  This paper presents a distributed optimization algorithm tailored for solving
optimal control problems arising in multi-building coordination. The buildings
coordinated by a grid operator, join a demand response program to balance the
voltage surge by using an energy cost defined criterion. In order to model the
hierarchical structure of the building network, we formulate a distributed
convex optimization problem with separable objectives and coupled affine
equality constraints. A variant of the Augmented Lagrangian based Alternating
Direction Inexact Newton (ALADIN) method for solving the considered class of
problems is then presented along with a convergence guarantee. To illustrate
the effectiveness of the proposed method, we compare it to the Alternating
Direction Method of Multipliers (ADMM) by running both an ALADIN and an ADMM
based model predictive controller on a benchmark case study.
