It is possible to obtain the differential voltage, line voltage, phase voltage, etc. by obtaining the sums and differences of instantaneous measurement values of voltage and current in each element.
- Differential voltage/current: Differential voltage and current between two elements are computed in the three-phase three-wire system.
- Line voltage/phase current: Line voltage and phase current that are not measured are computed in the three-phase three-wire system (Figure 1).
- Star-delta conversion: Line voltage is computed from the phase voltage using the three-phase four-wire system data.
- Delta-star conversion: Phase voltage is computed from the line voltage in the three-phase three-wire system (3V3A system)
Figure 1. Line voltage/phase current
Figure 2. Delta-star conversion