An Impedance Model-Based Multiparameter Identification Method of PMSM for Both Offline and Online Conditions

TLDR

Existing online motor parameter identification methods rely mainly on fundamental‑frequency voltage equations, resulting in poor accuracy at low current and low speed. This study proposes a high‑frequency equivalent‑impedance model–based parameter identification method for permanent‑magnet synchronous motors using HF signal injection on both dq axes. The method identifies resistance, dq‑axis inductances, and flux linkage both offline and online, employs a parameter‑sensitivity‑analysis algorithm to refine resistance and flux estimates, compensates inverter nonlinearities and HF effects, and selects injection amplitude and frequency to avoid disrupting normal motor operation. Validation on a 2.2‑kW motor and finite‑element analysis confirmed the approach, and experiments demonstrated accurate parameter identification across various operating conditions.

Abstract

Existing online motor parameter identification methods mostly depend on the fundamental frequency voltage equations, which lead to the unsatisfactory identification effect at low current and low speed operation. This article proposes a parameter identification method based on the high frequency (HF) equivalent impedance model of permanent magnet synchronous motor with HF signal injection at both the dq-axes. This method identifies the resistance and the dq-axis inductances offline and online, along with the flux linkage online. In order to improve the identification accuracy, the parameter sensitivity analysis-based algorithm is proposed to detect the resistance and the flux linkage. Meanwhile, the inverter nonlinearities and the HF influence on parameter identification are compensated effectively. In order not to affect the normal operation of the motor drive, the selection of the amplitude, and the frequency of the injected signal is investigated. The proposed method is validated on a 2.2-kW motor and confirmed by finite element analysis. The experimental results show the good identification effect in different operation conditions.