Investigation on Volt-VAr control using CVR at various photovoltaic penetration levels

This paper deals with the study of Volt-VAr control using Conservation Voltage Reduction (CVR) in distribution feeders penetrated at various levels of photovoltaic (PV) systems. For several decades, the practice of CVR has been implemented in utilities and the reports indicate that such practices have resulted in annual energy savings up to a few percentages, depending on factors such as the nature of the loads, climate, geographical area, etc. With more penetration of renewable sources of energy, such as photovoltaic systems, questions arise on how Volt-VAr control using CVR can be impacted and/or improved. Furthermore, it is desired to understand the behavior of aggregated loads at the main substation of the distribution system in order to estimate the effectiveness of CVR. As such, an actual distribution feeder has been simulated at various PV penetration levels, with and without implementation of CVR, and its CVR factor density has been calculated using aggregated load modeling based on ZIP parameters. Our results indicate that the increase in PV generation weakens the constant power component of the aggregated load, thus increasing the CVR factor density.