Segmentation restoration strategy of power grid based on combined optical storage system

Abstract

At present, new energy is introduced into the power system in large quantities. In order to make it replace the traditional hydropower and gas units as the black start power supply, segmentation restoration strategy of power grid based on the combined optical storage system is studied. Firstly, according to the structure and control mode of the optical storage system, the energy storage system establishes a stable grid-connected bus voltage is proposed, and the photovoltaic system is connected to the grid step by step. Secondly, in order to enhance the damping inertial support of photovoltaic power generation system, virtual synchronous control is proposed to be added to the inverter side of photovoltaic system. Finally, in the process of grid connection between the units to be started and the system load, the energy storage system is configured with additional damping controller to suppress the sub-synchronous oscillation generated by the grid black start, so as to ensure the stable recovery of the grid. In PSCAD/EMTDC, the electromagnetic transient simulation model of black start of the combined optical storage system is built and the simulation analysis is carried out. The results show that the busbar voltage deviation and system frequency deviation in the recovery process of the system are less than 0.65% and less than 1%, which meets the requirements of black start and verifies the feasibility of the start-up strategy proposed in the paper.

Keywords

• photovoltaic system
• energy storage system
• black start
• segmentation restoration
• virtual synchronous control
• additional damping controller