent claims

A system for reducing current harmonic distortion in a motor controller, wherein the motor controller is operative to control operation of a multi-phase motor, the system comprising:

at least two inputs, each input configured to receive a feedback signal corresponding to a current present in one phase of the motor;
a reference frame transformer operative to convert the feedback signals from the at least two inputs to a first synchronous current feedback signal and a second synchronous current feedback signal, wherein the first synchronous current feedback signal is at a fundamental frequency and the second synchronous current feedback signal is at a harmonic frequency;
a first current regulator configured to receive a current reference signal and the first synchronous current feedback signal as inputs and to generate a first regulator output signal corresponding to desired operation of the motor at the fundamental frequency;
and
a second current regulator configured to receive the second synchronous current feedback signal as an input and to generate a second regulator output signal at the harmonic frequency, wherein the motor controller is operative to sum the first regulator output signal and the second regulator output signal to generate a modified current regulator output signal.

2 more elements

A method for reducing current harmonic distortion in a motor controller, wherein the motor controller is operative to control operation of a multi-phase motor, the method comprising the steps of:

receiving a feedback signal from at least two current sensors, each feedback signal corresponding to a current present in one phase of the motor;
transforming the feedback signal to a first synchronous current feedback signal at a first frequency;
transforming the feedback signal to a second synchronous current feedback signal at a second frequency, wherein the second frequency is greater than the first frequency;
executing a first current regulator operatively tuned for the first frequency to generate a first regulator output signal as a function of the first synchronous current feedback signal;
executing a second current regulator operatively tuned for the second frequency to generate a second regulator output signal as a function of the second synchronous current feedback signal;
and
generating an output signal for the motor controller that is a function of the first regulator output signal and the second regulator output signal.

4 more elements

A motor controller for reducing current harmonic distortion output to a multi-phase motor, the motor controller comprising:

at least two current sensors, each current sensor configured to generate a feedback signal corresponding to a current output to one phase of the motor;
a memory device configured to store a series of instructions;
and
a processor operative to execute the series of instructions to:
receive the feedback signals from the at least two current sensors,
transform the feedback signals to a first synchronous current feedback signal at a first frequency,
transform the feedback signals to a second synchronous current feedback signal at a second frequency,
execute a current regulator to independently regulate current at the first frequency and at the second frequency, and
generate an output signal from the current regulator that is a function of the independently regulated first and second frequencies.

6 more elements

Dependencies are inferred from the claim text.

System and method for reducing current harmonic distortion in a motor controller

Life of this patent

System and method for reducing current harmonic distortion in a motor controller

Life of this patent

Abstract

Claims20