Abstract

The continual increasing performance of the desktop personal computer (PC) benefited from the advances in semiconductor technology presents increasing challenges for the power demands, such as higher power density, lower supply voltage with very tight tolerance, and higher supply current with very high slew rate (di/dt). The existing dc distributed power system (DC DPS) suffers from low efficiency and poor transient response. This thesis introduces a new power architecture--high frequency ac distributed power system (HFAC DPS). In this power architecture, the front-end inverter generates sinusoidal voltage and current distribution for the ac bus; and then on board AC voltage regulator module (AC VRM) converts the intermediate ac voltage to a specific low dc voltage to power the load. The objective of this thesis is to develop and implement HFAC DPS for the application of desktop computers. To achieve this objective, an asymmetrical pulse-width-modulated (APWM) resonant inverter and a PWM series resonant converter are proposed as the front-end inverter and AC VRM respectively. These two topologies both employ new control schemes to meet the future power requirements. Based on these two proposed topologies, HFAC DPS is implemented for a dual output application. In this thesis, at both system level and circuit level for each proposed topology, detailed steady-state and dynamic analyses are performed, performance characteristics are presented, and the design procedures are generated. Simulation and experimental results are obtained from the prototype circuits to demonstrate the proof-as-concept. The results obtained from this thesis present the following features of HFAC DPS: reduced power conversion stages, soft switching in each stage, high voltage and low current distribution, independent and tight voltage regulation at the point of load and excellent response against large transient signals in both dc input voltage and load current. All these features indicate that HFAC DPS has potentially better power delivery quality and easier thermal management than the existing DC DPS. Therefore, HFAC DPS can be considered as an alternative solution to powering the new generations of desktop personal computers.