摘要
真空断路器切除空载变压器是其运行操作中产生操作过电压最严重的情况之一。本文针对10 kV大电流接地系统真空断路器切除空载配电变压器所产生的操作过电压暂态特性进行了分析研究。首先通过建立该情况下的单相等值分析电路推导出空载变压器被开断后所产生的最高截流过电压的具体表达式;然后基于ATP仿真软件建立相应仿真模型,并通过在特定情况下计算结果与仿真结果的一致性验证所建立模型的正确性;最后对该系统中三种不同情况下所产生的相应操作过电压暂态特性进行研究。研究结果表明:不论空载变压器在何时被同期分断,其低压侧最高过电压倍数均略高于其高压侧;就单独一相而言,当断路器该相电流变化斜率为负而截流值为正值(包括零值)时,变压器高低压侧操作过电压数值均在其负峰值处达到最大值,反之亦然;真空断路器三相不同期分闸会对系统安全稳定运行产生更加严重的不利影响;相较于开断Yyn0型变压器,开断Ynyn0型变压器时其首开相与系统中性点处所要承受的电压水平更低。以上研究结论均可为实际工程应用提供理论依据。
The removal of the no-load transformer by the vacuum circuit breaker is one of the most serious cases of operating overvoltage during its operation. The paper analyzes and studies the transient characteristics of the operating over-voltage generated by the vacuum circuit breaker of the 10 kV large-current grounding system cutting off the no-load distribution transformer. First, by establishing a single-equal value analysis circuit in this case, the specific expression of the highest intercepting overvoltage generated after the no-load transformer is opened is derived. Then the corresponding simulation waveform is established based on the ATP simulation software, and the correctness of the established model is verified according to the consistency of the calculation result and the simulation result under certain circumstance. Finally, we studied the transient characteristics of the corresponding operating overvoltage in this system under three different conditions. The research results show that: no matter when the no-load transformer is disconnected at the same time, the maximum overvoltage multiples of its low-voltage side are slightly higher than that of its high-voltage side;when the current change slope of the phase of the circuit breaker is negative and the intercept value is positive(including zero), the operating overvoltage values of the transformer’s high and low voltage sides reach the maximum value at its negative peak value, and vice versa;the three-phase opening of the vacuum circuit breaker in different periods will have a more serious adverse effect on the safe and stable operation of the system;compared with the Yyn0 type transformer is opened, the first phase and the neutral point of the system have to withstand a lower voltage level when the Ynyn0 type transformer is opened. The above research conclusions can provide a theoretical basis of practical engineering applications.
作者
李璨
咸日常
张宁
胡玉耀
王玮
李佳琪
郭洋
LI Can;XIAN Richang;ZHANG Ning;HU Yuyao;WANG Wei;LI Jiaqi;GUO Yang(School of Electrical and Electronic Engineering,Shandong University of Technology,Zibo 255000,China;State Grid Shandong Electric Power Company Zibo Power Supply Company,Zibo 255000,China)
出处
《真空科学与技术学报》
EI
CAS
CSCD
北大核心
2022年第12期943-951,共9页
Chinese Journal of Vacuum Science and Technology
基金
国家重点研发计划智能电网技术与装备重点专项项目(2016YFB0900605)。
