An approach based on Takagi-Sugeno Fuzzy Inference System applied to the operation planning of hydrothermal systems

摘要

The operation planning in hydrothermal systems with great hydraulic participation, as it is the case of Brazilian system, seeks to determine an operation policy to specify how hydroelectric plants should be operated, in order to use the hydroelectric resources economically and reliably. This paper presents an application of Takagi-Sugeno Fuzzy Inference Systems to obtain an operation policy (PBFIS — Policy Based on Fuzzy Inference Systems) that follows the principles of the optimized operation of reservoirs for electric power generation. PBFIS is obtained through the application of an optimization algorithm for the operation of hydroelectric plants. From this optimization the relationships between the stored energy of the system and the volume of the reservoir of each plant are extracted. These relationships are represented in the consequent parameters of the fuzzy linguistic rules. Thus, PBFIS is used to estimate the operative volume of each hydroelectric plant, based on the value of the energy stored in the system. In order to verify the effectiveness of PBFIS, a computer simulation model of the operation of hydroelectric plants was used so as to compare it with the operation policy in parallel; with the operation policy based on functional approximations; and also with the result obtained through the application of the optimization of individualized plants' operation. With the proposed methodology, we try to demonstrate the viability of PBFIS' obtainment and application, and with the obtained results, we intend to illustrate the effectiveness and the gains which came from it.