AC POWER MEASURING DEVICE AND AC POWER MEASURING METHOD

摘要

An AC power measuring device has: voltage detection units (32a to 32c) for measuring the voltage waveforms of the respective phases of a set of three electrically insulated wires (14a to 14c) for supplying three-phase alternating current to a load, by capacitive coupling, without contacting the conductive wires of the electrically insulated wires; current detection units (38a to 38c) for measuring the current waveforms of the set of electrically insulated wires by electromagnetic induction coupling without contacting the conductive wires of the electrically insulated wires; and a processing unit (36) for normalizing the voltage waveforms of the respective phases so that the normalized voltage waveforms become amplitude ratios based on a grounded type of the three-phase alternating current, obtaining the inter-line voltage waveforms of the set of electrically insulated wires on the basis of the normalized voltage waveforms of the respective phases, and calculating the power supplied to the load on the basis of the inter-line voltage waveforms and the current waveforms.