Reference frames fit for controlling PWM rectifiers

Abstract

Abstract-Keep things simple when controlling bidirectional pulsewidth modulation rectifiers by considering the utility grid as a virtual electric machine. The advantage is that the air-gap flux of this big machine can be directly measured in a straightforward way. Therefore, as shown in this paper, principles of field orientation can be applied to control the power flow, yielding high-dynamic performance.

Synchronization methods applied on active power filters — A comparative study

“…3. Considering that the sum of the phase voltages is zero for three-wire systems, then: (9) where: (10) Moreover, the αβ transformation is used, that is, (11) where: (12) A normalized vector can be obtained dividing v αβ by its norm, that is: (13) where, the Euclidian norm of the vector is given by:…”

“…The filtered phase voltages vector (v BPF ) is transformed into filtered αβ voltages (v f αβ ), by using (11). A normalized synchronization vector v f αβn is obtained dividing v f αβ by its Euclidian norm (14), that is:…”

“…Many synchronization methods are presented in the literature, which can be classified in open-loop [7,[10][11][12] and closed-loop [8,9,13], being the choice for which of them to be used a SAF designer criterium. In this paper the synchronization methods were chosen based in the grid voltages measurements to generate the synchronism signals, moreover, in the different structural complexity and the possible rejection of harmonics and unbalances in the grid voltages.…”

Doubly-fed induction generator drive based WECS using fuzzy logic controller

“…By controlling the converters on both sides, the DFIG characteristics can be adjusted so as to achieve maximum effective power conversion or capturing capability for a wind turbine and to control its power generation with less fluctuation [17,18]. Many different d-q control algorithms have been proposed and used for controlling the DFIG machine by using the back-to-back converters for certain dynamic and Most algorithms are based on the active and reactive power control concept, a popular DFIG converter control mechanism used in modern wind turbines [19,20]. This control configuration is usually divided into RSC and GSC control systems.…”

Simple Control Schme of Three-Level PWM Converter Connecting Wind Turbine with Grid

“…This simple noise resistant solution is based on the assumption that the integration of the voltages leads to an imaginary Virtual Fluxes (VF) [11,13] …”