Multilayer fuzzy controller for control of power networks

In this paper, a multilayer fuzzy logic controller (MLFC) is proposed for the stability enhancement of the electric power system making use of a dynamic braking strategy. The proposed controller has two layers. The first layer, termed the supervisory layer, specifies the region of operation of the subcontrollers (SCs) within the second layer, called the execution layer. The outputs of the SCs are then fuzzily combined to achieve the overall objective of the system. The MLFC was found to be very "robust"-insensitive to changes in the network configuration. The scheme was tested on a nine-bus system with three generators and three loads and also on the IEEE four-generator test system. A comparison with a two-level hierarchical controller was made to show the effectiveness of the proposed method. The simulation results obtained support the concept of the multilayer fuzzy-logic-based braking resistor control scheme and that it is also a valuable tool for short-term and long-term stability crisis management.