This article presents a vector fitting (VF) algorithmbased robust circuit and controller parameters identification method for grid-connected voltage source converters (VSCs). The dq-domain impedance frequency responses (IFRs) of the VSCs are first measured using frequency scanning method, based...

...—Droop control is the most common approach for controlling microgrids (MGs) and interfacing distributed generators (DGs) due to its inherent power-sharing characteristics and low dependence on communication systems. However, the stability of MGs operated with this control paradigm is sensitive to...

Existing impedance-based stability criterion (IBSC) for electromagnetic stability assessment of multiple-grid-connected-inverter (GCI)-based power systems suffers from several limitations. First, global stability feature is hard to be obtained if Nyquist-criterion-based IBSC is used. Second, heavy...

This paper presents a modified dq impedance model of the three-phase voltage source grid-connected inverter (GCI)-grid system considering coupling effect between GCI part and grid part for small-signal stability analysis. Steady-state terminal voltage and current information of the GCI part which...

Complex space vector and complex transfer function theory is used to theoretically establish the dq impedance model of current-controlled grid-connected inverter (GCI) with considering phase-locked loop (PLL) dynamics, where contributions of current control loop and PLL on dq impedance...

Phase-locked loop (PLL) is commonly used to synchronize the phase angle of the injected current of voltage source grid-connected inverters (GCIs) with that of the voltage at point of common coupling. However, the quadrature-axis component of the dq impedance model of the GCIs presents negative...

This study presents a dq impedance-decoupled network modelling method of offshore wind power plant (OWPP) for stability analysis. DQ impedance frequency responses of grid-connected inverters (GCIs) and long transmission cables (LTCs) are first measured by frequency scanning method, which are...

Oscillation phenomena of offshore wind power plant (OWPP)in a wide frequency range can be caused due to impedance interactions between grid-connected inverters (GCIs) and transmission cables. In this paper, impedance model of GCI with outer power control loop, inner current control loop and phase...

The large-scale integration of different kinds of wind farms (WFs) in a transmission grid can bring special adaptability issues to the traditional phasor-based line differential protection in both the transient and steady states. In this paper, a novel composite fault model based differential...

This paper presents a gray-box hierarchical instability source identification method of multiple-inverter-fed power systems, which enables stability analysis at system, component, and parameter levels sequentially. Impedance frequency responses of all components are first obtained using frequency...