电流互感器二次侧回路状态检测装置研制

负载电流通过电流互感器(CT)接入电能表进行计量,若CT二次侧回路被人为改变以达到窃电目的,CT二次侧回路的阻抗特性会发生改变。通过在CT二次侧回路串接测试CT,由STM32微控制器产生特定频段的高频检测信号从测试CT二次侧的一端注入,并由STM32微控制器对从测试CT二次侧的另一端传回的高频信号进行采样和算法处理。CT二次侧回路状态不同,微控制器采集的信号也不同,对应的幅频特性也不同。试验表明,该装置可快速、准确地检测二次线圈电感量差别很大的CT二次侧回路的正常、开路、短路及异常状态。

Development of secondary circuit state detecting device for current transformer

The load current is connected to the meter for measurement via the current transformer (CT),if the CT secondary circuit is artificially changed to achieve the purpose of stealing,the impedance characteristics of CT secondary circuit will change.Through the CT secondary circuit in series test CT,the high frequency detection signal of the specific frequency band generated by the STM32 microcontroller is injected from one end of the test CT secondary side,and the high frequency signal returned from the other end of the test CT secondary side is sampled and processed by the STM32 microcontroller.If the status of CT secondary circuit is different,the signals collected by the microcontrollers are also different,and the corresponding amplitude-frequency characteristics are also different.Experiments show that the proposed device can quickly and accurately detect the normal,open,short circuit and abnormal state of the secondary circuit of CT with large difference in inductance of the secondary coil.