基于FACTS的次同步振荡抑制器对变压器工作特性影响研究

Research on Influence of FACTS-based Subsynchronous Oscillation Suppressor on Operating Characteristics of Transformer

为有效抑制风力输电系统中接入串联补偿装置或高压直流输电系统引起的产生次同步振荡现象,大量FACTS型次同步振荡抑制器被广泛采用,而该类装置大多需要经变压器接入系统,此时次同步分量注入变压器将会对变压器运行产生影响。针对此问题,文中分析了不同类型抑制器产生的次同步分量形态;随后对次分量对变压器饱和与铁心损耗特性的影响做了分析;并分别对系统中次同步电压、电流注入串、并联变压器的工作特性做了计算分析;基于分析结果探究了变压器铁心部分可承受次同步分量的情况做了研究。结果表明,次同步频率分量注入时会引起变压器铁心饱和及损耗增加;相比次同步频率电压,变压器能够承受更大比例的次同步频率电流,因此通过反向注入次同步频率电流抑制次同步振荡是一个有效的策略。

For suppressing effectively the sub synchronous oscillation due to access of the series compensation device to the wind power transmission system or the HVDC transmission system,a large number of type FACTS subsynchronous oscillation suppressors are widely used.However,most of the devices need to be connected to the system via transformer and,at this time,injection of subsynchronous component into transformers will affect operation of transformer.In view of this,the subsynchronous component morphology generated by different types of suppressors is analyzed;And then,the influence of subcomponent on transformer saturation and core loss characteristics is ana-lyzed.The operating characteristics that the subsynchro nous voltage and current of the system inject into the serial and parallel transformer is calculated and analysis.The situation that the transformer core can withstand the synchro-nous component is explored on the basis of analysis result.The result shows that the injection of the subsynchronous frequency component can cause core saturation and loss increase of transformer and,in comparison with the subsy chrounous frequency voltage,the transformer can withstand the subsynchrounous frequency current with large proportion.Therefore,it is an effective strategy to suppress the subsynchronous oscillation by way of injecting inversely subsynchronous frequency current.