Control method of the current flow in driver systems for brushless motors, particularly during the switching phase

摘要

The present invention relates to a current (I) control method for drive systems of multi-phase brushless motors, in particular at phase switching, wherein the motor coils (1,2,3) led to a common node (D) are driven by applying a respective drive voltage to the free end (A,B,C) of each coil (1,2,3) via corresponding power stages (4,5,6). The method comprises switching the current flow from one phase (1-2) to the next (1-3) in the direction of rotation of the motor at the phase switch, thereby forcing the unaffected one (2) of said coils by the phase switch into a state of high impedance. Advantageously, the decreasing rate of the current (I2) in the coil (2) unaffected by the phase switch can be twice as high as the decreasing rate of the current (I1) in the phase being switched from.