Study Of A Series Hybrid Active Power Filter Basing On DSP Control

The Active Power Filter (APF) is one of the most important means to eliminate harmonics, especially the Series Hybrid Active Power Filter (SHAPF) has great superiority in compensating harmonic distortion and improving power quality. In this thesis an improved SHAPF is studied basing on theoretic analysis, simulation, and experiments.In chapter one several basic types of APFs, from which all other APFs are deduced, and two harmonic current detection methods are discussed.In chapter two, the traditional SHAPF and an improved SHAPF aiming at enhancing the compensation characteristics and reducing the APF power rating, are investigated and compared in terms of their structures, principles, and compensation characteristics.In chapter three, the impact of the Passive Power Filter (PPF) characteristics on the performance of the SHAPF is analyzed. The requirements of the system to the main electrical parameters of the PPF, such as the inherent resonant frequency, quality factor, power rating, and the voltage stress etc., are discussed. And in terms of the minimal power rating requirement to the active power filter in the system the PPF is properly designed.In chapter four, the design principle of the controller, detection circuit, and the protect circuit based on DSP is presented. Two main factors, which give influence on the performance of the harmonics extraction, the steady-state precision and the dynamic performance of the low pass filter and the realtime character and the veracity of both the across zero synchronization signal and the period sampling driving signal are analyzed in detail.In chapter five the main parameters of the experimental prototype, the experimental results are presented and discussed.The conclusions and future works are given in chapter six.