Electrical Parameter Estimation Method for Surface-Mounted Permanent Magnet Synchronous Motors Considering Voltage Source Inverter Nonlinearity

This paper proposes an electrical parameter estimation method for permanent magnet synchronous motors (PMSMs) considering the voltage source inverter (VSI) nonlinearity. Accurate parameters are essential for high-performance control of PMSMs. Therefore, numerous studies have been conducted to obtain accurate parameters. However, the VSI nonlinearity causes voltage distortion, which causes parameter-estimation errors. To address this problem, this paper presents a solution using the double-frequency double-amplitude (DFDA) injection method based on the high-frequency (HF) injection method. The proposed method is a practical and novel method using simple mathematical calculations that takes into account VSI nonlinearity without using nonlinearity-compensation methods. It increases the accuracy and reduces the resistance-estimation step by simultaneously estimating the stator resistance and inductance. To demonstrate the efficacy and practicability of the proposed method, it was experimentally verified on a 400 W surface-mounted PMSM. The proposed method can simultaneously estimate the stator resistance and inductance with high accuracy within a short time and can, therefore, be applied to PMSM drives in various industries, such as robotics.