TITLE:
A General Method to Compute the Electric Flux Lines between Two Magnet Wires in Close Contact and Its Application for the Evaluation of Partial Discharge Risks in the Slots of Electric Machines Embedded in Future Transportation Systems
AUTHORS:
Philippe Collin, David Malec, Yvan Lefevre
KEYWORDS:
Partial Discharges, Dielectric Constant, Electric Motor, Finite Elements, Paschen’s Criterion, Ballistic Method
JOURNAL NAME:
Advances in Aerospace Science and Technology,
Vol.6 No.1,
March
8,
2021
ABSTRACT: The sizing of the Electrical Insulation System (EIS) is an important
challenge in electric motors of higher specific power
driven by faster inverters. That keeps increasing the electric stress which the winding is submitted in the stator
slot. Consequently, Partial Discharges (PD) are more likely to occur. Nowadays, the Paschen’s criterion is widely used to
evaluate the risk of partial discharge. It requires the knowledge of electric field lines. This paper presents a method
to precisely compute the electric field lines in a two-dimensional (2D)
electrostatic problem. The field of study is composed of two magnet wires in
close contact. Such configuration is representative of the turn-to-turn interaction in an electric motor slot. The problem
is solved using the scalar potential formulation only. The notion of flux tubes
is used for the post process of the electric field lines in a developed numerical code on Matlab. The
developed method is compared to a ballistic method already included on Matlab.
The work presented here is included in an automatic tool to suppress or reduce
the partial discharge risk in a stator slot of high power density motor destined for future transportation systems.