基于振荡状态反馈的直流微网储能换流器的有源阻尼控制技术  

Active Damping Control of Energy Storage Converter in DC Microgrid Based on Oscillatory State Feedback

作　　者：付媛[1] 李浩[1] 张祥宇[1] FU Yuan;LI Hao;ZHANG Xiangyu(State Key Laboratory of Alternate Electrical Power Systemwith Renewable Energy Sources,North China Electric Power University,Baoding 071003,China)

机构地区：[1]华北电力大学新能源电力系统国家重点实验室,保定071003

出　　处：《高电压技术》2021年第3期927-936,共10页High Voltage Engineering

基　　金：国家自然科学基金(51607070);中央高校基本科研业务费专项资金(2018MS90)。

摘　　要：直流微网中,光伏、风电侧换流器的功率跟踪控制以及负荷侧换流器的恒功率控制在扰动中均会表现出负阻抗特性,增加了系统振荡失稳的风险。首先推导含恒功率负荷的孤岛运行的直流微网小扰动线性化状态方程,理论分析储能换流器振荡电压、电流作为可调节控制参数对直流微网振荡特性的影响机理。其次,以直流电压与电流为状态反馈变量,设计了储能换流器下垂控制的占空比反馈环节,提出阻尼直流微网振荡的控制策略,并通过系统极点配置,实现参数优化设计。最后,通过根轨迹与仿真分析,验证所提出的控制策略对直流微网振荡具有显著阻尼能力,从而提高系统的动态稳定性。In a DC microgrid, during disturbances, the power tracking control of the converters on photovoltaic module and wind turbine side and the constant power control of the converters on the load side both present the negative impedance characteristics, increasing the risk of system oscillation instability. Firstly, a small disturbance linearized state equation of islanding DC microgrid with constant power load is deduced, and the influence mechanism of oscillation voltage and current of energy storage converter as adjustable control parameters on the system oscillation characteristics of DC power grid is theoretically analyzed. Secondly, by taking DC voltage and current as state feedback variables, a duty cycle feedback link for droop control of the energy storage converter is designed, and the control strategy of damping DC microgrid oscillation is proposed. In addition, the optimal design of parameters is realized by pole placement. Finally, through root locus and simulation analysis, it is verified that the proposed control strategy has significant damping capacity for DC microgrid oscillation, thus improving the dynamic stability of the system.

关 键 词：直流微网 储能换流器 阻尼振荡 状态反馈 极点配置 

分 类 号：TM721.1[电气工程—电力系统及自动化]