摘要
针对新疆哈密地区风、光、火打捆经天中特高压直流送出的复杂送端系统出现的次同步振荡引起某电厂大型火电机组跳机事件,首先根据主机厂提供的机组扭振特性参数,并结合现场实测数据,验证了系统侧存在与机组扭振模式互补频率的谐波电流是引起本次机组跳机事件的主要原因。新能源次同步振荡扰动因素众多,造成跳机电厂发生次同步振荡的扰动源不止一个,根据现场试验,存在多个次同步振荡扰动源,多重因素综合作用下激发系统产生次同步振荡,进一步,当系统振荡频率与机组扭振频率互补时,将导致火电机组侧次同步振荡。为避免大型机组切机对电网产生冲击,经仿真研究,建议在跳机电厂火电机组侧采用机端阻尼控制器与附加励磁阻尼控制器联合抑制措施,现场试验结果表明此联合抑制措施具有明显控制效果。
Aiming at the sub-synchronous oscillation event leading to the thermal power units ina power plant tripping,occurred in hybrid integration system with wind,light and thermal power transmitted by Tianzhong HVDC in Hami area,based on the torsional vibration characteristic parameters of the unit provided by the main engine factory,combined with the field measured data,it is verified that the harmonic current of the system side with a complementary frequency of the unit torsional vibration mode is the main cause of the tripping.There are many factors that cause the sub-synchronous oscillation of new energy,and there are more than one source of the sub-synchronous oscillation in the power plant.According to field tests,there are multiple sub-synchronous oscillation disturbance sources to stimulate the sub-synchronous oscillation of the system.Furthermore,when the system oscillation frequency is complementary to the unit torsional vibration frequency,it will lead to sub-synchronous oscillation at the side of thermal power unit.In order to avoid the impact of large-scale machine tripping on the power grid,it is suggested that a combined damping controller at the end of the unit and an additional excitation damping controller be adopted at the side of the thermal power units in the skip-generator power plant,the field test results show that the combined control measures have obvious control effect.
作者
杨志文
YANG Zhiwen(Shenhua Guoneng Hami Power Plant,Hami 839000 Xinjiang,China)
出处
《电力大数据》
2021年第8期83-92,共10页
Power Systems and Big Data
关键词
次同步振荡
阻尼
抑制措施
风电
火电机组
sub-synchronous oscillation
damping
suppression measures
wind power
thermal generating unit
