The invention provides an underground cable fault detection
system and fault detection method thereof. The underground cable fault detection
system comprises a cable fault
ranging device, a cable pathdetection device, and a fault point detection device. The cable fault
ranging device consists of a low-
voltage pulse
signal source, a high-
voltage pulse
signal source, and a high-speed receiving device to realize
signal detection in a low-
voltage pulse reflection method and a flashover method. The cable path detection device includes an alternating-current high-voltage
signal source and an
electromagnetic induction receiving device; the frequency and amplitude of the alternating-current high-voltage
signal source are adjustable; the alternating-current high-voltage
signal source excites a to-be-detected cable to generate an
electromagnetic field; and the
electromagnetic induction receiving device detects the
electromagnetic field generated by the to-be-detected cable. The fault point detection device includes a high-
voltage pulse signal source, a direct-current signal source, an alternating-current signal source, a step-voltage receiving device, an
electromagnetic induction receivingdevice, and an acousto-magnetic synchronous receiving device. The underground cable fault detection
system can be applied to detection of underground cable open-circuit, short-circuit, grounding, low-resistance, high-resistance flashover and high-resistance leakage faults to obtain an accurate fault point.