Controle por modos deslizantes aplicado a um DSTATCOM utilizado em sistemas com gerador de indução autoexcitado para compensação de harmônicos e desbalanceamento

Abstract

This dissertation aims to present the design of a distribution synchronous static compensator (DSTATCOM) control system applied to the voltage regulation and harmonic and unbalanced load currents compensation in self excited induction generator (SEIG) based systems. For this, it is considered an isolated three-phase three-wire generic system, with a constant speed primary machine. The process of mathematical modeling of the system and of the design of the necessary voltage and current controllers are demonstrated. The system consists of closed-loop controllers, with external loops for regulating the voltages in the AC and DC buses, and internal loops for the DSTATCOM current control. For the external loops, classical PI controllers are used. Specifically in relation to the current loop, it is proposed a sliding mode controller. The use of this technique is justified by characteristics such as fast dynamic response, robustness and rejection of disturbances, wich are desirable to carry out the proposed compensation in the system. The resulting designed controller presents a rapid transient response with low coupling influence, and is not sensitive to frequency variantions of the isolated system, presenting itself as an alternative to current controllers proposed by the literature for this specific application, such as hysteresis or proportional resonant. Simulation and experimental results are shown for the connection of non-linear, unbalanced loads, and a combination of both. The results demonstrate the feasibility of the proposed control system to the DSTATCOM, being possible to regulate the voltage and effectively reduce the harmonic and unblance content of the SEIG current and voltages to the values recommended by the IEEE 519-2014 and IEEE 1159-2009 standards.