| 摘要 |
An electronic watt-hour meter with a phase fail detection function and a phase fail detection method are provided to increase reliability by operating a phase fail detection algorithm interlockingly with a wattage measuring algorism in a CPU(Central Processing Unit). An electronic watt-hour meter with a phase fail detection function is composed of a voltage conversion unit(22) converting voltage of the input power into a micro voltage signal; a current conversion unit(23) converting load current of the input power into a micro current signal; an analog-digital conversion unit(24) converting the micro voltage and micro current signals output from the voltage and current conversion units, into each digital signal; and a phase fail detecting unit(27) embedding firmware and detecting a phase fail by processing the micro voltage and micro current signals digitalized in the analog-digital conversion unit, through the firmware. The phase fail detecting unit calculates an area value by summing up the micro voltage and micro current signals digitalized in the analog-digital conversion unit for the predetermined time. The phase fail detecting unit analyzes the change of the calculated area value and then determines that a phase fail is generated if the area value drops below a reference value. |
