The document describes the design of a hybrid electric drive system consisting of: a power supply circuit, pulse width modulation for speed control, digital logic programmed with Verilog in a GAL chip, and an H-bridge circuit for bi-directional motor control. Key aspects of the design include dynamic and counter-current braking functionality. Testing showed the motor could ramp up and down speed as specified and brake in a controlled manner within current limits. The total cost of components for the designed circuit was under $50.
Project Report submitted By Munesh Kumar Singh, Aditya Vikram Singh, Anitya Kumar Shukla and Devendra Kumar for the award of B.Tech in Electrical and Electronics Engineering at Kanpur Institute of Technology, Kanpur in 2012.
Analysis and control of four quadrant operation of three phase brushless dc (...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Project Report submitted By Munesh Kumar Singh, Aditya Vikram Singh, Anitya Kumar Shukla and Devendra Kumar for the award of B.Tech in Electrical and Electronics Engineering at Kanpur Institute of Technology, Kanpur in 2012.
Analysis and control of four quadrant operation of three phase brushless dc (...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Speed Torque Characteristics of BLDC Motor with Load Variationsijtsrd
Nowadays, Brushless DC motors are in high demand due to its high efficiency and other significant features. As there is no use of brushes, this type of motor is having many advantages like high torque to inertia ratio, high speed, and power density and low cost compared to conventional brushed motors. This paper determines speed torque characteristics of brushless dc motor with different load variation by using the proposed method and the developed controller. The variation in motor speed torque characteristics for half load, full load, and overloading condition is analyzed. This research has been conducted to analyze the model and compared with the simulation results which are very useful in studying the performance of motor system. The simulation is carried out in MATLAB Simulink environment. Ishita Gupta | Akash Varshney "Speed-Torque Characteristics of BLDC Motor with Load Variations" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-4 , June 2020, URL: https://www.ijtsrd.com/papers/ijtsrd31197.pdf Paper Url :https://www.ijtsrd.com/engineering/electrical-engineering/31197/speedtorque-characteristics-of-bldc-motor-with-load-variations/ishita-gupta
BLDC Motor Performance & Endurance Test Set up, consist Various types of Dynamometers & Control configurations as Manual Torque Control, PLC Controlled, PC Based Data Acquisition.
BLDC Motors, as they are compact in size, lighter in weight & Most Efficient than other Electric Motors, They are used as Hub Motor Electric Vehicles –Scooters, Electric Bicycle, BLDC Shafted Motors for Solar Power Submersible Pumps, Sump Pumps, for various applications in Automotive, Aerospace, Military, Medical, Lifts, Cranes, Elevators,
Air Condition & Refrigerator Compressors, Fans, Cleaners-Scrubbers, Sweepers, Lawn movers, Trade mills & fitness equipments & many more applications.
Dynamometers employed to test motors are:
Powder Dynamometers, Eddy Current dynamometers, Tandem Dynamometers, AC Regenerative dynamometers,
DC regenerative dynamometers.
Our Proprietary APPSYS MOTOR TEST software developed, using National Instruments LabView Platform, for BLDC Motor test, to monitor & display Motor Electrical Input Power, Mechanical Output Power,Motor Efficiency, Input Voltage, Current, Power Factor, Motor No Load Current, Full Load Current,No Load & Full Load Speed, No Load & Full Load Torque,Motor temperature, Bearing temperature, Winding temperature, etc.
PC based Motor test set up consist: Window XP /Win7 operating systems, PC hardware & PCI Data Card with necessary Digital & Analogueinputs & outputs, Power analyzer, Electrical Input Power (Motor Power Sensor to sense Motor Power -To monitor Motorelectrical Input Power & for Calculation of efficiency) & Mechanical Output Power –Speed &Torque, Efficiency are displayed on Monitor & stored in tabular form &graphs in MS Excel format.
