  With the rapid development of renewable and distributed energies, the
underlying dynamics of power systems are no longer dominated by large
synchronous generators, but by numerous dynamic components with heterogeneous
characteristics. In such a situation, the traditional stability analysis method
may fail due to the challenges of heterogeneity and scalability. In this paper,
we handle this issue by fundamental circuit theory. Inspired by the work of
Brayton and Moser in the nonlinear RLC circuit, we extend the concept of the
voltage potential to phasor circuits and offer new results into the distributed
stability analytics in power systems. We show that under certain distributed
passivity-like conditions the system-wide stability can be ensured. The
simulation of a 3-bus system is also provided to verify our results.
