Hi Prof. Kuruppu. Thanks or the great lecture. Regarding the Ld estimation, I think there are two points that called me the attetion. The first one is related to the alignment of the stator and rotor magnetic flux. They should be in the same orientation, that is, North with North, shouldn' t they? It seems that they are opposite (38.06 min). The other point is that when we are applying a one-phase source to a - bc, the induced fluxes provocated by the windings b and c into the winding "a" are in opposition to its self-flux (in d direction). This will reflect differently, when the machine is supplied by three-phase sources, in its voltage terminals becouse in this situation there will be positive contribution in d direction. Is this consideration right? Thanks again for the lecture!
Hi Fabiano, nice to here from you. Actually, north and north will repel. North attracts to south pole and vice versa. That is why the rotor alignment will be like that. The inductance is a scalar measurement. You have to look at if it is an a or an a' winding. The current in those two travel in opposite directions, causing the fields generated by the two to have opposite polarity. So with a three phase source, you end up generating a rotating magnetic field. With a DC source your field is fixed with the goal of measuring the inductance. Hope this helps.
Hi, thanks for this lecture. It was useful and easy to follow. I have a question regarding the measurement of the d and q-axis inductance. You mention to lock the rotor by injecting a current in phase A and connecting phase B-C together with the negative of the source. Does this method work with delta-wound PMSMs? Again thanks for sharing your lectures!
Your D and Q axis are based on your rotor flux. But I'm not familiar with Delta winding pattern. If the stator flux vector is the same between Delta and Wye, then the approach should be the same. I'm curious, why you are using a Delta winding? What is the benefit?
Hello sir, I have hardware setup of AC DC AC power converter , PMSM coupled with PMSG and FPGA based OPALRT system. I generate spwm signal by keeping v/f ratio constant and inverter output current is feeding to the motor. Motor is running at 375 rpm, when reference speed of motor is increasing motor is start vibrating. Even in real time I changed voltage and frequency of modulated signal by keeping v/f ratio constant. Please sir help me
@@SandunKuruppu Thank you very much for the lecture, it was very helpful! I get the point about the model accuracy, but I am still wondering how I can calculate Ld and Lq from the FE results? Wouldn't this mean that I need to simulate a locked rotor system and then calculate the impedence?
Hi Prof. Kuruppu. Thanks or the great lecture. Regarding the Ld estimation, I think there are two points that called me the attetion. The first one is related to the alignment of the stator and rotor magnetic flux. They should be in the same orientation, that is, North with North, shouldn' t they? It seems that they are opposite (38.06 min). The other point is that when we are applying a one-phase source to a - bc, the induced fluxes provocated by the windings b and c into the winding "a" are in opposition to its self-flux (in d direction). This will reflect differently, when the machine is supplied by three-phase sources, in its voltage terminals becouse in this situation there will be positive contribution in d direction. Is this consideration right? Thanks again for the lecture!
Hi Fabiano, nice to here from you. Actually, north and north will repel. North attracts to south pole and vice versa. That is why the rotor alignment will be like that. The inductance is a scalar measurement.
You have to look at if it is an a or an a' winding. The current in those two travel in opposite directions, causing the fields generated by the two to have opposite polarity. So with a three phase source, you end up generating a rotating magnetic field. With a DC source your field is fixed with the goal of measuring the inductance. Hope this helps.
Can we apply maximum voltage to motor at time of starting e.g.-380 v AC input.
Do you mean for characterization? Which step of the characterization are you referring to?
How we know which phase belongs to a and which phases belongs to b and c
Based on back EMF sequence.
Hi, thanks for this lecture. It was useful and easy to follow. I have a question regarding the measurement of the d and q-axis inductance. You mention to lock the rotor by injecting a current in phase A and connecting phase B-C together with the negative of the source. Does this method work with delta-wound PMSMs? Again thanks for sharing your lectures!
Your D and Q axis are based on your rotor flux. But I'm not familiar with Delta winding pattern. If the stator flux vector is the same between Delta and Wye, then the approach should be the same. I'm curious, why you are using a Delta winding? What is the benefit?
what hardware is required to measure impedance?
And what is the value of w that need to b put while calculating Ld?
You can use an RLC meter.
Hello sir,
I have hardware setup of AC DC AC power converter , PMSM coupled with PMSG and FPGA based OPALRT system. I generate spwm signal by keeping v/f ratio constant and inverter output current is feeding to the motor.
Motor is running at 375 rpm, when reference speed of motor is increasing motor is start vibrating. Even in real time I changed voltage and frequency of modulated signal by keeping v/f ratio constant.
Please sir help me
Are you trying to do V/f control for a PMSM?
Nice explanation. Can we calculate Ld and Lq directly from FE results ?
You can. But the results are as accurate as your model.
@@SandunKuruppu Thank you very much for the lecture, it was very helpful! I get the point about the model accuracy, but I am still wondering how I can calculate Ld and Lq from the FE results? Wouldn't this mean that I need to simulate a locked rotor system and then calculate the impedence?
@@MarcoWheemo In a way, yes. But in FE models you can do these much more easily. Sometimes there are macros built in for calculation.
@@SandunKuruppu thanks for the quick reply!
@SandunKuruppu
Sir, is there a book talks about the characterization of other machines like IM, wounded Synchronous machine?