Harmonic Power Modeling for Converter-Driven Stability Study

With the increasing use of power converters in power systems, harmonic resonance stability (also called converter-driven stability) has become a multi-converter-related issue. Compared with the traditional single-converter grid connection stability, it is important to identify the dominant converters for different unstable modes in multi-converter systems. Therefore, this study addresses this objective by analyzing harmonic power dynamics. First, the concept of the harmonic power model is introduced within the context of a single-converter system. Subsequently, the harmonic power model is extended to investigate the stability of a multi-converter system. The results show that the proposed model effectively obtains the interfaced power dynamics of the converters, enabling the identification of the dominant converters for different resonance modes. The accuracy of the proposed method is validated using the electromagnetic transient (EMT) simulations in MATLAB/Simulink.