This work presents the analysis and proposes nonlinear controls of a wind energy conversion system (WECS) to pass through symmetrical and asymmetrical voltage failures. The WECS is equipped with a nonsalient pole permanent magnet synchronous generator (PMSG) and two full converters, synchronous generator side converter (SGSC) and grid side converter (GSC), joined by a direct current (DC) link. As a consequence of the strong disturbances considered, a general strategy based on grid voltage values changes control references at SGSC and GSC. This strategy uses two flags for indicating normal grid voltages, symmetrical faults, or asymmetrical ones. Then, while control laws deal with model uncertainties and fast disturbances due to wind gusts, the strategy changes references to surpass strong, probably unbalanced, grid voltages disturbances. To assure robust properties, controllers are designed via a conjunction of Lyapunov and passivity theories. The proposed controllers and the strategy are tested under realistic wind conditions, uncertain parameters, and strong voltage disturbances.

中文翻译：

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不对称电压故障下的风能转换系统：分析与非线性控制

这项工作提出了分析并提出了风能转换系统 (WECS) 的非线性控制，以通过对称和不对称电压故障。WECS 配备了一个非凸极永磁同步发电机 (PMSG) 和两个完整的变流器，即同步发电机侧变流器 (SGSC) 和电网侧变流器 (GSC)，由直流 (DC) 链路连接。由于考虑了强干扰，基于电网电压值的一般策略会改变 SGSC 和 GSC 的控制参考。该策略使用两个标志来指示正常电网电压、对称故障或不对称故障。然后，当控制律处理由阵风引起的模型不确定性和快速扰动时，该策略改变了参考以超越强的、可能不平衡的电网电压扰动。为了确保鲁棒性，控制器是通过结合李雅普诺夫和无源理论来设计的。所提出的控制器和策略在实际风况、不确定参数和强电压扰动下进行了测试。