基于模型辨识的新型牵引供电系统直流馈线保护原理  

Principle of DC feeder protection for new traction power supply system based on model identification

作　　者：和敬涵[1] 廖南杰 李猛 卫云辉 郭旭刚 李强 HE Jinghan;LIAO Nanjie;LI Meng;WEI Yunhui;GUO Xugang;LI Qiang(School of Electrical Engineering,Beijing Jiaotong University,Beijing 100044,China;China Academy of Railway Sciences,Beijing 100089,China)

机构地区：[1]北京交通大学电气工程学院,北京100044 [2]中国铁道科学研究院集团有限公司机车车辆研究所,北京100089

出　　处：《电力自动化设备》2023年第10期95-102,共8页Electric Power Automation Equipment

基　　金：国家自然科学基金委员会-国家电网公司智能电网联合基金资助项目(U2066210)。

摘　　要：基于双向换流器的柔性直流牵引供电系统中,直流线路故障电流上升速度极快,且机车启动同样会造成馈线电流快速增长,其暂态特征和远端故障电流相似,要求保护在极短时间内区分两者。对此,提出基于模型辨识的直流馈线保护方法,通过模型辨识原理求解时域微分方程,从而求解不同时刻的等效电阻,同时对所计算的等效电阻进行统计分布验证,并利用方差系数构造保护判据。所提方案能够在5 ms内准确区分故障电流和机车启动电流,实现保护的可靠动作。大量仿真结果表明,在过渡电阻为100Ω的短路故障下保护依然能可靠动作,同时具有30 dB的抗噪声能力和100μs的耐同步误差能力。In the flexible direct current(DC)traction power supply system based on bi-directional converter,the DC line fault current rises very fast,and the locomotive start-up also causes the feeder current to grow rapidly,and its transient characteristics are similar to those of the far-end fault current,which requires the protection to distinguish between the two in a very short time.In this regard,a DC feeder protection method based on model identification is proposed.The model identification principle is used to solve the equivalent impedance at different times by means of time-domain differential equations,and to verify the statistical distribution of the calculated equivalent impedance and construct the protection criterion using the variance coefficient.The proposed scheme can accurately distinguish the fault current from the locomotive star-up current within 5 ms,and achieve a reliable protection action.Extensive simulation results show that the pro⁃tection can still operate reliably under short circuit fault with transition resistance of 100Ω,and has 30 dB anti-noise ability and 100μs anti-synchronization error ability.

关 键 词：柔性直流牵引供电系统 继电保护 故障电流 机车启动电流 模型辨识 方差系数 

分 类 号：TM77[电气工程—电力系统及自动化] TM922