METHOD OF DETERMINATION OF PARAMETERS OF INDUCTION MOTOR Russian patent published in 2015 - IPC G01R31/34 

FIELD: electricity.

SUBSTANCE: method of determination of parameters of the electric motor consists in that during starting and operation of the induction motor the instant values of currents and voltage of two stator phases and the frequency of rotation of the shaft of the induction motor are measured simultaneously; the measured instant values of currents and voltage are transformed from natural coordinate system into rectangular stationary system of coordinates, sequentially four temporary delays of the transformed currents and voltage and frequency of rotation of the shaft of the induction motor are performed, the obtained values are saved and used for determination of active resistance and equivalent inductance of the stator winding reduced to the stator of active resistance and equivalent inductance of the rotor winding, and the inductance pre-determined by the magnetic flux in the air gap of the electric motor in real time as follows: $$\begin{array}{l}{R}_1=-\frac{K_3}{K_4},{R^{\prime }}_2=\frac{K_3-K_5}{K_4},L_1=\frac{K_3-K_5}{K_2},\\ L_m=L_1\cdot \sqrt{1-\frac{1}{K_4}\cdot L_1},\sigma =-\frac{R_1}{K_3\cdot L_1},T_2=\frac{1}{K_2\cdot \sigma \cdot L_1},L_2=\frac{T_2}{{R^{\prime }}_2},\end{array}$$ where R₁ - active resistance of the stator winding, Ohm; $${R^{\prime }}_2$$ - active resistance of the rotor winding reduced to the stator, Ohm; L₁ - equivalent inductance of the stator winding, H; L_m - the resultant inductance pre-determined by the magnetic flux in the air gap of the induction motor, H; σ - rotor dispersion coefficient; T₂ - rotor time constant, with; L₂ - equivalent inductance of the rotor winding, H; K₁, K₂, K₃, K₄, K₅ - the coefficients determined by the least squares method.

EFFECT: simultaneous determination of all electromagnetic parameters of the induction motor in real time.

2 cl, 4 dwg, 1 tbl