Power Electronics for the 22nd Century

The System Technology (popularly known as converter topologies, magnetics and control) has changed very little in last 50 years and is, in fact, the key reason why the Power Electronics as a whole has progressed much less... [ view full abstract ]

The System Technology (popularly known as converter topologies, magnetics and control) has changed very little in last 50 years and is, in fact, the key reason why the Power Electronics as a whole has progressed much less despite the tremendous advances made in development of the new switching devices (MOSFET and IGBTs before and GaN and SiC MOSFETs now) with ever increasing switching devices power and speed.
The conventional converter topologies are analyzed and the sources of their deficiencies are established. This, in turns, leads to the new switching methods and the corresponding novel switching converter topologies which are overcoming all these deficiencies. However, no incremental change will do, but a fresh new look is needed offered by this tutorial on Power Electronics: A New Beginning!

Part 1: Topologies, Magnetics and Control (review)
The Part 1 is an executive summary of the material Dr. Ćuk has taught as a two- quarter Power Electronics course at California Institute of Technology (Caltech), Pasadena for over 25 years. It was also taken by over 5,000 Power Electronics Specialists who attended his public and in-house courses world-wide. The detailed synopsis of that course is described in the enclosed 3 page brochure. Part 2 expands on that knowledge to introduce new switching methods and novel converter topologies.

Have you ever asked yourself what switching converter topologies and switching methods have been used 50 years ago? One should not be surprised to find that the same conventional converter topologies, such as: buck, forward, flyback and bridge-type converters, and the PWM square-wave switching method are still exclusively used today! Their resonant variations, such as LLC converter and resonant flyback converter have not lived up to the hype! Tutorial explains why?

Magnetics Fundamentals and Magnetic BH loop Demonstrations

The tutorial uses the video demonstration of the BH loop properties of ferrite magnetics materials and demonstrate their saturation and the core loss properties. The videos were generated on a custom designed BH loop tester with 1MHz bandwidth (see enclosed brochure).

Part 2: New Switching Methods and Novel Converter Topologies
Closer look at the conventional converter topologies uncovers that they share the following bad traits:
1. Excessive (3 to 4 times) device voltage and current over DC output voltage! 2. Output diode rectifier switching (turn-on and turn-off) at full DC current!
3. Excessive voltage and current stresses of the input active switches!
4. Hard switching and switching losses of the primary side active devices!
5. Transformer flux excursions are up to ten times higher than optimally possible! 6. Transformer leakage inductance is the major source of losses and noise!
7. Transformer of flyback and LLC converters both store energy!
The root-cause of all these bad traits is discovered and the solutions which eliminate all of them simultaneously is provided by the new switching methods and corresponding novel converter topologies:
a) Hybrid switching
b) Storageless switching method
c) New converter topologies for DC-DC, AC-DC and DC-AC conversion
A number of new topologies are demonstrated such as:
1. First True Bridgeless PFC converter with isolation in a single stage.
2. Isolated Storageless Converter with output voltage regulation over wide range. 3. Voltage regulator modules (VRM) with fast transient and ultra-high efficiency which eliminate the need for present multistage synchronous buck solutions.
Live Design Demonstrations via Simulation
The performance of several new converters are illustrated throughout tutorial by live demonstration of salient waveforms generated on site via a state-of-the-art simulation program PLECS from PLEXIM (www.plexim.com).
Optimal Design of Magnetics Components

PWM inductors store DC energy and become quickly useless with increased current and power leaving only one option: unchecked increase of switching frequency to MHz levels and higher. The tutorial uncovers how the novel converter topologies result in tenfold reduction of magnetics size (both inductors and transformers!) while switching at moderate 100 kHz switching frequencies .