Decoupled Double Synchronous Reference Frame PLL for Power Converters Control推荐.pdf

584 IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 22, NO. 2, MARCH 2007 Decoupled Double Synchronous Reference Frame PLL for Power Converters Control Pedro Rodríguez, Member, IEEE, Josep Pou, Member, IEEE, Joan Bergas, Member, IEEE, J. Ignacio Candela, Member, IEEE, Rolando P. Burgos, Member, IEEE, and Dushan Boroyevich, Fellow, IEEE Abstract— This paper deals with a crucial aspect in the con- frames [3]–[5]. Regardless of the technique used in the system trol of grid-connected power converters, i.e., the detection of detection, the amplitude and the phase of the positive-sequence the fundamental-frequency positive-sequence component of the component must be fast and accurately obtained, even if the utility voltage under unbalanced and distorted conditions. Specif- ically, it proposes a positive-sequence detector based on a new utility voltage is distorted and unbalanced. decoupled double synchronous reference frame phase-locked loop There are two main approaches to detect the positive sequence (DDSRF–PLL), which completely eliminates the detection errors component of the utility voltage. The first one assumes that the of conventional synchronous reference frame PLL’s (SRF–PLL). frequency of the utility is a constant and well-known magnitude, This is achieved by transforming both positive- and negative-se- and is usually based on 1) instantaneous symmetrical compo- quence components of the utility voltage into the double SRF, from which a decoupling network is developed in order to cleanly nents (ISC) [6], 2) on space vector filters (SVF) [7], or on 3) the extract and separate the positive- and negative-sequence com-