Impact Assessment of High Penetrations of Grid-connected Photovoltaic (PV) System on the Low Voltage Distribution Network

摘要

In recent years, the use of photovoltaic (PV) systems as an integral part of building facades or roofs has become one of the fastest growing markets worldwide. Therefore, grid-connected photovoltaic (GCPV) systems could have great potential to supply part of the consumer's own power demand. However, when the house or business requires less power than the PV system is generating, the surplus power will be fed back to the grid. Because the existing distribution networks are not designed and constructed to accommodate high penetration of distributed energy systems, it is possible to have reverse power flow and increase the steady-state voltage level on feeder lines especially during periods of low load demand and high generation. This paper assesses the effect of high penetration levels of small-scale grid-connected PV systems on the voltage quality of the UK low voltage distribution network feeders. The worst case scenario of high penetration of grid-connected PV systems with a typical daily summer load profile is considered to estimate the amount of voltage variation on distribution network feeders. The power system dynamic program MATLAB is used to carry out this assessment.