PC Auto & PC Manual mode selector Soft push button switch on Monitorscreen. In PC Auto mode, Data is captured on predetermined (Site settable) time & Torque Loading in 100 steps (independently settable), whereas in PCManual mode –Data is captured manually by pressing data capture soft buttonon screen. Captured data is exported to MS Excel in Table forms & inGraphs form to showTorque-Speed characteristics, Torque-Current and Speed-Current, Efficiency characteristics,Torque-Speed Oscillations at steady stateTorque at different temperatures, Temp measurements etc.& custom characteristics required by clients.
Accessories such as Motor Temperature, Winding Temperature measurements, Motors mounting Test bed, Test Stands with T slot having X, Y & Z adjustment for Length, Width & Height adjustments is also offered along with dynamometer
Modelling and Simulation of DC-Motor Electric Drive Control System with Varia...IDES Editor
This work represents a mathematical analysis and
simulation of dc-motor electric drive control system with
variable moment of inertia. A separately-excited dc motor is
used in this control system. A mathematical model for this
motor has been simulated and tested in Matlab/Simulink. A
closed-loop control system for this dc electric drive system is
proposed. The proposed control system is based on the
technical optimum method of design. The controlled variable
of this system is the load angular speed. In this control system
the moment of inertia is considered to be variable. It varies as
a function of time. A speed controller and a current controller
are designed for the suggested model to meet the desired
performance specifications by using the technical optimum
method. These controllers are attached to the control system
and the closed-loop response is observed by simulation and
testing this model. The results show the high-performance of
the designed control system.
FOUR QUADRANT SPEED CONTROL OF DC MOTOR USING AT89S52 MICROCONTROLLERJournal For Research
Speed control of a machine is the most vital and important part in any industrial organization. This paper is designed to develop a four quadrant speed control system for a DC motor using microcontroller. The motor is operated in four quadrants i.e. clockwise, counter clock-wise, forward brake and reverse brake. It also has a feature of speed control. The four quadrant operation of the dc motor is best suited for industries where motors are used and as per requirement they can rotate in clockwise, counter-clockwise and also apply brakes immediately in both the directions. In case of a specific operation in industrial environment, the motor needs to be stopped immediately. In such scenario, this proposed system is very apt as forward brake and reverse brake are its integral features. Instantaneous brake in both the directions happens as a result of applying a reverse voltage across the running motor for a brief period and the speed control of the motor can be achieved with the PWM pulses generated by the microcontroller. The microcontroller used in this project is from 8051 family. Push buttons are provided for the operation of the motor which are interfaced to the microcontroller that provides an input signal to it and controls the speed of the motor through a motor driver IC. The speed and direction of DC motor has been observed on digital CRO. Microcontroller programming has been written in assembly language by using notepad and it has been converted in hex file by using micro vision Kiel. The burning of programming in the 8051 microcontroller chip has been done by using positron boot loader software.
Speed Torque Characteristics of BLDC Motor with Load Variationsijtsrd
Nowadays, Brushless DC motors are in high demand due to its high efficiency and other significant features. As there is no use of brushes, this type of motor is having many advantages like high torque to inertia ratio, high speed, and power density and low cost compared to conventional brushed motors. This paper determines speed torque characteristics of brushless dc motor with different load variation by using the proposed method and the developed controller. The variation in motor speed torque characteristics for half load, full load, and overloading condition is analyzed. This research has been conducted to analyze the model and compared with the simulation results which are very useful in studying the performance of motor system. The simulation is carried out in MATLAB Simulink environment. Ishita Gupta | Akash Varshney "Speed-Torque Characteristics of BLDC Motor with Load Variations" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-4 , June 2020, URL: https://www.ijtsrd.com/papers/ijtsrd31197.pdf Paper Url :https://www.ijtsrd.com/engineering/electrical-engineering/31197/speedtorque-characteristics-of-bldc-motor-with-load-variations/ishita-gupta
BLDC Motor Performance & Endurance Test Set up, consist Various types of Dynamometers & Control configurations as Manual Torque Control, PLC Controlled, PC Based Data Acquisition.
