In view of the existing problems of rotor groove harmonic method based on stator current, some scholars have proposed that the sucker of the stator winding is connected as a detection coil. The resulting rotor groove harmonic signal will not be offset to zero due to the motor structure, and signal processing has a certain simplification effect. However, it can only be applied to three-phase Motors. Some scholars have also proposed to install a magnetic guide material in the induction motor housing, and arrange the coil induction rotor groove harmonic voltage on it. This method can significantly simplify the speed estimation algorithm and apply to a wider range, but the rotor groove harmonic signal amplitude in the coil is small, and the signal-to-noise ratio is poor, and it is difficult to guarantee the accuracy of the rotation speed estimation under extreme conditions.
In this paper, a new method is proposed to arrange the inductive coil inductive rotor groove harmonics inside the motor. By studying the influence of induction coil arrangement on the signal-to-noise ratio of rotor groove harmonics, an optimal design method of induction coil is proposed, which further enhances the signal-to-noise ratio of rotor groove harmonics and reduces the difficulty of signal processing. Through simulation and experiment, the validity of the theoretical analysis and the method is verified. The result of speed estimation in the experiment proves that the method has good accuracy.
This paper analyzes the influence of the combined signal synthesis of inductive coil span and coil on the amplitude and signal-to-noise ratio of rotor grooves, and the reliability and accuracy of the method can be improved by optimizing the design of these two elements.
The simulation and experiment verify the correctness of the theory and method. The optimized induction coil has high accuracy in the high-speed operation of the motor, and it is necessary to continue to study the feasible treatment method in the low-speed operation of the motor.
