| 引用本文: | 陈 俊,郭自刚,张琦雪,严 伟,沈全荣.基于比率制动特性的电压互感器中线断线判别方法[J].电力自动化设备,2011,31(4): |
| CHEN Jun,GUO Zigang,ZHANG Qixue,YAN Wei,SHEN Quanrong.Identification of PT neutral line break based on percentage restraint[J].Electric Power Automation Equipment,2011,31(4): |
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| 摘要: |
| 分析了电压互感器（TV）中线断线时的电气特征，即三相电压中将产生3次谐波分量，且大小相等、方向相同。试验结果表明，TV中线断线时，相电压和自产零序电压中的3次谐波幅值随TV原边输入电压增大而增大。在理论分析和模拟试验的基础上，提出了一种基于比率制动特性的TV中线断线判别新方法，在没有保护元件启动的情况下，当TV自产零序电压3次谐波幅值与三相电压最大基波幅值的比值大于比率定值时，判为TV中线断线，延时动作于报警。理论分析和现场数据表明：该方法能够真实反映TV中线断线的电气特征，可以准确判断TV中线断线，并且具有运算量小、易于程序实现等特点。 |
| 关键词: 电压互感器 中线断线 3次谐波电压 比率制动 |
| DOI： |
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| Identification of PT neutral line break based on percentage restraint |
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CHEN Jun, GUO Zigang, ZHANG Qixue, YAN Wei, SHEN Quanrong
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NARI-Relays Electric Co.，Ltd.，Nanjing 211102，China
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| Abstract: |
| The electrical characteristic of PT with broken neutral line is analyzed：the third harmonics of three-phase voltages are enhanced，with same amplitude and direction. Test shows that，when PT neutral line is broken，the third harmonics of phase voltage and generated zero-sequence voltage increase along with the increase of input voltage. Therefore，it is proposed to identify the PT neutral line break according to the ratio of zero-sequence voltage third harmonic to maximal phase voltage. Theoretical analysis and site data indicate that，the proposed method detects PT neutral line break accurately，with small computation and suitable for programming. |
| Key words: PT neutral line break third harmonic voltage percentage restraint |
