双馈风机定子侧变流器的附加阻尼抑制次同步振荡方法

Sub-synchronous Resonance Mitigation Scheme by Stator Side Converter in Doubly Fed Induction Generator

为了抑制次同步振荡,基于双馈风机定子侧变流器提出了一种新的附加阻尼控制策略。首先从双馈风机发生次同步振荡的机理出发,把风机转速变化时导致的转矩变化分为转子变化量和定子变化量两部分,通过在定子侧变流器控制策略中引入附加控制,从而产生一个与转速增量反相的附加转矩,为系统提出正阻尼。然后,通过PSCAD/EMTDC时域仿真,对比附加阻尼控制前后抑制效果。研究表明:通过风机自身控制抑制次同步振荡,具有很好的相应速度和抑制效果,可以使风机在低转速或者高串补度的条件下安全稳定运行,可以降低成本,具有很强的工程价值和实际意义。

We propose a new supplementary damping control strategy for sub-synchronous resonance by grid side con- vener in doubly fed induction generator （DFIG）. Based on the mechanism of sub-synchronous resonance in DFIG, the electromagnetic torque variation under the variation of rotor speed can be divided into two pans, i.e. rotor torque variation and stator torque variation. A novel subsynchronous supplementary damping control strategy by rotor side converter is then proposed. Supplementary controller is added to the stator side converter and a supplementary torque which is in opposite phase with rotor speed is generated to provide positive damping. PSCAD/EMTDC simulation is carried out to compare the results of supplementary damping. Results show that supplementary damping controller has fast response speed and suppression result. DFIG can keep stable under various rotor speeds and compensation levels. Supplementary damping control can greatly reduce the cost and has significant practical value.