
2012年第6卷第1期 2012,Vol.6,No.1
南方电网技术
SOUTHERN POWER SYSTEM TECHNOLOGY
文章编号:1674-0629(2012)01-0013-06
中图分类号:TM864
特约专稿
Featured Articles 文献标志码:A
黑启动过程中空载变压器合闸过电压及其限制措施
蔡汉生',陈喜鹏「,胡玉峰2,贾磊1,史丹1
(1,南方电网科学研究院,广州510080;2.中国南方电网有限责任公司,广州510623)
摘要:空载变压器合阐时可能产生的幅值较高、持续时间较长的谱源过电压会导致避雷器吸收能量过大而损坏。研究黑启动电源通过升压变压器带空载长线路,在空载变压器合闻时导致的过电压情况,并提出了限制合闸过电压的措施。结论为:不采取措施下进行空载变压器合间,在绝大多数情况下金属氧化物避雷器(MOA)吸收能量超过避需器自身的能耗允许水平;若500kV主变压器合前第三绕组带上一定客量的低压电抗器,可以有效地降低空载变压器合闸过电压水平及MOA吸收能量;加载地区负荷和在主变压器断路器安装选相合闸装置对抑制空载变压器合阐过电压的效果明显。关键调:黑启动;空载变压器;合闸过电压;谱振过电压
TheOvervoltageofNo-loadTransformerClosinginBlackStartProcess
andItsRestrictions
CAI Hansheng', CHEN Xipeng', HU Yufeng, JIA Lei', SHI Dan(1. Electric Power Research Institute, CSG, Guangzhou 510080, China; 2. China Southern Power Grid Co., Ltd., Guangzhou 510623, China)
Abstract: The resonance overvoltage of high amplitude and long duration, which likely occurs in no-load transformer closing, can lead to a damage to the metal oxide arrester (MOA) as the MOA absorbs excessive energy. This paper analyzes the overvoltage of no-load transformer closing in the condition of black start source connected with no-load long line, and puts forward restrictions for it The results show that when without any restriction, the energy consumption of MOA is more than the allowable level in no-load transformer closing; but the consumption and the overvoltage level can be effectively reduced with a measure of setting some low resistance on the tertiary winding before 500 kV amin transformer closing; the other two effective measures to restrict the overvoltage
are to load regional load and to install phase selectoion making device in the circuit breaker for main transformer Key words: black start; no-load transformer; closing overvoltage; resonance overvoltage
空载变压器合闸是电网黑启动过程中必不可
少的操作之一。空载变压器合闸时因变压器的非线性励磁特性即变压器励磁电感在饱和与不饱和之间的周期性变化,可能会在合闻母线或其他母线上产生幅值较高、持续时间较长的谐振过电压,并导致避雷器吸收能量过大而损坏[1-4]。空载变压器合闸过电压与合闸前系统的阻抗特性密切相关,特别是黑启动初期由于系统阻尼较弱,空载变压器合闸过电压尤为突出。随着目标网架及地区负荷的逐渐恢复,系统阻尼越来越大,这将有利于限制空载变压器合
技术及装置开发与应用”项目(2009BAA23B03)。
Foundation items: National Science & Technology Support Program Dur-ing the Eleventh Five-year Plan Period: “Development and Application of Key Technology and Equipments to Resist Extreme Weather for Power Grid"(2009BAA23B03).
万方数据
闸过电压2,3]。本文主要研究黑启动电源通过升压变压器带220kV/500kV空载长线路,在空载变压器合闻闸时导致的变压器母线过电压及金属氧化物避雷器(metaloxidearrester,MOA)吸收能量情况,并提出了合闸过电压的限制措施。
1计算模型和计算方案 1.1计算模型
空载变压器合闸过电压仿真计算模型如图1所示,其中图1(a)为合闸前未带上地区负荷,图1(b)为合闸前带上部分地区负荷。
仿真计算中,发电机采用次暂态电势和次暂态电抗模型;线路采用频率相关模型;母线及主变压器高压侧MOA额定电压均为200kV/420kV;断路器采用统计开关模型(统计200次),合闸相角在一