| The energy sector is moving towards extensive use of power electronic (PE) converters to interface distributed generation (DG) units and modern converter-interfaced loads (CILs). Therefore, the conventional distribution-grid is gradually transformed into a multi-stage PE converter-dominated network. However, interaction dynamics among equivalent source and load converters may adversely influence the overall stability even if each converter stage is inherently functional and stable.;In multi-cascaded PE stages, the equivalent load/source admittance ratio should satisfy the Nyquist stability criterion to ensure stable operation. Moreover, tightly-regulated PE converters induce negative input admittance in the small-signal sense, which reduces overall stability margins.;This thesis addresses interaction dynamics in emerging PE distribution systems by using small-signal linearization to derive equivalent input/output admittance models of typical PE converters. Active compensators are designed to maintain the system stability. Theoretical analysis and extensive simulation results are presented to validate the developed models and the proposed active compensators. |
