Novel multi-objective optimization method of electric and magnetic field emissions from double-circuit overhead power line

Abstract

Summary This paper proposes a novel method for determining optimal arrangements of overhead double‐circuit power line conductors aimed to reduce electric and magnetic field emissions. Extremely low frequency electric and magnetic field optimization problems have multiple objectives. Multiple‐objective optimization allows the simultaneous optimization of two or more conflicting objectives and determination of mutually non‐dominated solutions. The multi‐objective optimization technique used in this paper is based on Genetic Algorithm to obtain a set of mutually non‐dominated solutions (Pareto optimal set) for the two objectives: the electric and magnetic field strengths near overhead double‐circuit power line. Also, additional assessment criteria were defined for the selection of several decision scenarios from the Pareto optimal set. The results and practical aspects of the proposed methodology are demonstrated on two typical 400‐kV double‐circuit overhead power lines. The efficiency of the proposed multiple‐objective optimization method is compared with the existing one based on single‐objective optimization function. Copyright © 2016 John Wiley & Sons, Ltd.

Optimization of electric and magnetic field emissions produced by independent parallel overhead power lines

“…1 shows a basic catenary geometry for a sagged conductor, where c f is the conductor's sag. A catenary of OHPL is described by equation [5]:…”

“…The components of the electric field strength coefficient of the straight segment and their images in the x, y and z directions are [5]:…”

“…The worst-case scenario, for single-circuit OHPL, takes into consideration maximum values for lines current and conductor sag, while in double-circuit OHPL the same phase shift angle for both terns of phase conductors is the additional hypothesis [4]. The effects of rearranging the double-circuit phase succession and optimization methods used to solve problems of optimal arrangements of double-circuit OHPL intended to decrease electric and magnetic field emissions are the subject of numerous studies (for an overview see [5]).…”

“…the magnetic flux density and electric field strength limit values, respectively; ( , ) m g y z -the inequality constraints; M -the number of inequality constraints; and upper limits of decision variables; Nthe number of all conductors.The inequality constraints ( , ) m g y z are defined to satisfy the predefined values of[5]:…”

A Survey on Optimization Techniques Applied to Magnetic Field Mitigation in Power Systems

“…For example, by installing compactors along overhead line spans (realized through rod insulators forming equilateral triangles), a 56% reduction of the maximum ground-level MF is achievable, in comparison to an overhead transmission line realized with compacted towers (the solution that, at present, minimizes the magnetic field without compactors) [14]. However, this solution also entails a new problem, which includes higher voltage gradients on conductors and insulators, resulting in higher audible noise, radio interference, and increased hardware corona [15][16][17][18]. Additionally, the mitigation achieved can be limited, especially in UPC, where the current rating (ampacity) may be affected by these techniques [19].…”