异步联网后的云南电网中PSS2B增益改进

Gain improvement of PSS2B in Yunnan Power Grid after asynchronous connection

目前云南电网部分机组存在双输入型电力系统稳定器(PSS2B)高频段增益限制中低频段增益的问题,提出新型的PSS2B(New-PSS2B),目的是增大中低频段的增益,并减少高频段对中低频段增益的限制。在PSASP用户自定义模型(UDM)中搭建New-PSS2B自定义模型,通过研究分析改进前后PSS2B模型的增益,发现采用New-PSS2B有效提高了中低频段增益。基于PSASP仿真软件,在单机无穷大系统中调用NewPSS2B模块,通过仿真验证了New-PSS2B在中低频段各个频率点抑制低频振荡的效果都优于原有的PSS2B,说明了New-PSS2B具有在全频段都能提供合适阻尼的能力,也能满足电网抑制低频振荡的要求。

Currently,some units in Yunnan Power Grid have the problem that the high frequency gain of PSS2B(dualinput Power System Stabilizer) restricts the gain of the middle and low frequency band. A New-PSS2B(New structure of PSS2B) is proposed to increase the gain of middle and low frequency band and reduce the restriction of high frequency band on the gain of medium and low frequency band. New-PSS2B user-defined model is built in PSASP UDM(User-Defined Model). It can be found that the New-PSS2B can effectively improve the medium and low frequency gain by analyzing the gain of PSS2B and New-PSS2B model. Finally,the New-PSS2B model is implemented to single-machine infinite system on PSASP. Simulative results verify that the New-PSS2B is superior to the existing PSS2B in terms of suppressing low-frequency oscillation at each frequency point in both medium and low frequency band. These results indicate that the New-PSS2B provides sufficient damping in the whole frequency band and satisfies the requirements of low frequency oscillation suppression in power grid.