Position Sensorless Control for IPMSM Based on Extended EMF and Voltage Injection Synchronized with PWM Carrier

Improvement of low‐speed sensorless control with multi‐layer neural network

“…Next, let us confirm INFORM method and conventional method based on extended EMF and high‐frequency voltage injection synchronized with carrier 3 in terms of errors of pole position estimation under environment with strong switching noise. With INFORM method, current changes characterized in Equation () are put to 3 ϕ / αβ transform in Equation (), and arctangent is applied in Equation () to find magnetic pole position.…”

“…With the method based on extended EMF and high‐frequency voltage injection synchronized with carrier described in Reference, 3 voltage needed for pole position estimation is applied, and thus produced extended EMF in Equations (), () is utilized. In so doing, current change due to injection of high‐frequency voltage v inj is shown in Equation ().…”

“…In the recent years, increasing demand for position sensorless control of PMSM (Permanent Magnet Synchronous Motor) drives has resulted in proposal of various control schemes. As regards low‐speed sensorless drives considered in this paper, the mainstream approach is the use of PMSM saliency; in so doing, feature quantities corresponding to inductance change must be detected in some way 1–13 . Among previously proposed methods, those using injection of high‐frequency voltage in dq rotating coordinates are the most reported in terms of practical examples.…”

“…However, high‐frequency voltage injection may be difficult in some applications because of noise that grows depending on the frequency. Methods were explored to reduce noise by injecting voltage synchronized to carrier frequency 2–4,9 but with these methods, too, noise at carrier frequency grows after voltage injection.…”