基于综合阻抗的光伏发电并网联络线纵联保护  

The Pilot Protection of Grid Connection Lines for Photovoltaic Power Generation Based on Integrated Impedance

作　　者：桂小智 蒙天赐 潘本仁 马龙 梁振锋[2] GUI Xiaozhi;MENG Tianci;PAN Benren;MA Long;LIANG Zhenfeng(State Grid Jiangxi Electric Power Research Institute,Nanchang 330096,Jiangxi,China;School of Electrical Engineering,Xi’an University of Technology,Xi’an 710054,Shaanxi,China;State Grid Baoji Electric Power Supply Company,Baoji 721004,Shaanxi,China)

机构地区：[1]国网江西省电力有限公司电力科学研究院,江西南昌330096 [2]西安理工大学电气工程学院,陕西西安710054 [3]国网宝鸡供电公司,陕西宝鸡721004

出　　处：《电网与清洁能源》2023年第8期139-144,154,共7页Power System and Clean Energy

基　　金：国网江西省电力有限公司科技项目(52182020008H)。

摘　　要：针对光伏发电并网联络线纵联保护灵敏度不足的问题,提出一种基于综合阻抗的光伏发电并网联络线纵联保护方法。分析了光伏发电并网联络线故障时,光伏发电系统的故障电流特征。建立了光伏并网联络线区内、外故障时的线路模型,构建了由线路两端电压电流之比得到的综合阻抗。当并网联络线区内故障时,故障相综合阻抗模值较小,非故障相的模值很大;并网联络线区外故障时,综合阻抗模值很大。据此构成保护判据,并利用线路等值电容计算保护定值。利用PSCAD建立光伏并网系统并进行了并网联络线故障仿真,考虑了不同故障位置、类型、过渡电阻及光伏出力大小等因素,仿真表明,所提方法能识别区内、外故障,且耐过渡电阻能力较强。To address sensitivity deficiency of the pilot protection of the tie-line of photovoltaic(PV)power generation,a pilot protection method of PV power generation based on the integrated impedance is proposed.The current characteristics of the tie-line of PV power generation are analyzed when it faults.The circuit model of photovoltaic grid connection is established,and the comprehensive impedance is obtained from the ratio of voltage and current at both ends of the circuit.When the fault is in the zone of the tie-line area,the integrated impedance modulus of the fault phase is small,but the non-fault phase modulus is large.When the fault is outside,the integrated impedance modulus is large.Based on this,the protection criterion is constituted and the protection setting value is calculated by equivalent capacitance of the line.A simulation model for the PV grid-connected system faults is built with PSCAD,and the fault locations,fault types,transition resistance and photovoltaic output are considered.The simulation results show that the proposed method can reliably identify internal and external faults,and has a strong ability to resist transition resistance.

关 键 词：综合阻抗 光伏发电并网联络线 纵联保护 

分 类 号：TM773[电气工程—电力系统及自动化]