Title :
A Robust Fault Detection and Isolation Method in Load Frequency Control Loops
Author :
Caliskan, Fikret ; Genc, Istemihan
Author_Institution :
Dept. of Control Eng., Istanbul Tech. Univ., Istanbul
Abstract :
In this paper, a robust sensor and actuator fault detection and isolation (FDI) method based on unknown input observers (UIO) is adopted and applied to the load frequency control loops of interconnected power systems. Changes in load demand are regarded as the unknown disturbances in the system and the designed UIOs and thus the proposed method are robust to these disturbances. Using selected different sets of measured variables in the UIO design, simulations are performed for the dynamical model of a power control system composed of two areas. As we distinguish the cases for successful and unsuccessful sensor and controller FDI, it is shown that the proposed scheme is able to detect and isolate sensor and controller faults for proper selections of measured variables. By using residuals generated by the UIOs, the designed ldquofault detection and isolation logicrdquo system shows the operator which sensor or controller is faulty. Hence the faulty sensor or controller can be replaced by a healthy one for a more reliable operation.
Keywords :
electric actuators; electric sensing devices; fault diagnosis; frequency control; power system control; power system faults; power system interconnection; actuator; faulty sensor; interconnected power system; isolation method; load frequency control loop; power control system dynamical model; robust fault detection; unknown input observer; Actuators; Electrical fault detection; Fault detection; Frequency control; Power system faults; Power system interconnection; Power system modeling; Power system simulation; Robust control; Sensor systems; Fault diagnosis; load frequency control; power system operation;
Journal_Title :
Power Systems, IEEE Transactions on
DOI :
10.1109/TPWRS.2008.2004831