Network reconfiguration is a classical optimal operation problem of electrical distribution networks. This problem aims at a specific topology optimization and chooses the optimal switch status of sectionalizing switches, tie-switches, and soft open points. The objective is maintaining real-time load balancing and loss reduction for distribution networks with the growing penetration of distributed energy resources and coordinating real-time transactive dispatch tasks between supply and demand at the market level of distribution networks. This chapter revisits the fundamentals of DistFlow equations and its convex relaxation formulations, and then introduces the disjunctive convex hull relaxation (DCHR) approach to tackle the disjunctive nature for distribution network reconfiguration problems. With continuous parent–child relationship variables as disjunctive variables, this DCHR approach is theoretically tighter than the McCormick linearization method and the Big-M method, and it is especially suitable for distribution networks with directional power flows. Through case studies, the chapter demonstrates the computing performance in terms of running time and iterations using a DCHR approach yields superior numerical performance than prior relaxation methods.