用于供电品质改善的多功能三电平混合储能变流器设计研究

Research on the Multifunctional Three-Level Hybrid Energy Storage Converter for Power Quality Improvement

分布式储能具备灵活的电能调控特性,利用其接口变流器的可控性可以实现对诸如无功、三相不平衡等稳态扰动和电压暂降、供电中断等暂态扰动的治理,从而以多功能的形式减少电网扰动、改善负荷供电品质,有助于提高分布式储能系统的应用效能。为实现该目标,提出一种多功能三电平混合储能变流器,以两级式三电平拓扑为载体提升系统电能变换效率,以超级电容和储能电池的混合接入为手段实现暂态/稳态性能的综合优化,以多功能控制及其平滑切换策略的设计实现稳态及暂态电能质量问题的高效治理。仿真和实验验证了所设计系统在改善供电品质方面的可行性和有效性。

The distributed energy storage has flexible energy regulation characteristics,and the controllability of its interface converter can be used to control steady-state disturbances such as reactive power and three-phase imbalance,as well as transient disturbances such as voltage sags and power supply interruptions,which thus can reduce power grid disturbances and improve the quality of load power supply in a multifunctional manner,and help to improve the application efficiency of distributed energy storage systems.To facilitate this goal,this paper a multifunctional three-level hybrid energy storage converter,which uses a two-stage three-level topology as the carrier to improve the efficiency of system energy conversion,achieves comprehensive optimization of transient/steady-state performance by means of the hybrid connection of supercapacitors and energy storage batteries,and realizes efficient governance of steady-state and transient power quality problems by designing the multifunctional control and smooth switching strategy.The Simulation and experiments have verified the feasibility and effectiveness of the proposed methods.