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Assessing the Performance of ROCOF Relay for Anti-Islanding Protection of Distributed Generation under Subcritical Region of Power Imbalance

Conference Paper


Abstract


  • In practice, the load-curve and distributed generation (DG) penetration level determines the power imbalance level that a network can experience if islanding occurs. Therefore, with the prior knowledge of load-curve and DG penetration level, the setpoint of rate-of-change-of-frequency (ROCOF) relays can be adjusted so as to make them suitable for a real network. This paper first investigates the subcritical power imbalance region of ROCOF relays through analytical formulation followed by extensive simulation study in order to establish the maximum boundary limit of ROCOF's nondetection zone (NDZ) under all possible deficit/excess of active and/or reactive power imbalance scenarios. Second, ROCOF's reliability (assessed by detection rate and false alarm rate) is expressed analytically and then, validated numerically by simulating a test network of Australia in MATLAB and OPAL-RT real-time digital simulation platform. Finally, ROCOF's performance is assessed through receiver operating characteristics curves and a detailed reliability study under variable setpoints and detection time of the relays; the assessment considers the number of islanding events associated with the time-wise percentage of power imbalance level computed from the net load demand and variable DG penetration in a real network. All these test results demonstrate a clear operational guideline for ROCOF relay.

Publication Date


  • 2019

Citation


  • Alam, M. R., Begum, M. T. A., & Muttaqi, K. M. (2019). Assessing the Performance of ROCOF Relay for Anti-Islanding Protection of Distributed Generation under Subcritical Region of Power Imbalance. In IEEE Transactions on Industry Applications Vol. 55 (pp. 5395-5405). doi:10.1109/TIA.2019.2927667

Scopus Eid


  • 2-s2.0-85071334212

Start Page


  • 5395

End Page


  • 5405

Volume


  • 55

Issue


  • 5

Abstract


  • In practice, the load-curve and distributed generation (DG) penetration level determines the power imbalance level that a network can experience if islanding occurs. Therefore, with the prior knowledge of load-curve and DG penetration level, the setpoint of rate-of-change-of-frequency (ROCOF) relays can be adjusted so as to make them suitable for a real network. This paper first investigates the subcritical power imbalance region of ROCOF relays through analytical formulation followed by extensive simulation study in order to establish the maximum boundary limit of ROCOF's nondetection zone (NDZ) under all possible deficit/excess of active and/or reactive power imbalance scenarios. Second, ROCOF's reliability (assessed by detection rate and false alarm rate) is expressed analytically and then, validated numerically by simulating a test network of Australia in MATLAB and OPAL-RT real-time digital simulation platform. Finally, ROCOF's performance is assessed through receiver operating characteristics curves and a detailed reliability study under variable setpoints and detection time of the relays; the assessment considers the number of islanding events associated with the time-wise percentage of power imbalance level computed from the net load demand and variable DG penetration in a real network. All these test results demonstrate a clear operational guideline for ROCOF relay.

Publication Date


  • 2019

Citation


  • Alam, M. R., Begum, M. T. A., & Muttaqi, K. M. (2019). Assessing the Performance of ROCOF Relay for Anti-Islanding Protection of Distributed Generation under Subcritical Region of Power Imbalance. In IEEE Transactions on Industry Applications Vol. 55 (pp. 5395-5405). doi:10.1109/TIA.2019.2927667

Scopus Eid


  • 2-s2.0-85071334212

Start Page


  • 5395

End Page


  • 5405

Volume


  • 55

Issue


  • 5