配电网典型故障下的直流偏置电压产生条件及其导致的PT熔断分析

doi:10.19595/j.cnki.1000-6753.tces.231914

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摘要

电磁式电压互感器(Potential Transformer, PT)高压侧保护用熔断器频繁熔断问题广泛存在于10~35kV的中性点不接地配电网中,增加电网运维负担,威胁供电可靠性。为厘清PT高压侧熔断器频繁熔断的深层机理,本文基于叠加原理,采用数值计算方法,分析出典型故障下的系统空载暂态电压,发现该电压呈现出交直流复合的特殊形态——工频电压附加直流偏置电压,归纳总结出直流偏置电压的形成条件和机理为：故障消失时,三相杂散电容的净电荷不为零(Q_n≠0),且Q_n无泄放路径而形成直流偏置电压。在线路长度、PT阻抗、负载及无功补偿装置等不同因素影响下,研究了Q_n泄放路径对直流偏置电压的影响规律,发现直流偏置电压作用下PT深度饱和是触发熔断器熔断的最终原因。最后,通过PSCAD/EMTDC中的10kV配电网模型和380V/150V的实物动态模拟试验平台进行了仿真与试验验证。

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	温伟杰
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关键词 ：电磁式电压互感器, 配电网, 熔断器, 瞬时性接地故障, 直流偏置电压

Abstract：

The melting of fuse installed at the high-voltage side of the electromagnetic potential transformers (PTs) occurs frequently in the ungrounded power distribution system with rated voltage of 10~35kV, increasing the maintenance burden and endangering the reliability of power system. Focused on this problem, research on the mechanism of PT fuse melting is conducted, and the research shows that the deep saturation of the PT under the effect of the DC bias voltage (DCBV) is the ultimate cause of the fuse melting.
The paper presents theoretical derivations, simulation verifications, and experimental results regarding the generation conditions of DCBV and the mechanism of PT fuse melting. Firstly, the equivalent circuit of the power system without load during the whole fault process (single-phase ground fault, intermittent arcing ground fault, and two-phase ground fault) were derived. Subsequently, based on the principle of superposition, the equivalent circuit after the fault disappearance was decomposed into zero-input and zero-state circuits. By superimposing the zero-input response and zero-state response, the analytical expression of system voltage was obtained. According to the relationship between the DCBV and the net charge (Q_n) of stray capacitors at the moment when the fault disappears, it is inferred Q_n≠0 is the generation condition of DCBV.
Changing the discharge channels of Q_n may affect characteristics of DCBV, showing different waveform and decay time. By taking stray capacitance, PT impedance mode, load, and reactive power compensation device into consideration, factors related with DCBV were discussed. Finally, simulation in PSCAD/EMTDC and down-scaled experiments were conducted for verification. The main findings and conclusions of this paper are listed as follows:
1) In an ungrounded power system, if Q_n≠0, and without discharging channels, Q_n has to be redistributed on the stray capacitors, resulting in the DCBV. In the case of single-phase ground faults (intermittent arc ground faults), two-phase ground faults, three-phase ground faults, Q_n may not be zero at the fault disappear moment, generating DCBV; In the case of a two-phase short circuit fault, Q_n is always zero, hence there is no existence of DCBV.
2) Factors including stray capacitance, PT impedance, load, and reactive power compensation capacity, are related with the characteristics of DCBV. A greater stray capacitance and reactive power compensation capacity could lead to a slower decay speed of DCBV. Under light load and no-load conditions, the DCBV persists for a longer duration, whereas under heavy load, the DCBV quickly diminishes. The use of different PT impedance modes can lead to variations in the form of the capacitor voltage.
3) Large impedance (inductance and resistance) of high voltage winding of PT can result in the stray capacitor discharge circuit entering an overdamped state, leading to a decaying DC component in the zero-input response of the capacitor voltage. On the other hand, small impedance of high voltage winding of PT may trigger the switching of the PT branch between saturation and non-saturation states. The voltage on stray capacitors exhibits a waveform similar to ferro resonance. This continuous excitation current pulsing heat accumulation is the ultimate cause of the fuse melting.

Key words： Electromagnetic voltage transformers distribution networks fuses transient grounding faults DC bias voltage

收稿日期: 2023-11-16

PACS:

TM451.3

基金资助:

国家电网公司总部项目（5500-202155116A-0-0-00）和国家自然科学基金项目（52277120）资助

通讯作者: 陈晓龙,男,1985年生,副教授,硕士生导师,研究方向为电力系统故障分析、保护与控制等。E-mail：xiaolong@tju.edu.cn

作者简介: 温伟杰,女,1989年生,副教授,硕士生导师,研究方向柔性直流输配电网继电保护、AC/DC换流装备、交直流开关设备、大功率电力电子开断技术。E-mail：weijie.wen@tju.edu.cn

引用本文:

温伟杰, 胡铁伟, 陈晓龙, 王磊, 李斌. 配电网典型故障下的直流偏置电压产生条件及其导致的PT熔断分析[J]. 电工技术学报, 0, (): 231914-231914. Wen Weijie, Hu Tiewei, Chen Xiaolong, Wang Lei, Li Bin. Generation Condition of DCBV and the Analysis of PT Fusing Caused by it Under Typical Faults in the Distribution Network. Transactions of China Electrotechnical Society, 0, (): 231914-231914.

