SENSORLESS CONTROL METHOD FOR BRUSHLESS MOTOR, AND SENSORLESS CONTROLLER FOR BRUSHLESS MOTOR

摘要

PPROBLEM TO BE SOLVED: To provide a sensorless controller for brushless motor which allows the time of inhibiting the detection of a zero cross point to be set simply after switching of a current application pattern. PSOLUTION: A sensorless controller for brushless motor is equipped with a load detecting means 17. It stores beforehand an regular change that the magnitude relation between each terminal voltage Vu, Vv and Vw of two or more phases of stator coils (not shown in figure) and specified voltage E/2 should take. It samples in time series the magnitude relation between each terminal voltage Vu, Vv and Vw and the specified voltage E/2, and detects the interval at the point of time when the magnitude relation has changed, and controls the energization of the stator coil, based on the above regular change, after passage of a delay time based on the detected interval from the point of time, and inhibits the sampling for a specified time from the point of time of the start of energization control. It is equipped with a means 3 which determines n (n is a natural number), based on the load detected by the load detecting means 17, and a means 3 which calculates the quotient of a delay time/n, and it makes the calculated quotient the above specified time. PCOPYRIGHT: (C)2007,JPO&INPIT