Single Phase Transformator Simulation
Good day everyone,
I'm trying to simulate a single phase transformator by using Simulink. I've got the current values: R1 = 3 Ohm R2 = 0.03 Ohm X1 = 6.5 Ohm X2 = 0.07 Ohm Rc = 100k Ohm Xm = 15k Ohm f = 60 Hz Uprim = 2400V Usec = 240V S = 29kVA cos Phi = 0.8
And I've made the current calculations: L1 = X1/2*pi*f = 17,24 mH L2 = X2/2*pi*f = 185.68 uH Lm = Xm/2*pi*f = 39.79 H S = Urms*Irms => Irms = 120.83 A P = Urms*Irms*cos Phi = 23200 W Q = Urms*Irms*sin Phi = 17400 VAr Q>0 so Q = ohms-inductive => QL = 17400, QC = 0
I've made the current circuit and simulated it, but somehow my secondairy output voltage is only at 225Vrms. Can someone explain to me why that's the case? Did do something wrong in my calculations or in my simulation?
1 Comment
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Hi Jacky,
You are doing it right and are getting correct results.
The reason for getting 225V instead of 240V at output is: Voltage Regulation
Every transformer is rated at voltages E1 & E2, which are no load induced emfs when either primary or secondary is energized with respective voltages. i.e. If you energize the transformer primary at 2400V, you'd get 240V at secondary.
Now, when the transformer is loaded, some current starts to flow through the secondary winding. This results into terminal voltage of transformer being different than the induced EMF. This is explained by following relationship:
V2 = E2 - I2*R2
Where, V2: Terminal voltage, E2: Induced voltage, I2: Secondary current, R2: Secondary wdg resistance
Depending upon load, the output voltage is going to appear differently at the terminals and this phenomena is defined as voltage regulation of the transformer.
In your case, you are simulating at full load condition and the transformer is functioning at:
% Voltage Regulation = (240-225)/225 = 6.66%
If you reduce the load to about 1% of the rated load to simulate no-load condition (as open circuits would give you an error in simulation), you should get 240V at the output.
Hope this was helpful.
You may read more here: https://en.wikipedia.org/wiki/Voltage_regulation
