摘要
随着电磁式电压互感器(PT)励磁特性的提高,PT产生铁磁谐振的条件、区域等特征发生了变化,这导致电网原有针对铁磁谐振采用的消谐措施有效性也随之降低。基于云南电网某变电站典型PT的铁磁谐振,应用PSCAD/EMTDC软件建立了仿真计算模型,研究线路系统电容电流和PT励磁特性对铁磁谐振的影响。同时,基于建立了10 kV铁磁谐振模拟试验平台,进行了几种典型PT的铁磁谐振模拟试验,以验证PT仿真计算模型。试验和计算结果表明:PT的铁磁谐振模拟试验和仿真计算波形具有良好的一致性; 10 kV和35 kV配电网系统虽有不同的铁磁谐振区间,但均在线路(电容)与PT(电感)的阻抗比为0. 13时发生工频谐振;阻抗比过高极易导致谐振时PT电流过大,而且两个电压系统的影响区域也不同;在特定的阻抗比区间内,会产生很高的铁磁谐振过电压。
With the improvement of the excitation characteristics of the electromagnetic voltage transformer( or PT),the ferroresonance characteristics excited from the PT have changed,including its motivating condition and resonance region. This makes the effectiveness of the original ferroresonance suppressing measures in the distribution network reduced. The ferromagnetic resonance occurs frequently in some of distribution lines and substations in Yunnan. Based these typical PTs,this paper established the numerical calculation model with the PSCAD/EMTDC software and studied the effects of impedance ratio of line( capacitance) to PT( inductance) in distribution network on ferroresonance characteristics. Based a10 kV ferroresonance simulating test platform established,the numerical calculation model of PT was verified by the some of resonance simulating tests with four typical PTs. The simulation and calculation results show that the waveform of PT ferroresonance measurement has good consistency with the numerical calculation. Although the 10 kV and 35 kV distribution systems have different ferroresonance resonance regions,their power frequency resonance occurs at the same impedance ratio of 0. 13. The extremely high impedance ratio would easily cause the high current in PT,and the influence area of impedance ratio for10 kV distribution system is inconsistent with 35 kV. A high overvoltage of ferroresonance would produce in a specific area of impedance ratio.
作者
张志磊
郭涛
田石金
刘学忠
刘红文
ZHANG Zhilei;GUO Tao;TIAN Shijin;LIU Xuezhong;LIU Hongwen(Yunnan Power Grid Corporation Honghe Power Supply Bureau,Mengzi 661100,China;State Key Laboratory of Electrical Insulation and Power Equipment,Xi’an Jiaotong University,Xi’an 710049,China;Yunnan Power Grid corporation Electric Power Sicence Research Institute,Kunming 650011,China)
出处
《电瓷避雷器》
CAS
北大核心
2019年第1期71-75,83,共6页
Insulators and Surge Arresters