BLDC Motors, as they are compact in size, lighter in weight & Most Efficient than other Electric Motors, They are used as Hub Motor Electric Vehicles –Scooters, Electric Bicycle, BLDC Shafted Motors for Solar Power Submersible Pumps, Sump Pumps, for various applications in Automotive, Aerospace, Military, Medical, Lifts, Cranes, Elevators,
Air Condition & Refrigerator Compressors, Fans, Cleaners-Scrubbers, Sweepers, Lawn movers, Trade mills & fitness equipments & many more applications.
Dynamometers employed to test motors are:
Powder Dynamometers, Eddy Current dynamometers, Tandem Dynamometers, AC Regenerative dynamometers,
DC regenerative dynamometers.
Our Proprietary APPSYS MOTOR TEST software developed, using National Instruments LabView Platform, for BLDC Motor test, to monitor & display Motor Electrical Input Power, Mechanical Output Power,Motor Efficiency, Input Voltage, Current, Power Factor, Motor No Load Current, Full Load Current,No Load & Full Load Speed, No Load & Full Load Torque,Motor temperature, Bearing temperature, Winding temperature, etc.
PC based Motor test set up consist: Window XP /Win7 operating systems, PC hardware & PCI Data Card with necessary Digital & Analogueinputs & outputs, Power analyzer, Electrical Input Power (Motor Power Sensor to sense Motor Power -To monitor Motorelectrical Input Power & for Calculation of efficiency) & Mechanical Output Power –Speed &Torque, Efficiency are displayed on Monitor & stored in tabular form &graphs in MS Excel format.
PC Auto & PC Manual mode selector Soft push button switch on Monitorscreen. In PC Auto mode, Data is captured on predetermined (Site settable) time & Torque Loading in 100 steps (independently settable), whereas in PCManual mode –Data is captured manually by pressing data capture soft buttonon screen. Captured data is exported to MS Excel in Table forms & inGraphs form to showTorque-Speed characteristics, Torque-Current and Speed-Current, Efficiency characteristics,Torque-Speed Oscillations at steady stateTorque at different temperatures, Temp measurements etc.& custom characteristics required by clients.
Accessories such as Motor Temperature, Winding Temperature measurements, Motors mounting Test bed, Test Stands with T slot having X, Y & Z adjustment for Length, Width & Height adjustments is also offered along with dynamometer
Modelling and Simulation of DC-Motor Electric Drive Control System with Varia...IDES Editor
This work represents a mathematical analysis and
simulation of dc-motor electric drive control system with
variable moment of inertia. A separately-excited dc motor is
used in this control system. A mathematical model for this
motor has been simulated and tested in Matlab/Simulink. A
closed-loop control system for this dc electric drive system is
proposed. The proposed control system is based on the
technical optimum method of design. The controlled variable
of this system is the load angular speed. In this control system
the moment of inertia is considered to be variable. It varies as
a function of time. A speed controller and a current controller
are designed for the suggested model to meet the desired
performance specifications by using the technical optimum
method. These controllers are attached to the control system
and the closed-loop response is observed by simulation and
testing this model. The results show the high-performance of
the designed control system.
FOUR QUADRANT SPEED CONTROL OF DC MOTOR USING AT89S52 MICROCONTROLLERJournal For Research
Speed control of a machine is the most vital and important part in any industrial organization. This paper is designed to develop a four quadrant speed control system for a DC motor using microcontroller. The motor is operated in four quadrants i.e. clockwise, counter clock-wise, forward brake and reverse brake. It also has a feature of speed control. The four quadrant operation of the dc motor is best suited for industries where motors are used and as per requirement they can rotate in clockwise, counter-clockwise and also apply brakes immediately in both the directions. In case of a specific operation in industrial environment, the motor needs to be stopped immediately. In such scenario, this proposed system is very apt as forward brake and reverse brake are its integral features. Instantaneous brake in both the directions happens as a result of applying a reverse voltage across the running motor for a brief period and the speed control of the motor can be achieved with the PWM pulses generated by the microcontroller. The microcontroller used in this project is from 8051 family. Push buttons are provided for the operation of the motor which are interfaced to the microcontroller that provides an input signal to it and controls the speed of the motor through a motor driver IC. The speed and direction of DC motor has been observed on digital CRO. Microcontroller programming has been written in assembly language by using notepad and it has been converted in hex file by using micro vision Kiel. The burning of programming in the 8051 microcontroller chip has been done by using positron boot loader software.
