Controlo automático da tensão da rede elétrica BT com um sistema de microgeração

Sergio Sampaio Pacheco

Key information

Authors:

Sergio Sampaio Pacheco (Sergio Sampaio Pacheco)

Supervisors:

Sónia Maria Nunes dos Santos Paulo Ferreira Pinto (Sónia Maria Nunes dos Santos Paulo Ferreira Pinto); Pedro Miguel Batista de Sousa Correia da Costa

Published in

01/29/2021

Abstract

This thesis has as main focus the study and development of a centralized solution to be able to control an overvoltage in a microgenerator connected to a low voltage network. Since 2014, through Decree-Law nº153 / 2014, in Portugal, domestic electric energy users can participate in the electric energy production market through micro-generation, namely with the Self-Consumption Production Units (UPAC) and with the Small Production Units (UPP). Although this decentralization of electricity production has several advantages, it also has disadvantages in terms of the quality of electricity (QEE). A significant disadvantage is the fact that with the connection of one or more micro-generators to a low voltage network, overvoltages may occur, that is, when the effective voltage value is higher than the maximum value of the voltage defined by standard NP EN 50160. In this sense, the intention is to carry out the voltage control at the terminals of a micro-generator, locally. For this purpose, a voltage controller was developed that acts to control possible overvoltage through the consumption of reactive power from the electrical network, and by reducing the active power injected into the grid. Besides, in the control process, it is privileged to maximize the active power produced by the micro-generator, to be injected into the network. To test the performance of the controller, a low voltage network was simulated using MATLAB®. In addition, a laboratory assembly was carried out, to scale, using a commercially available microgenerator, to obtain experimental validation of the proposed control method.