The course includes a detailed study of the mechanisms of switching loss, hard switching, and soft switching. Both traditional resonant converters and up-to-date approaches to soft switching are included. Applications emphasized include dc-dc converters for computer power and portable applications, and dc-ac inverters for gas discharge lighting. Analysis approaches include steady-state analysis in the frequency domain (using sinusoidal approximation) and time domain (state plane analysis), and small-signal ac modeling using the averaged switch modeling and the phasor transform methods. Topics include optimization of system efficiency at both full- and light-load conditions for improved energy efficiency.
Introduction
- Resonant converter applications and approaches. Typical circuits. Course outline.
Sinusoidal analysis: steady state
- The classical series resonant, parallel resonant, LCC, and similar dc-dc and dc-ac converters
- The sinusoidal approximation for resonant converter analysis: how to gain insight into resonant converter operation
- Zero-voltage and zero-current switching
- Resonant converter design techniques based on frequency response
- Series resonant converter
- Parallel resonant converter
- LCC resonant converter
Sinusoidal analysis: small-signal ac behavior with frequency modulation
- Spectra and envelope response
- Phasor transform method
State-plane analysis of resonant and soft-switching converters
- Fundamentals of state-plane and averaged analysis of resonant circuits
- Analysis of ringing and switching loss in PWM converters
- Exact analysis of the series resonant converter
- CCM
- DCM
- Exact analysis of the parallel resonant converter
Resonant switch and related converters
- The ZCS and ZVS quasi-resonant converters
- State-plane analysis
- Characteristics
- Discussion
- Averaged modeling of converter dynamics
- Quasi-square-wave converters
- ZVS and ZCS topologies
- Waveforms and characteristics
- Zero-voltage transition converters
- Waveforms and characteristics
- Phase control
- Multiresonant switches
- Active clamp forward and flyback converters
Server systems, portable power, energy efficiency and green power issues (time permitting)
- Modeling efficiency vs. load, origins of loss
- Variable frequency approaches to improving light-load efficiency
- DCM, pulse-frequency modulation
- Burst mode
- Effects of parallel modules
- DC transformers
One midterm exam and one final exam. Ten to twelve one-week homework assignments.
DM 01/13/12