Controle de l'energie injectee dans un reseau electrique par un convertisseur triphase utilisant un regulateur base sur un modele interne sinusoidal.

摘要

This project deals with the control of three-phase PWM voltage source converters connected to the grid. The control structure is based on an inner loop and an outer loop. The inner loop controls the transfer of power between the dc link and the grid. The outer loop provides the reference current to the inner loop and is designed to maintain a constant dc link voltage.; With "field-oriented control" it is possible to deliver near-sinusoidal currents to the grid at unity power factor. Voltages and currents are transformed to the rotating d-q reference frame, where control becomes quite straightforward. Because the current space vector in the rotating d-q reference frame is fixed, the PI controllers operate on dc, rather than sinusoidal signals. In steady state, vectors of ac current appear as constants in the synchronous reference frame; therefore, static errors can be nullified by the use of conventional PI controllers.; The disadvantage of classical control structures is the difficulty in controlling variables with sinusoidal references because of the limited ability of PI controllers to accurately track time varying inputs.; This project describes a simpler, but otherwise equivalent control technique which solves this problem without the burden of transforming time-dependent three-phase quantities into the time-invariant d-q reference frame and vice versa. This new control structure is based on a complex controller (i.e. with real and imaginary parts), which achieves zero steady-state error by controlling the current space vector directly in the stationary d-q reference frame.; The mathematical equivalence with field-oriented control is fully demonstrated. It turns out that the gains of the new complex regulator are exactly identical to those of the conventional PI controller. Simulation results are also presented which clearly show the indistinguishability of the two control systems. Experimental results for both steady state and transient operating modes are also presented and show the efficiency and superiority of the proposed control technique.