Main content area

Distributed generation network design considering ground capacitive couplings

El Halabi, N., García-Gracia, M., Comech, M.P., Oyarbide, E.
Renewable energy 2012 v.45 pp. 119-127
couplings, models, renewable energy sources
Distributed Generation (DG) systems using power-electronics-based grid interfaces magnify the problem of ground capacitive couplings in modern distribution networks. The application of simplified models to DG installations neglects the current distortion, potential rise, and losses in the system as consequence of the capacitive coupling within the installation. These capacitive couplings represent a leakage impedance loop for the capacitive currents imposed by the high-frequency switching of power converters. This paper proposes a suitable method to reproduce this DG harmonic current injection into the distribution network. The capacitive coupling proposed for DG installation with ground is modeled as a parallel resistance and capacitor arrangement, and leads to an accurate approximation to the real operation response of the DG networks. Simulation results are presented together with solutions based on the proposed model to minimize the capacitive ground current in DG networks. Objectives include for meeting typical power quality regulations concerning harmonic distortion, improving safety, and optimizing the efficiency of the installation.