Overvoltage Mitigation in Distributed Networks Connected to DG Systems

The rise in electricity prices along with the low cost of photovoltaic (PV) systems installation has led to high integration of PV into the low voltage (LV) networks. This type of increase in integration of PV causes technical problems related to network stability, power quality, electric outage, and load increase in the local electricity grid. The most prominent of these problems is overvoltage. This paper investigates overvoltage problem caused by the increase of Distributed Generation (DG) in Low Voltage (LV) distribution networks, mainly PV generation. A Case study was developed using the OpenDSS simulation tool [1] to overcome the overvoltage problem due to high penetration of the PV systems in the LV distribution network. This study indicates several scenarios to specify the extent of this negative impact presented with graphs of this study. A proposed solution is introduced in this paper to deal with this type of voltage changes caused by DG sources in the LV network. The suggested solution to overcome this problem is based on an advanced inverter to handle such differences in voltage patterns in the network due to DG integration with the existing power grid. Such advanced inverter would be able to deal with the overvoltage issues at the point of interconnection (POI) by different types of modes according to the situation of the feeder.