In this paper, the time-domain equivalent circuit for three-phase delta-connected loads, within the frame of the Clarke transformation and the space vector approach,is derived. The proposed theoretical derivation is a further contribution to extend the general theory of the space-vector approach for transient analysis of three-phase networks. In fact, since space vectors are defined in the time domain, the proposed methodology can be used for three-phase transient analysis, whereas the conventional steady-state analysis results as a special case. The theoretically derived equivalent circuit is validated through Matlab/Simulink simulation of a case study consisting in a specific three-phase active load. Keywords—Clarke transformation, power system analysis, space vec