摘要
通过样例对配电变压器一次侧CT参数选择进行了详细的分析,列出了选择步骤,说明了应根据工程的实际情况确定CT参数,高压柜内CT测量绕组的实际负荷决定了其二次额定电流宜选为5A。CT一次额定电流的确定不仅取决于变压器一次侧额定电流,而且与继电保护整定之间的关系异常密切。采用按保护最大整定值确定准确限值系数、兼顾微机保护装置量程确定额定准确限值一次电流、适当提高CT的变比、经复核和校验后最终确定CT参数的方法可取得技术合理、经济适用的应用效果。
The paper analyses the detremination of CT＇s parameters for the distribution transformer primary side with several samples, lists detremination steps, illustrates that parameters of CT should be determined according to the actual situation of the project, and the second rated current should be selected for 5A according to the actual load of the CT＇s measurement winding. The determination of CT＇s rated primary current is not only depended on the transformer＇s rated primary current, but also unusually related to the relay protection setting. So, the accuracy limit factor is determined by the maximum setting values of relay protection, the microcomputer protection relay＇s range should be considered when the rated accuracy limit primary current is determined, rated transformation ratio should be increased properly, and the CT＇s parameters are determined after review and check. The application effect of this method is reasonable on technology, applicable and economical.
出处
《电气技术》
2015年第3期74-78,共5页
Electrical Engineering
关键词
电流互感器
配电变压器
准确级
准确限值系数
整定值
current transformer
distribution transformer
accuracy class
accuracy limit factor
setting values
