High-frequency Diagnostic Current Injection-Based Permanent Magnet Temperature Estimation of IPMSM at Standstill

This paper presents permanent magnet temperature estimation for an Interior Permanent Magnet Synchronous Motor by injecting high-frequency diagnostics d-axis current. Different from preceding methods, the estimation in this paper uses permanent magnet’s temperature dependency of high-frequency d-axis inductance. Experimental study using a test motor of 4kW and a three-phase linear amplifier as pure sinusoidal high-frequency current source shows that the proposed estimation method needs very precise measurement accuracy even at standstill.