Khai D. T. Ngo

Generalization of resonant switches and quasi-resonant DC-DC converters

The concept of resonant switch topology is defined and is used to develop a procedure to classify known quasi-resonant converters or to synthesize new ones. Two new resonant switch topologies and the corresponding classes of converters are identified by the synthesis procedure. The steady-state performance of one converter is analyzed and verified.

Low Frequency Characterization of PWM Converters

Low frequency components of states or outputs in pulse-width modulation (PWM) dc and ac converters can be characterized by differential equations called describing state-space equations. These equations are derived by inspection of converter topology and use of switching functions and duty ratios. Their steady-state and small-signal dynamic solutions show how energy-storage elements in a converter/load system shape the frequency response of conversion functions established by the switches.

Analysis of a series resonant converter pulse width-modulated or current-controlled for low switching loss

Pulsewidth modulation (PWM) and current-controlled switching are applied to a full-bridge series resonant converter to regulate the output from no load to full load with low switching loss and with a narrow range of frequency variation. Drive strategies, control law, component stress, and other steady-state functions are analyzed for both switching modes.

Analysis of a series resonant converter pulsewidth-modulated or current-controlled for low switching loss

Pulsewidth modulation (PWM) and current-controlled switching are applied to a full-bridge series resonant converter to regulate the output from no load to full load with low switching loss and with a narrow range of frequency variation. Drive strategies, control law, component stress, and other steady-state functions are analyzed for both switching modes.

Low-frequency characterization of PWM converters

Low-frequency components of states or outputs in PWM dc and ac converters can be characterized by differential equations called describing equations. These equations are derived by inspection of converter topology and use of switching functions and duty ratios. Their steady-state and small-signal dynamic solution shows how energy-storage elements in a converter/load system shape the frequency response of conversion functions established by the switches.