Finding a Significant Other Can be Good for Your Teeth, Science SaysJacob_Sharp
If you want better teeth, let Cupid’s arrow find you, a collaborated study by the University of Queensland’s School of Dentistry and School of Health and Rehabilitation Sciences says. The UQ researchers observed 265 adults to determine how the dynamics of romantic relationships affect oral health.
6 Tips to Create Killer Insurance Marketing Strategies for Your WebsiteArlo Gibb
With effective, powerful insurance marketing strategies, you can attract visitors and get more leads from your website. Get started with these important steps and create great insurance marketing that increases leads for your insurance brokers.
ETHIOPIAN STYLE DECORATIVE DESIGNS”: A NEW TECHNICAL GUIDE BOOK FOR ARTISANDessalegn Oulte
The Purpose of this work is to contribute new quality decorative designs to the Ethiopian hand craft industry in order to maintain their uniqueness and attractiveness in such a way that they would widely penetrate the international market. Preliminary pattern designs and motifs in this book can be used (with or without modification) for adorning pottery , traditional weaving, wood carving bamboo work, metal work, basketry, jewelry, leather work, silver smiths, goldsmiths, painting, rock carving, horn work, ,iconography, manuscript illumination, calligraphy, mural paintings, body painting /decoration, fashion design, architecture, wallpaper design, patterning, knitting, crochet work, sewing /embroidery, interior and exterior designs, painting, sculpture, ceramics, furniture, textile, basketry, and other so many hand craft industries.
The book is also intended to be reference material for educating and training art students and hand craft makers on the composition, behavior and use of lines, shapes and colors in making decorative patterns and motifs for hand crafts and other visual arts. Hence, it lays a solid foundation for systematic study, conception and documentation of decorative and visual arts implemented in hand craft industries.
All the works are inspired by the Ethiopian traditional designs used in different hand crafts, especially traditional SHEMA.
Automatic power factor correction by fine tuning of graded capacitorsIJARIIT
Today’s power system demands improved power factor in order to harness various advantages associated with improved
power factor. Till date, various methods have been deployed to improve the power factor of the power system. This paper mainly
focuses on a novel methodology for reactive power compensation and thereby power factor improvement at the load end. This
paper presents a novel approach of capacitance grading for achieving fine tuning of power factor. The concept for automatic
power factor correction by fine tuning of graded capacitors with the help of microcontroller and binary logic is proposed,
simulated, and implemented. The method presented is of iterative nature and is cost competitive over other deployed methods.
An algorithm is developed and a model is made to deploy the concept of iteration with binary logic. The same is tested on an
induction motor and results obtained are analyzed.
This predefined speed control of BLDC motor runs a motor at user desired speed by using EEPROM for storing speed. It is an effective speed control method.
Designed a microwave amplifier circuit with a required bandwidth of 250MHz at a center frequency of 3.7GHz experiencing 6.5dB gain within Keysight ADS.
1. University of Washington
Department of Electrical Engineering
EE453 Electric Drives
Hybrid Electric Drive System
Authors:
Brianne Foster
Spencer Minder
William Yuen
Instructor:
Professor Mohamed A.
