Sensorless control method for brushless motor, sensorless control device for brushless motor, and electric pump

摘要

PPROBLEM TO BE SOLVED: To provide a sensorless control method for a brushless motor capable of preventing generation of a delay in calculation of delay time for energization by reducing uneven interval between zero cross points of terminal voltage of a stator winding. PSOLUTION: This control method is a sensorless control method for the brushless motor which stores regular changes to take a magnitude correlation between each terminal voltage and predetermined voltage, performs sampling in time sequence for the magnitude correlation between each terminal voltage and predetermined voltage (S4), detects an interval obtained when the magnitude correlation subjected to sampling changes (S10), and controls energization of a stator winding based on the detected interval and the regular changes. Moreover, those control method stores a second interval Tzb as the latest interval by one before the first interval Tza, calculate Td=(Tza/2)-(Tzb/n), where n2 (S18) and controls energization of the stator winding from the timing a delay is made by Td after the magnitude correlation subjected to sampling has changed. PCOPYRIGHT: (C)2005,JPO&NCIPI