Using a Static and Dynamic Security Assessment Tool to Evaluate the Effects of Increasing Wind Power Penetration in Future Operating Conditions of the Brazilian Interconnected Power System

摘要

The way the Brazilian Interconnected Power System is operated has gradually changed during recent years. Due to environmental restrictions, to exploit the large hydropower potential located in Northern Brazil, run-of-river hydropower plants with low capacity factor have been built. Approximately 30 GW in river basins submitted to a highly variable rainfall pattern will be commissioned in the coming years. This rainfall pattern implies in well-defined dry and wet seasons. Fortunately, there is a seasonal complementarity between inflows in Northern rivers and the incidence of winds in Northeastern Brazil. The current wind power installed capacity of 6.56 GW is expected to grow up to 14.1 GW by 2017, according to the Ministry of Mines and Energy's Ten-Year Energy Expansion Plan 2023-PDE 2023. ONS, the Brazilian ISO, is in charge of performing operation planning studies in a three years horizon. These studies constitute the Expansion and Reinforcements Plan and may eventually point out the need for some kind of network reinforcement to ensure reliable operation from steady-state and dynamic points of view. These studies aim to identify potential problems due to situations not considered in long term planning, in charge of EPE, the Energy Research Office, such as multiple contingencies, and detect the need for additional reactive power support, as new facilities and transmission lines may be commissioned in a time frame different from the one originally planned. This paper proposes the use of a parallel static and dynamic security assessment tool under development by CEPEL, the Brazilian Electric Energy Research Center, as a way to speed up the investigation of new Brazilian Interconnected Power System's operating conditions that will happen in the near future due to increasing wind power penetration in Northeastern Brazil. The Expansion and Reinforcements Plan's scenarios for 2017 were considered as a start to analyze the multiple possible combinations between hydro and wind power dispatch. The main aim was to simulate an increase in the use of Northeastern wind power so that Southeastern reservoirs can recover from the severe dry season started in the end of 2013, caused by the El Nino climate phenomenon. Results are presented for two cases that reproduce severe load and generation scenarios for dry and wet seasons.