Patent ID: 6566830
Filing Date: 2003-05-20
Classification: H02P

Abstract:
A method for controlling the start of a permanent magnet machine, said method comprising:assigning a parameter value indicative of an estimated initial rotor position of the machine wherein the assigned parameter value is based on angular sector information provided by a sensor assembly configured to sense a plurality of rotor angular sectors, and further wherein the assigning of the parameter value comprises assigning a rotor position angle corresponding to one of the edges of the respective angular sector sensed by the sensor assembly; energizing the machine with a level of current being sufficiently high to start rotor motion in a desired direction in the event the initial rotor position estimate is sufficiently close to the actual rotor position of the machine; sensing whether any incremental changes in rotor position occurs in response to the energizing action; in the event no changes in rotor position are sensed, incrementally adjusting the estimated rotor position by a first set of angular values until changes in rotor position are sensed; in the event changes in rotor position are sensed, providing a rotor alignment signal as rotor motion continues; and aligning the estimated rotor position relative to the actual rotor position based on the alignment signal.