附加励磁阻尼控制对励磁系统常规功能的影响

Influence of Supplementary Excitation Damping Control on Regular Functions of Excitation System

内蒙古上都电厂由于采用固定串补面临次同步谐振(SSR)威胁,通过技术经济论证,拟实施以附加励磁阻尼控制(SEDC)为核心的综合治理方案。SEDC属于励磁系统的附加控制,其控制输出与励磁系统常规控制输出叠加,在励磁电压上形成次同步频率分量,进而产生次同步频率阻尼电磁转矩以抑制SSR。分析并避免SEDC对励磁系统常规功能的影响是SEDC方案工程实施必须解决的基础问题。采用理论分析、仿真计算与现场实验相结合的方法进行研究,结果表明:合理设置SEDC限幅及增益,系统稳态、暂态下,SEDC均不会对励磁系统常规功能产生显著影响。

The high compensation level of fixed-series-capacitor for the Shangdu transmission system can result in SSR. The SEDC is proposed as the countermeasure based on technical and economical demonstration. The output of SEDC is added to the regular output of excitation system to produce a sub-synchronous frequency component on field voltage for the sub-synchronous frequency damping electromagnetic torque. The influence of SEDC on regular functions of excitation system is a fundamental issue in practical applications. Researches on this field are carried out with theoretical analyses, digital simulations and hardware experiments. Results show that in system steady and transient state, SEDC does not affect the normal functions of excitation system with reasonable controller gains and limit settings.