Research on Control Strategy of Transient Disturbance Based on the Three-level Hybrid Energy Storage Converter

Abstract

This paper proposes a control strategy of transient disturbance based on the three-level hybrid energy storage converter. The hybrid energy storage control strategy switches to the supercapacitor when the voltage sag occurs. Its characteristics of high power density can provide rapid and smooth voltage support for the distribution network so that the distribution network system will not be greatly affected by the impact. In the case of long-term voltage sag or power failure, it is important to switch to the energy storage battery and use its characteristics of high energy density to provide an emergency power supply to support the continuous operation of essential equipment. The control strategy proposed in this paper can realize the coordinated working between supercapacitor and energy storage battery and the fast and stable switching between two different working states of the energy storage system, which effectively solves voltage sag in the main power grid. Finally, a prototype is built, and the simulation and experimental results both verify the correctness and feasibility of the proposed control strategy.