A multi-scale transients model of a doubly fed induction generator (DFIG)-based wind energy conversion system (WECS) is developed, implemented, and validated. All ac circuit and control quantities of the electrical part are modeled by analytic signals rather than just real signals. In addition to the real parts, the analytic signals also comprise orthogonal imaginary parts. While measured Fourier spectra of real ac quantities involve positive and negative frequency components, they only involve positive frequency components when extended and represented as analytic signals. With the introduced shift frequency operator, the analytic signal can now be shifted in the frequency domain to reduce its maximum frequency contents and thus allow for a larger time-step size in accordance with the Nyquist criterion. If the shift frequency is set equal to the ac fundamental frequency, then the affiliated ac voltages and currents become dynamic phasors. At a zero shift, however, instantaneous signals can be tracked as in an electromagnetic transients program (EMTP). This is illustrated here for the voltage sourced converters (VSC) of the WECS. By appropriate selection of the shift frequency, both electromagnetic and electromechanical transients are simulated efficiently. Studies involving wind power fluctuations, three-phase-to-ground fault and single-phase-to-ground fault confirm these claims.

中文翻译：

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基于双馈风能转换系统的多尺度建模与仿真

开发、实施和验证了基于双馈感应发电机 (DFIG) 的风能转换系统 (WECS) 的多尺度瞬态模型。电气部分的所有交流电路和控制量都是通过分析信号而不是实际信号来建模的。除了实部之外，解析信号还包括正交虚部。虽然实交流量的实测傅立叶频谱涉及正和负频率分量，但当扩展并表示为解析信号时，它们仅涉及正频率分量。使用引入的移频算子，现在可以在频域中移动解析信号以减少其最大频率内容，从而根据奈奎斯特准则允许更大的时间步长。如果将偏移频率设置为等于交流基频，则附属的交流电压和电流成为动态相量。然而，在零偏移处，可以像在电磁瞬变程序 (EMTP) 中一样跟踪瞬时信号。此处针对 WECS 的电压源转换器 (VSC) 说明了这一点。By appropriate selection of the shift frequency, both electromagnetic and electromechanical transients are simulated efficiently. 涉及风电波动、三相接地故障和单相接地故障的研究证实了这些说法。此处针对 WECS 的电压源转换器 (VSC) 说明了这一点。By appropriate selection of the shift frequency, both electromagnetic and electromechanical transients are simulated efficiently. 涉及风电波动、三相接地故障和单相接地故障的研究证实了这些说法。此处针对 WECS 的电压源转换器 (VSC) 说明了这一点。By appropriate selection of the shift frequency, both electromagnetic and electromechanical transients are simulated efficiently. 涉及风电波动、三相接地故障和单相接地故障的研究证实了这些说法。