文章摘要
何越,张勇,陈亦平,等.增强型调速器对云南电网超低频振荡影响分析[J].电力系统自动化. DOI: 10.7500/AEPS20190123001.
HE Yue,ZHANG Yong,CHEN Yiping, et al.Analysis on the Impact of Enhanced Governor on Ultra-low Frequency Oscillation in Yunnan Power Grid[J].Automation of Electric Power Systems. DOI: 10.7500/AEPS20190123001.
增强型调速器对云南电网超低频振荡影响分析
Analysis on the Impact of Enhanced Governor on Ultra-low Frequency Oscillation in Yunnan Power Grid
DOI:10.7500/AEPS20190123001
关键词: 异步联网  超低频振荡  调速器  频率稳定
KeyWords: asynchronous interconnection  ultra-low frequency oscillation  governor  frequency stability
上网日期:2019-05-10
基金项目:中国南方电网有限责任公司科技项目(ZDKJXM20160001)
作者单位E-mail
何越 中国南方电网电力调度控制中心 heyue@csg.cn 
张勇 中国南方电网电力调度控制中心 zhangyong@csg.cn 
陈亦平 中国南方电网电力调度控制中心 chenyiping@csg.cn 
莫维科 华南理工大学 mowk@csg.cn 
摘要:
      云南电网部分水电机组采用增强型调速器,其动态特性对频率稳定影响重大,是在云南系统内引发超低频振荡的重要扰动源之一,严重威胁异步电网频率安全。为揭示水电机组增强型调速器对云南异步系统频率影响,通过与普通型调速器进行对比,对增强型调速器进行了精确建模,对其动态特性进行了频域解析,并针对系统频差从不同方向穿越一次调频死区时的动力学行为进行了理论计算和时域仿真。在此基础上,论证增强型调速器在水电机组一次调频死区附近没有稳定平衡点,且当系统频差缓慢穿回一次调频死区时,增强型调速器将在超低频段引入约90度的相位滞后,降低系统频率安全稳定裕度。最后,借助小扰动分析工具计算了包含水轮机、调速器、发电机模型的单机系统特征根,并通过对比仿真,验证了建模计算的有效性和正确性,说明增强型调速器不仅与水锤效应在超低频段有相似的负阻尼效应,还是引发超低频振荡的扰动源头之一,使超低频振荡持续且无法衰减。
Abstract:
      Enhanced governor was widely adopt in hydro-power generators to improve the performance of the primary frequency regulation around the dead band, which also proved to be one of the main disturbance sources of the ultra-low frequency oscillation with great effect on the whole system’s frequency, and it would greatly threaten the frequency stability of Yunnan asynchronous power grid. To reveal the effect of the hydro-power enhanced governor on Yunnan asynchronous system frequency, the precise model of the typical enhanced governor was derived comparing with traditional normal governor, and the dynamic characteristic of which was analyzed by frequency domain analysis. The dynamic behavior of the system frequency difference across the dead zone of frequency modulation from different directions was also analyzed in very detail. On this basis, it is demonstrated that the enhanced governor does not have a stable equilibrium point near the primary frequency modulation dead zone of the hydro-power units, and when the system frequency difference slowly passes back to the dead zone, the enhanced governor will introduce a phase lag of about 90 degrees in the ultra-low frequency band, reducing the safety and stability margin of the system frequency. In this paper, the validity and correctness of the modeling calculation including the turbine, the governor and the generator model are calculated, and the effect of the enhancement type is not only with the water hammer effect in ultra-low band, but also one of the source of the disturbance of ultra-low frequency oscillation, which keeps the ultra-low frequency oscillation continuously and cannot be attenuated.
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