Method for adjusting parameters of an electric motor and variable speed drive using such a method

Claim 2

Method for adjusting motor parameters in a variable speed drive intended to control an electric induction motor (M), wherein the method comprises: a step for determining a first difference (ΔI Q ) between a motor torque current reference (I Qref ) and a motor torque current measurement (I Qm ), and a second difference (ΔI D ) between a motor flux current reference (I Dref ) and a motor flux current measurement (I Dm ), a step for calculating a correction value (ΔR R ) of the motor's rotor resistance and a correction value (ΔL R ) of the motor's rotor inductance from the integral term of said first difference (ΔI Q ) and from the integral term of said second difference (ΔI D ), a step for adjusting values of parameters of the motor model based on said correction values (ΔL R , ΔR R ) of the rotor inductance and the rotor resistance, a step for generating control voltages (U D , U Q ) to be applied to the motor (M), using said adjusted motor parameter values.

Claim 3

Method according to claim 1 , wherein the torque current reference (I Qref ) is obtained from a motor speed reference (W ref ) and from a motor speed measurement (W m ).

Claim 4

Method according to claim 2 , wherein the method is executed in the variable speed drive when the motor speed measurement (W m ) exceeds a predetermined threshold value.

Claim 5

Variable speed drive intended to control an electric induction motor (M), equipped with a processing unit ( 10 ) including a current regulator block ( 15 ) delivering control voltages of the motor (M), wherein the current regulator block ( 15 ) comprises: an integrator block ( 16 ) to determine a first difference (ΔI Q ) between a motor torque current reference (I Qref ) and a motor torque current measurement (I Qm ), and a second difference (ΔI D ) between a motor flux current reference (I Dref ) and a motor flux current measurement (I Dm ), an adaptor block ( 18 ) calculating a correction value (ΔR R ) of the motor's rotor resistance and a correction value (ΔL R ) of the motor's rotor inductance from the integral term of said first difference (ΔI Q ) and from the integral term of said second difference (ΔI D ), and adjusting values of parameters of the motor model based on said correction values (ΔL R , ΔR R ) of the rotor inductance and the rotor resistance, a compensation block ( 17 ) using said adjusted motor parameter values to generate control voltages (U D , U Q ) to be applied to the motor (M).

Claim 6

Variable speed drive intended to control an electric induction motor (M), equipped with a processing unit ( 10 ) including a current regulator block ( 15 ) delivering control voltages of the motor (M), wherein the current regulator block ( 15 ) comprises: an integrator block ( 16 ) to determine a first difference (ΔI Q ) between a motor torque current reference (I Qref ) and a motor torque current measurement (I Qm ), and a second difference (ΔI D ) between a motor flux current reference (I Dref ) and a motor flux current measurement (I Dm ), an adaptor block ( 18 ) calculating a correction value (ΔR R ) of the motor's rotor resistance and a correction value (ΔL R ) of the motor's rotor inductance from the integral term of said first difference (ΔI Q ) and from the integral term of said second difference (ΔI D ), and adjusting values of parameters of the motor model based on said correction values (ΔL R , ΔR R ) of the rotor inductance and the rotor resistance, a compensation block ( 17 ) using said adjusted motor parameter values to generate control voltages (U D , U Q ) to be applied to the motor (M).

Claim 7

Variable speed drive according to claim 4 , wherein the processing unit ( 10 ) includes a speed regulator block ( 11 ) calculating the torque current reference (I Qref ) from a motor speed reference (W ref ) and from a motor speed measurement (W m ).

Claim 8

Variable speed drive according to claim 5 , wherein the calculation of the rotor resistance correction value (ΔR R ) and of the rotor inductance correction value (ΔL R ) is implemented in the adaptor block ( 18 ) when the motor speed measurement (W m ) exceeds a predetermined threshold value.