[Introduction] The application scenarios of peak shaving and valley filling by energy storage connected to the distribution network are studied to clarify the influence of energy storage access on network losses and voltage quality on the distribution network side. [Method] The paper analyzed the change trend of network loss power with the energy storage injection current and access position during peak hours of energy storage discharge, and then analyzed the change trend of network loss power with the energy storage injection current and access position when the energy storage system was connected and charged during valley hours. For the influence of energy storage connected to the distribution network for peak shaving and valley filling on the voltage of the distribution network, the influence of different energy storage injection currents and access positions on the voltage distribution along the distribution network was studied from the perspective of energy storage discharge during peak hours and energy storage charging during valley hours. Finally, considering the total voltage deviation index of the distribution network, the influence on the total voltage deviation index after the distribution network which was connected to energy storage was studied. [Result] Through simulation calculations, the influence trend of energy storage participating in peak shaving and valley filling for the distribution network on network loss power and voltage loss is analyzed when different fixed or continuous values of energy storage current and access position are taken, and it is compared with theoretical analysis. [Conclusion] The study will provide useful references for the coordinated planning and optimized operation of various energy storage facilities in the distribution network, and it has good engineering reference value
