Madam, in implementation phase , ypu have shown 2 speeds signals. 1 signal which is setpoint at which we want to run motor. Second signal coming from motor feed back which is actual speed. But in DTC there is no feed back sensor mounted on motor which measures the actual speed.
From the three-phase currents that are sensed, torque can be calculated. Synchronous speed can be inferred from d(flux angle)/dt. With the calculated torque vale and synchronous speed, actual rotor speed can be deduced. No mechanical speed sensor needed.
And one more thing. You have mentioned that when we have the speed reference, then you have created a block in red colour just above the speed controller & said that when speed ref we have , the flux estimation can be done. My point of view is that when we have the speed ref, then our drive will calculate the output frequency . Because freq is directly related to speed. However in order the constant V/f ratio, the drive shall choose the right voltage value to be send to output. Then when drive will decide the output voltage ( based on frequency) the stator flux will automatically be set at certain value . Am i right ?
In most of the cases, especially in induction motor drive, we will set the flux at rated value as long as the reference speed is below base speed. For operating above base speed, flux weakening is employed where the reference flux is set at a lower value than the rated flux. (Flux above based speed=rated flux*rated speed/new reference speed) Voltage is automatically decided based on flux error, torque error and voltage vector selection table.
If you are sensing three-phase currents, then to convert them into d-q, you will need these transformations. these d-q currents are used in flux and torque calculations.
very awesome lectures. every ee students should watch.
You explained in very well manner & in depth. ❤
Can you please make a detailed video on FOC / Vector control as well
Lectures 38 and 39 are on FOC
Madam, in implementation phase , ypu have shown 2 speeds signals. 1 signal which is setpoint at which we want to run motor. Second signal coming from motor feed back which is actual speed.
But in DTC there is no feed back sensor mounted on motor which measures the actual speed.
From the three-phase currents that are sensed, torque can be calculated. Synchronous speed can be inferred from d(flux angle)/dt. With the calculated torque vale and synchronous speed, actual rotor speed can be deduced. No mechanical speed sensor needed.
And one more thing. You have mentioned that when we have the speed reference, then you have created a block in red colour just above the speed controller & said that when speed ref we have , the flux estimation can be done.
My point of view is that when we have the speed ref, then our drive will calculate the output frequency . Because freq is directly related to speed. However in order the constant V/f ratio, the drive shall choose the right voltage value to be send to output.
Then when drive will decide the output voltage ( based on frequency) the stator flux will automatically be set at certain value .
Am i right ?
In most of the cases, especially in induction motor drive, we will set the flux at rated value as long as the reference speed is below base speed. For operating above base speed, flux weakening is employed where the reference flux is set at a lower value than the rated flux. (Flux above based speed=rated flux*rated speed/new reference speed)
Voltage is automatically decided based on flux error, torque error and voltage vector selection table.
In DTC , There is no park / clarke transformation is required ?
If you are sensing three-phase currents, then to convert them into d-q, you will need these transformations. these d-q currents are used in flux and torque calculations.
Which one is the book that explains this whole DTC calculation ?
Sensorless Vector and Direct torque control of AC motors by Peter Vas
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@@bhuvaneswarigsfreeonlineco4109 i really appreciate your efforts to share such a great knowledge 💖