直流微电网暂态自适应虚拟惯性控制策略及其参数可行域研究

Research on transient adaptive virtual inertia control strategy of DC microgrid and its parameter feasibility region

附加虚拟电容控制能够挖掘直流微电网隐藏的惯性,从而缓解新能源渗透下直流母线电压对功率波动敏感的问题,但其无法满足系统在动态调节过程中灵活的惯性需求。为了向直流微电网提供灵活惯性支撑能力,通过在源侧换流器控制中耦合电压参数与惯性参数改变系统电量积累进程,提出一种能够实时响应微电网运行工况变化并投入可变虚拟电容的暂态自适应虚拟惯性控制策略。借助系统小信号模型和根轨迹分析,揭示惯性参数变化对系统稳定性的影响。在此基础上,采用控制理论配置极点的方法为参数选取提供有效约束,实现控制参数的优化设计。搭建五端直流微电网仿真系统,验证暂态自适应虚拟惯性控制提供的动态虚拟电容灵活的暂态自适应能力。

The additional virtual capacitor control can excavate the hidden inertia of DC microgrid,so as to alleviate the sensitive problem of DC bus voltage to power fluctuation under the penetration of new energy,but it can not meet the flexible inertia requirements of the system in the process of dynamic regulation.In order to provide flexible inertial support capability for DC microgrid,by coupling voltage parameters and inertia parameters in source side converter control to change the process of system power accumulation,a transient adaptive virtual inertia control strategy is proposed which can respond to the changes of microgrid operating conditions in real time and input variable virtual capacitance.With the help of the system small signal model and root locus analysis,the influence of inertia parameter change on the system stability is revealed.On this basis,the control theory is used to assign poles to provide effective constraints for parameter selection and optimize the design of control parameters.Finally,a five-terminal DC microgrid simulation system is built to verify the flexible transient adaptive capability of dynamic virtual capacitance provided by transient adaptive virtual inertia control.