Procedure to determine Quality Index

specAmotor checks the information of publicly available information such as product catalogs etc. for correctness and consistency and indicates where information is ambiguous or incomplete with the following procedure. This procedure can handle all PM DC, brushless and AC synchronous motors [see Construction motors].

1. If crucial data is not present than the motor is not admitted to the database. At least it should be possible to determine the temperature of the motor, the heat development and electrical currents and voltages.

2. If data is missing it is examined if the data can indirectly be deduced from other quantities.

   Example: If the motor constant is not given, but the torque and the current in the same situation (and known temperature) than from that information the motor constant can be determined.

3. If data is missing and the data can not indirectly be deduced than it is examined if a replacement value can be applied.

   Example: The maximum admissible rise of temperature of the windings is set to 100 ^oC if this can not be derived from the manufacturer data, and if the isolation class according to norm IEC 60034-1 is not given (because from this norm the allowed temperature rise can be determined indirectly namely according to the previously described step).

4. If redundant information is present it will be calculated if that information is not ambiguous. If it is ambiguous, a notice of this will be made in the results. A lot of information is derived from the torque-speed characteristic.

   Example: The steepness of the motor is shown in the torque-speed characteristic and this can also be determined from the motor constant and the winding resistance. If the two values do not match a notice will be made of this.

5. Examined will be if the thermal data is thus detailed, so that the winding temperature and the temperature of the motor housing can be determined seperately (instead of determining a generic motor temperature, after all 'the' temperature of the motor does not exist. The hotspots will be somewhere between the windings, and the house of the motor will have a lower temperature). If this is the case than a more detailed thermal model is used.

6. There will be indicated what the consequences are of information is missing or incomplete or ambiguous.

   Example: If C_th,total is not given than will be indicated that this means for the user that the time, at which thermal stability occurs, can not be calculated.

7. A quality index will be determined to give a general impression of the quality of the data. This quality index is being shown in the motor ranking.

Go to Qualty Index page.