Slip Ring VS. Squirrel Cage Induction Motors | What EXACTLY you need to know?

[@ervivekchoubey]

What is VFD or VVVfD and how does it work - watch here: kzbin.info/www/bejne/qp66e5Kmoaqfja8

[@wummadisettymohanakrishna4402]

Sir you explained it like an expert with professionalism

[@ervivekchoubey]

Thank you very much 😊

[@RajSingh-eu4cw]

You are really good. Add a video for VFD working in detail

[@ervivekchoubey]

Already added. Have a look : kzbin.info/www/bejne/qp66e5Kmoaqfja8

[@anusharapeti4202]

Sir really know the reasons about this topic clearly . Thank you

[@saulgrayson2499]

a trick: watch series at flixzone. Been using them for watching loads of movies recently.

[@roycegerardo9708]

@Saul Grayson Yea, I've been watching on flixzone} for since december myself =)

[@MenzelMotors]

good explanation of both types of electric motors

[@ervivekchoubey]

Thank you

[@sarayyumk147]

Thank you so much for the wonderful explanation. It helped me a lot!!

[@ervivekchoubey]

Great to know that. Please share in your circles 😊

[@Dump_Truckk]

Thanks for the video my brother helped heaps

[@anandh1967]

Love you bro

[@haythammoutasem753]

I have two squrriel gage indication motor but they have different voltage at the stator windings (400_230)volt the 400 v burned the stator windings and the 230 v has erosion at rotor shaft( rotor damage) ... My question can I change the rotor form 400 v to 230 v stator (the both rotors has the same dimensions)

[@ervivekchoubey]

It can work but the thing is that there will be heat generation and even the motor might not work because the rotor is designed to rotate at 400V so at 230, the motor might just try to run but fail thus withdrawing huge current and heating the 230V stator winding. The air gap magnetic field flux is directly proportional to voltage and it generates the required torque. So, lower voltage means lower torque and the motor may fail to start off or shall run at very low speed.

[@haythammoutasem753]

@@ervivekchoubey thanks for the quick response

[@kettch42]

Your slide showed the stator wired delta and rotor wired as Y. Is that for a reason? The ones I have seen are opposite. Are there problems with harmonics on the rotor from the rheostat?

[@ervivekchoubey]

Well different designs are possible. I haven't particularly emphasized on the design here But according to me, Delta connected stator or delta connected primary of Transformer is preferred in some places because the delta connection causes natural elimination of the third harmonic zero sequence current. Out of all the harmonics, the third harmonic current is the most severe and causes disturbance in the overall torque. But a delta connection would let the zero sequence current to flow within the delta but not in the line. So, before the 3 phase RMF links the rotor, the third harmonic flux is eliminated. On the other hand, the rotor is star connected which provides a neutral path and also as the rotor is star connected so the line voltage is √3 times the phase voltage and hence the number of turns required is lesser compared to a simple winding for same voltage. This decreases the complexity in rotor winding as well as decreases the rotor weight and helps in rotor acceleration smoothly.

[@ervivekchoubey]

Not exactly, rheostat is just linear resistance. It will not cause any problem of harmonics. Instead the resistor helps to increase the starting torque whereas harmonics causes failure in torque building.

[@irishguy200007]

What about single phase operation?

[@ervivekchoubey]

Single phase induction motors aren't used for heavy duty works. These are mostly used in applications like fans and blowers.

[@wummadisettymohanakrishna4402]

What shall one do to replace an slip ring motor with squirrel cage motor and also can a vfd is used with slip ring motor.

[@ervivekchoubey]

Both machines have different physical design and capacity so one can't be transformed into other. The only way is to get another motor instead of slip-ring motors. There is no such restriction with slip-ring motors however VFD in addition to slip-ring will be an overdo and the entire setup will be costlier. So we choose economical alternative which is squirrel cage motor and connect it to VFD which is sufficient. Slip-rings aren't required as the VFD will automatically set tje the required high starting torque and low starting current during the start phase.

[@ervivekchoubey]

Here's all about VFD and how it works kzbin.info/www/bejne/qp66e5Kmoaqfja8 Just in case you need...

[@wummadisettymohanakrishna4402]

@@ervivekchoubey thank you sir

[@wummadisettymohanakrishna4402]

@@ervivekchoubey sir I have doubt my requirement is I have to replace a 132 KW ,970 rpm,415 v ,50 hz AC slip ring motor with a suitable squirrel cage motor but I am poor in this aspect .I would like to hear from you on this please explain

[@ervivekchoubey]

I can't explain you the different aspects involved as the type of load requirement, temperature and other similar factors are involved which can't be explained in writing. Important thing is that the active power rating should remain same or higher alongwith the voltage rating and range. Also you have to ensure that the power factor remains high. Torque at start should be high with low starting current so that there is no abrupt voltage drop. These are (but not limited to) things to take care off.

