摘要: |
为了使得基于直流注入原理的小电流接地故障选线定位保护的注入直流电流不影响供电系统运行,提出根据中性点对地电压的变化自适应调节限流电阻的阻值,将直流发生器注入故障系统的直流电流限制在规定范围内。白炽灯的灯丝电阻具有正特性,其阻值随着端电压的升高而增大,因此将一定数量的白炽灯和固定阻值电阻串联作为自适应可调限流电阻以调节注入直流电流。对自适应可调电阻的工作原理进行了分析,给出了白炽灯型号和数量的选择原则。现场实验结果证明了所提方法的有效性和实用性。 |
关键词: 小电流接地系统 直流注入 直流发生器 限流电阻 自适应调节 故障定位 |
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基金项目:专利:中华人民共和国实用新型专利(ZL2009200227467)
基金项目:山东省自然科学基金资助项目(ZR2012EEL19);临沂市科技发展计划资助项目(201312018) |
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Adaptive output current adjustment of direct current generator |
ZHANG Huifen, ZHANG Enping
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School of Electrical Engineering,University of Jinan,Ji’nan 250022,China
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Abstract: |
Since the injecting DC of the protection for faulty line selection and fault location may influence the proper operation of distribution system,it is proposed to keep the output current of its DC generator within a prescriptive range by adjusting its current-limiting resistance adaptively according to the voltage of neutral point. As the filament resistance of incandescent lamp has positive characteristics that its resistance increases along with the increase of the terminal voltage,a certain number of incandescent lamps and a fixed resistor,in series connection,can be used as the adaptive current-limiting resistor for adjusting the injecting DC. The operating principle of current-limiting resistor is analyzed and the selection principles of incandescent lamp type and number are given. The effectiveness and practicality of the proposed method are verified by the field experimental results. |
Key words: small current grounding system direct current injection DC generator current-limiting resistor adaptive adjustment electric fault location |