EN IEC 60034-2-3:2020 pdf free.Rotating electrical machines – Part 2-3: Specific test methods for determining losses and efficiency of converter-fed AC motors (IEC 60034-2-3:2020).
6.42-3-C- Alternate Efficiency Determination Method(AEDM)
This represents the calculation of the efficiency by the use of a tool sometimes referred to as an analytical model.Multiple steps are required to qualify this model.Since the calculations are influenced by manufacturing techniques each manufacturer will have to qualify their own analytical model.Qualification requires the following conditions to be fulfilled:
Use of the recognized test procedure according to 6.2.
The test lab shall be qualified to reliably perform the tests with the required accuracy.. Enough different types or base models chosen to be tested and evaluated to prove the tool is accurate across all products.
An adequate sample of each base model of an identical design shall be tested to verify that the tool accurately predicts the nominal efficiency.
All inputs are based on a statistical analysis that ensures their accuracy.NOTE 1 Adequate in this context means at least 3 pieces per selected model.
The base models chosen should typically range in rated power，enclosure,speed,electricalcharacteristics and other differing physical or functional characteristics which affect energyconsumption or efficiency.
NOTE 2 lt is envisaged to develop the AEDM in future editions of this document to become an alternate preferredmethod.
6.5 2-3-D – Determination of efficiency by calculation
In case of large motors with rated output powers higher than 2 MW, if the motor rating exceeds the available testing capabilities，the determination of the additional high frequency losses caused by converter operation based on calculations may be an alternative procedure to givean order of magnitude of the additional losses. This calculation has to be based on the realpulse patterns of the converter,the frequency-dependent equivalent circuit parameters of theelectric motor and by using motor models capable of covering the effects of the higher frequencies.
7 lnterpolation of losses at any operating point
For the loss determination in any operating point,losses either measured or calculated according to the procedures given in the previous subclauses might be used as interpolationpoints.An interpolation function is given to calculate the losses at any other operating point.
For induction motors,at all test points the relative motor voltage should not be lower than therelative motor frequency.For synchronous motors designed for operation with lower flux/voltage(e.g. for efficiency reasons) the determination of the 7 load point is allowed with reduced fluxalso. In this case the flux reduction shall be noted in the motor documentation.
The first load point (90 % speed and 100 % torque) for this test series shall be conducted after thermal equilibrium (rate of change 1 K or less per half hour) has been reached. Thetemperature at the other 6 load points should be as close as possible to the tempera ture of thefirst load point.EN IEC 60034-2-3 pdf download.