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[1] Ren Hongtao, Zhang Ying.Study on fault waveform library of PT high voltage side fuse in hydropower station[J]. Journal of Physics: Conference Series, 2023, 2488(1): 012018.
[2] 赵梦雅. 中压配电网电压互感器熔丝熔断防治措施的研究[D]. 北京: 华北电力大学, 2016.
Zhao Mengya.Study on the prevention measures of TV fuses blowing in medium voltage distribution network[D]. Beijing: North China Electric Power University, 2016.
[3] 张琰. 10kV电压互感器一次侧保护用熔断器轻熔断故障机理仿真研究[D]. 武汉: 华中科技大学, 2023.
[4] 王宾, 张超, 丁心志. 中性点直接接地系统单相串联铁磁谐振时域解析分析[J]. 中国电机工程学报, 2022, 42(6): 2124-2133.
Wang Bin, Zhang Chao, Ding Xinzhi.Time domain analytical analysis of single-phase series ferromagnetic resonance in neutral point solid grounding power system[J]. Proceedings of the CSEE, 2022, 42(6): 2124-2133.
[5] Huang Weixiang, Yu Xiaoyong, Wu Lifang, et al.Simulation analysis of PT resonance for distribution network practical test platform[C]//2020 12th IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC), Nanjing, China, 2020: 1-5.
[6] Zhen L, JianBin C, Yuan X, et al. The ferroresonance of 10kV distribution PT during live working operation[C]//The 16th IET International Conference on AC and DC Power Transmission (ACDC 2020), Online Conference, 2021.
[7] Lu Pan, Wang Wen, Zhou Meina, et al.Method for actively suppressing ferromagnetic resonance of distribution network by resistive current[C]//2021 IEEE 1st International Power Electronics and Application Symposium (PEAS), Shanghai, China, 2021: 1-6.
[8] 林莉, 王军兵, 唐凤英, 等. 10kV电压互感器损坏的仿真计算研究[J]. 电力系统保护与控制, 2012, 40(17): 51-55.
Lin Li, Wang Junbing, Tang Fengying, et al.Simulation and computational analysis on potential transformer damage in 10kV system[J]. Power System Protection and Control, 2012, 40(17): 51-55.
[9] 杨鸣, 熊钊, 司马文霞, 等. 电磁式电压互感器“低频过电压激励-响应” 逆问题求解[J]. 电工技术学报, 2021, 36(17): 3605-3613.
Yang Ming, Xiong Zhao, Sima Wenxia, et al.Solution of the inverse problem of “low-frequency overvoltage excitation to response” for electromagnetic potential transformers[J]. Transactions of China Electrotechnical Society, 2021, 36(17): 3605-3613.
[10] Shott H S, Peterson H S.Criteria for neutral stability of wye-grounded-primary broken-delta-secondary transformer circuits[J]. Transactions of the American Institute of Electrical Engineers, 1941, 60(11): 997-1002.
[11] 耿军平. 配电网谐振过电压暂态过程的仿真计算研究[D]. 镇江: 江苏大学, 2018.
Geng Junping.Simulation and research on the transient process of distribute network resonant overvoltage[D]. Zhenjiang: Jiangsu University, 2018.
[12] 李蕾. 10kV配电网中铁磁谐振过电压及抑制措施的研究[D]. 济南: 山东大学, 2018.
Li Lei.Study on Ferroresonance overvoltage and suppression measures in 10kV distribution network[D]. Jinan: Shandong University, 2018.
[13] Peng Guixi, Yuan Shuangchen, Gao Xinhan, et al.Compound elimination method of potential transformer ferroresonance in distribution network[C]//2022 9th International Forum on Electrical Engineering and Automation (IFEEA), Zhuhai, China, 2022: 332-336.
[14] Yang J, Si X, Zhang G, et al. Risk assessment of ferroresonance in distribution network[C]//22nd International Symposium on High Voltage Engineering (ISH2021), Hybrid Conference, Xi’an, China,2021:.
[15] 王明钦, 陈维江, 李永君, 等. 油田35kV系统电压互感器高压熔断器异常熔断故障的抑制措施[J]. 电网技术, 2012, 36(12): 283-288.
Wang Mingqin, Chen Weijiang, Li Yongjun, et al.A countermeasure to deal with abnormal fusing of high voltage fuse for potential transformer in 35 kV oilfield power distribution system[J]. Power System Technology, 2012, 36(12): 283-288.
