초록 ▼

A single phase permanent magnet motor includes a rotor, a stator, and a quadrature axis winding positioned out-of-phase from a main winding of the stator for generating an output signal representative of rotor angular position. An integrator can be coupled to the quadrature axis winding for phase re

A single phase permanent magnet motor includes a rotor, a stator, and a quadrature axis winding positioned out-of-phase from a main winding of the stator for generating an output signal representative of rotor angular position. An integrator can be coupled to the quadrature axis winding for phase retarding the output signal, and a comparator can be coupled to the integrator for detecting zero crossings of the phase retarded output signal to provide a commutation signal. The quadrature axis winding can be positioned about ninety electrical degrees out-of-phase from the main winding of the stator, and the integrator can be adapted to phase retard the output signal by a number of degrees which decreases as a speed of the motor increases. At low speeds the phase retard is preferably at about ninety degrees so that the phase retarded signal becomes in-phase with the main stator winding back EMF voltage. The motor may further include a rectifier coupled to the quadrature axis winding for rectifying the output signal, and a lowpass filter for filtering the rectified output signal to provide a signal proportional to velocity. Also the single phase motor is commutated for maximum torque production.

대표청구항 ▼

[ What is claimed is:] [1.] A motor comprising:a rotor;a stator;a position sensor for generating an output signal representative of rotor angular position, said output signal having an angular relationship with back electromotive force (EMF) generated by a main winding of the stator; anda commutatio

[ What is claimed is:] [1.] A motor comprising:a rotor;a stator;a position sensor for generating an output signal representative of rotor angular position, said output signal having an angular relationship with back electromotive force (EMF) generated by a main winding of the stator; anda commutation estimator circuit responsive to the output signal generated by the position sensor for estimating zero crossings of the back EMF in the main winding and generating a commutation signal to commutate the main winding of the stator in advance of the estimated zero crossings of the back EMF by an angle .theta. calculated by the following: ]EQU6 ] where .omega. is the speed of the rotor, I.sub.PEAK is a peak current in the main winding corresponding to a desired speed and/or torque of the motor, L is the motor inductance in the main winding, and V.sub.S is the voltage across the main winding.