Performance Evaluation of Optical Fiber Current Transformer based Over-current Protection

Optical Fiber Current transformers (OFCTs) are achieving increased acceptance and use in high voltage system due to their superior performance characteristics. It brings new feature to modern power system protection such as high accuracy, low weight, easy installation, and no-saturation. In this paper, a new OFCT is designed and implemented a long with a digital numeric system to protect electrical-feeder from over-current due to faults. Both the optical sensing head and electronic processing block are illustrated. A detailed experimental study to confirm the performances of the device is also reported. According to the measured values of ac rms current up to 2 kA, a calibration procedure was performed. The operational characteristics of the OFCT are investigated and three different scenarios based on Prototype were carried-out to evaluate the operation of the over-current protection using OFCT. The experiential results clearly illustrate the OFCT is capable to eliminate the distortion of the electrical signals caused by conventional (CT) and hence, greatly improving the reliability of the numerical protection system.