[16] 梁志瑞, 赵梦雅, 牛胜锁, 等. 配电网电压互感器熔丝熔断防治措施的缺陷及新措施研究[J]. 电力自动化设备, 2016, 36(9): 17-24, 32.
Liang Zhirui, Zhao Mengya, Niu Shengsuo, et al.Defects of measures against PT fuse melting in distribution network and research of new measure[J]. Electric Power Automation Equipment, 2016, 36(9): 17-24, 32.
[17] Ren Hongtao, Wei Xianguang, Wu Haifeng.Research on fuse failure and countermeasure of potential transformer in non-effect grounding system[C]//2022 5th Asia Conference on Energy and Electrical Engineering (ACEEE), Kuala Lumpur, Malaysia, 2022: 64-68.
[18] Lu Pan, Wang Wen, Yu Qian, et al.Permanent single-line-to-ground fault removal method for Ferro-resonance avoidance in neutral ungrounded distribution network[J]. IEEE Access, 2022, 10: 53724-53734.
[19] Xie Shuntian, Zhou Yuan, Tang Xiaojun, et al.Test and simulation of PT saturation characteristics during single-phase grounding fault recovery of 10kV distribution system[C]//2020 IEEE International Conference on High Voltage Engineering and Application (ICHVE), Beijing, China, 2020: 1-4.
[20] 韩羞草. 电压互感器高压保险熔断问题研究[D]. 北京: 华北电力大学, 2022.
Han Xiucao.Research on the fusing of voltage transformers’ high voltage fuse[D]. Beijing: North China Electric Power University, 2022.
[21] Zhao X. Guo H, Yang Y.Research on suppression of fuses of potential transformer fuse[C]//Journal of Physics: Conference Series, 2023, 2418(1).
[22] Zhao Xiaofeng, Qiu Yingdan, Li Qian, et al.Simulation analysis and suppression method of PT low frequency oscillation in distribution network[C]//2018 International Conference on Power System Technology (POWERCON), Guangzhou, China, 2018: 3151-3157.
[23] Wei Jufang, Yao Chuang, He Xiao, et al.Study of PT fuse meltdown triggered by low-frequency non-linear oscillation in distribution network[C]//Eighth International Conference on Energy Materials and Electrical Engineering (ICEMEE 2022), 2023, 12598: 677-687.
[24] 林莉, 何月, 王军兵, 等. 中性点不接地电网单相接地时电压互感器损坏机理[J]. 高电压技术, 2013, 39(5): 1114-1120.
Lin Li, He Yue, Wang Junbing, et al.Mechanism of potential transformer damaged in ungrounded neutral power system[J]. High Voltage Engineering, 2013, 39(5): 1114-1120.
[25] 任于展, 武仕朴, 汪友华, 等. 基于暂态电流差极值的电力变压器剩磁测量方法[J]. 电工技术学报, 2022, 37(5): 1088-1097.
Ren Yuzhan, Wu Shipu, Wang Youhua, et al.Residual flux measurement method of power transformer based on extreme value of transient current difference[J]. Transactions of China Electrotechnical Society, 2022, 37(5): 1088-1097.
[26] 赖胜杰, 夏成军, 纪焕聪, 等. 计及负荷等值阻抗的配电网合环转供电分析模型[J]. 电工技术学报, 2022, 37(11): 2859-2868.
Lai Shengjie, Xia Chengjun, Ji Huancong, et al.An analysis model for power transfer from loop closing in distribution network considering load equivalent impedance[J]. Transactions of China Electrotechnical Society, 2022, 37(11): 2859-2868.
[27] 李露露, 李永培, 周新月, 等. 10kV交联聚乙烯电缆内部多形态间歇性电弧故障建模[J]. 电工技术学报, 2022, 37(23): 6104-6115.
Li Lulu, Li Yongpei, Zhou Xinyue, et al.Modeling of internal multiform intermittent arc fault for 10kV XLPE cable[J]. Transactions of China Electrotechnical Society, 2022, 37(23): 6104-6115.
[28] 黄文美, 郭萍萍, 郭万里, 等. 直流偏置对磁致伸缩材料高频动态损耗及磁特性的影响分析[J]. 电工技术学报, 2022, 37(22): 5765-5775.
Huang Wenmei, Guo Pingping, Guo Wanli, et al.Impact analysis of DC bias on high-frequency dynamic loss and magnetic characteristics for magnetostrictive materials[J]. Transactions of China Electrotechnical Society, 2022, 37(22): 5765-5775.