High-Frequency Motor Modeling by Harmonic Magnetic Field Analysis Considering Magnetic Saturation and DC Bias Magnetic Field

Abstract

Harmonic magnetic field analysis considering magnetic saturation and a DC bias magnetic field has been developed to rapidly calculate the high-frequency inductance and resistance of a motor during operation and to build its equivalent circuit model to describe the corresponding high-frequency phenomena. This novel analysis method has been found to be faster than the conventional nonlinear transient analysis by 6-7 times (in the 2D case) or 17-20 times (in the 3D case). When the proposed technique is applied to a typical permanent magnet synchronous motor, it is observed that the resistance increases at frequencies above 100Hz, and the inductance decreases at frequencies above 1kHz. It is also noted that the high-frequency inductance and resistance reduce to 1/5 of their original values as the phase current increases, while their variations with the rotor position are no more than 13%.