带量程扩展器的工频感应分流器的校准与应用

Calibration and Application of Range Extended Inductive Current Dividers

工频电流比较仪准确度通常达到0.001级以上,用于检定0.01级及以上的标准电流互感器。电流比较仪的一次电流和二次电流都采用分段串并联结构,变换一个电流比需要改动多个连接片。由于电流比相当多,检定时换接线工作量大,容易出错。工频感应分流器准确度可以达到10-6量级,只要选择适当的抽头就能得到需要的电流比,可以大大减轻检定工作量。如果使用零磁通电流互感器作为量程扩展器,就可以覆盖电流互感器的全部量程,与电流比较仪共同用于精密电流互感器的检定。

Current comparators are widely used in calibration of current transformers. In its application a great number of connecting sheets are connected by individual ranges. The reconnection could offer errors. An inductive current divider is also high accuracy ratio standard but is rarely used in current transformer calibration for its poor ranges. To cascade after zero-flux current transformers the measuring range of inductive current divider can be largely extended. It is feasible that the extended inductive current dividers serve as ratio standards in current transformer calibration together with current comparators.