| 引用本文: | 张琦雪,谢 亮,陈佳胜,陈 俊,尹 春.通过比较发电机3次谐波电压识别TV断线的新方法[J].电力自动化设备,2011,31(5): |
| ZHANG Qixue,XIE Liang,CHEN Jiasheng,CHEN Jun,YIN Chun.PT failure detection by synchronous generator third-harmonic voltage comparison[J].Electric Power Automation Equipment,2011,31(5): |
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| 摘要: |
| 发电机机端电压互感器（TV）高压侧出现的间隙性断线，若故障轻微，则基波电压变化不大。利用正序电压和负序电压判别TV断线的方法有可能无法识别故障，且发电机定子接地3次谐波电压判据有可能误报警。通过分析，发电机定子单相接地故障时，TV 3次谐波电压会发生变化，各相3次谐波电压变化是相同的，差异较小。但是，TV断线时（包括间隙性断线），断线相与非断线相的3次谐波电压有明显的差异。因此，提出一种判别TV断线的新方法，该方法通过比较3次谐波电压最大值与最小值，采用比率制动判据实现。动模试验结果验证了该方法的有效性。 |
| 关键词: 电压互感器 故障检测 3次谐波电压 比率制动 |
| DOI： |
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| PT failure detection by synchronous generator third-harmonic voltage comparison |
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ZHANG Qixue1, XIE Liang2, CHEN Jiasheng1, CHEN Jun1, YIN Chun1
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1.NARI-Relays Electric Co.，Ltd.，Nanjing 211102，China;2.Nanjing Power Supply Company，Nanjing 210036，China
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| Abstract: |
| The fundamental voltage changes slightly when a minor occasional HV-side wire break of synchronous generator PT（Potential Transformer） happens. The fault may not be recognized by the positive-sequence or negative-sequence voltage criterion，and the third-harmonic voltage criterion of generator stator SGF（Single-phase Grounding Fault） may issue a false alarm. Analysis illustrates that，the PT third-harmonic voltage changes，equally in three phases when SGF occurs，while the change of faulty phase is apparently different from that of healthy phases when PT wire break（including occasional HV-side wire break） occurs. Therefore，a PT wire break detection method is proposed，which adopts the percentage restraint criterion by comparing the maximum third-harmonic voltage with the minimum one. Its validity is confirmed by dynamic experiments. |
| Key words: potential transformer failure detection third-harmonic voltage percentage restraint |
