风电采用MGP并网的小干扰建模和阻尼特性

发布时间：2018-10-12 11:32

【摘要】：针对高比例新能源给电网带来的低惯量和弱阻尼问题,提出新能源同步机的并网方式,即新能源驱动同步电动机—同步发电机(MGP)后并网。详细阐述了MGP的小干扰建模方法。首先,分析MGP的功角关系并考虑励磁系统动态,建立包含自动电压调节器和电力系统稳定器的小干扰模型,指出MGP存在阻尼转矩叠加效应。然后,考虑双馈风机状态变量,建立其与MGP对接的完整的小干扰状态方程。在此基础上,推导了基于K系数的动态特性和转矩分量表示法,揭示MGP的阻尼转矩叠加效应的本质是双励磁耦合特性。最后,基于模型建立单机无穷大算例,对比了MGP和传统机组的小干扰稳定特性;在双馈风机采用传统和MGP两种并网方式下,研究了双励磁耦合特性对风机主导的振荡模态的影响。结果表明,提出的小干扰建模方法可以准确反映MGP系统的双励磁耦合特性,该特性能够有效提升阻尼转矩分量和改善系统振荡模态。
[Abstract]:In order to solve the problem of low inertia and weak damping caused by high proportion of new energy sources, a new energy synchronous motor (MGP) grid connection mode is proposed. The small disturbance modeling method of MGP is described in detail. Firstly, by analyzing the power angle relation of MGP and considering the excitation system dynamics, a small disturbance model including automatic voltage regulator and power system stabilizer is established, and the damping torque superposition effect in MGP is pointed out. Then, considering the state variables of the doubly-fed fan, a complete small disturbance state equation is established for its docking with MGP. On this basis, the dynamic characteristics based on K coefficient and the representation of torque components are derived. It is revealed that the nature of the damping torque superposition effect of MGP is the coupling property of double excitation. Finally, based on the model, the small disturbance stability characteristics of MGP and traditional units are compared, and two grid-connected modes of doubly-fed fan and MGP are used. The effect of coupling characteristics of double excitation on the oscillation modes dominated by blower is studied. The results show that the proposed small disturbance modeling method can accurately reflect the dual excitation coupling characteristics of the MGP system, which can effectively enhance the damping torque component and improve the oscillation mode of the system.
【作者单位】：新能源电力系统国家重点实验室(华北电力大学);
【分类号】：TM614;TM743

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