Robot and Servo Drive Lab.
Digital Control Strategy for Four Quadrant Operation
of Three Phase BLDC Motor With Load Variations
C. Sheeba Joice, S. R. Paranjothi, and V. Jawahar Senthil Kumar
IEEE TRANSACTIONS ON INDUSTRIAL INFORMATICS, VOL. 9, NO. 2, MAY 2013 p974-982
Professor: MING-SHYAN WANG
Student: WEI-CHIN FANG
Department of Electrical Engineering
Southern Taiwan University of Science and Technology
2016/7/16
Outline

FOUR QUADRANT OPERATION OF BLDC MOTOR



DIGITAL CONTROLLER









BLDC Motor
Four Quadrant Operation
PI Controller
PWM Module
ADC Module
COMPLETE DRIVE SYSTEM
SIMULINK MODEL
PRACTICAL IMPLEMENTATION
RESULTS
CONCLUSION
REFERENCES
2016/7/16
Department of Electrical Engineering
Robot and Servo Drive Lab.
Southern Taiwan University of Science and Technology
2
Abstract

This paper deals with the digital control of three phase BLDC motor. The
motor is controlled in all the four quadrants without any loss of power; in
fact energy is conserved during the regenerative period.
2016/7/16
Department of Electrical Engineering
Robot and Servo Drive Lab.
Southern Taiwan University of Science and Technology
3
BLDC Motor

The numbers shown around the
peripheral of the motor diagram
in Fig. 1 represent the sensor
position code.
Fig. 1. BLDC Motor Star connected.
2016/7/16
Department of Electrical Engineering
Robot and Servo Drive Lab.
Southern Taiwan University of Science and Technology
4
BLDC Motor
Fig. 2. Equivalent Circuit of power stage of BLDC motor.

The rotor position decoder has six outputs which control the upper and
lower phase leg MOSFETs of Fig. 2.
2016/7/16
Department of Electrical Engineering
Robot and Servo Drive Lab.
Southern Taiwan University of Science and Technology
5
Four Quadrant Operation

There are four possible modes or
quadrants of operation using a
Brushless DC Motor which is
depicted in Fig. 3.
Fig. 3. Four Quadrants of operation.
2016/7/16
Department of Electrical Engineering
Robot and Servo Drive Lab.
Southern Taiwan University of Science and Technology
6
Four Quadrant Operation

When BLDC motor (Fig. 4) is
operating in the first and third
quadrant, the supplied voltage is
greater than the back emf which is
forward motoring and reverse
motoring modes respectively, but
the direction of current flow
differs.
Fig. 4. Operating Modes.
2016/7/16
Department of Electrical Engineering
Robot and Servo Drive Lab.
Southern Taiwan University of Science and Technology
7
PI Controller


The regulation of speed is accomplished with PI Controller. By increasing
the proportional gain of the speed controller, the controller’s sensitivity is
increased to have faster reaction for small speed regulation errors.
This allows a better initial tracking of the speed reference by a faster
reaction of the current reference issued by the speed controller. This
increased sensitivity also reduces the speed overshooting.
2016/7/16
Department of Electrical Engineering
Robot and Servo Drive Lab.
Southern Taiwan University of Science and Technology
8
PWM Module


The PWM module simplifies the task of generating multiple synchronized
Pulse Width Modulated (PWM) outputs. It has six PWMI/O pins with three
duty cycle generators.
For each duty cycle, there is a duty cycle register that will be accessible by
the user while the second duty cycle register holds the actual compared
value used in the present PWM period.
2016/7/16
Department of Electrical Engineering
Robot and Servo Drive Lab.
Southern Taiwan University of Science and Technology
9
ADC Module






The 10 bit high speed analog to digital converter (A/D) allows conversion
of an analog input signal to a 10 bit digital number.
This module is based on Successive Approximation Register (SAR)
architecture, and provides a maximum sampling rate of 500 ksps.
The timer registers are used to store the duty cycle of the PWM pulses that
are generated.
In the Hall sensor mode, the input capture module is set for capture on
every edge, rising and falling,
The interrupt on Capture mode setting bits,
,is ignored, since every
capture generates an interrupt.
The output compare module generates an interrupt to trigger the relay
circuit during regenerative mode.
2016/7/16
Department of Electrical Engineering
Robot and Servo Drive Lab.
Southern Taiwan University of Science and Technology
10
COMPLETE DRIVE SYSTEM



Four quadrant Zero current transition converter (4Q—ZCT)
was implemented for DC motor and single controllable switch for four
quadrant operation was implemented for SRM drive.
The common regenerative braking methods include adding an extra
converter, or adding an extra ultra-capacitor, or switching sequence change
of power switches.
Relay circuits are employed to run the motor during the accelerating mode
and charge the battery during the regenerative mode.
2016/7/16
Department of Electrical Engineering
Robot and Servo Drive Lab.
Southern Taiwan University of Science and Technology
11
COMPLETE DRIVE SYSTEM
Fig. 5. Closed Loop Drive.

