Initial position estimation of permanent magnet synchronous motors based on variation behavior of winding inductances

Abstract

An estimation method of initial rotor position is a difficult research branch in permanent magnet synchronous motors(PMSM), it is also an important research branch in sensorless technique. In PMSM with a saliency pole structured rotor, influenced by saliency effects, the self-inductance and mutualinductance present periodicity variation, Starting from this feature Firstly, the method of injecting high frequency low voltage pulses is utilized for identifying the line inductance and then the influence of winding current to line inductance are thorough analyzed by Fourier series decomposition. Secondly, using the rotational coordinate transformation, the fundamental harmonic and third harmonic can be eliminated to some extent, and then the inductance can be presented by a sine function, then the position vs. inductance characteristics are modeled for estimating the rotor position. The experimental results show that the proposed method estimates the initial rotor position reliably and efficiently.Index Terms-permanent magnet synchronous motor(PMSM) ; high frequency low voltage pulses; initial rotor position; the position vs. inductance model; rotational coordinate transformation;

Estimation of Rotor Position for Permanent Magnet Synchronous Motor at Standstill Using Sensorless Voltage Control Scheme

“…Moreover, starting-up the PMSM without accurate prior knowledge about the initial rotor position may cause a rotor stiffness or running in reverse direction. However, the reliance on sensors to realize this task involves significant drawbacks due to their high cost, unreliable usage and large size [5]- [7]. Many techniques have been presented to achieve sensorless rotor position estimation and running for PMSMs.…”