Apparatus and method for controlling a bldc motor
AssigneeLG Electronics Inc.
InventorsSun-Kyoung Lim, Ki-Bok Lee, Jun-Bo Yun
Life of this patent
Estimating the term…
Abstract
An apparatus for controlling a BLDC motor includes a frequency controller configured to increase frequency of a drive signal that is applied to the motor to reach a first target speed at a relatively low speed region. The apparatus also includes a sensorless controller configured to observe location of a rotor of the motor at the low speed region, and provide a control signal to the motor by comparing a command speed with an estimated speed based on detection of a voltage and/or a current of the motor at a relatively high speed region. Further, the apparatus includes a control unit configured to select one of the frequency controller and the sensorless controller based on the speed of the motor.
Claims21
An apparatus for controlling a BLDG motor comprising:
- a frequency controller configured to increase frequency of a drive signal that is applied to the motor to promote motor movement to a first target speed at a relatively low speed region;
- a current and voltage detecting unit configured to detect a current or voltage of the motor;
- a sensorless controller configured to observe location of a rotor of the motor at the relatively low speed region, and provide a control signal to the motor by comparing a second target speed with an estimated speed based on the detected voltage or current of the motor at a relatively high speed region;
- and
- a control unit configured to select one of the frequency controller and the sensorless controller based on determination that the relatively low speed region is finished.
An apparatus for controlling a BLDC motor comprising:
- a frequency controller configured to provide at least one frequency of a drive signal to the motor by using an open loop control method to promote motor movement to a first target speed at a relatively low speed region;
- a current and voltage detecting unit configured to detect a current or voltage of the motor;
- a sensorless controller configured to observe location of a rotor of the motor in the relatively low speed region, and provide a control signal to the motor based on a difference between a second target speed of the motor and an estimated speed of the motor based on the detected voltage or current of the motor at a relatively high speed region;
- and
- a control unit configured to select the frequency controller or the sensorless controller based on determination that the relatively low speed region is finished.
A method for controlling a BLDC motor comprising:
- increasing frequency of a drive signal applied to the motor by using an open loop control method to promote motor movement to a first target speed at a relatively low speed region;
- observing a position of a rotor of the motor by a sensorless controller based on detection of a current or a voltage of the motor;
- in response to detection of an end point of the low speed region, converting a motor control mode to a closed loop control method to control the motor movement by the sensorless controller;
- and
- controlling the motor speed to follow a second target speed based on a difference between an estimated speed by detection of the current or the voltage of the motor and the second target speed at a relatively high speed region.
Dependencies are inferred from the claim text.