Motor control apparatus
AssigneeDenso Corporation
InventorJun Tarui
Life of this patent
Estimating the term…
Abstract
A motor control apparatus includes a counter, a margin calculation portion, and a cycle set portion. The counter counts a total number of switching the current supply phase of the coils when the rotor is rotationally driven. A rotation angle of the rotor is detected on a basis of the number of switching. The margin calculation portion calculates a torque margin that is a difference between an output torque of the motor and a load torque acting on the motor. The cycle set portion sets a current supply switching cycle to shorten as the torque margin is greater. The current supply switching cycle is a cycle switching the current supply phase of the coils.
Claims4
A motor control apparatus controlling a synchronous motor including a stator that has a plurality of phases of coils and a rotor that rotates upon receiving a magnetic force caused by a rotation magnetic field generated by sequentially switching a current supply phase of the coils, the motor control apparatus comprising:
- a microcomputer configured to include:
- (i) a counter counting a total number of switching the current supply phase of the coils when the rotor is rotationally driven, wherein a rotation angle of the rotor is detected on a basis of the number of switching;
- (ii) a margin calculation portion calculating a torque margin that is a difference between an output torque of the motor and a load torque acting on the motor;
- and
- (iii) a cycle set portion setting a current supply switching cycle to shorten as the torque margin is greater, wherein the current supply switching cycle is a cycle switching the current supply phase of the coils, wherein:
- the cycle portion decides a next value of the current supply switching cycle, the next value of the current supply switching cycle being decided by dividing a present value of the current supply switching cycle by the torque margin;
- and
- the motor control apparatus does not use an encoder.
Dependencies are inferred from the claim text.