Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Optimal Power Flow in Four-Wire Distribution Networks: Formulation and
  Benchmarking   In recent years, several applications have been proposed in the context of
distribution networks. Many of these can be formulated as an optimal power flow
problem, a mathematical optimization program which includes a model of the
steady-state physics of the electricity network. If the network loading is
balanced and the lines are transposed, the network model can be simplified to a
single-phase equivalent model. However, these assumptions do not apply to
low-voltage distribution networks, so the network model should model the
effects of phase unbalance correctly. In many parts of the world, the
low-voltage distribution network has four conductors, i.e. three phases and a
neutral. This paper develops OPF formulations for such networks, including
transformers, shunts and voltage-dependent loads, in two variable spaces, i.e.
current-voltage and power-voltage, and compares them for robustness and
scalability. A case study across 128 low-voltage networks also quantifies the
modelling error introduced by Kron reductions and its impact on the solve time.
This work highlights the advantages of formulations in current-voltage
variables over power-voltage, for four-wire networks.

17
The categories of this paper are: q-fin
12
The categories of this paper are: nucl-th
3
The categories of this paper are: physics
5
The categories of this paper are: gr-qc
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol
29
The categories of this paper are: funct-an
16
The categories of this paper are: stat
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
1
The categories of this paper are: cs
15
The categories of this paper are: nucl-ex
23
The categories of this paper are: solv-int
28
The categories of this paper are: alg-geom
30
The categories of this paper are: q-alg
4
The categories of this paper are: cond-mat