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arXiv · 1512.06903

Linear Approximations to AC Power Flow in Rectangular Coordinates

Sairaj V. Dhople·Swaroop S. Guggilam·Yu Christine Chen
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Abstract

This paper explores solutions to linearized powerflow equations with bus-voltage phasors represented in rectangular coordinates. The key idea is to solve for complex-valued perturbations around a nominal voltage profile from a set of linear equations that are obtained by neglecting quadratic terms in the original nonlinear power-flow equations. We prove that for lossless networks, the voltage profile where the real part of the perturbation is suppressed satisfies active-power balance in the original nonlinear system of equations. This result motivates the development of approximate solutions that improve over conventional DC power-flow approximations, since the model includes ZIP loads. For distribution networks that only contain ZIP loads in addition to a slack bus, we recover a linear relationship between the approximate voltage profile and the constant-current component of the loads and the nodal active and reactive-power injections.

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Sairaj V. Dhople, Swaroop S. Guggilam, Yu Christine Chen. 2015-12-21. Linear Approximations to AC Power Flow in Rectangular Coordinates. https://arxiv.org/abs/1512.06903

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