Course syllabus
Course-PM
ENM061 Power electronic converters lp2 HT19 (7.5 hp)
Course is offered by the department of Electrical Engineering
Contact details
Lectures: Mebtu Beza (mebtu.beza@chalmers.se), Tel: 031-772 1617, Room 3535
Tutorials: Zeyang Geng (zeyang.geng@chalmers.se), Tel: 031-772 1650, Room 3510
Pspice exercises: Georgios Mademlis (georgios.mademlis@chalmers.se), Tel: 031-772 1659, Room 3520
Anton Kersten (kersten@chalmers.se), Tel: 031-772 1638, Room 3539
Anant Narula (anant.narula@chalmers.se), Tel: 031-772 1655, Room 3535
Junfei Tang (junfei.tang@chalmers.se), Tel: 031-772 1663, Room 3544
Masoumeh Amirpour (sepideh.amirpour@chalmers.se), Tel: 031-772 1628, Room 3566
Zeyang Geng (zeyang.geng@chalmers.se), Tel: 031-772 1650, Room 3510
Practical labs: Anant Narula (anant.narula@chalmers.se), Tel: 031-772 1655, Room 3535
Masoumeh Amirpour (sepideh.amirpour@chalmers.se), Tel: 031-772 1628, Room 3566
Robert Karlsson (robert.karlsson@chalmers.se), Tel: 031-772 1646, Room 3564
Introduction
Power electronics deals with the conversion of electrical energy by applying solid state electronics. Power electronic converters can be applied in many different areas such as computers, electric vehicles and power systems. The course presents an introduction to the different circuits used to convert and control electrical energy. It also covers methods for designing converters which in combination with selection of suitable converter topologies, power semiconductors and passive components will give the students a basic knowledge of power electronic converters.
Course purpose
The main goal of the course is to make the students familiar with the operating principles of the most common power electronic converter topologies. Basic converter design, analysis of wave-shapes and efficiency calculations are among the items that the students will be able to perform after having participated in the course. The students will perform both simulations using Cadence PSpice as well as experimental work on real DC/DC-converters. The course also lays the foundation for the continuation course 'ENM070 - Power Electronic Devices and Applications'. The items treated in the course are also useful for engineering work in many different areas, e.g. design of power supplies, electric drive systems or power system applications.
Schedule
Course literature
Mohan, Undeland, Robbins, Power Electronics - Converters, Applications and Design, Wiley 2003, 3rd ed.
Extra handouts will be given out during the course.
Course content and organization
Lectures and tutorials:
- Review: electric and mathematic prerequisites, voltage and current relations for passive components, mean and RMS-value, Fourier analysis.
- Active and passive components: diodes, thyristors, MOSFETs, GTOs, IGBTs, inductors, transformers and capacitors.
- DC/DC converters without isolation: buck, boost, buck-boost and the H-bridge converter.
- DC/DC-converters with isolation: flyback, forward, half-bridge, push-pull and the full-bridge converter.
- DC/AC-generation: single-phase and three-phase AC-generation, square-wave and PWM-modulated inverters, multilevel inverters.
- Diode rectifiers: single- and three-phase diode rectifiers with continuous and discontinuous DC-side current.
- Thyristor converters: single- and three-phase thyristor rectifiers with varying DC-side load.
- Converter enhancements: dynamic modeling, controller design, and improved configurations
- Heat distribution and life-time: Loss calculations, thermal calculations, cooling requirements and component life-time.
Laboratory experiments (compulsory):
All home assignments must be prepared before each lab. The lab-PM can be downloaded from the course website at least one week in advance of each occasion.
- Buck converter
- Flyback converter
PSpice assignments (compulsory):
All home assignments must be prepared before each occasion. The simulation files can be downloaded from the course website one week in advance of each occasion.
- A basic power electronic circuit
- Buck and Boost converter
- Flyback converter
- Single-phase inverter
- Three-phase inverter
- Single- and three-phase diode rectifier
- Converter enhancements: Loss analysis and control
Before each PSpice occasion (12.30-13.15) there is an additional time slot for approval of previously completed PSpice tasks (E-Studio). Please use this to avoid crowding during the lab occasions.
