METHOD TO MEASURE ANGULAR SPEED OF ROTATION OF THREE-PHASE INDUCTION MOTOR Russian patent published in 2014 - IPC G01P3/44 

FIELD: measurement equipment.

SUBSTANCE: method consists in measurement of instantaneous values of phase currents i_a, i_b and voltages u_a, u_b on phases A and B, supplied to a stator, temperature t_c of stator winding conductors and frequency f of the main harmonic of voltage of the stator of the three-phase induction electric motor, with available active resistance of the stator winding R_s, active resistance of the reduced rotor $$t_{пр},$$ full inductance of the stator winding L_s, reduced full inductance of the rotor winding $${R^{\prime }}_r$$ mutual inductance of stator and rotor windings L_µ. They determine the ratio α as the ratio of full inductance of the stator winding L_s  to the reduced full inductance of the rotor winding $${L^{\prime }}_r,$$ the ratio β as the ratio of mutual inductance of stator and rotor windings L_µ to the reduced full inductance $${L^{\prime }}_r^{},$$ time constant of the rotor winding $${T^{\prime }}_r$$ as the ratio of the reduced full inductance $${L^{\prime }}_r$$ to the given active resistance of the rotor winding $${R^{\prime }}_r.$$ They determine the resistance of the stator winding with account of the temperature coefficient, a dynamic differential component of the relative value of the angular speed, a dynamic integral component of the relative value of the angular speed and instantaneous value of the angular speed. Then, using the produced values, they determine the angular speed of rotation ω(t) of the three-phase induction motor.

EFFECT: increased accuracy of determination of angular speed of rotation in dynamic modes of electric drive operation.

10 dwg