Analysis and design of high-order resonant converters and a unified approach to power factor correction

This thesis essentially consists of two parts. The first part (from Chapter 2 to Chapter 4) discusses the performance characteristics of the new third-order resonant dc-to-dc converters which is carried out through the state-plane diagram method. This method is also necessary in the analysis and design of the power factor correction circuits which are the content of the second part. Based on analyses of these converters, a linear system model for such converters operated in the continuous conduction mode is derived which is at once useful in both generating new resonant converter topologies and predicting their steady state performance characteristics. The second part (from Chapter 5 to Chapter 7) deals with the analysis and design of the power factor correction circuits in resonant converters. Based on the relationship among the average input power, output power, and the energy stored in the tank circuit of a resonant ac-to-dc converter, we present a unified classification of the power factor correction circuits. This classification divides the power factor correction circuits into two sets: The first set consists of those power factor correction circuits whose energy stored in the tank circuit is programmable through either a tank capacitor voltage or a tank inductor current programmed control scheme. Therefore, they possess the potential of having both a high power factor and a fast output regulation. The power factor correction circuits falling into the second set do not have the programmable tank energy. Therefore, high power factor are obtained at the cost of a sluggish output regulation. Based on the classification, three unified control techniques for power factor correction circuits utilizing the current driven resonant converter topologies are proposed, namely the input current programmed control, the tank capacitor voltage programmed control, and the tank inductor current programmed control.