并网异步风电机组有功功率的振荡频率分析

Analysis of oscillation frequency for active power of a grid-connected asynchronous wind turbine generator system

为了准确研究影响并网风电机组功率波动因素及规律,提出了不同运行工况以及不同风力机模型和参数对异步风电机组有功功率的振荡频率研究。首先,采用等效集中质量法,结合异步发电机电磁暂态模型,建立了不同风力机传动链等效的异步风电机组数学模型。其次,在风速扰动下,对不同传动链模型、传动链刚度系数以及不同风速扰动频率时机组有功功率振荡的频率进行仿真分析。最后,在电网三相短路故障情况下,针对等效两个质量块传动链模型,对不同传动链刚度系数和故障持续时间的机组有功功率振荡频率进行仿真。研究结果表明相同振荡频率下的有功功率幅值与风力机模型、传动链刚度系数以及故障持续时间密切相关。

In order to analyze accurately the factors and rules of influencing the power oscillation of a grid-connected wind turbine generator system, the frequency analysis for active power oscillation of a wind turbine with squirrel-cage induction generator （SCIG） system is proposed according to different operational conditions and different wind turbine models and parameters. Firstly, by using the equivalent lump mass method, and combining the electro-magnetic transient models of SCIG, the mathematical models of the wind turbine with a SCIG are presented with different wind turbine drive-train equivalent models. Secondly, according to a wind speed disturbance, simulations on the frequency for active power oscillation of the WTGS are investigated under the conditions of different drive-train models, rigid coefficients, and different wind speed disturbed frequencies. Finally, according to a 3-phase short-cireuit fault of the connected grid, by using a two-mass equivalent drive-train model, simulations on the frequency for active power oscillation of the WTGS are also investigated under the conditions of different drive-train rigid coefficients and different fault durations. The compared results have shown that the active power oscillation amplitude at the same oscillation frequency is related closely with the drive train models, drive-train rigid coefficient and the fault duration. This work is supported by National Natural Science Foundation of China （No. 50607022）.