IEC 60034-2-3:2020 pdf free download – Rotating electrical machines – Part 2-3: Specific test methods for determining losses and efficiency of converter-fed AC motors.
The bandwidth of power meters and sensors shall be sufficiently wide that the error in themeasurement of total active power for the entire frequency range (beyond 50 Hz and 60 Hz) is less than or equal to 0,3 % of the apparent power.
NOTE 2 In general,a bandwidth from 0 Hz up to 10 times of switching frequency is sufficient.
lt is preferred to feed current and voltage directly into the power analyser. If an external current
transducer is required,no conventional current transformersshall be used. Instead，widebandwidth shunts or zero-flux transducers shall be used.
Fundamental voltage shall be measured at the motor terminals using a digital power analyserequipped with suitable software (FFT,Fast Fourier Transformation).
Internal line filters in digital power meters shall be turned off. Synchronization flters (also knownas zero-cross filters) that are not in the signal path may be used.
For power measurement, the three-wattmeter method is preferred.All cables used to transmitmeasurement signals shall be shielded. lt has to be noted, that the cable shield is not routedthrough the current transducers.
5.1.3Mechanical output of the motor
The instrumentation used to measure supply frequency shall have an accuracy of ±0,1 % of fullscale.The speed measurement should be accurate within 0,1 revolution per minute for speedsup to 3 0o0 min -1 and 0,03 % above.
The instrumentation used to measure the torque shall have a minimum class of 0.2 when therated efficiency is expected to be below 92 %，0,1 below 95 %and 0,05 or better for higherefficiencies. The minimum torque measured shall be at least 10 % of the torque measurement
device’s rated torque. lf a better class instrument is used,the allowed torque range can beextended accordingly.
5.2Converter set-up5.2.1General
For all tests using the comparable converter，it should be parameterized according to therequirements of this document or, if a unique combination of converter and motor is to be tested,the converter should be parameterized according to the specific application requirements. Thechosen parameter settings shall be recorded in the test report.
5.2.2Comparable converter set-up for rated voltages up to 1 kV
The comparable converter has to be understood as a voltage source independent of loadcurrent.
lt has to be noted, that the so-called comparable converter operating mode is not intended or
requested for any commercial application， but it is a typical set-up.The purpose of thecomparable converter set-up is to establish comparable test conditions for motors designed for
operation with commercially available converters.
The reference conditions defined below shall only be used for verification of compliance withnational energy efficiency regulations, in particular the 90 % speed and 100 % torque load point.
For all other purposes including the interpolation procedure according to Annex A preferablythe original system configuration should be used.
The following reference conditions are defined:
Two level voltage source converter.
No additional components influencing output voltage or output current shall be installedbetween the comparable converter and the motor, except those required for the measuring instruments.
Operation at 90 % speed and rated torque with constant rated flux (approx.90 % of ratedvoltage) for both induction machines and synchronous machines.
NOTE The rated fux is defined by the rated voltage given on the name plate of the motor. Therefore, ameasurement at the 90 % speed and 100 % torque point with rated fux will be fuly replicable for regulationauthorities.
For motors with a rated speed up to 3 600 min -1, the switching frequency shall not be higherthan 5 kHz.
For motors with a rated speed above 3 600 min-1,the switching frequency shall not behigher than 10 kHz.
The conductor cross-sectional area of the motor cable should be selected such that the voltage drop is not significant at rated load. An example for a typical test setup can be found inIEC61800-9-2:2017.IEC 60034-2-3 pdf download.