Patent ID: 8245545
Filing Date: 2012-08-21
Classification: D06F,Y02B

Abstract:
1. A motor controller, comprising: a power converter configured to energize a motor based on a commutation signal, the motor including a rotor including a permanent magnet and a coil-wound stator; an estimator configured to estimate a rotor rotational speed and a rotor rotational position; a controller configured to output the commutation signal to the power converter, the commutation signal taking a predetermined energization pattern based on a command rotational speed during startup, and being outputted based on the rotational position estimated by the estimator during position estimation; a current detector configured to detect current flowing in the coil winding; an input power calculator configured to calculate a value corresponding to an input power of the motor by a voltage applied to the coil winding and the current detected by the current detector; an output power calculator configured to calculate a value corresponding to an output power of the motor by the rotational speed estimated by the estimator; and a rotational abnormality determiner configured to determine occurrence of rotational abnormality based on comparison of the value corresponding to the input power calculated by the input power calculator with the value corresponding to the output power calculated by the output power calculator, wherein the rotation abnormality determiner is configured to determine occurrence of rotation abnormality based on rotation abnormality reference obtained by dividing the value corresponding to the output power calculated by the output power calculator by the value corresponding to the input power calculated by the input power calculator as represented by equation: in which Vdq indicates an amplitude of voltage applied to the coil winding, Vθ indicates a phase of the voltage applied to the coil winding, Iθ indicates a phase of the current flowing in the coil winding, ω indicates a rotational speed of the rotor, and Kt indicates a torque constant.