published_or_final_version / abstract / toc / Statistics / Master / Master of Philosophy

published_or_final_version / abstract / toc / Statistics and Actuarial Science / Master / Master of Philosophy

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

published_or_final_version / abstract / toc / Statistics and Actuarial Science / Doctoral / Doctor of Philosophy

published_or_final_version / Statistics / Master / Master of Philosophy

published_or_final_version / Statistics and Actuarial Science / Master / Master of Philosophy

published_or_final_version / Statistics and Actuarial Science / Master / Master of Philosophy

The objective of this work is to design a damping controller for a thyristor controlled series capacitor (TCSC) to damp robustly inter-area oscillations in power systems with an immunity against sub-synchronous resonance (SSR) oscillations which may lead to torsional oscillations. The new control strategy has two main loops; an SSR mitigation loop and a bang-bang loop, the latter is designed with the aim of damping inter-area oscillations with a settling time 8-10 sec. The appropriate selection of the bang-bang series compensation component, ∆KC, is addressed by considering the Eigen analysis of the generators’ shafts and an impedance scan of the series compensated line for different compensation levels. The SSR mitigation loop is designed with the aim of providing a fine tune control signal to be added to the main value of the inserted series compensation (KC), to damp SSR oscillations and related torsional mode of oscillations. To address this issue, a new observer-based multiple model adaptive control algorithm is designed to control a multi-stage TCSC. The SSR modelling challenges associated with the load dynamics and with the insertion of the series compensation into the transmission system are overcome by a fine tuning control loop, which adjusts the resultant series compensation (KC). Considering the integration and coordination of oscillation damping and distance protection in the transmission system, a new adaptive technique must be designed to control the distance relay (DR) to prevent its mal operation (during the damping process). The new strategy is illustrated through an 11-bus 4-machine 2-area benchmark power system. The performance and advantages of the new algorithm are validated using time domain simulation via PSCAD software.

Αποδεικνύουμε την ύπαρξη καθολικών σειρών taylor στην περίπτωση συγκεκριμένου μη απλά συνεκτικού τόπου, καθώς και την ύπαρξη ενός πυκνού διανυσματικού υποχώρου. / We prove the existence of universal taylor series in the case of a specific non simply connected domain. We also prove the existence of a dense vector subspace.

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