El-Sharkawi
March 10, 2009
3. List of Figures
1 Block Diagram of the Motor Driver . . . . . . . . . . . . . . . . . . . 2
2 Circuit Schematic of the Motor Driver . . . . . . . . . . . . . . . . . 3
3 Logic Circuit in the GAL16V8 . . . . . . . . . . . . . . . . . . . . . . 5
4 Verilog Timing Diagram . . . . . . . . . . . . . . . . . . . . . . . . . 5
5 Dynamic Braking Current Loop Dissipation . . . . . . . . . . . . . . 7
6 Dynamic Braking MOSFETs . . . . . . . . . . . . . . . . . . . . . . . 7
7 Gate-to-Source Voltage of the the High and Low Side Driver . . . . . 8
8 GAL Signal to Ground at q1 and q2 . . . . . . . . . . . . . . . . . . 9
9 Voltage Across the Load at Various Points . . . . . . . . . . . . . . . 9
ii
4. List of Tables
1 Test Cases for the GAL16V8 Chip . . . . . . . . . . . . . . . . . . . . 4
2 List of All Components and Total Purchasing Price . . . . . . . . . . 10
iii
5. Electric Drive Design EE453, Winter 2009
0.1 Introduction
In recent years the demand for hybrid electric motors has increased significantly due
to rising oil costs and the transition to more energy efficient machines. The earlier
versions of these hybrid motor’s had simple controller circuits. Skip to the present
and the complexity of these circuits has multiplied. The advantages to using an
electric motor includes the uses of counter-current and regenerative braking. These
features allow the motor to use itself to brake and to generate energy in certain
braking situations. With the increase in demand for electric motor controllers this
report presents a cost efficient design of an electric motor controller. The design
utilizes a power supply circuit, Pulse Width Modulation speed and braking control,
and Bi-directional motor rotation.
0.2 Design Specifications
The specifications for the driver circuit are as follows:
Starting
• The motor should start by pushing a button
• The maximum starting current at full load should not exceed twice the rated
current
• The motor should reach the rated speed in less than 3 seconds
• The ramping of the speed should be smooth
Speed Control
• Speed change can be made on command
• User can regulate the speed by low power analog or digital devices
• Speed regulation should be smooth
• Motor should be able to run at low speeds without jerking
Braking
• User can select either dynamic or counter current braking
• The braking current should be limited to 3 times the rated current
• The user can select the rapidity of braking
Page 1 of 16
6. Electric Drive Design EE453, Winter 2009
0.3 Overview
Figure 1 shows a block diagram of the key components of the circuit. The components
include: the power supply circuit, the Pulse Width Modulation circuit, the digital
logic circuit, and the H-Bridge circuit.
Figure 1: Block Diagram of the Motor Driver
0.4 Circuit Design
The design of the motor drive circuit consisted of a power supply, digital logic incor-
porated in a gate-array logic (GAL) device, pulse-width modulation, H-bridge, and
several switches and push-buttons for easy user control. The circuit schematic can
be seen in Figure 2. Note that there are actually two SG3524 ICs but due to space
limitations, it could not be shown.
Page 2 of 16
7. Electric Drive Design EE453, Winter 2009
Figure 2: Circuit Schematic of the Motor Driver
Page 3 of 16
8. Electric Drive Design EE453, Winter 2009
0.4.1 Power Supply
The power supply consists of a 25.2V center-tapped 2A transformer, full-bridge rec-
tifier, 1000µF filter capacitor, and a variable voltage regulator. The voltage supplied
by the transformer is 40VDC. The filtering capacitor needed a high voltage rating
and capacitance in order to reduce ripple when a load is connected. This voltage is
stepped down to 26.4VDC via two parallel connected LM317t variable voltage regu-
lators. Supply voltages of 12VDC and 5VDC were created off of the 26.4VDC using
a 12V and 5V regulator. Extra caution was implemented by using two circuit break-
ers connected to the secondary side and a 2A fuse connected to the primary of the
transformer.
0.4.2 Digital Logic
To provide the basic control functions of the motor controller, digital logic was im-
plemented in a GAL16V8D IC. The advantages of digital logic are: its very robust,
it can be altered easily, and is cost efficient. The digital logic was programmed us-
ing Verilog HDL. This allowed flexibility in reprogramming any logic modifications.
