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 nonresonant approaches to zero-voltage 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 (Bode plot) and time domain (state plane analysis), and ac modeling using the averaged switch modeling and the phasor transform methods. Topics added to the course in 2006 are: small-signal modeling of resonant converter transfer functions, and optimization of system efficiency at both full- and light-load conditions.
Introduction
- Resonant inverter 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, and green power issues (time permitting)
- Modeling efficiency vs. load, origins of loss
- Variable frequency approaches to improving light-load efficiency
- DCM
- Burst mode
- Effects of parallel modules
- DC transformers
One midterm exam and one final exam. Ten to twelve one-week homework assignments.
MS 01/10/08