The traveling wave method for down-lead disconnection detection is a highly promising detection method.However

due to the limited length of the down-lead

higher demands are imposed on response time and signal strength of the current detection sensors in the detection system.The structural performance of current detection sensor is studied

and sensor parameters adapted to nanosecondlevel pulse signal response are experimentally selected.The experimental system consists of a signal generator

a down-lead

a current detection sensor

and an oscilloscope.The signal generator injects a square-wave signal into one end of the down-lead

creating a pulsed current inside the down-lead at the instant of voltage jump.The signal is captured by the sensor

and the oscilloscope reads the signal waveform.According to the parameters in the waveform signal

such as excitation signal rise time and amplitude

echo signal time and amplitude

noise amplitude

signal-to-noise ratio

and so on

the signal detection capability of the current detection sensor under different parameter conditions is analyzed.The experimental results show that the coil has good responsiveness under the conditions that the number of turns of the coil is 3

the specification of the magnetic core is 64mm×40mm×20mm

and the diameter of the winding wire is 1.76mm.