New Digital Nonlinear-Carrier Power Factor Correction and Mixed-Signal Maximum Power Point Tracking Controllers for Renewable Power System Applications

Abstract

A new power factor correction (PFC) application and implementation for a small wind power system and a mixed-signal maximum power point tracking (MPPT) integrated circuit (IC) controller for a micro photovoltaic (PV) power system are proposed in this dissertation An algorithm for implementing the nonlinear-carrier (NLC) control method for a single-phase PFC rectifier without an input voltage sensing circuit an error amplifier in the current shaping loop or other external control components Unity power factor and low harmonic distortion are achieved by adopting NLC control with a variable slope ramp This ramp is created through a slope comparison without any dividers The proposed method not only achieves a high power factor but also efficiently simplifies the complexity of IC realization A single-phase boost rectifier and a small wind power system are implemented to verify the performance of the proposed PFC control The test platforms are 400 W single-phase boost rectifier and 1100 W small wind power system respectively A mixed-signal MPPT IC controller implemented with a mixed-signal multiplier is applied for a PV power system The mixed-signal MPPT IC controller which can be easily implemented on a low-cost single-chip IC is based on the perturbation and observation method The mixed-signal multiplier combines features of analog control with digital control Compared with digital MPPT controllers up to 10-bit high resolution analog to digital converters are significantly reduced to simplify the hardware complexity of the IC realization Compared with analog MPPT controllers which have a narrow linearity range of low supply voltage the proposed controller has high linearity range of low supply voltage and precise calculations for MPPT to extend the input voltage control range of the PV power system The measurement results include single chip test and a 200 W PV power system

Date of Award	2016 Feb 18
Original language	English
Supervisor	Hong-Tzer Yang (Supervisor)