| More and more asynchronous motor are being applied in agriculture. Since the working environments of motors are generally adverse and the working time is long, the aging speed of their parts is fast. Consequently, motors are too run into fault to product shutdown. In order to reduce losses resulted from motor faults, this paper has made an analysis of faults for agricultural asynchronous motor, and a detection system is designed.Basing on principle of three-phase asynchronous motor, structural composition and operational principle of the motor has been studied. Common fault and it’s mechanisms of three-phase asynchronous motor are summarized. An analysis of motor mode, vibration and steady state thermal analysis are made.An analysis of the vibration mode and steady thermal of the stator is made with finite element analysis software ANSYS. According to the inherent frequency analysis of three-phase asynchronous motor, the former 7th order mode belong to the rigid body vibration and the later 53th order are elasticity vibration. Moreover, four types of steady thermal analysis of the stator are made. The temperature cloud of analytical result indicates that stator temperature declines from inside to outside, and temperature varies evenly. The analytical result changes linearly. Hence, the analyzing of motor fault from vibration signal and thermal signal is proved to be feasible.To collect vibration, electric current and temperature signal, hardware circuit are designed. Embedded chip of ARM core is applied in the hardware system as a master control module of collection section to receive, process and send data; K-type chromium-nickel silicon thermocouple is applied as forepart for temperature collection; electromagnetic vibration sensor is applied for gathering vibration signal of the motor; current signal collection relies on the three-phase alternating current sensor under transformer principle, and the system design is completed. |
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