The first step in the design process involved creating the desired user inputs such as
direction control, counter-current braking, and dynamic braking. Second, Karnaugh
maps(Kmaps) were created by determining the state of the output by changing the
input combinations. After simplying the Kmaps into logic equations, a logic diagram
was made. The logic diagram provides a visual representation of how the logic is con-
trolled and allows easy coding in Verilog HDL. Next the logic was coded and tested
in Verilog. Finally the logic, which can be seen in Figure 3, was put onto the GAL
device using ISPLEVER. A timing diagram from the Verilog test code and truth table
for the digital logic can be seen in Figure 4 and Table 1, respectively.
Table 1: Test Cases for the GAL16V8 Chip
Dir DynB ccB Output
0 0 0 q1, q2
0 0 1 q3, q4
0 1 0 q1
0 1 1 X
1 0 0 q3, q4
1 0 1 q1, q2
1 1 1 q3
Page 4 of 16
9. Electric Drive Design EE453, Winter 2009
Figure 3: Logic Circuit in the GAL16V8
Figure 4: Verilog Timing Diagram
0.4.3 Pulse-Width Modulation (PWM)
A SG3524 chip provided the pulse-width modulation for the circuit. The preferred
choice for motor speed control is a PWM signal. By varying the duty cycle of the
pulse width, the dc voltage supplied to the motor is regulated. Another advantage of
a PWM signal is that the pulses reach the full supply voltage and will produce more
torque in a motor by being able to overcome the internal motor resistance.
In this particular circuit, there are two PWM signals - one for speed control and
another for braking. Two PWM signals were used because the braking speed had to
be independent of the speed control. For example, in the single PWM case, if the
Page 5 of 16
10. Electric Drive Design EE453, Winter 2009
user were to accelerate at full speed and switch to counter-current braking, not only
would there be a large spike in current but the user would not be able to control the
rapidity of the braking. To eliminate this problem and create a more robust braking
system, a braking PWM was implemented.
0.4.4 H-Bridge
An H-bride consisting of all N-channel MOSFETs was implemented to allow forward
and reverse direction control of the DC motor. The driver for the MOSFETS is the
IRF2181 is a high-side and low-side driver IC.
One potential problem with using all N-channel MOSFETs is that its drain lead is
connected to VCC. The goal is to turn the MOSFET on such that the top of the
motor is at Vcc potential. This means that the MOSFET’s source lead will be raised
to VCC’s potential. The gate voltage needs to be 4.5 to 7V higher than the source
to keep the MOSFET turned on. In other words, the gate voltage needs to be higher
than VCC by 4.5 to 7V. This problem was fixed by a built-in charge-pump featured
in the MOSFET driver. The charge-pump consists of a boot-strap capacitor that
charges to a voltage of 10V, which allows the gate voltage to be higher than VCC.
0.5 Braking
In an electric motor, there are two different types of braking: dynamic and counter-
current. Dynamic braking is the traditional braking method in a vehicle where high
losses occur due to heat dissipation from friction. Counter-current braking utilizes
the motor to electrically brake without high losses. Regenerative braking, which
occurs when the motor speed becomes higher than the no-load speed without changing
direction, is the main advantage of counter-current braking.
0.5.1 Dynamic
Dynamic braking was implemented by using the H-bridge. The most efficient method
for dynamic braking involves turning on one MOSFET. The energy from the motor
is dissipated through a loop which comprises a high-side MOSFET q1 and a free-
wheeling diode from the other high-side MOSFET q3. This is displayed in Figure 5.
For the forward direction, MOSFET q1 on the high-side stays on while MOSFET q2
on the low-side turns off. For the reverse direction, MOSFET q3 on the high-side
stays on while MOSFET q4 on the low-side turns off. This methodology can be seen
in Figure 6.