The course consists of approximately:
- 18 lectures (2 x 45min)
- 13 tutorials (2 x 45min)
- 2 practical laborations (4h)
- 7 PSpice computer assignments (2h)
Changes made since the last occasion
- Limit the time spent on prerequisite knowledge topics in the beginning of the course.
- The experimental lab PM will be in the course homepage much earlier than a week before the lab starts.
- Efficient use of the consultation which will be decided in due time.
- Bonus point system will incorporate negative points to make students put an effort to sit for the exam.
Learning objectives and syllabus
Learning objectives:
- Determine Fourier components and total harmonic distortion (THD) for basic current and voltage wave-shapes.
- Recognize the operating principle of the most common active components (e.g. diode, thyristor, IGBT, and MOSFET) as well as the most common passive components (e.g. capacitors, transformers and inductors).
- Explain and exemplify how pulse width modulation (PWM) works. Describe the purpose as well as the means to control the desired quantity and recognize the need for a controller circuit within the power electronic converter.
- Analyze and perform analytical calculations of ideal DC/DC converters such as the buck, boost, buck-boost, flyback and the forward converter. The operating principle of each topology is differentiated and thoroughly evaluated in both continuous and discontinuous conduction mode by its current and voltage wave-shapes. In addition to this, other topologies (e.g. the push-pull, half-bridge and full-bridge converter) and circuit enhancements (e.g. converter interleaving) are exemplified.
- Describe the basic operating principle of both single-phase and three-phase DC/AC inverters. Different modulation strategies (e.g. PWM and square wave operation) are implemented and the resulting current and voltage waveforms are evaluated and compared.
- Explain the operation of multilevel converters (e.g. 3-level and 5-level NPC and MMC topologies) by current and voltage waveform analysis and apply the benefits and drawbacks to e.g. harmonics and losses.
- Perform calculations on single- and three-phase diode rectifiers operating with voltage-stiff and current-stiff DC-side. Apply the concept of line impedance within the converter circuit (current commutation) and evaluate the influence.
- Perform calculations on single- and three-phase thyristor rectifiers operating with a current stiff DC-side. Apply the concept of line impedance within the converter circuit (current commutation) and evaluate the influence. Analyze more advanced topologies (e.g. 12-pulse connection) of the thyristor rectifier and distinguish the benefits and drawbacks.
- Identify simple power electronic converter diagrams and schematics. Recognize the different parts in a physical circuit on which basic wave-shape and efficiency measurements is performed.
- Perform an average small-signal dynamic modeling of a step-down converter in order to demonstrate how a corresponding analog and digital controllers can be designed.
- Determine the losses in both passive and active components. The resulting temperature in the active component is evaluated and an appropriate heat-sink is chosen. Have a basic understanding of how the lifetime of a component can be determined.
- Implement and test the various power electronic converter circuits, containing discrete elements, using Spice-based computer softwares as well as perform practical labs to have a firsthand experience on how real DC/DC converters operate. The exercises will help to understand the operating principles of the various converter circuits, analyze waveforms, evaluate parameter variations and perform harmonic/Fourier analysis.
Link to the syllabus on Studieportalen.
Examination form
A written exam at the end of the course decides the final grade (U, 3, 4 or 5). The limits for the grades 3, 4 and 5 are 40%, 60% and 80% of the maximum point, respectively. Only a Chalmers-approved calculator and attached formula sheet are allowed on the exam. Registration (20 Aug – 19 Dec 2019) is compulsory to be allowed to sit for the exam.
Approved Laboratory (1.5 ECTS):
Both practical and PSpice exercises must be completed and approved to obtain a final grade (U or G).
Midterm Exam: Nov. 25/2019 at 8:00
An optional midterm exam gives bonus points (1, 2, 3) to be added to the final points of the written exam. The limit for these bonus points are 40%, 60% and 80% of the maximum point, respectively. A score of less than 20% gives -1 bonus point and a score between 20 – 39% gives 0 bonus points. The bonus points are valid for the standard exam and all re-exams one year from the date of the mid-term exam.
For detailed course content and schedule, see the attached course description in the files section.
Course summary:
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