Research on Decoupling of Units in Distribution Networks

The intricate interactions between substantial line impedance and diverse integration techniques have resulted in a strong coupling among PV inverters, imposing a significant challenge to achieve the independent and efficient voltage/power regulation for PV units. To tackle the challenges, this paper presents a novel approach to decouple distributed PV units connected to a distribution network via different interconnection methods. Firstly, an equivalent line impedance derivation method is proposed to streamline the complex coupled distribution network into a unified "PV unit - line impedance – grid" structure while preserving the node information. Then, a "Line Impedance Equivalent Coefficient (LEC)" is defined to capture the evolving characteristics of the equivalent line impedance. Moreover, by treating the chain structure as a special radial form, the proposed method handles diverse network structures with a minimal computational complexity. Simulation results from Matlab/Simulink demonstrate the effectiveness of this method in decoupling radial, chain and hybrid networks.