Page 6 of 16
11. Electric Drive Design EE453, Winter 2009
Figure 5: Dynamic Braking Current Loop Dissipation
Figure 6: Dynamic Braking MOSFETs
0.5.2 Counter-current
The key concept of counter-current braking is utilizing the motor to brake itself. This
is done by supplying a torque in the opposite direction that the speed of the motor
is traveling. There are two types of counter-current braking: Plugging and Terminal
Voltage Reversal(TVR). Plugging is only applicable in constant torque situations.
Therefore the counter-current braking implemented in the circuit is TVR. Essentially
this is done by switching the motor into reverse direction and applying a low duty
cycle braking PWM. The digital logic in the circuit turns off the MOSFET pair
that is controlling the speed and switches to the opposite pair of MOSFETS. The
braking PWM is set to a low duty cycle to prevent shoot-thru in the H-bridge when
switching MOSFET pairs. The braking speed can then be ramped to a higher value.
Page 7 of 16
12. Electric Drive Design EE453, Winter 2009
As expected, the counter-current braking system is faster than the dynamic braking
system.
0.6 Results
The electric motor drive that was designed performed to the specifications. The mo-
tor can ramp-up to full speed and ramp-down to a slower speed as defined by the user.
In addition, the motor is capable of dynamic and controllable counter-current braking.
The first test involved testing the MOSFET driver ICs. Figure 7 shows the gate-to-
source voltage of the high and low side MOSFET. As expected, the VGS is greater
than VDS of q1 which indicates that the charge-pump of the upper MOSFET operates
properly.
(a) VGS q1 at 80% duty cycle (b) VGS q2 at 80% duty cycle
Figure 7: Gate-to-Source Voltage of the the High and Low Side Driver
The actual timing signal that was used to drive MOSFETs q1 and q2 from the
GAL16V8 can be seen in 8a and 8b.
When a DC motor is added as the load and the voltage is measured across it, the
output waveforms appear to be accurate. At 80% duty cycle, several waveforms were
captured to depict the voltage seen at the load. Figure 9a shows q1 from its source
to ground. Figure 9b shows q2 from its drain to ground. Finally, Figure 9c shows
the math function of subtracting 9a from 9b.
Page 8 of 16
13. Electric Drive Design EE453, Winter 2009
(a) GAL q1 signal at 80% duty cycle (b) GAL q2 signal at 80% duty cycle
Figure 8: GAL Signal to Ground at q1 and q2
(a) q1 Source-to-Ground Voltage (b) q2 Drain-to-Ground Voltage
(c) q1-Source to q2-Drain
Figure 9: Voltage Across the Load at Various Points
Page 9 of 16
14. Electric Drive Design EE453, Winter 2009
Using a digital multi-meter, the motor was placed in series and the measured braking
current was about 1.2A. The DC motor’s rated current was about 4A. This means
that the circuit design is below three times the rated current of the DC motor.
0.7 Cost Analysis
The list for all of the components, cost per unit, and total cost for the electric drive
circuit that was design can be seen in Table 2. To keep the project cost low, the
majority of the components were purchased in bulk from a online distributor (such
as Digi-Key).
Table 2: List of All Components and Total Purchasing Price
Item
Component Quantity Cost Per Unit ($)
25.2V CT 2.0A Transformer 1 10.49
25A, 50V Full-Wave Bridge Rectifier 1 3.29
IR2181 MOSFET Driver 2 3.60
IRFB4212 N-Channel MOSFETS 4 1.20
SG3524 PWM 2 1.60
L78S12 Voltage Regulator 1 0.68
LM317T Variable Voltage Regulator 1 0.60
L7805 Voltage Regulator 1 0.60
Resistors 16 0.10
Potentiometers 2 0.40
Ceramic Capacitors 17 0.20
1000µF, 50V Electrolytic Capacitor 1 0.70
Total 49 37.36
0.8 Conclusion
The electric motor controller design works according to the specifications. By using
digital logic to control the inputs such counter current braking, dynamic braking, and
direction, the circuit was streamlined and simple to implement. The motor controller
Page 10 of 16
15. Electric Drive Design EE453, Winter 2009
excelled in terms of cost efficiency, smooth speed and braking control, size, and user
control.
