VERFAHREN ZUM ABLEITEN DER POL-POSITION VON PERMANENTMAGNETISCHEN BÜRSTENLOSEN MOTOREN

摘要

In order to estimate a magnetic pole position of a permanent magnet type brushless motor, the following steps are conducted. A given gamma axis and a given delta axis in an advanced from the gamma axis by an electrical angle of 90 DEG are set. A closed-loop electric current control system in the gamma axis direction is formed while forming an open-loop electric current control system in the delta axis direction. It is calculated an interference current generating in the delta axis direction when a current command in the gamma axis direction is given as a stepwise alternating current command. The gamma axis is finely advanced by an angle of DELTA &thetas; when a sign of a product of an integral value of the interference current and a value of the current command in the gamma axis direction is positive. Alternatively, the gamma axis is finely delayed by an angle of DELTA &thetas; when the sign is negative. Thereby, the gamma axis is made accord with either a d axis as a true magnetic axis or with a -d axis advanced by 180 DEG from the true magnetic axis.