Research on bearing current damage description model of variable frequency motor

Abstract

The bearing failure seriously affects the normal operation of the motor. In this paper, the early damage of bearing wear caused by the shaft current in the operating state of the variable frequency motor is proposed. From the perspective of the bearing capacitance storage capacitor charge, the method based on analyzing the relationship between pitting pit size and shaft current per unit area of bearing track surface is proposed, so that the model can directly judge whether the bearing is in an absolutely safe running state. In this paper, the description model between the size of the pitting pit per unit area of the bearing track surface and the mechanical and electrical parameters is derived based on the assumption that the charge required for the formation of pitting pits per unit area of the bearing track surface. It is shown that the shaft current can promote the bearing to produce pitting pit, which leads to the early damage of the bearing, and the size of the pitting pit is positively related to the shaft current. Matlab/Simulink simulation verifies the correctness of the description model.