| 摘要 |
PROBLEM TO BE SOLVED: To provide an inter-voltage/current phase delay estimation device which estimates a phase delay between a voltage waveform and a current waveform by using a non-contact type voltage/current sensor, and its method.SOLUTION: An inter-voltage/current phase delay estimation device operates periodically (for example, every minute, every 3 minutes or the like), measures a voltage by a voltage waveform measurement part 101, and detects a zero-cross point of a voltage of a trigger detection part from the measured voltage waveform. A current waveform measurement part 103 measures a current waveform by only an integer cycle amount of a power supply waveform with a the zero-cross point of the voltage as a trigger, and accumulates the measured current waveform in a current waveform accumulation part 104. A phase delay measurement part 105 calculates an effective value of each current waveform accumulated in the current waveform accumulation part 104, and a power factor between each current waveform and a simulated voltage waveform having a phase delay, and calculates a phase delay at which the power factor becomes maximum. The phase delays are calculated on all of the current waveforms which are accumulated in the current waveform accumulation part 104, and an average of the phase delays is calculated by an averaging part 153.SELECTED DRAWING: Figure 1 |
