Trying to model a 3 phase induction motor circuit for a certain production line

We have a setup where we are monitoring the current supplied to the a 3 phase induction motor in a manufacturing plant. The current is read using CT sensors attached to the supply .

We are trying to identify current patterns during various fault situation but don't have enough data to do so. Hence, I am trying to model similar circuit in matlab simulink.

Model attached.

The nameplate spec of the motor are as follows :

RPM = 1380, A = 1.05, PF = 0.74, V = 415+-10% ,Hz = 50+-5%, kW = 0.37, HP = 0.50, EFF = 66.0, Frame = 71 , AMB = 50 ,IP = 55, InCl = 'F', Duty = 87, Emcl = 'TEFC'

Am from data science background and having trouble here regarding the parameters to be set. This mode made with the help of a few youtube videos. I have used parameters for the model from an example model on simulink except the First 3 [pow,volt,freq]. I have also set the supply voltage phases with a difference of 120 deg, freq = 50Hz and the supply voltage as Supply Voltage = (sqrt(2) * Vrms) / sqrt(3) Where Vrms is the given voltage on motor nameplate, which comes to be as 338.85 for this motor.

The problem I am facing is that the readings are supposed to be in ranges of 0.6 (as in the real world reading we are getting) as the motor is of max 1.04 Amps, but here the readings are of greater values. I thought of using Gain block before scope to scale these but one of the electrical guys said I should look into setting the parameters right.

The whole project is on me now and I don't have any mentor for this domain. Any help in setting up the simulation right is appreciated. Thank you!!.

Answer 1

[Joel Van Sickel]

Try using the motor parameter estimation tool on the block. Here are some parameter to help you out.

Nominal torque = 2.58

synchrnoous speed = 1500

Nominal speed = 1380

leave the ratios alone for now.

I don't know how close this will get you to your lab results, but it does bring the current down to something a bit more believable.

Regards,

JOel

[Deepak]

Thank you for the response. However, I am failing to understand what do you mean by "motor parameter estimation tool on the block". Is that a part of the block set I need to install as an addon and add it in the model? I installed Motor Control Blockset but it didnt have such block. Sorry if that seems like a silly question.

[Joel Van Sickel]

the motor block that you are using in one of the tabs has a paramter estimation button. You can check the documention to learn more about it.

[Deepak]

Oh I see, that makes things much easier. Thanks. Also I found out the the 3 ratios from the motor's spec sheet along with a bunch of other values

Torque(kgm) = 0.26, Efficiency % [ FL,3/4L,1/2L] = [66.0 65.0 58.0], Power Factor [ FL,3/4L,1/2L] = [0.74 0.64 0.53], GD^2 (kgm2) = 0.0022, Wt.(kg) = 20 , I(ST)/I(N) = 3.5, T(ST)/T(N) = 1.9, T(PO)/T(N) = 2.1.

Setting the following parameters changed the motor type to double cage too.

The Speed (RPM) under constant full load (2.56) comes as around 13 and under no load is 30 which is far cry from the rated speed. Am assuming its due to those resistances being so high which I might have to look into it a bit further. Anyways, thanks for your inputs. Much appreciated.

[Deepak]

Setting up the supply voltage appropritately helped. The peak supply voltage for each phase would be 415V * sqrt(2) = 587V