Approach on Active Distribution Grid Planning by Using the Feasible Operation Region

With the ongoing electrification of heat and mobility a large amount of high-power devices is added to the distribution system level. Their so far assumed power behavior is expected to change in case of an active participation in emerging flexibility markets. Thus, conventional grid planning approaches, using simultaneity factors, incompletely map the utilization potentials of grids, which is challenging for distribution grid planners. In this paper, a new approach on active distribution grid planning under application of the feasible operation region (FOR) is presented to improve the integration of new devices by comprehensively identifying grid operation constraints. The FOR is aggregated at the vertical system interconnection by using a modified particle swarm optimization (PSO) method with an initial-points sampling strategy. As exemplary case-study a generic low-voltage network with simple string topology is used. By analyzing the accruing data from the PSO, the constraining limits of thermal line currents and transformer rating are focused. Results show, that specific limiting elements can be identified within the whole vertical PQ-area. The main contribution of this paper is the combination of grid operational application of the feasible active and reactive power area with grid planning purposes, which represents a new approach in contrast to existing literature. Through this approach, the necessity of line or transformer reinforcement is derivable, when integrating new power flexibility providing units (FPU). Also, the usage of available power flexibilities to postpone grid expansion is enhanced with better knowledge of the existing limits.