Open-Circuit Radial Stray Magnetic Flux Density Based Noninvasive Diagnosis for Mixed Eccentricity Parameters of Interior Permanent Magnet Synchronous Motors in Electric Vehicles

Abstract

By measuring the open-circuit radial stray magnetic flux density (RSMFD) of three spatial points, a novel diagnostic method for the eccentricity of interior permanent magnetic motors (IPMSMs) in electric vehicles (EVs) is proposed. Outperforming traditional methods, the proposed method can non-invasively diagnose not only the severities of static eccentricity (SE), dynamic eccentricity (DE), and mixed eccentricity (ME), but also the eccentricity location. In this paper, diagnosis results are described through three eccentricity parameters: SE ratio, DE ratio, and SE angle. Firstly, an analytical model of the open-circuit RSMFD of the IPMSM is proposed, with its accuracy validated by experiments. The pattern of the impact of the eccentricity parameters on the open-circuit RSMFD is analyzed to form the basis of the proposed method. Then, an eccentricity prototype motor, which can continuously emulate the eccentricity according to any listed eccentricity parameters, is developed. A test rig is built to collect the open-circuit RSMFD and validate the analytical calculation results. Finally, an eccentricity diagnostic model based on the open-circuit RSMFD is established. The diagnosis results proved the non-invasiveness, effectiveness, and viability of the proposed method.

Impact of Static Air-Gap Eccentricity Fault on Synchronous Generator Efficiency

“…Besides, Bruzzese C. et al found that the amplitude of the second harmonic ripple in rotor current is proportional to the degree of the SAGE fault [7], and the first and third harmonic amplitudes of the electromotive force increased significantly under the SAGE fault [8]. Based on the electromechanical characteristics, diagnosis and monitoring of SAGE faults are carried out [9][10][11][12][13][14]. In addition, the magnetic flux and the shaft voltage are common and useful indicators to measure air-gap eccentricity.…”

Parameter Identification of Permanent Magnet Synchronous Motor Based on CGCRAO Algorithm

“…In order to achieve efficient control of PMSMs in these fields, scholars have designed many advanced controllers, such as field-oriented control (FOC) [5] and direct torque control (DTC) [6]. The accurate model and parameters of the PMSM are crucial for the performance release of these controls and the design of fault diagnosis systems [7].…”

Analysis of Cogging Torque of Permanent Magnet Motors Under Mixed-Eccentricity and Manufacturing Tolerances

“…Presently, the air-gap model for ME is usually written as the sum of SE and DE. Based on this model, the influence of ME on the radial force of PM motors [14], the dynamical model of induction motors under ME [15] and the influence of ME on air-gap flux density of PM motors [16] were analyzed. Yet the application of this model relies on a complex analysis process, where the influence of ME on cogging torque harmonic components could not be comprehensively explained.…”