The Study On The Advanced Static Var Generator With One-cycle Control

On the basis of the research project of my tutor and the analysis of existing principles of advanced static var generator, this dissertation,for the first time, proposes an ASVG with a nonlinear control method - one-cycle control, after the study of ASVG's main circuit,present detection system and control methods. The ASVG has highly theoretical and practical values. The main contents in this dissertation are as follows:According to the theory of asymmetry operation, this dissertation has a research on the principle of ASVG's main circuit, eliminating the fundamental negative, zero sequence and harmonic current so as to realize operation in stabilization.After the summarization of present literatures, analyses and comparisons are made on the ASVG's main circuit, present detection system and control methods. This dissertation present the principles, characteristics and deficiencies of every scheme.The principle of one-cycle control is introduced in detail, its characteristics is analyzed. The method to combine it with ASVG is discussed. On the basis of the mathematic model of ASVG with one-cycle control, the reason that arouse the voltage fluctuation on dc side and imbalance of capacitances' voltage is found out. A simple and efficacious method is proposed according to one-cycle control.In the end, simulations are carried out by the mathematic model of ASVG with one-cycle control. The simulating results indicate the ASVG put forward in the dissertation can not only fulfill the multifunction such as compensating harmonics,reactive power,balancing the loads and so on, but also suppresses the voltage fluctuation on dc side and balance of capacitances' voltage.