The schematic diagram of the drive arrangement of the three phase BLDC
motor is shown in Fig. 5.
2016/7/16
Department of Electrical Engineering
Robot and Servo Drive Lab.
Southern Taiwan University of Science and Technology
12
COMPLETE DRIVE SYSTEM

Whenever there is a reversal of
direction of rotation it implies
there is a change in the quadrant.
2016/7/16
Fig. 6. Relay Circuit.
Department of Electrical Engineering
Robot and Servo Drive Lab.
Southern Taiwan University of Science and Technology
13
SIMULINK MODEL
2016/7/16
Fig. 7. Simulink Model of Four Quadrant Drive.
Department of Electrical Engineering
Robot and Servo Drive Lab.
Southern Taiwan University of Science and Technology
14
SIMULINK MODEL
Fig. 8. Modeling of Controller.

The model of the controller shown in Fig. 8, receives the Hall signals as its
input, converts it in to appropriate voltage signals.
2016/7/16
Department of Electrical Engineering
Robot and Servo Drive Lab.
Southern Taiwan University of Science and Technology
15
SIMULINK MODEL
Fig. 9. Output of Simulink model—Rotor speed(rpm), Stator current (A), Stator back emf (V).
2016/7/16
Department of Electrical Engineering
Robot and Servo Drive Lab.
Southern Taiwan University of Science and Technology
16
SIMULINK MODEL
Fig. 10. Reference Speed and Actual Speed in rpm.
2016/7/16
Department of Electrical Engineering
Robot and Servo Drive Lab.
Southern Taiwan University of Science and Technology
17
PRACTICAL IMPLEMENTATION
2016/7/16
Department of Electrical Engineering
Robot and Servo Drive Lab.
Southern Taiwan University of Science and Technology
18
PRACTICAL IMPLEMENTATION
2016/7/16
Fig. 12. Flowchart for four quadrant controller.
Department of Electrical Engineering
Robot and Servo Drive Lab.
Southern Taiwan University of Science and Technology
19
RESULTS
Fig. 13. Hall Sensor signals and Phase Current.
2016/7/16
Department of Electrical Engineering
Robot and Servo Drive Lab.
Southern Taiwan University of Science and Technology
20
RESULTS
Fig. 14. Trapezoidal Voltages of RY and YB.
2016/7/16
Department of Electrical Engineering
Robot and Servo Drive Lab.
Southern Taiwan University of Science and Technology
21
RESULTS
Fig. 15. PWM Pulses—Control signals to the Inverter.
2016/7/16
Department of Electrical Engineering
Robot and Servo Drive Lab.
Southern Taiwan University of Science and Technology
22
RESULTS
2016/7/16
Fig. 16. Quadrant transition.
Department of Electrical Engineering
Robot and Servo Drive Lab.
Southern Taiwan University of Science and Technology
23
RESULTS
Fig. 17. Speed Control with load of 0.5 kg.
2016/7/16
Department of Electrical Engineering
Robot and Servo Drive Lab.
Southern Taiwan University of Science and Technology
24
RESULTS
2016/7/16
Fig. 18. Energization with no load.
Department of Electrical Engineering
Robot and Servo Drive Lab.
Southern Taiwan University of Science and Technology
25
RESULTS
Fig. 19. Energization with a load of 0.5 kg.
Fig. 20. Energization with a load of 1 kg.
2016/7/16
Department of Electrical Engineering
Robot and Servo Drive Lab.
Southern Taiwan University of Science and Technology
26
RESULTS
Fig. 21. Energization of the Battery.
2016/7/16
Department of Electrical Engineering
Robot and Servo Drive Lab.
Southern Taiwan University of Science and Technology
27
CONCLUSION

The significant advantages of the proposed work are: simple hardware
circuit, reliability of the control algorithm, excellent speed control, smooth
transition between the quadrants and efficient conservation of energy is
achieved with and without load conditions.
2016/7/16
Department of Electrical Engineering
Robot and Servo Drive Lab.
Southern Taiwan University of Science and Technology
28
REFERENCES


[1] C. S. Joice, Dr. S. R. Paranjothi, and Dr. V. J. S. Kumar, “Practical
implementation of four quadrant operation of three phase Brushless DC
motor using dsPIC,” in Proc. IConRAEeCE 2011, 2011, pp. 91–94, IEEE.
[2] T. W. Ching, “Four-Quadrant Zero-Current-Transition Converter-Fed
Dc Motor Drives for Electric Propulsion ,” Journal of Asian Electric
Vehicle Vol. 4 (2006) No. 2 P 911-917.
2016/7/16
Department of Electrical Engineering
Robot and Servo Drive Lab.
Southern Taiwan University of Science and Technology
29