Phase Domain Synchronous Machine Model Research Articles

A New Internal Fault Detection and Classification Technique for Synchronous Generator

A new internal fault detection and classification technique for the synchronous generators is presented. First, the presence of an abnormal/fault condition is detected based on the negative sequence component (NSC) of neutral end current. Thereafter, the internal fault and abnormal/external-fault conditions are discriminated by utilizing the instantaneous phase angle between the NSCs of the terminal voltage and current. Subsequently, the internal fault is classified based on phase angle between NSCs of terminal voltage and neutral end current along with the zero sequence component of the neutral end current. Efficacy of the proposed scheme has been verified on a phase domain synchronous machine model developed on the real time digital simulator (RTDS). The results derived from various fault datasets show that the proposed technique is able to effectively distinguish between internal and external faults including special cases, such as current transformer saturation, overloading, and unbalance condition. Further, it provides added capability of detecting and identifying inter-turn faults irrespective of the winding configuration of the generator. Comparative assessment of the proposed scheme in terms of detection time and incorporation of different types of faults with the existing techniques proves its superiority.

High-sensitivity stator fault protection for synchronous generators: A time-domain approach based on mathematical morphology

This work presents an analytical methodology for synchronous generators stator faults protection. The proposed method is built on a differential protection relay strategy. A morphological filter is applied on the differential current providing real-time signal characterization. Unlike the traditional percentage differential relay, the proposed analytical methodology is able to detect all types of stator faults, including those close to the neutral end, which generates small differential currents due to the high impedance grounding of generator. Validation is done with OPAL-RT using a phase-domain synchronous machine model, which represents realistic operating conditions. The results of test cases highlights the method's dependability and security. Easy to implement models without hard-to-design parameters indicates the method’s potential for real-life applications.

Enhanced phase-domain synchronous machine model including saturation

PurposeThe phase-domain synchronous machine model has advantages compared to the d/q model, as no transformation of currents is necessary at each time step in a network analysis. The purpose of this paper is to enhance the phase-domain model to calculate the current distribution of the damper bars, including the saturation.Design/methodology/approachThe new enhanced phase-domain model of the synchronous machine has been modelled using Matlab-Simulink. The parameters of the model have been calculated by using FEA software.FindingsIt is shown that the simulation results of the new model show very good accordance to the reference model during a three-phase short circuit.Originality/valueThe enhanced model includes the calculation of the currents in the damper bar and is able to include the harmonics of the inductances.

相座標同期機モデルによる電力系統過渡解析の数値安定性の向上

相座標同期機モデルによる電力系統過渡解析の数値安定性の向上