Nonlinear Modeling and Stability Analysis of Grid-Tied Paralleled-Converters Systems Based on the Proposed Dual-Iterative Equal Area Criterion
Nonlinear Modeling and Stability Analysis of Grid-Tied Paralleled-Converters Systems Based on the Proposed Dual-Iterative Equal Area Criterion
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DOI：
10.1109/tpel.2023.3246763
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发表时间：
2023-06
影响因子：
6.7
通讯作者：
Xilin Li;Zhen Tian;X. Zha;P. Sun;Yufei Hu;Meng Huang;Jianjun Sun
中科院分区：
文献类型：
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作者：
Xilin Li;Zhen Tian;X. Zha;P. Sun;Yufei Hu;Meng Huang;Jianjun Sun
随着分布式可再生能源发电和并网的快速发展，功率变换系统的稳定性问题近年来得到了广泛的研究。以往的研究主要集中在单台变流器接入弱电网时的暂态稳定性。然而，多个转炉系统的非线性动力学和稳定性机理尚不清楚。本文建立了一个统一的逆变器并联系统的非线性模型，揭示了多个逆变器与弱电网之间的相互作用功率和相互作用的阻尼。为了分析相互作用的功率和阻尼项对系统稳定性的影响，提出了一种双重迭代等面积准则(DITEAC)，并对加速面积和减速面积进行了双层迭代计算。与前人的研究相比，DITEAC方法能够处理非线性相互作用的阻尼力，降低了由于不等分尺度引起的保守性，从而大大提高了稳定边界的计算精度。充分讨论了所提出的统一非线性模型和DITEAC方法扩展到N个变流器系统的可行性。最后，给出了仿真和半实物实验结果，验证了该方法的有效性。
With the rapid development of distributed renewable energy generation and integration, stability issues of power converters systems have been widely studied in recent years. Many previous studies focus on the transient stability of a single converter connected to the weak grid. However, the nonlinear dynamics and stability mechanism of multiple converters systems remain unclear. In this article, a unified nonlinear model of the paralleled-converters system is established, which reveals the interactive power and interactive damping among multiple converters and the weak grid. To analyze the impacts of the interactive power and damping terms on system stability, a dual-iterative equal area criterion (DITEAC) is proposed with a dual-layer iterative calculation of the accelerating area and decelerating area. Compared with the previous studies, the proposed DITEAC method could deal with the nonlinear interactive damping and reduce the conservatism caused by the inequality scaling, which greatly improves the calculation accuracy of stability boundaries. The expansion feasibility of the proposed unified nonlinear model and DITEAC method to the N-converters system is fully discussed. Eventually, simulation and hardware-in-loop experiment results are presented to verify the effectiveness of the proposed method.