A combined dq-MIMO and sequence-SISO impedance-based stability assessment scheme for IBR interfaced system

A combined dq-MIMO and sequence-SISO impedance-based stability assessment scheme for IBR interfaced system

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The electromagnetic transient (EMT)-type impedance scanning methods conducted in positive sequence domain and dq-frame (p-scan and dq-scan, respectively) have been widely used for identifying inverter-based resource (IBR) instabilities.They obtain the sequence domain single-input single-output (sequence-SISO) and dq-frame multi-input multi-output (dq-MIMO) impedance models of an IBR, respectively.The dq-MIMO impedance-based stability assessment (IBSA) is more accurate compared to the sequence-SISO IBSA as it considers the mirror frequency effect (MFE).However, unlike the sequence-SISO, the dq-MIMO IBSA cannot differentiate the resonance frequency from its mirror frequency, because the dynamics in dq-frame incorporate both the read more positive and negative sequence impedances of IBR.This paper proposes a new IBSA scheme to eliminate swisse high strength magnesium powder berry this shortcoming.

First, a dq-MIMO IBSA is carried out to obtain the accurate dq-frame resonance frequency and stability margin.Then a sequence-SISO IBSA is conducted to determine the phase domain resonance frequency.The sequence-SISO impedance models are transformed from the dq-MIMO model.The proposed scheme has lower computational costs than the existing dq-MIMO IBSA methods.The effectiveness of the proposed scheme is validated on a test system incorporating full-size converter-based wind park (FSC-based WP).

This paper also demonstrates the possibility of weak grid instability occurrence in supersynchronous frequency range.