[@rameshchandrachandu2654]

Pls make video about LRS operated motor sir

[@ervivekchoubey]

Okay I'll try

[@StrsAmbrg]

What is the different between slip ring induction motor than universal motor (that are many used for electrical tools like drill, grinder, blender, etc)?

[@ervivekchoubey]

Induction motor whether Slip-ring or squirrel cage, works only on AC current which generates time-varying air gap magnetic field. Whereas, a universal motor is the one which can operate on both AC and DC current like a DC series motor. This is because torque in DC motors is directly proportional to product of field current and armature current. As this is a SERIES motor therefore both armature circuit and field remain in series and receive the same current. So, the torque becomes directly proportional to square of the armature current and thus it doesn't matter whether the current is AC or DC, the torque is always positive. Induction motor works on the principle of induction where both stator and rotor aren't physically connected but are magnetically coupled whereas in a Universal motor like DC series, the stationary and rotating part isn't physically isolated. For high traction and control purpose we use AC Induction motor rather than DC series.

[@StrsAmbrg]

@@ervivekchoubey many thanks for your kind explanation.

[@StrsAmbrg]

@@ervivekchoubey Friend, can you please explain or make a video how to calculate a rotation speed of a DC and universal motor? I am confused with the parallel path. What is the benefit of having many slots than just few slots? I am a technician, so I appreciate if you show with real armature. There are many lecture videos explaining it, but hard for me to underatand as the explanation are too theoritical. Need real example by showing in a real motor.

[@ervivekchoubey]

Okay, I'll look into it. Basically, slots are done for one purpose that is to effectively link the magnetic field. More slots will effectively hold the magnetic field rather than allowing it to leak out and get wasted. Another advantage is the proper distribution of the coils on the rotor. More the no. of slots, more distributed winding will be there and therefore the magnetic field will also be suitably distributed. This helps in building up the machine torque as well as keeps the motor in balance. This is because the winding will be distributed so the entire rotor will be having equally distributed weight rather than some parts having more weight than the other. So, this will keep the rotor balanced and also reduce the risks associated with the centripetal force.

[@StrsAmbrg]

@@ervivekchoubey I hope you may post a video about it. My most question is about "what is a parallel path" in DC/Universal motor. But good if you cover it completely, your viewer will be happy.

[@apurvmj]

Good quality video

[@ervivekchoubey]

Thank you so much.

[@apurvmj]

@@ervivekchoubey I am a civil engineer. But currently working on ebike as hobby. Would u suggest whether it's suitable to use a slipring induction motor with rotor energy recovery system for electric vehicles instead of BLDC.

[@ervivekchoubey]

@@apurvmj as far as I know BLDC would be a better option owing to its high speed performance and easy interface. Slip-ring induction motor will be bulky and not a great option even with power recovery scheme. Otherwise you can use squirrel cage induction motor with VVVFD. But if its possible then use BLDC that's what I would recommend. Regards.

[@apurvmj]

@@ervivekchoubey thanks

[@ervivekchoubey]

@@apurvmj No problem :)

[@rthony7780]

where is the inductance coming from the squirrel cage rotor bars??? @6:30 you showed an RL circuit. dont you mean the inductance come from the stator winding of the motor???

[@ervivekchoubey]

The stator winding generates time-varying magnetic field which links with the rotor (squirrel cage bars). Being shorted at both ends, current begins to flow through the rotor bars. That's why there is a rotor inductance because it tries to resist the effect of stator magnetic field flux and hence begins to rotate.

[@rthony7780]

@@ervivekchoubey thanks for explaining

[@KhanhNguyen-zp3tu]

How can I identify different motors from appearance?

[@ervivekchoubey]

Here's a good explanation to your question: www.researchgate.net/post/How_can_we_visually_differentiate_between_DC_Motor_and_AC_Motor

[@kuntaldutta959]

Why the no of rotor bar of a squirrel cage rotor is prime ?

[@ervivekchoubey]

Prime numbers are non divisible numbers. Rotor slots are odd prime numbers so that it doesn't falls under the stator pole and locks magnetically (cogging). Number of stator poles are even and the only way to ensure that rotor poles don't lock with the stator poles is making odd and prime number of rotor poles.

[@MrWom80]

why are they all Indian ?????

[@ervivekchoubey]

Because we know the market requirement better than many others I guess.

[@eglintonflats]

You do not know what you talking about.

[@ervivekchoubey]

Sorry to hear that. Could you elaborate what's exactly isn't clear?

[@omnisalkar7440]

you confuse

[@ervivekchoubey]

What did you find confusing?

[@subscriptionletterbin5956]

very difficult to listen to heavy accented English.