Energy saving in a low-voltage power distribution network by optimising the photovoltaic-system reactive-power generation

The paper evaluates the energy savings in a low-voltage power distribution network by optimising the photovoltaic-system (PVS) reactive-power generation. The evaluation is made on a model of a real low-voltage power distribution network with two 50 kWp PVSs installed. The time frame of energy-savings evaluation is one year. The PVS active power is determined on the basis of the average solar irradiance measured over halfhour intervals and the active-power load is determined on the basis of the measured load profile. Since the installed photovoltaic systems are relatively large, smaller PVSs of the rated power of just 5 kWp are also analysed. The results show that the existing PVSs can contribute to the reduction of energy losses in the distribution network by optimizing their reactive power generation. However, the reduction of energy losses can be even higher if there are smaller PVSs installed at the consumption sites instead of larger ones.