Design and Simulation Study of an Adaptive Combo PFC/PWM Controller

• Main Authors: Wei-Chi Su, 蘇韋吉
• Other Authors: Ying-Yu Tzou
• Format: Others
• Language: en_US
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/38963836614350196747

碩士 === 國立交通大學 === 電機與控制工程系所 === 95 === A two-stage PFC AC/DC converter includes the pre-stage which is a boost AC/DC converter and the post-stage which is a buck DC/DC converter. Its primary application is used in the power supplies of PCs and servers which need high quality power and fast dynamic response. For two-stage PFC AC/DC converter, this thesis proposes a IC structure of combo PFC/PWM controller which is realized by analog circuits and has the ability of current adaptive control. It can be used in the pre-stage used a single phase bridgeless boost converter and the post-stage used an isolated half-bridge DC/DC converter. The proposed structure of combo PFC/PWM controller includes the design and analysis of a PFC controller which uses a one-cycle controller for PWM control to decouple the line voltage variation in regulation of a proportional line current. The OCC scheme can realize a direct voltage-second control of the boost inductance to achieve linear control of the inductance current control with input voltage decoupling and can be implemented by simple analog circuit compared with the conventional multiplier based approach. However, the implementation of the rest integrator with minimum offset current and sensing voltage noises requires a careful design in practical applications. In the adaptive PWM controller design, the design of a DC/DC converter with on-chip passive adaptive controller with the sensed average inductor current is presented. The sensed switched current and a voltage-controlled floating resistor can be used for the adaptive control of a DC/DC converter. The nonlinear carrier control can adjust carrier according to input voltage to reduce the input disturbance. Simulation results show the proposed adaptive control scheme can achieve a fast dynamic power on transient response as well as a robust voltage regulation against large loading current variation.