Otimização da conexão de geração eólica em sistemas de potência considerando a técnica de Transmission Switching

Abstract

The continuous growth of investment in wind energy in recent years has made Brazil stand out in the world ranking that measures the installed capacity of this type of generation. Recent studies are focusing on Offshore Wind Farms (OWFs). Considering the installation of new OWFs in locations pre-defined by wind studies, determining the best connection points for OWF to the onshore system grid requires a comprehensive analysis that takes into account technical, economic and environmental restrictions. In this work, three methodologies are proposed whose objective is to maximize the use of firm wind energy by determining the ideal connection point for wind farms (WFs), offshore or not, in an Electrical Power System (EPS), taking into account the electrical losses of the existing transmission system, as well as the limits of transmission lines and multiple load scenarios. The first methodology is based on the Optimal Transmission Switching (OTS) technique and aims to optimally connect an OWF to an onshore system, a topic that has not been explored much in the literature. This methodology considers a list of candidate transmission lines for connecting the wind generation. The N-1 security criterion is also accounted for. The second methodology considers a new formulation of the Power Transfer Distribution Factors (PTDF). Usually, PTDFs are calculated based on the fact that the system’s reference bus will absorb any power imbalance. However, one of the contributions of this work is the proposal of a new PTDF formulation to carry out a more realistic analysis of a system’s operation, developed based on the Linear Power Flow (LPF) methodology and the conventional generators’ participation factors. Different WFs can be connected to the system simultaneously. The results are compared to those obtained by the original PTDF formulation to determine the benefits of the new approach. The third methodology is a combination of the other two to take advantage of both. An OWF is connected via a single connection from a group of candidate lines. Analyses are carried out considering the daily variations in demand through load levels and the N-1 security criterion. The proposed methodologies were implemented using Python 3 and were evaluated considering the 6-Bus, 11-Bus, IEEE Reliability Test and IEEE 118-Bus systems. The results presented validate and demonstrate the effectiveness of the proposed techniques.