Approximate active power distributions for standard household loads

The large feed-ins of photovoltaic (PV) systems in low voltage (LV) grids result in increasing voltage magnitudes and line loadings. While the rise of voltage magnitudes can be limited e.g. by distribution transformers (DTs) with on-load tap changers, high line loadings cannot even be detected by network operators due to a lack of network observability. LV state estimation (SE) systems can provide a way to determine the required network states and line loadings. Measured operational network variables, e.g. voltage magnitudes and power values of PV systems, can be used as input data for the SE. Nevertheless, power measurements of households are not available and thus the household loads have to be approximately determined. This paper presents approximate active power distributions (AAPDs) for standard household loads, derived on the basis of field-trial data. They are an innovative way for the necessary generation of active power pseudo-values (APPVs) for LV SE with statistical errors following a Gaussian distribution. Despite the simplicity of the AAPDs the errors made within the current calculation is acceptable.