| 引用本文: | 邓聪,江亚群,黄纯.基于不同次数谐波下品质因数一致性的孤岛检测方法[J].电力自动化设备,2020,40(12): |
| DENG Cong,JIANG Yaqun,HUANG Chun.Islanding detection method based on consistency of quality factor under different harmonic orders[J].Electric Power Automation Equipment,2020,40(12): |
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| 摘要: |
| 针对基于谐波电压或阻抗的孤岛检测方法所存在的盲区较大且阈值难以设定的问题，提出一种基于不同次数谐波下品质因数一致性的孤岛检测判据，并结合q轴谐波电流扰动法作为新型孤岛检测方案。推导了微网发生孤岛后负载品质因数的计算公式。由于负载固有的品质因数与谐波次数无关，发生孤岛后不同次数谐波下的品质因数是一致的，而并网时计算的品质因数没有确定的物理含义，不同次数谐波下其值差异大，利用这一特性判别是否发生孤岛。理论分析了所提方法的可行检测区，结果表明其能实现孤岛的小盲区快速检测，且满足计算要求所需要的谐波扰动很小，对电能质量影响小。相比于谐波电压或阻抗检测法，所提方法对主网参数的适应性更强，阈值设定简单。在多种负载和线路参数场景下进行了仿真分析，结果验证了所提方法的正确性和有效性。 |
| 关键词: 孤岛检测 谐波电流 品质因数 检测盲区 并网 一致性 |
| DOI：10.16081/j.epae.202009001 |
| 分类号:TM761 |
| 基金项目:国家自然科学基金资助项目(51677060)；湖南省自然科学基金资助项目(2019JJ60012) |
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| Islanding detection method based on consistency of quality factor under different harmonic orders |
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DENG Cong, JIANG Yaqun, HUANG Chun
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College of Electrical and Information Engineering, Hunan University, Changsha 410082, China
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| Abstract: |
| In order to solve the problem that the harmonic voltage or impedance-based islanding detection method has a large non-detection zone and the threshold is difficult to set, an islanding detection criterion based on the consistency of quality factor under different harmonic orders is proposed, and the q-axis harmonic current disturbance method is combined as a new islanding detection scheme. The computational formula of load quality factor after microgrid islanding is derived. Since the inherent quality factor of load has no concern with harmonic orders, the quality factors under different harmonic orders are consistent after islanding, while the quality factor calculated during the grid-connection has no definite physical meaning, and its value varies greatly under different harmonic orders. This characteristic is used to determine whether islanding occurs. The feasible detection zone of the proposed method is analyzed theoretically, and the results show that the proposed method can realize the rapid detection of small non-detection zone, and the harmonic disturbance required to meet the calculation requirements is small, which has small influence on power quality. Compared with the harmonic voltage or impedance-based detection methods, the proposed method is more adaptable to the main network parameters, and its threshold setting is simple. Simulative results under various load and line parameter scenarios verify the correctness and effectiveness of the proposed method. |
| Key words: islanding detection harmonic current quality factor non-detection zone grid-connection consistency |
