基于阻抗测量的风电场谐振特性分析

目前,针对风电机组引起的谐振问题的研究分析方法比较复杂,计算繁琐,通常以含有线路串联补偿的模型为主,不考虑换流器或简化换流器控制作用,与实际系统相比存在较大误差。为计算简便,减小误差,提出一种基于谐波阻抗测量仿真分析的方法,对风电系统模型进行谐振特性分析。该方法简单方便,避免大规模数据的整理和计算,可充分考虑风机换流器的影响,减少简化系统带来的误差。以目前实际装机较多的双馈感应风机为研究对象,以PSCAD/EMTDC为工具,通过电磁暂态仿真,建立典型双馈风电机组接入交流系统的模型以及西北含风电场某实际系统模型。用以上方法进行谐振特性分析,结果表明,双馈感应风电机组在运行过程中有可能表现为容性阻抗,而交流电网呈感性,故整个系统形成RLC谐振回路,易引发谐振。

Analysis of resonant characteristics of wind farm based on impedance measurement

At present, the research and analysis method of resonant problem caused by wind turbine is complex, the calculation is cumbersome, which is mainly related to the model of line series compensation, regardless of converter or simplified converter control, so there is large error with the actual system. In order to calculate the simplicity and reduce the error, a method based on harmonic impedance measurement simulation analysis is proposed in this paper to analyze the resonant characteristics of the wind power system model. The method is simple and convenient, and avoids the collation and calculation of large-scale data, which can fully consider the influence of wind converter and reduce the error caused by simplifying the system. Taking the doubly fed induction generator with more actual installed machine as the research object, the PSCAD/EMTDC is used as the tool, and through the electromagnetic transient simulation, the model of the typical doubly fed wind generator access AC system and a practical system model of the Northwest wind farm are established. The resonant characteristics are analyzed by the above methods, and the results show that the doubly fed induction generator may exhibit capacitive impedance in the course of operation, while the AC power grid is sensual, so the whole system forms an RLC resonant circuit, which is easy to trigger resonance. This work is supported by National Natural Science Foundation of China (No. 51767001).