Maximum Rooftop Photovoltaic Hosting Capacity with Harmonics as Limiting Factor – Case Study for Mauritius

Abstract

With a growing urge to opt for environmentally friendly sources of energy, coupled with financial incentives that such schemes attract, many residential consumers are installing small rooftop photovoltaic systems at home. All these systems use electronics in their inverters and controllers; which contribute to harmonics in their outputs. Cumulative harmonic content in the distribution network can have adverse effect on the quality of supply and consequently affect sensitive equipment. To this effect, the IEEE 519-2014 standard defines the acceptable limits for harmonics in such network. Different types of network will react differently to the level of harmonics present depending on the network impedance. In this study, an actual residential area was modelled and fed with residential consumption data and photovoltaics outputs collected from the field. The level of harmonic pollution was observed with increasing penetration level of photovoltaic units and using different sizes of such units. The results were benchmarked against the limits specified in the IEEE 519-2014 standard. The losses these harmonics introduce in the network were also assessed. The findings can be used by an electrical utility to limit the amount of rooftops photovoltaic being connected so as not to degrade quality of supply.