When controlling the load dispatching mode for a power system, one of the crucial parameters to control and to adjust is the active power flow in controlled power system sections (hereinafter referred to as power flow). The tolerance range of these flows is set to guarantee power system stability. Taking into consideration the correlation between the range of allowed power flows and a set of various factors - ambient temperature, contiguous grid topology, security constrained unit commitment, state and adjustment of emergency control schemes, and others - and the requirements for their account, the computation of allowed flows is becoming a more and more laborious assignment. The task is complicated by the fact that power systems are subject to considerable changes in the grid topology due to the commissioning of new equipment or decommissioning of out-of-date one; divergences in parameters of electric grid equipment; nodal loads redistribution in accordance with seasons and the time of day, etc. In all such instances, it is required to analyze the compliance of set-point power flows with the changed power system parameters. The precise analysis consists in recalculating flow magnitudes and comparing them with the current set-point flow magnitudes with the view of their further adjustment. Therefore, in order to simplify computations of allowed power flows within the tolerance range, it is important to create such algorithms and methodology that will result in automatization of allowed power flow calculations. The main aim of the study is to work out a simplified method for computing the allowed active power flow in controlled power system sections. The methods used in the study: steady state power system equation analysis and modeling of steady state power systems with «RastrWin» software. The results. The author has proposed the simplified method for computing the allowed active power flow in controlled power system sections. The validity of this method was tested and assessed in the controlled section of model in the article.