Learning objectives
ELECTRIC MACHINES AND DRIVES
1) Knowledge and understanding
This module aims at providing students with basic knowledge and understanding of:
- single phase and three phase transformer behavior
- DC and AC rotating machines behavior
- step motors
- basic of machine and drive controls
2) Applying knowledge and understanding
Students will be made able to:
- computing transformer apparent power and voltage drop depending on load conditions
- choosing the suitable electric machine depending on duty cycle
- sizing the electric drive
- designing the braking resistance
INDUSTRIAL ELECTRONIC
1) Knowledge and understanding
This module aims at providing students with basic knowledge and understanding of:
- sensors and transducers for electro-mechanical systems and applications
- circuits based on operational amplifiers for analog signal processing
- simple combinatory and sequential digital circuits
- basic principles and methods for analog and digital automatic control - power electronic converters
2) Applying knowledge and understanding
Students will be made able to:
- choose the most suitable sensors and transducers for a specific application based on their characteristics and the specifications of the problem
- analyze the behavior of simple circuits based on operational amplifiers
- analyze and design simple analog automatic control loops
- synthesize combinatory logic circuits
- analyze the behavior of the most important electronic power converters and evaluate their performance based on the voltage and current waveforms
Prerequisites
FOR BOTH MODULES
The students are expected to be familiar with the notions of mathematics, physics, electrical and electronic circuits taught in the 1st level degree in Mechanical Engineering.
Course unit content
ELECTRIC MACHINES AND DRIVES
a) An Introduction to Electric machines
b) Transformers
c) Rotating machines
d) Electric Drives
INDUSTRIAL ELECTRONIC
1. Basics of semiconductor devices and power switches.
2. High power converters.
Single-phase and three-phase rectifiers. DC/DC converters: buck, boost, buck-bust, H-bridge. Single-phase and three-phase full-bridge inverters.
3. Sensors and transducers
Displacement, position and proximity. Velocity and motion. Force. Fluid pressure. Flow and level of liquids. Temperature. Optical sensors.
4. Signal conditioning.
Operational amplifiers. Protection. Filtering. Wheatstone bridge. Pulse-Width Modulation (PWM).
5. Digital signals.
Analog and digital sgnals. D/A and A/D converters. Multiplexer. Data acquisition. Digital Signal Processing (DSP).
6. Closed-loop controls
On-off control. Proportional-Integral-Differential (PID) controller. Digital controllers. Adaptive control.
Full programme
ELECTRIC MACHINES AND DRIVES
a) An Introduction to Electric machines
Electric machines classification. The main components of the electric machines.
Joule losses and iron losses: the efficiency of the electrical machines.
b) Transformers
Ideal transformer and real transformer.
No load operations and rated load operations.
Voltage drop, power, losses and efficiency of electrical transformer. Three phases transformers.
c) Rotating machines
Induction machines: mechanical and electrical behaviour. Induction motor start-up and velocity regulation.
Direct Current machines: electrical and mechanical behaviour, start-up and velocity regulation.
Permanet Magnet Synchronous Machines (PMSM): a.c. and d.c. PMSM, electrical and mechanical behaviour.
Permanet magnet step motor, reluctance step motor and hybrid step motor.
Electric Drives classification.
d) Electric Drives
The main components of electric drives: speed and position transducers, current transducers. Analog and digital PID regulators, PLC.
Electric drives based on permanent dc motors: torque control and velocity control.
DC motor supply: soft switching chopper.
Electric drives based on PMSM: torque control and velocity control. Electric drives based on induction motors: torque and speed control. Incremental electrical drives: basic stepping motor control circuits.
INDUSTRIAL ELECTRONIC
1. Sensors and transducers
Terminology. Displacement, position and proximity:potentiometer; capacitive sensors; inductive sensors; optical encoder; proximity switches; Hall-effect sensors. Velocity and motion: tachogenerator; AC generator; pyroelectric sensors. Force and pressure: load cells; piezoelectric sensors. Temperature: bimetallic stripes; RTD; thermistor; thermodiode and thermotransistor; thermocouples. Optical sensors: photodiode and phototransistor; photoresistor; CCD.
2. Basic of semiconductor devices and solid-state power switches
Pn diode. Npn bipolar junction transistor. N- and P-channel MOSFET. IGBT. 3. Signal conditioning
Amplifiers and network functions. Differential amplifiers. Operational amplifiers: frequency behavior. Examples of application of operational amplifiers. 741 amplifier. Instrumentation amplifier: INA114. Logarithmic amplifier. Comparator. Protection and isolation circuits. Passive and active filters. Wheatstone bridge. A/D conversion: sampling and Shannon theorem. D/A converters: weighted resistor DAC; ladder DAC; ZN558D. A/D converters: successive approximations ADC; ZN439; flash converters. Sample & hold amplifier. Multiplexer. Data acquisition boards.
4. Digital signals
Combinatory logic and logic operators; laws of De Morgan. Karnaugh maps; parity generator; comparator; decoder. Sequential logic: asynchronous and synchronous SR flip-flops; D and T flip-flops; JK flip- flop; registers; timer 555.
5. Closed-loop controls
Lag and steady-state error. On-off control. Proportional-integral- differential (PID) control. Digital control. Adaptive control.
6. Static energy conversion
Introduction and power converter figures of merit. Single-phase half-wave rectifier; battery charger. Single-phase full-wave rectifier with center-tapped transformer. Single-phase full-wave bridge rectifier. Low- pass filters. Single-phase full-wave bridge rectifier with RLE load. Three- phase full-wave bridge rectifier. Switching DC/DC converters: Buck; Boost; Buck-Boost; H-bridge; PWM modulation. DC/AC converters (inverters):
single-phase half-bridge inverter; single-phase full-bridge inverter; three- phase full-bridge inverter. Full-bridge inverter modulation: single-pulse PWM, multiple-pulse PWM, sinusoidal PWM; space vector modulation.
Bibliography
E.Bassi, A.Bossi “Macchine e Azionamenti Elettrici” UTET, Milano ISBN: 88-7933-184-1
W. Bolton, "Mechatronics - electronic control systems in mechanical and electrical engineering", 4th ed., Pearson Educational, ISBN 978-0-13- 240763-2.
M. Rashid, "Power electronics", 3rd ed., Prentice-Hall, ISBN 0-13-122815- 3.
Teaching methods
FOR BOTH MODULES
Classroom lectures and exercises solved by the instructor and by students. Some lectures use slides available to students for downloading.
Assessment methods and criteria
FOR BOTH MODULES
Oral exam. There is a single exam for the two modules making up the integrated course. Students will have to demonstrate knowledge of the components and circuits treated in the lectures, and understanding of their behavior and operation. It is considered important that students be able to solve simple quantitative exercises by hand calculation.
Other information
FOR BOTH MODULES
Slides and other supporting material available on lea.unipr.it
