直驱风机对火电机组次同步振荡的影响及抑制方法

风火打捆系统中,风电机组的并网使得火电机组的次同步振荡情况变得更为复杂。基于IEEE第一标准模型搭建了风火打捆经串补外送系统,推导了直驱风机输出功率与火电机组次同步阻尼的关系,分析了其对火电机组次同步振荡的影响机理,并通过PSCAD平台结合复转矩系数法和时域仿真分析进行验证。基于此机理,提出了一种在直驱风机的网侧变流器控制系统无功外环处附加阻尼控制的抑制方法,并对其关键参数的优化设计方法进行了分析,时域仿真结果表明所提出的附加阻尼控制可以有效抑制火电机组的次同步振荡。

Impact of PMSG to Thermal Power Units on Sub-synchronous Oscillation Characteristics and Suppression Strategy

In the wind-thermal bundling system, the integration of wind turbines makes the sub-synchronous oscillation of thermal power units more complicated. In this paper, based on the first standard model of IEEE, the wind-thermal bundling system model is built, and the relationship between the PMSG output and the sub-synchronous damping of the thermal power unit is derived. The mechanism of its influence on the sub-synchronous oscillation of the thermal units is analyzed, and verified by the complex torque coefficient method and the time-domain simulation analysis on the PSCAD platform. Based on this mechanism, a suppression method of additional damping control at the outer control ring of the PMSG grid-side converter is proposed, and the optimization designing method for the key parameters configuration is analyzed. The time-domain simulation results show that the additional damping control can effectively suppress the sub-synchronous oscillation of the thermal power unit.