2results about How to "Reduce electromagnetic torque ripple" patented technology

This invention relates to the field of electric motors, and more particularly to an electric motor rotor. The electric motor rotor includes: a trapezoidal slot formed on the outer circumferential surface of the motor rotor, the trapezoidal slot having a base edge; a magnet slot, the axis of symmetry of the magnet slot passing through the center of the inner diameter of the motor rotor, the trapezoidal slot being formed on at least one side of the axis of symmetry of the magnet slot, the magnet slot having a first side line; and a magnetic stabilizing hole formed between the outer circumferential surface of the motor rotor and the magnet slot, the longitudinal axis of the magnetic stabilizing hole being perpendicular to the first side line, the magnetic stabilizing hole and the trapezoidal slot being on the same side of the axis of symmetry of the magnet slot, the axis of symmetry of the trapezoidal slot passing through the center of the inner diameter of the motor rotor, an angle α1 between the longitudinal axis of the magnetic stabilizing hole and the axis of symmetry of the trapezoidal slot, and an angle α2 between the longitudinal axis of the magnetic stabilizing hole and the axis of symmetry of the magnet slot, α1 and α2 satisfying 0.701≤(α1-α2) / α1≤0.958. This invention also relates to an electric motor. This invention can effectively reduce the no-load back EMF harmonics of the motor, improving motor efficiency and operational smoothness.

This invention relates to the field of motor control technology, specifically to a method and system for mitigating open-circuit faults in a three-phase induction motor. The method includes: obtaining a speed setpoint and the actual speed to form a speed deviation; inputting the speed deviation into a composite speed controller in a closed-loop V / f control structure to generate a frequency adjustment quantity; determining a target frequency command based on the frequency adjustment quantity and pole number conversion relationship, and generating a stator voltage amplitude command under a constant V / f ratio; obtaining the synchronous electrical angle through integration and generating a modulation signal; performing pulse width modulation based on the modulation signal to drive the three-phase inverter to output three-phase drive voltage; and when a stator phase open circuit causes a double-frequency disturbance in the dq coordinate system, using a resonant adjustment branch for tracking compensation to reduce speed fluctuations and electromagnetic torque pulsation, maintaining continuous motor rotation. This invention solves the problem of high control system complexity in existing induction motors due to reliance on independent fault detection and complex fault-tolerant switching mechanisms.