Experimental Validation of HomHBFEM Simulations of Fast Corrector Magnets for PETRA IV

TL;DR

This paper validates the HomHBFEM simulation method for PETRA IV's fast corrector magnets by comparing simulation results with measurements, demonstrating accuracy across a broad frequency range.

Contribution

It introduces and experimentally validates a novel homogenized harmonic balance finite element method for efficient nonlinear eddy-current simulations of laminated magnets.

Findings

Good agreement between simulations and measurements from 10 Hz to 10 kHz.

HomHBFEM enables efficient 3D nonlinear eddy-current simulations without fine mesh or time-stepping.

Validated for PETRA IV's fast corrector magnets.

Abstract

This paper presents experimental validation of the homogenized harmonic balance finite element method (HomHBFEM), which we have developed as a dedicated simulation technique for magnets with fast excitation cycles, in particular the fast corrector (FC) magnets for PETRA IV at DESY. The HomHBFEM allows efficient three-dimensional nonlinear eddy-current simulations of laminated magnets at elevated frequencies with a relatively coarse finite element (FE) mesh and without computationally expensive time-stepping. This is achieved by combining a frequency-domain-based homogenization technique with the harmonic balance FE method. The simulation results for the magnetic flux density along the axis of the FC magnets as a function of frequency and the resulting integrated transfer function (ITF) are compared to Hall probe and search coil measurements of the first prototype FC magnet for PETRA IV. A good agreement between simulated and measured ITFs is achieved for excitation frequencies from 10 Hz to 10 kHz.