The driver circuit is also very versatile when it comes to using a higher voltage motor.
Since the IR2181 MOSFET driver chips are fully operational to +600V, this circuit
can handle up to +600V motor as a load. In order to drive a larger load, the only
components that need to be changed are a larger power supply, and MOSFETs and
boot-strap capacitors rated for higher voltages.
One possible improvement to the current design is the digital logic in the GAL IC. The
problem with the current logic is that there is not enough dead-time when counter-
current braking is activated. The present logic works when handled properly but it is
not ”dummy proof”. An attempt to implement a state machine in the logic did not
fully materialize due to time constraints and availability of a clock signal.
Page 11 of 16
18. Electric Drive Design EE453, Winter 2009
module testBench ;
wire q1 , q2 , q3 , q4 ;
motorControl mymotorControl (q1 , q2 , q3 , q4 , dynB , ccB , dir ,pWM,brpWM) ;
t e s t I t myTester (dynB , ccB , dir ,pWM,brpWM, q1 , q2 , q3 , q4 ) ;
endmodule
//Turtle state module(converts 4 bit lsfr output into one hot coding on led)
module motorControl (q1 , q2 , q3 , q4 , dynB , ccB , dir ,pWM,brpWM) ;
input dynB , ccB , dir ,pWM,brpWM;
output q1 , q2 , q3 , q4 ;
not invdynB (ndynB , dynB ) ;
not invdir ( ndir , dir ) ;
and andA(outandA , ndir , dynB) ,
andB(outandB , ndynB , outxorA ) ,
andC(outandC , dir , dynB) ,
andD(outandD , ndynB , outxorB ) ;
xor xorA( outxorA , ccB , ndir ) ,
xorB ( outxorB , ccB , dir ) ;
or orA( outorA , outandA , outandB ) ,
orB ( outorB , outandC , outandD ) ,
orC( outorC , dynB , ccB ) ;
not notorC (outNotOrC , outorC ) ;
and andE( outandE ,brpWM, outorC ) ,
andF( outandF ,pWM, outNotOrC ) ;
or orD( outorD , outandE , outandF ) ;
and andG(q1 , outorA , outorD ) ,
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19. Electric Drive Design EE453, Winter 2009
andH(q2 , outandB , outorD ) ,
andI (q3 , outorB , outorD ) ,
andJ (q4 , outandD , outorD ) ;
endmodule
module t e s t I t (dynB , ccB , dir ,pWM,brpWM, q1 , q2 , q3 , q4 ) ;
input q1 , q2 , q3 , q4 ;
output dynB , ccB , dir ,pWM,brpWM;
parameter period = 1;
parameter stimDelay = 10;
reg dynB , ccB , dir ,pWM,brpWM;
always
#period pWM = ˜pWM;
always
#period brpWM = ˜brpWM;
i n i t i a l
begin
dynB = 0;
ccB = 0;
dir= 0;
pWM= 1;
brpWM=0;
end
i n i t i a l
begin
$monitor( $time , ” dynB ccB dir pWM = %b%b%b%b /n q1 q2 q3 q4 = %b%b%b
dynB , ccB , dir ,pWM, q1 , q2 , q3 , q4 ) ;
begin
#stimDelay { dir , dynB , ccB}=0; //Expect to see q1, q2
only on
#stimDelay { dir , dynB , ccB}=1; //Expect to see q3, q4
only on
#stimDelay { dir , dynB , ccB}=2; //Expect q1 on only
#stimDelay { dir , dynB , ccB}=3; //not allowed
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20. Electric Drive Design EE453, Winter 2009
#stimDelay { dir , dynB , ccB}=4; // q3 and q4
#stimDelay { dir , dynB , ccB}=5;// Expect q1 and q2 on
#stimDelay { dir , dynB , ccB}=6;// Expect q3
end
#(2∗stimDelay ) ;
$stop ;
$finish ;
end
endmodule
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