LEAK CURRENT DETECTION DEVICE AND METHOD

摘要

PROBLEM TO BE SOLVED: To provide a leak current detection device and method for detecting a leak current caused by insulation resistance to ground.SOLUTION: A leak current detection device includes: a current trance sensor assembly 10 for clamping a measuring object electric line and detecting leak current; a voltage detection part 14 for detecting a voltage applied to the measuring object electric line; a phase pulse width measuring part 20 for detecting the phase difference between a signal waveform of the voltage detected by the voltage detection part 14 and a signal waveform of the leak current detected by the current trance sensor assembly 10; a power supply frequency measuring part 21 for measuring a power supply frequency applied to the measuring object electric line on the basis of the signal waveform of the voltage detected by the voltage detection part 14; a phase angle calculation part 22 for calculating a phase angle of the leak current flowing through the measuring object electric line on the basis of the phase difference and the power supply frequency; and a leak current calculation part 27 for calculating a leak current component caused by insulation resistance to ground included in the leak current on the basis of the leak current detected by the current trance sensor assembly 10 and the phase angle.