Abstract
A previously reported vector control method for position sensorless permanent magnet synchronous motors involves the use of controllers with simple block configurations. However, the performance of this method can be affected by the erroneous setting of the motor parameters because a feedback compensator is not used. In this study, the effects of these errors on the steady-state performance of the drive control examined under various error conditions. It was found that the amplitude of the motor current increases when the parameter error is nonzero; the effect of the back-EMF parameter error was especially found to be large. On the basis of this observation, the use of a new compensator named “back-EMF parameter adjustment” is proposed. Simulation results and experimental results showed that the proposed method can compensate for the increase in the amplitude of the motor current resulting from the occurrence of motor parameter errors. A theoretical analysis showed that the performance of our vector control method, which involves the use of the new compensator, is affected only by errors in the d-axis inductance parameter Ld. Therefore, even if there are errors in the other motor parameters, the motor current for the constant load condition can be minimized by using the proposed method.
