ELECTRICAL LEAK DETECTING APPARATUS AND ELECTRICAL LEAK DETECTING METHOD FOR IMPROVING THE ELECTRICAL LEAK DETECTING ACCURACY

摘要

According to an embodiment of the present invention, disclosed is an electric leakage detection apparatus which comprises: a ground voltage measuring unit for measuring a ground voltage; an ADC unit for sampling the measured ground voltage and converting the same into a digital value; a root means square calculating unit for calculating a root means square converted into the digital value; a Fourier transform unit for calculating voltage for each harmonic component which is an integer multiple of a basic frequency (a power frequency of an AC commercial power source) by performing Fourier transform on measured ground voltage on the basis of the root means square of the ground voltage; a content calculation unit for calculating voltage content for the basic frequency with respect to voltage obtained by summing voltages for each harmonic component on the basis of the voltage for each harmonic component; a harmonic distortion factor calculating unit for calculating a total harmonic distortion factor and a harmonic distortion factor on the basis of the voltage for each harmonic component; a zero-crossing calculation unit for calculating the number of zero-crossing times which define that the ground voltage, which is converted into the digital value, passes through zero voltage for a predetermined time (T1); and an electric leakage suspicious area determining unit for determining that the ground voltage is generated by an electric leakage of the AC commercial power source on the basis of at least one of the root means square of the ground voltage, the voltage content, the total harmonic distortion factor, the harmonic distortion factor, and the number of the zero-crossing times, and determining an area where the ground voltage is measured as an electric leakage suspicious area on the basis of a result of the determination.