Research On Vibration And Noise Characteristics For The Planar Switched Reluctance Motors

Planar switched reluctance motors(PSRMs) are a kind of novel special motor to achieve direct driver, which have the advantages of simple structure, ease of manufacture,low cost, high reliability, and low mechanical loss. Therefore, PSRMs are a promising candidate in processing and manufacturing field. However, the wide application of PSRMs is restricted due to the biggish vibration and noise of PSRMs. In order to reduce the vibration and noise and improve the position precision of PSRMs, the characteristics of vibration and noise for a PSRM is investigated in this paper.Mechanical structure of the PSRM is given, and principle of the PSRM is expounded. For the PSRM, the voltage balance equation, the dynamic equation, and the electromagnetic equations are derived, and then the transient power, acceleration, and electromagnetic forces are formulated. Structure of the PSRM control system is presented. Based on d SPACE, the experimental setup of the PSRM control system is established using the prototype of PSRMs developed in our laboratory.The vibration characteristic of the PSRM including the normal force characteristic and modal characteristic are researched. The measuring scheme of the normal force is designed, and the normal force characteristic is measured by the strain electrical measuring technology. The theory of modal analysis is clarified, and the simplified finite element model of the PSRM is built by ANSYS. Based on the finite element model, the model analysis is performed, and the 1st-20 th natural frequencies and the corresponding modal shapes of the PSRM are obtained. The platform of modal test for the PSRM is built, and the modal test is carried out. The impact of the normal force ripple on the vibration of the PSRM is analyzed through the results of normal force characteristic and modal characteristic.The sound intensity equations of the noise radiation for the PSRM are derived from the sound energy density equation, and the impact of mechanical structure on the noise radiation is discussed for the PSRM based on the sound intensity equations. The principle of noise testing for the PSRM is stated, the platform of noise testing is built, and the environmental noise is measured. The simulation models based on MATLAB/Simulink for the open-loop and closed-loop PSRM systems are designed, and the noise characteristics are investigated respectively under constant current and position control algorithm.The research of the vibration characteristics for the PSRM demonstrates that: 1) the results of finite element modal analysis coincide with that of modal test; 2) large amplitude of the vibration is occurred at the peak frequency as the peak frequency of the normal force ripple is closed to the natural frequency of the PSRM, and thus the main root of the vibration of the PSRM from the normal force ripple is verified. The study of the noise characteristics for the PSRM manifests that: 1) under the same noise source power, the sound intensity of the noise radiation for the PSRM with larger base size is stronger than that with smaller base size; 2) the sound power level of the noise for the PSRM increases as the current increases, and the open-loop PSRM has peak spectrum of sound power level of noise at certain natural frequencies; 3) for the closed-loop PSRM, the peak frequencies of normal force ripple avoid the natural frequencies of the PSRM due to the adjustment of position control algorithm, and therefore the noise of the closed-loop PSRM is smaller than that of the open-loop PSRM. The research results of this paper provide rationale for the structural optimization design and the suppression of vibration and noise of PSRMs.