Apparatus and method for optimally controlling flux in an AC motor
AssigneeGeneral Electric Company
InventorsEddy Ying Yin Ho, Anthony Michael Klodowski
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Abstract
A method and apparatus for controlling flux in an induction motor. During initial start of an induction motor drive the motor flux has to be charged up. The method provides time optimal flux forcing under limited inverter ampere capability. Command stator flux and current are generated and coordinated through a motor flux model. Charging of the motor flux and flux current are accelerated up to nominal operating values in coordinated manner.
Claims33
A preflux forcing controller for an asynchronous, alternating current (AC) induction motor drive system comprising:
- means for generating a flux reference value;
- means for generating a flux boosting value;
- means for generating a preflux current value to perform a flux acceleration procedure;
- means for processing the flux reference value, the flux boosting value, and the preflux current value to determine an output signal;
- and
- means for providing at least one command signal to the motor based on the output signal;
- and
- wherein the means for processing generates a command stator flux, and wherein a command stator flux value is continually increased until the command stator flux value reaches a value substantially equal to the flux reference value plus the flux boosting value, at which time the command stator flux value is reduced by the flux boosting value.
A method of forcing flux in an asynchronous, alternating current (AC) induction motor, drive system comprising the steps of:
- generating a flux reference value;
- generating a flux boosting value;
- generating a preflux current value to perform a flux acceleration procedure;
- processing the flux reference value, the flux boosting value, and the preflux current value to determine an output signal;
- and
- providing at least one command signal to the motor based on the output signal;
- and
- generating a command stator flux, and wherein a command stator flux value is continually increased until the command stator flux value reaches a value substantially equal to the flux reference value plus the flux boosting value, at which time the command stator flux value is reduced by the flux boosting value.
A preflux forcing controller for an asynchronous, alternating current (AC) induction motor, drive system comprising:
- a command flux generator configured to generate a flux reference value;
- a flux boost generator configured to generate a flux boosting value;
- a preflux current generator configured to generate a preflux current value to perform a flux acceleration procedure;
- processing circuitry configured to process the flux reference value, the flux boosting value, and the preflux current value to determine an output signal;
- and
- a current regulator and voltage feedforward model of a motor drive configured to provide voltage commands based on the output signal;
- and
- wherein the processing circuitry generates a command stator flux, and wherein a command stator flux value is continually increased until the command stator flux value reaches a value substantially equal to the flux reference value plus the flux boosting value, at which time the command stator flux value is reduced by the flux boosting value.
A motor drive system for an asynchronous, alternating current (AC) induction motor, drive system comprising:
- a command flux generator configured to generate a flux reference value;
- a flux boost generator configured to generate a flux boosting value;
- a preflux current generator configured to generate a preflux current value so as to perform a flux acceleration procedure;
- processing circuitry configured to process the flux reference value, the flux boosting value, and the preflux current value to determine an output signal;
- a current regulator and voltage feedforward model of a motor drive configured to provide voltage commands based on the output signal;
- a DC bus;
- a voltage regulation and DC bus compensation module coupled to an output of said current regulator model and voltage feedforward and configured to generate a voltage signal and a phase angle signal;
- a vector rotate and pulse width modulation module coupled to an output of said voltage regulation and DC bus compensation module and configured to generate switching signals based on the voltage signal and the phase angle signal;
- and
- an inverter having bridges disposed across said DC bus and being coupled to said vector rotate and pulse width modulation module to generate a voltage signal intended to induce a desired current in an AC induction motor based on the switching signals;
- and
- an AC motor coupled to an output of said inverter;
- and
- wherein the processing circuitry generates a command stator flux, and wherein a command stator flux value is continually increased until the command stator flux value reaches a value substantially equal to the flux reference value plus the flux boosting value, at which time the command stator flux value is reduced by the flux boosting value.
Dependencies are inferred from the claim text.