Off-Line Detection of Static Eccentricity of PMSM Robust to Machine Operating Temperature and Rotor Position Misalignment Using Incremental Inductance Approach
Anmol Aggarwal, Ibrahim M. Allafi, Elias G. Strangas, John S. Agapiou
Abstract
In this article, an incremental inductance approach is used for static eccentricity detection under off-line condition. This method uses the DC values of the q-axis voltage, which makes it independent of the bandwidth of the controller. In this work, a new feature, the height of hump of the incremental inductance curve, along with the known feature, saturation current in the d-axis, was used for fault detection. It is shown that this new feature is independent of the machine operating temperature, which makes the method robust with respect to machine operating temperature. It is also shown that the proposed method is robust to the rotor position misalignment. A new controller for off-line testing was designed, which controls both the speed and saturation of the machine. Using this controller, the hardware requirements for constant rotation of the machine are reduced while keeping the method independent of the bandwidth of the controller. Finally, a MATLAB-based computer program was developed to calculate the features: saturation current in the d-axis and height of hump of the incremental inductance curve. Six different machines, combinations of two stators and three rotors, were used to validate the proposed method through experiments.