Voltage reduction due to reverse power flow in distribution feeder with photovoltaic system

Abstract

In this work, voltage reduction due to reverse power flow from a photovoltaic (PV) system is explained by a measurement and theoretical analysis of electric circuits. Although it is well accepted that a reverse power flow leads to a rise in distribution feeder voltage, our measurements indicated that distribution feeder voltage reduces with an increase in reverse power flow in presence of a large PV system. In our theoretical analysis, a power–voltage curve analysis is performed using a simple two-node distribution system model. We found that the voltage reduction could be satisfactorily rationalized by the magnitude of the line impedance, reverse apparent power flow, phase angle of the line impedance, and power factor of the photovoltaic system. This finding indicates that an increase in the magnitude of line impedance and/or reverse apparent power flow result in a voltage reduction. Similarly, an increase in the ratio of line reactance to line resistance and leading reactive power generation at the receiving end also cause a voltage reduction. The derived theoretical results show good agreement with the measured values.