The Optimization Of Control Techniques In Series Hybrid Active Power Filter

The state-of-the-art of active power filters (APFs) is described first. In order to improve the harmonic suppression performance of APFs, a novel topology of Series Hybrid Active Power Filters where a series LC resonance circuit is added, is analyzed in this thesis.Both veracity and real-time requirements to the harmonic detection circuit are important factors which influence the performance of APFs. An exponential average low pass filter with a cascade form to effectively solve the conflict between the veracity of harmonic detection and real-time requirements is proposed in this thesis. The finite word length of DSP design and realization of a high performance DSP based digital low pass filter are presented in detail.When using grid harmonic current detection control strategy, a conflict between the filter performance and the system stability occurs. This thesis presents a novel control strategy through a proportional plus derivative controller to solve this problem.Keeping the DC-link voltage of the series active power filter as a constant is required to obtain high filter performance. A small-signal model of the DC-link voltage and the controller design are presented in this thesis too.The simulation and experimental results validate these proposed methods.