초록 ▼

A multi-phase induction motor torque control method comprising the steps of establishing an adaptive speed observer and an adaptive flux observer using a speed sensorless control scheme. Rotor speed is estimated based on filtered current and voltage command signals as inputs. A flux observer based o

A multi-phase induction motor torque control method comprising the steps of establishing an adaptive speed observer and an adaptive flux observer using a speed sensorless control scheme. Rotor speed is estimated based on filtered current and voltage command signals as inputs. A flux observer based on the estimated rotor speed and rotor flux angle is calculated using the estimated rotor flux. Torque is determined following estimation of speed and flux.

대표청구항 ▼

1. A torque control method for a three-phase induction motor wherein the operator commands reference torque and flux values, the motor having a rotor and a stator with windings establishing a rotating flux field, the method comprising the steps of: measuring three-phase stator current and calcula

1. A torque control method for a three-phase induction motor wherein the operator commands reference torque and flux values, the motor having a rotor and a stator with windings establishing a rotating flux field, the method comprising the steps of: measuring three-phase stator current and calculating two-phase stator current from the three-phase stator current; filtering stator current to develop a high pass filter current output and a low pass filter current output; calculating stator voltage and filtering calculated stator voltage; estimating stator current as a function of rotor speed estimation, calculating stator current error and adjusting the estimated rotor speed using stator current error thereby developing an estimation of rotor speed as a function of filtered stator current and filtered stator voltage; defining a rotor flux observer to calculate a rotor flux estimation and estimating a rotor flux vector; estimating motor torque using flux orientation and stator current; and calculating stator voltage based on the commanded reference torque, the commanded reference flux, flux estimation, torque estimation and measured stator current. 2. The method set forth in claim 1 wherein the filtered stator current and filtered stator voltage are computed and used to create a reference model for rotor speed estimation; the estimation of rotor speed comprising calculating the adjustment of estimated rotor speed and the stator current estimate, the rotor speed estimation being used to compute rotor flux angle, and the rotor flux angle being used to control induction motor torque. 3. The method set forth in claim 1 wherein estimation of a rotor flux vector is determined by the equation: where: λr,is,vs--rotor flux vector estimate, stator current and stator voltage command ω--angular speed of the rotor Rr,Rs--rotor and stator resistance M--mutual inductance Lr,Ls--rotor and stator inductance σ=1-M2/LsLr--leakage parameter np--number of pole pairs a(t) and b(t) are linear combinations of the filtered stator current. 4. The method set forth in claim 2 wherein estimation of a rotor flux vector is determined by the equation: where: λr,is,vs--rotor flux vector estimate, stator current and stator voltage command ω--angular speed of the rotor Rr,Rs--rotor and stator resistance M--mutual inductance Lr,Ls--rotor and stator inductance σ=1-M2/LsLr--leakage parameter np--number of pole pairs a(t) and b(t) are linear combinations of the filtered stator current.