Frequency stabilization in a parallel AC DC interconnected power systems using intelligent techniques

Abstract

Electric power systems consist of a number of control areas, which generate power to match the power demand. Control areas are usually interconnected to meet out the power demand. However poor balancing between generated power and demand will cause the more complexity and less reliability of interconnected power systems. Insufficient transmission capability of interconnection leads to bottle necks in the system and reduce the system stability. In an electric power generation, disturbance caused by load variation will result in deviation of system frequency from its nominal value and creates inadvertent power exchanges between control areas. To overcome such a situation, the modern interconnected power system network requires high performance Automatic Load Frequency Controller (ALFC) and its implementation for a wide range of frequency variation. In the proposed research work, a three area AC-DC interconnected reheat thermal power systems are considered for the system study. The performance of the controller for the proposed three area AC-DC interconnected power system has been studied by using conventional integral controller. Then there is an opportunity to utilize Supervisory Expert Fuzzy Controller (SEFC) that tunes or coordinates with the direct fuzzy logic controller. The lower level controller provides the solution to a particular situation and the upper level controller provides a mechanism to the main goal of the system. The responses to various load changes in the three area system are studied and the performance of the SEFC is compared with the integral controller and the fuzzy logic controller. The response of the SEFC showed that the better control performance in terms of settling time, stability and robustness. By implementing SEFC, the frequency stabilization of multi area interconnected power system can be enhanced further. newline