Finance

Physics

Inductance

Mathematics

Statistics

Mean squared error

Square (algebra)

Voltage

Artificial intelligence

Harmonics

Position (finance)

Economics

Control (management)

Programming language

Geometry

SIGNAL (programming language)

Computer science

Quantum mechanics

Square wave

Control theory (sociology)

IEEE Transactions on Industry Applications

In this paper, the theoretical analysis of the position estimation error in position-sensorless operation using pulsating square wave signal injection is presented. The purpose of this paper is to analyze the phenomenon that the position estimation performance varies depending on the injection frequency. Mathematical derivation supported by simulation and experimental results shows that, in no-load condition, the voltage distortion induces position estimation error with 3rd-order harmonics if the frequency of the injected square wave is the same to the switching frequency. While, if the frequency is a half of the switching frequency or heavier load condition in either injection frequency, the effect of nonideal characteristics of inverter disappears and there is no 3rd harmonics in the position estimation error. Therefore, only the effect of cross-coupling inductance is reflected in the estimation error. As the result, the position estimation error appears in the form of 6th-order harmonics due to the spatial harmonics of inductances, and the error is relatively small compared with the switching frequency injection case. The theoretical analysis was verified by simulation and experimental results.

Analysis on Position Estimation Error in Position-Sensorless Operation of IPMSM Using Pulsating Square Wave Signal Injection