Although impedance-based method has been proposed to effectively analyze interaction stability, the existing all-in-one impedance model-based method might encounter difficulty in identifying the physical significance of potential instability factors in the electric vehicle charging station and in solving the analytical solution of stabilization method aimed at entirely mitigating the voltage low-frequency oscillation (LFO) of each bandwidth due to its modeling complexity and high-order property. To address this issue, an analytical loop-correction stabilization method is designed based on the multi-timescale reduced-order impedance model to improve the dynamics of each bandwidth. Initially, the reduced-order expression of multi-timescale impedance model are presented by fitting the bode curve of closed voltage- and inertia-loop gain ( G _vcl ( s ) and G _vir ( s )). Subsequently, the analytical solution of loop-correction stabilization method can be designed and then performed to advance the phase and/or amplitude response of G _vcl ( s ) and G _vir ( s ). The negative damping within droop- and voltage-loop bandwidths is partly eliminated or completely offset, the LFO amplitude is suppressed and the LFO duration is shortened obviously due to the system stability enhancement and dynamic improvement. The voltage LFO of each timescale can be mitigated individually by the loop correction within each bandwidth. The bode-diagram-based solving process of this analytical loop-correction stabilization method is highly compatible for practical engineering applications. Finally, the effectiveness of proposed analytical loop-correction stabilization method is validated by physical experiment.

中文翻译：

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电动汽车直流充电站降阶阻抗模型及解析环路校正稳定方法


虽然基于阻抗的方法已经被提出来有效地分析相互作用稳定性，但现有的基于阻抗模型的一体化方法可能会在识别电动汽车充电站中潜在不稳定因素的物理意义和求解解析解方面遇到困难由于其建模复杂性和高阶特性，稳定方法旨在完全减轻每个带宽的电压低频振荡（LFO）。为了解决这个问题，设计了一种基于多时间尺度降阶阻抗模型的解析环路校正稳定方法，以改善每个带宽的动态性。首先，通过拟合闭环电压和惯性环增益的伯德曲线（G vcl（s）和G vir（s）），给出了多时间尺度阻抗模型的降阶表达式。随后，可以设计并执行环路校正稳定方法的解析解，以推进G vcl (s)和G vir (s)的相位和/或幅度响应。由于系统稳定性增强和动态改善，下垂环路和电压环路带宽内的负阻尼被部分消除或完全抵消，LFO幅度被抑制，LFO持续时间明显缩短。每个时间尺度的电压 LFO 可以通过每个带宽内的环路校正单独减轻。这种解析环路校正稳定方法基于伯德图的求解过程与实际工程应用高度兼容。最后，通过物理实验验证了所提出的分析环路校正稳定方法的有效性。