Magnetics for Power Electronic Converters

Go to Course: https://www.coursera.org/learn/magnetics-for-power-electronic-converters-v2

Introduction

# Course Review: Magnetics for Power Electronic Converters on Coursera In the constantly evolving field of electrical engineering, specifically in power electronics, professionals often face the complex task of not only designing converters but also the magnetic components that accompany them. For those looking to deepen their understanding and expertise in this vital area, the "Magnetics for Power Electronic Converters" course offered on Coursera presents a comprehensive and rigorous pathway to mastering the analysis and design of magnetic components. ## Course Overview This course delves into the foundational principles and advanced design techniques necessary for creating inductors and transformers used in power electronic converters. Presented as ECEA 5703, it is recognized for academic credit towards the Master of Science in Electrical Engineering degree at CU Boulder, making it an attractive option for both students and professionals seeking formal recognition for their learning. The course begins with an introduction to the physical principles that govern the operation of magnetic components, which are critical in the development of efficient power electronic converters. By covering essential concepts such as inductance, core material saturation, air gaps, energy storage in inductors, and reluctance, learners will build a solid base from which to explore more advanced topics. ## Syllabus Breakdown 1. **Basic Magnetics** - The course kicks off with a review of magnetics theory, which is crucial for understanding switching converters. You will learn about magnetic circuits, inductor modeling, and transformer modeling, providing the mental frameworks necessary to examine the operation and losses associated with magnetic devices in converters. 2. **AC Copper Losses** - This segment addresses critical loss mechanisms, including eddy currents in winding conductors that can spiral copper losses well beyond what is expected from DC resistance alone. Students will explore the skin effect and proximity effect, particularly important in high-frequency converters. Practical computation methods for these losses are introduced, which proves invaluable for real-world applications. 3. **Inductor Design** - Participants will engage in the practical side of circuit design by learning to construct inductors tailored for switching converters. The Geometric Constant (Kg) method becomes a key focus here, as students are guided on how to design magnetic elements like filter inductors while considering specifications for maximum flux density and copper loss to achieve optimal performance. 4. **Transformer Design** - This module tackles the design of transformers and AC inductors within the broader context of switching converters. Acknowledging the balance between core and copper losses is essential, and students will work through design problems that emphasize minimizing total loss, including practical examples involving isolated Cuk converters and full bridge converters. ## Course Pros and Cons ### Pros - **Comprehensive Content:** The course covers both theoretical underpinnings and practical design methodologies, making it suitable for a range of engineering professionals. - **Flexibility:** As a self-paced online course, it allows learners to fit their studies around personal and professional commitments. - **Academic Credit:** The opportunity to earn academic credit and valuable credentials adds significant value, making it ideal for those pursuing a Master’s degree in Electrical Engineering. - **Industry-Relevance:** The focus on real-world applications and losses found in high-frequency converters aligns well with the current trends in power electronics. ### Cons - **Complex Subject Matter:** The technical depth may be challenging for individuals without a strong background in electrical engineering or related fields. - **Self-Directed Learning:** As with any online course, the success of the student greatly depends on their motivation and self-discipline to engage with the material. ## Recommendation For electrical engineers, particularly those involved in power electronics, the "Magnetics for Power Electronic Converters" course on Coursera is a highly recommended resource. It equips engineers with the necessary tools to effectively model and design magnetic components, thereby enhancing their overall skill set and professional value. Whether you are seeking formal academic credit or aiming to expand your knowledge in practical applications, this course offers a robust learning experience that can significantly impact your career. In conclusion, if you are looking to deepen your expertise and make informed contributions to the field of power electronics, enrolling in this course will be a decisive step in the right direction. The blend of theory, practical design challenges, and academic recognition makes it a standout opportunity for anyone passionate about the integration of magnetics in electrical engineering.

Syllabus

Basic Magnetics

Magnetics are an integral part of every switching converter. Often, the design of the magnetic devices cannot be isolated from the converter design. The power electronics engineer must not only model and design the converter, but must model and design the magnetics as well. Modeling and design of magnetics for switching converters is the topic of this course. In this module, basic magnetics theory is reviewed, including magnetic circuits, inductor modeling, and transformer modeling. This provides the technical tools needed in the remainder of the course to understand operation of magnetic devices, model their losses, and design magnetic devices for switching converters.

Eddy currents also cause power losses in winding conductors. This can lead to copper losses significantly in excess of the value predicted by the dc winding resistance. The specific conductor eddy current mechanisms are called the "skin effect" and the "proximity effect". These effects are most pronounced in high-current conductors of multilayer windings, particularly in high-frequency converters. This module explains these physical mechanisms and provides practical methods to compute these losses.

The goal of this chapter is to design inductors for switching converters. Specifically, magnetic elements such as filter inductors are designed using the Geometric Constant (Kg) method. The maximum flux density Bmax is specified in advance, and the element is designed to attain a given copper loss. Both single-winding inductors and multiple-winding elements such as coupled inductors and flyback transformers are considered.

In a substantial class of magnetic applications, the operating flux density is limited by core loss rather than saturation. For example, in a conventional high-frequency transformer, usually it is necessary to limit the core loss by operating at a reduced value of the peak ac flux density. Hence, design of core-loss-limited magnetic devices is characterized by finding the ac flux density that minimizes total core plus copper loss.This module considers the design of transformers and ac inductors for switching converters, including minimization of total loss. Design examples include the isolation transformers of a full bridge two-output converter and of an isolated Cuk converter.