Patent ID: 8019562
Filing Date: 2011-09-13
Classification: G01R,H02H,H02P

Abstract:
1. A method implemented in a speed controller to detect a loss of one phase, two phases or three phases in a three-phase permanent-magnet synchronous motor, running or stopped at rest, said controller executing a control in closed loop operation, said method comprising: determining, with the speed controller, a reference flux current as a function of a reference torque current, said reference torque current being calculated from a reference speed applied to the motor and a measurement of the speed or the position carried out on the motor; applying, with the speed controller, the reference flux current to inject currents over various phases of the motor wherein the reference flux current is decremented according to a control ramp until its value is zero; and measuring, with the speed controller, the currents over at least two phases and determining the loss of one phase, of two phases or of three phases from these measured currents.