Research on Position Estimation of Common-Mode Current Based on High-Frequency Motor Model

With the development and application of wide bandgap semiconductors, the dynamic performance of motor drives has been further improved. However, as the switching frequency increases exponentially, the influence of parasitic capacitance and inductance between motor windings cannot be ignored. In this paper, low, medium, and high-frequency motor models based on the impedance characteristics of permanent magnet synchronous motors are established. Subsequently, using the high-frequency motor model, our group explore the coupling mechanism between high-frequency common-mode oscillating current within the switching period and the rotor position saliency. Finally, the relationship curve between rotor position and common-mode current amplitude is obtained, which fully validates the hypothesis that motor position information is embedded in the common-mode current.