Trânsito energético optimizado e estabilidade de pequeno sinal na rede eléctrica nacional integrada através da implementação de FACTS

Abstract

Mozambique has an energy potential that will place it as a regional powerhouse in the sector. In the coming years, domestic demand for electricity is expected to grow exponentially. for electrical energy. It is in this vein that several plans have been established for the creation of new generation plants. However, it is necessary to reinforce the country's transmission network in order to to accompany this growth in demand for power. The main component in this process of restructuring the transmission grid is the interconnection of the Central-North grid to the Southern grid construction of new lines to increase transfer capacity and provide redundancy at the main delivery points of the redundancy to the main delivery points of the National Electricity Grid. However, the interconnection brings with it two problems, namely: it implies greater complexity in controlling the flow of power flow control in order to make the most of the energy transport infrastructures without compromising its technical limits of security and stability of the network; instability of small signal, as a consequence of the interconnection of different generation areas through "weak" lines. "weak" lines. It is in this context that the present work fits, proposing the integration of FACTS devices in the grid to overcome the challenges listed above. FACTS devices are a technology that has been extensively studied and has registered a growing application in the power transmission system, which is caused by the fact that they allow the increase of the transmission capacity of a transmission network and also the improvement of the stability of the system, with greater emphasis on voltage and angle stability at small signals. Therefore, firstly the description of the already integrated national electrical grid will be made. Afterwards it will be made the analysis of the maximum load limit (i.e., voltage stability) at the delivery points where load growth is forecasted using the optimised energy transit technique, and in parallel to this, the existence of critical modes of oscillation is assessed through modal analysis. From this analysis it was observed that: there are delivery points with low stability margin; of the 36 dominant oscillation modes of the system, four (4) are unstable and one is undamped. Finally, the selection and sizing of the FACTS to be implemented is done, where it was SVC/STATCOMs are very effective in increasing the transmission capacity, however, this same However, this same effectiveness tends to increase even more with the use of the control optimised energy transient control; there is an improvement in the network stability, thanks the insertion of an additional controller to the FACTS control system (secondary control). It has also been shown that FACTS systems are economically competitive with some new line construction projects.