Standards Development

Scope

The purpose of this part of IEC 60404 is to define the general principle and technical details of the methods of measurement of the DC magnetic properties of permanent magnet materials in an open magnetic circuit using a superconducting magnet (SCM).

This method is applicable to permanent magnet materials, such as those specified in IEC 60404-8-1, the properties of which are presumed homogeneous throughout their volume.

There are two methods:

– the SCM-Vibrating Sample Magnetometer (VSM) method;

– the SCM-Extraction method.

Purpose

The purpose of this new item is to standardize an open magnetic field measurement method using superconducting magnets that enables accurate measurement of the magnetic properties of highperformance permanent magnet materials, which has been difficult to measure with conventional measurement methods.

High-performance permanent magnet materials with high coercivity, e.g. Nd-Fe-B magnets, have been used in the electric and automobile industry and its usage increases rapidly to meet the need to improve energy saving and to increase efficiency of electromagnetic applications, e.g. traction motors for Electric Vehicle (EV) and Hybrid Electric Vehicle (HEV), which are urgently demanded to contribute to the problem of global warming.

However, there has been no standard method which can determine all the magnetic properties of the high-performance permanent magnet materials with coercivity HcJ higher than 2 MA/m to meet the need of the industry. The method specified in IEC 60404-5, which is a method of measurement in a closed magnetic circuit, can lead to significant measurement errors for measurement of HcJ ≥ 1,6 MA/m due to magnetic saturation in parts of the pole faces of the yoke.

Electric and automobile industry can develop more efficient motors faster and contribute to reduction of CO2 emission by knowing the accurate magnetic properties of high-performance magnet materials using this measurement method.