This paper shows that a multi-generator, multi-load and multi-branch network is mathematically equivalent to a system that has one generator supplying one load through one transmission line that has multiple “phases”. Based on this observation, a transformation is proposed to analyze complex power systems. The Transform results in a set of decoupled one-source one-load networks, very similar to the creation of sequence networks with the symmetrical components transform. By analyzing the characteristics of each decoupled network, one can extract important information, such as voltage instability modes, of a complex power network. The proposed transform has the potential to establish the theoretical foundation for processing and interpreting multi-location phasor data collected by wide-area monitoring systems.