A novel configuration of all-optical differential protection scheme

  • Muhammad Nasir

Student thesis: Doctoral Thesis


Advantages of the optical current sensing techniques have stimulated the development of the optical differential protection schemes for busbar protection. However, these optical differential schemes adopt mixed optical-numerical processes that use a platform based on modern numerical/microprocessor protection schemes. Therefore, opportunities to improve these mixed optical-numerical protection schemes still exist. This thesis proposes a novel configuration to perform an optical differential protection scheme that is implemented using a designed arrangement of basic optical components. In this design, the inherent operational functionality of the current differential connection is realised in the optical domain with a designed configuration of optical components. Due to the purely optical nature of the scheme, the need for complex numerical processing, which consists of direct digitisation of the output from individual sensors followed by digital signal processing within the relay, is eliminated. Therefore, the designed scheme could minimize the differential protection complexity while retaining the quality of the differential scheme. Moreover, it has also the potential for a significant reduction in the protection operating time. To verify and validate the optical configuration, one model is proposed, but simulated with different components and validated by simulation and experiment. The simulation results show that, firstly, the proposed scheme is verified, and both of the model and configurations are correct. Secondly, the proposed optical system which uses the polarization-maintaining optical fibre as fibre links has successfully met the protection performance objectives with respect to sensitivity (dependability), security, and speed of operation. Furthermore, a prototype of the proposed scheme has been constructed, and the obtained empirical data further validated the outcome from the simulation models. The validation by the empirical data provided, first, the proposed arrangement of the optical components were correctly configured, and the models of the optical components were correctly represented. Second, the experimental data have been successfully predicted by the simulation models. Finally, the proposed scheme prototype achieved good discrimination necessary for protection purposes.
Date of Award20 Apr 2020
Original languageEnglish
Awarding Institution
  • University Of Strathclyde
SupervisorAdam Dysko (Supervisor) & Pawel Niewczas (Supervisor)

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