Comparison of fault current levels between grid-connected photovoltaic system and synchronous machine distributed generation in a distribution system

Abstract

This thesis presents the comparison of fault current levels between grid-connected photovoltaic (GCPV) system and synchronous machine distributed generator (SG). Their impacts are studied using 23-bus, 65MVAsc, 23kV distribution system with the total load of 700W. Modeling of the GCPV is based on a PV model described by Shockley diode equation with a series resistance, a boost converter with maximum power point tracking (MPPT) technique, and a pulse width modulation (PWM) inverter with a voltage regulator. The siulation is carried out using the MATLAB-SIMULINK. Both GCPV and SG with various penetration levels are installed at various buses in the system. Various fault positions are assumed in order to assess the fault current contributon from the GCPV system to the man grid by comparing with the fault current contribution from the SG. Result comparison between the system with GCPV installaton and SG installation is discussed. Impacts of fault current contribution on protection coordination are considered based on IEEE Std C37.112-1996.