Advanced

Sensorless Control of Brushless DC Motor in Hydraulic Application

Djup, Martin and Allar, Elias (2015)
Department of Automatic Control
Abstract
In this master thesis we have studied the possibilities of implementing and controlling the speed of a brushless DC motor in an hydraulic application developed by BorgWarner TorqTransfer Systems AB. The hydraulic application is a coupling that give vehicles intelligent all-wheel drive.

Today, the hydraulic application uses hydraulic pressure controlled by an ordinary DC motor to produce the all-wheel drive. The purpose of this thesis was to test if the DC motor could be substituted to a brushless variant by looking at different ways of controlling the speed of the brushless motor and evaluate its possibilities. The controllers were tested and evaluated by constructing a model of the brushless DC motor, together with different... (More)
In this master thesis we have studied the possibilities of implementing and controlling the speed of a brushless DC motor in an hydraulic application developed by BorgWarner TorqTransfer Systems AB. The hydraulic application is a coupling that give vehicles intelligent all-wheel drive.

Today, the hydraulic application uses hydraulic pressure controlled by an ordinary DC motor to produce the all-wheel drive. The purpose of this thesis was to test if the DC motor could be substituted to a brushless variant by looking at different ways of controlling the speed of the brushless motor and evaluate its possibilities. The controllers were tested and evaluated by constructing a model of the brushless DC motor, together with different controllers, in Simulink.

Two kinds of controllers were implemented and tested in Simulink. The first one was field-oriented control with field weakening, and the second one was sixstep commutation. Field-oriented control is a very computationally heavy method compared to the six-step commutation which is one of the simplest ways to control a brushless DC motor.
What makes the control implementation a little bit harder is that there can be no angle- or speed sensors involved, so both control methods need to be sensorless. The field-oriented control with field weakening was made sensorless with a sliding mode observer and the six-step commutation was made sensorless via back-EMF sensing.

The results show that the alternative that seems to have the upper hand is the field-oriented control, even if it may be harder to implement. It also shows that if some more work is put on the control design, the six-step commutation may also be a good candidate. Overall, this thesis shows that it is theoretically possible to implement a brushless DC motor in the hydraulic application. (Less)
Please use this url to cite or link to this publication:
author
Djup, Martin and Allar, Elias
supervisor
organization
year
type
H3 - Professional qualifications (4 Years - )
subject
ISSN
0280-5316
other publication id
ISRN LUTFD2/TFRT--5979--SE
language
English
id
7442408
date added to LUP
2015-06-26 13:09:49
date last changed
2015-07-02 17:02:40
@misc{7442408,
  abstract     = {In this master thesis we have studied the possibilities of implementing and controlling the speed of a brushless DC motor in an hydraulic application developed by BorgWarner TorqTransfer Systems AB. The hydraulic application is a coupling that give vehicles intelligent all-wheel drive.

Today, the hydraulic application uses hydraulic pressure controlled by an ordinary DC motor to produce the all-wheel drive. The purpose of this thesis was to test if the DC motor could be substituted to a brushless variant by looking at different ways of controlling the speed of the brushless motor and evaluate its possibilities. The controllers were tested and evaluated by constructing a model of the brushless DC motor, together with different controllers, in Simulink.

 Two kinds of controllers were implemented and tested in Simulink. The first one was field-oriented control with field weakening, and the second one was sixstep commutation. Field-oriented control is a very computationally heavy method compared to the six-step commutation which is one of the simplest ways to control a brushless DC motor.
 What makes the control implementation a little bit harder is that there can be no angle- or speed sensors involved, so both control methods need to be sensorless. The field-oriented control with field weakening was made sensorless with a sliding mode observer and the six-step commutation was made sensorless via back-EMF sensing.

 The results show that the alternative that seems to have the upper hand is the field-oriented control, even if it may be harder to implement. It also shows that if some more work is put on the control design, the six-step commutation may also be a good candidate. Overall, this thesis shows that it is theoretically possible to implement a brushless DC motor in the hydraulic application.},
  author       = {Djup, Martin and Allar, Elias},
  issn         = {0280-5316},
  language     = {eng},
  note         = {Student Paper},
  title        = {Sensorless Control of Brushless DC Motor in Hydraulic Application},
  year         = {2015},
}