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【2017年整理】3.2 单侧电源辐射网络相间短路的距离保护.ppt

发布:2017-06-06约8.39千字共53页下载文档
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为了正确反映保护安装处到短路点之间的距离,必须加入相间电压和同名相的两相电流差。 继电器1 继电器2 继电器3 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. KZ1: (2)三相短路 测量阻抗: KZ1 、 KZ2 、 KZ3都能正确反应故障位置,若故障点落在保护范围,3个继电器都起动。 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. (3)二相短路 KZ1: Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. KZ2:测量阻抗落在区外,不能起动。 同理,B-C短路,K2起动;C-A短路,K3起动。因此,要接3个阻抗继电器分别反应不同的相间故障。 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 3. 反映接地短路故障的阻抗继电器接线 作用:作为接地短路故障测量元件。 当发生单相金属性接地短路故障时,只有故障相的电压降低,故障点相对地电压为零。 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 以A相为例,故障点对地电压为零。 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 将故障点电压和电流分解为序分量,则 保护安装处三序分量电压为 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 保护安装处A相电压为: Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 若加入继电器电压、电流为 则测量阻抗为 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 为了正确测量阻抗,加入继电器电压、电流应为: 其中: 测量阻抗: Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 加入相电压、带零序电流补偿的相电流,阻抗继电器就能正确测量保护安装处至短路点间距离。 继电器1 继电器2 继电器3 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 电流保护简单可靠 整定、保护范围、灵敏度受电网接线方式、运行方式影响大 电流、电压保护一般只适用于35kV及以下电压等级的配电网。35kV及其以上的复杂电网很难满足选择性、灵敏性和速动性的要求 对于110kV及以上电压等级的复杂网,线路保护采用何种保护方式? →距离保护 3.2 单侧电源辐射网络相间短路的距离保护 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Pr
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