Power losses derived of instantaneous compensation in three-phase four-wire systems

The effect that the instantaneous compensation in three-phase four-wire systems, including or not the compensation of the neutral current, has on the supply-line power losses is studied in this paper. According to the instantaneous value concept, the noninstantaneous-active current can be reduced without altering the instantaneous active power. Two approaches are considered in this paper for instantaneous compensation: a) for eliminating the total noninstantaneous-active current but the neutral current can still flow; b) for eliminating the modified noninstantaneous-active current but the neutral current is compensated. It demonstrates that, in common situations of medium and low relative-values of the zero-sequence voltage, the total losses (line and neutral losses) obtained with the second approach are lower than those obtained with the first approach. Experimental results confirm the theoretical properties and show the compensator performance.