Analysis of Nonlinear Dynamics of Permanent Magnet Magnetic Contactor via Novel Computationally Efficient Analytical Method Considering Stray and Leakage Fluxes

Abstract

Improving the efficiency and end-use of energy distribution can significantly reduce global energy consumption. As the magnetic contactor (MC) is the most common switchgear used for control in most grids, minimizing its energy consumption has motivated the development of a permanent magnet (PM) MC that exhibits several advantages over conventional solenoid MCs. However, analyzing the transient magnetic behavior of a PM MC requires computationally expensive 3D finite element analysis (FEA). Herein, a modified version of a recently proposed nonlinear transient path energy method (NT-PEM) is proposed as an analytical alternative to FEA. Within the modification to NT-PEM, a new topology for nonlinear dynamic magnetic equivalent circuit (ND-MEC) is proposed with a methodology for accurate evaluation of stray and leakage flux path parameters. For coil leakage reluctances, a novel path function based on a conchoid’s arc is proposed. For stray reluctances, a path function based on the average length of an elliptical arc is proposed. This path function, along with the proposed permeability correction for nonlinear core reluctance calculation routines, led to a four-fold reduction in NT-PEM analysis time from the original version of the proposed method. The feasibility of the proposed NT-PEM is verified via comparison with commercial 3D FEA and experimental data obtained from a PM MC with a single coil and single PM. NT-PEM and FEA equally displayed accurate results, indicating that NT-PEM is a promising computationally efficient alternative to FEA owing to significantly reduced analysis time, which is essential when considering numerous designs and design parameters.

Keywords

• Magnetic contactor
• MEC
• nonlinear dynamics
• NT-PEM
• permanent magnets
• stray flux modeling