Oscillatory localization and impedance-coordinated method for multi-converter power systems based on the impedance network matrix

• A stability criterion is derived based on an impedance network model. • A method for the oscillatory localisation of multi-converter power systems is proposed. • An impedance-coordinated optimisation method is designed based on a dominant oscillating converter. The Bus participation factor (PF) has been identified as an effective method for identifying the power converters and buses contributing significantly to harmonic instability. However, the PF depends on the system’s eigenvalue calculations, which require extensive computational resources and presents a significant challenge in identifying the oscillation source in multi-converter power systems (MCPS). This paper presents a novel approach to active impedance perturbation localization based on the derivation of stability margin sensitivity from the impedance participation factor. The method is designed to be universally applicable to large-scale MCPS with intricate configurations to simplify the localization of the oscillation source without the computational complexity involved in eigenvalue calculations. Moreover, to reinforce the system’s stability, an impedance-coordinated control approach is proposed to enhance the robustness of MCPS. This strategy employs virtual impedance reshaping grounded in the stability margin sensitivity impedance assignment. Subsequently, a 10-bus MCPS is utilized as the test system, demonstrating the ease of implementing the proposed method for localizing dominant oscillatory converters. The effectiveness and accuracy of the proposed method are substantiated through specific case studies and hardware-in-the-loop (HIL) experimental results. This work was supported in part by the National Natural Science Foundation of China (52277186), and in part by the Jiangsu Postgraduate Research and Practical Innovation Project (KYCX23_0375).