FIELD: electronic energy meters; detection of current and voltage unbalance in power supplied to energy meters. SUBSTANCE: method involves voltage or current measurement for each phase and evaluation of respective normalized quantity as well as value of normalized phase quantities. Then high value of normalized phase quantity is compared with first threshold value and ratio of normalized phase quantities, with second threshold value. Unbalance is recognized by increase in first threshold value above high value of normalized phase quantity and by decrease in ratio of normalized phase quantities below second threshold value. EFFECT: facilitated detection of current and voltage unbalance in multiphase power supply. 19 cl, 2 dwg
