Linear hall device based field oriented control motor drive system

Patent metadata

Field	Value
Publication number	US-10447186-B2
Application number	US-201715615951-A
Country	US
Kind code	B2
Filing date	Jun 7, 2017
Priority date	Dec 4, 2015
Publication date	Oct 15, 2019
Grant date	Oct 15, 2019

Abstract

A motor control system for a permanent magnet synchronous motor (PMSM) uses two linear Hall devices to produce a first signal indicative of a strength of a first magnetic field component produced by a set of rotor magnets and to simultaneously produce a second signal indicative of a strength of second magnetic field component produced by the rotor magnets that is approximately orthogonal to the first magnetic field component. An angular position and angular velocity of the rotor is calculated based on the first signal and the second signal. A plurality of phase signals is produced based on the calculated angular position and angular velocity. Current in a plurality of field windings of the motor is controlled using the plurality of phase signals.

First claim

What is claimed is:

1. A method for controlling an electric motor, the method comprising:
simultaneously producing: using a first linear Hall device, a first signal indicative of a strength of a first magnetic field component produced by a set of rotor magnets within a rotor of the electric motor; and, using a second linear Hall device, a second signal indicative of a strength of a second magnetic field component produced by the set of rotor magnets that is approximately orthogonal to the first magnetic field component;
normalizing the first and second signals to produce first and second normalized signals;
calculating an angular position and angular velocity of the rotor based on the first normalized signal and the second normalized signal;
producing a plurality of phase signals based on the calculated angular position and angular velocity; and
controlling current in a plurality of field windings of the electric motor using the plurality of phase signals.

2. The method of claim 1 , in which the first linear Hall device is located adjacent the rotor, and in which the second linear Hall device is positioned perpendicular to the first linear Hall device.

3. A motor drive system comprising:
a multidimensional Hall device array including at least a first linear Hall device and a second linear Hall device, the first linear Hall device having a first output, the second linear Hall device having a second output, the first linear Hall device configured to produce a first signal at the first output indicative of magnetic field strength, and the second linear Hall device configured to produce a second signal at the second output indicative of the magnetic field strength, wherein the first Hall device is configured to receive a first bias compensation current to remove an offset from the first signal, and the second Hall device is configured to receive a second bias compensation current to remove an offset from the second signal;
angle-speed calculation logic having an angle-speed output, a first input coupled to the first output, and a second input coupled to the second output, the angle-speed calculation logic configured to produce angular speed information at the angle-speed output based on the first and second signals; and
motor controller and drive logic having an input coupled to the angle-speed output, and having motor control outputs adapted to be coupled to a motor, the motor controller and drive logic configured to provide a plurality of phase signals at the motor control outputs based on the angular speed information.

4. The system of claim 3 , in which the second linear Hall device is positioned perpendicular to the first linear Hall device.

5. The system of claim 3 , in which the multidimensional Hall device array, the angle-speed calculation logic and the motor controller and drive logic are all formed on a single integrated circuit (IC).

6. A permanent magnet synchronous motor (PMSM) comprising:
a stator having a plurality of phase inputs and field windings coupled to the phase inputs, the stator configured to receive phase signals at the phase inputs, and the field windings configured to conduct current based on the phase signals;
a rotor configured to rotate with reference to the stator, the rotor having a plurality of rotor magnets configured to produce a magnetic field based on the conducted current; and
a motor drive system positioned so as to be within the magnetic field, the motor drive system including a first linear Hall device and a second linear Hall device positioned perpendicular to each other;
wherein the first linear Hall device and the second linear Hall device are provided on a single integrated circuit (IC).

7. The PMSM of claim 6 , in which the first linear Hall device has a first output, the second linear Hall device has a second output, the first linear Hall device is configured to produce a first signal at the first output indicative of magnetic field strength, the second linear Hall device is configured to produce a second signal at the second output indicative of the magnetic field strength, and the motor drive system includes:
angle-speed calculation logic having an angle-speed output, a first input coupled to the first output, and a second input coupled to the second output, the angle-speed calculation logic configured to produce angular speed information at the angle-speed output based on the first and second signals; and
motor controller and drive logic having an input coupled to the angle-speed output, and having motor control outputs coupled to the phase inputs, the motor controller and drive logic configured to provide the phase signals at the motor control outputs based on the angular speed information.

8. The PMSM of claim 7 , in which the first linear Hall device, the second linear Hall device, the angle-speed calculation logic and the motor controller and drive logic are all formed on the single integrated circuit (IC).

Assignees

• Texas Instruments Inc

Inventors

• Fedigan Stephen John
• Jain Anuj
• Magee David Patrick

Classifications

• H02P21/06

  Rotor flux based control involving the use of rotor position or rotor speed sensors · CPC title

• H02K29/08

  using magnetic effect devices, e.g. Hall-plates, magneto-resistors (H02K29/12 takes precedence) · CPC title

• H02P25/03

  with brushless excitation · CPC title

• H02P6/16 Primary

  Circuit arrangements for detecting position · CPC title

• G01R33/077

  Vertical Hall-effect devices · CPC title