The AC Optimal power flow (OPF) problem is one of the most fundamental problems in power systems engineering. For the past decades, researchers have been relying on unproven heuristics to tackle OPF. The hardness of OPF stems from two issues: (1) non-convexity and (2) combinatoric constraints (e.g., discrete power injection/ejection constraints). The recent advances in providing sufficient cond...

Simulations have shown that while semi-definite relaxations of AC optimal power flow (AC-OPF) on three-phase radial networks with only wye connections tend to be exact, the presence delta seem render them inexact. This article shows such inexactness originates from non-uniqueness relaxation solutions and numerical errors amplified by non-uniqueness. finding motivates two algorithms recover exac...

The purpose of this thesis is to investigate the cost-optimal placement and sizing of battery storage as a PV integration measure in the distribution grid level. Additionally, potential synergies between PV generation, battery storage, smart PV curtailment and electric mobility are also explored within this thesis. Accordingly, a versatile optimization tool has been developed in order to identi...

Optimal Power Flow (OPF) is an important operational and planning problem in minimizing the chosen objective functions of the power systems. The recent developments in power electronics have enabled introduction of dc links in the AC power systems with a view of making the operation more flexible, secure and economical. This paper formulates a new OPF to embrace dc link equations and presents a...

Nonlinear AC Optimal Power Flow (OPF) problems are commonly approximated by linearized DC OPF problems to obtain real power solutions for restructured wholesale power markets. We first present a standard DC OPF problem, which has the numerically desirable form of a strictly convex quadratic programming (SCQP) problem when voltage angles are eliminated by substitution. We next augment this stand...

The present paper applies the recently proposed Augmented Lagrangian Alternating Direction Inexact Newton (ALADIN) method to solve non-convex AC Optimal Power Flow Problems (OPF) in a distributed fashion. In contrast to the often used Alternaring Direction of Multipliers Method (ADMM), ALADIN guarantees locally quadratic convergence for AC-OPF. Numerical results for IEEE 5–300 bus test cases in...

Linear optimal power flow (OPF) formulations are powerful tools applied to a large number of problems in systems, e.g., economic dispatch, expansion planning, state estimation, congestion management, electricity markets, among others. This article proposes novel mixed-integer linear programming formulation for the ac-OPF three-phase unbalanced distribution networks. The model aims minimize tota...