中性点非直接接系地统中单相接地故障的保护.ppt

南京信息工程大学南京信息工程大学 电气工程与自动化系电气工程与自动化系 电力系统继电保护电力系统继电保护 2.4 中性点非直接接地系统中单相 接地故障的保护 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 2.4 中性点非直接接地系统中单相接地故障的保护 中性点非直接接地系统 中性点不接地、中性点经消弧线圈接地、中性点经电阻接地 单相接地短路，故障电流很小，允许继续运行12个小时 发出信号，供运行人员查找接地的线路 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 2.4.1 中性点不接地系统单相接地故障的特点 K点A相接地 A相电压为零，电容电流为零 其他两相对地电压升高为 倍， 对地电容电流增大 倍 电源负荷 （最简单的网络） Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 2.4.1 中性点不接地系统单相接地故障的特点 （2.59） （2.60） （2.61） 非故障相电流 有效值 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 2.4.1 中性点不接地系统单相接地故障的特点 非故障I线 （2.62） 有效值 （2.63） 非故障线路特点： 非故障线路中零序电流为线路I本 身的电容电流 电容性无功功率的方向：母线- 线路 发电机多条线路 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 2.4.1 中性点不接地系统单相接地故障的特点 故障II线 （2.65） （2.66） （2.67） （2.68） 发电机多条线路 故障线路特点：零序电流为全系统非 故障元件对地电容电流之和 电容性无功功率的方向：线路-母线 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 2.4.1 中性点不接地系统单相接地故障的特点 总结： 全系统出现零序电 压 非故障元件： 零序电流数值等 于电容电流 方向：母线-线路 故障元件： 零序电流数值等于全系统非故障元件电容电流之和 方向：线路-母线 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 2.4.2 中性点经消弧线圈接地系统中单相接地故障 的特点 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 2.4.2 中性点经消弧线圈接地系统中单相接地故障 的特点 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 2.4.2 中性点经消弧线圈接地系统中单相接地故障 的特点 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 2.4.2 中性点经消弧线圈接地系统中单相接地故障 的特点 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 2.4.2 中性点经消弧线圈接地系统中单相接地故障 的特点 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 2.4.3 零序电压保护 绝缘监视 无选择性 告警、不跳闸 由运行人员依次短时断开 每条线路，并继之将断开 线路投入 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 2.4.4 零序电流和零序功率方向保护 零序电流保护 原理：故障线路零序电流非故障线路零序电流 一般使用零序电流互感器，若使用零序电流过滤器需考虑Ibp 动作电流 灵敏系数 （2.72） （2.73） 零序功率方向保护 原理：故障与非故障线路零序功率方向不同 Evaluation only.Eva