Utilization of energy storages in low voltage grids with high penetration of photovoltaics – addressing voltage issues

This contribution focuses on voltage issues in low voltage distribution grids which are highly penetrated with distributed generation (DG), especially photovoltaic (PV) plants. It describes a model of selected part of distribution network, created in Matlab/Simulink, based on real data, and the impact of PV power plants on voltage amplitude in accordance with DIN EN 50160 during the summer week, depending on the percentage share of PV production in total consumption. Using sensitivity analysis are identified critical nodes and respective share of DG, which causes exceeding of voltage magnitude limit values. Assumptions about negative effect on voltage fluctuations were confirmed at higher penetration levels. In order to prevent this phenomenon, unconventional way of distributed voltage regulation through absorption of active power by energy storages installed in critical nodes is proposed and simulated. The functionality, benefits and drawbacks of this approach are evaluated and compared to similar more commonly used measures.