引用本文: | 汪冬辉,姚 旭,张坤贤,许文宣,焦在滨,康小宁.独立运行微电网的故障特征分析[J].电力自动化设备,2014,34(3): |
| WANG Donghui,YAO Xu,ZHANG Kunxian,XU Wenxuan,JIAO Zaibin,KANG Xiaoning.Analysis on fault characteristics of independent microgrid[J].Electric Power Automation Equipment,2014,34(3): |
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摘要: |
根据某海岛的微电网结构建立了电磁暂态仿真模型,其包含4种微电源:储能、柴油发电机、直驱风机和光伏发电单元。在模型中设置多种故障,分析相应的故障特征及故障对传统继电保护的影响,并得出如下结论:在各微电源故障期间均能提供一定的故障电流,并且其自身保护按低电压穿越要求整定的前提下,馈线上的电流速断保护受各微电源故障电流受限的影响无法使用,而过电流保护受影响很小;电网电压严重跌落时,采用PQ控制的微电源故障电流频率将偏离工频,由此可能导致故障馈线母线侧的过电流保护失效,此时只能依靠纵联保护;在包含PQ控制的微电网中,不应配置基于故障分量的继电保护装置。 |
关键词: 微电网 独立运行 光伏电池 故障特征 继电保护 故障分析 故障电流 模型 |
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基金项目:国家自然科学基金资助项目(51177127);国家重点基础研究发展计划(973计划)项目(2012CB215105) |
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Analysis on fault characteristics of independent microgrid |
WANG Donghui1, YAO Xu2, ZHANG Kunxian2, XU Wenxuan1, JIAO Zaibin1, KANG Xiaoning1
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1.School of Electrical Engineering,Xi’an Jiaotong University,Xi’an 710049,China;2.Gansu Province Electric Power Company,Lanzhou 730030,China
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Abstract: |
A electromagnetic transient simulation model is built according to the microgrid topology of an island,which contains four kinds of microsource:battery storage,diesel generator,direct-driven wind turbine and photovoltaic unit. Different faults are set in the model,and the corresponding fault characteristics,as well as their influences on traditional relay protection,are analyzed. Conclusions:on the condition that all microsources can provide fixed fault current and their own protectors are set based on LVRT(Low Voltage Ride Through) rule,current fast-tripping protection of feeder is invalid because of the limitation of microsources’ fault currents,but it has slight impact on over-current protection;when grid voltage badly dips,the frequency of fault currents of microsources with PQ control will deviate from 50 Hz,which may cause the failure of over-current protection at faulty feeder side,therefore,pilot protection should be used;the fault-component-based protection should not be configured in the microgrid,which contains PQ control. |
Key words: microgrid independent operation photovoltaic cells fault characteristics relay protection failure analysis electric fault currents models |