A Software Tool for Setting Upstream Active Power Protection in a Meshed Distribution Network

The paper deals with a problem of upstream active power flows in MV/LV meshed distribution networks in case of a fault at MV side. The concept of upstream active power protection (UAPP) is presented as an alternative to directional overcurrent relays. The paper contribution is focused on a software tool for calculation of the UAPP setting. Presented method is based on short-circuit faults simulations using numerical model of the network in order to define threshold values respecting limiting conditions at each MV/LV transformer. The paper discusses one-stage/two-stage and individual/global variant of setting the UAPP units. The algorithm principle is demonstrated using extensive MV/LV meshed network model with graphical illustration of derived thresholds.