Transformer

Содержание и основные понятия

The variable flux in the heart creates the EDS in the secondary winding. The stress ratio is approximately equal to the number of turns.
GEF · 11 grade
PIF · Baseline
Interactive model
transformer
Primary wrapping
Heart
Transmission line
01
The physical picture
What happens and what boundaries the model has.
Main message
The variable flux in the heart creates the EDS in the secondary winding. The stress ratio is approximately equal to the number of turns.
The transformer doesn't work with a strictly constant current.
Increased voltage at the same power reduces current and losses in lines.
The real CPD reduces the heat of the wrapping, the vortex currents, and the dispersing of the field.
How to reason
First, name the system and the interaction, then select the values, and only then write down the law. The formula works within the model's assumptions.
02
Laws and values
Symbols should be read as a relationship of values, not as a recipe for substitution.
U
2
U
1
=
N
2
N
1
\frac{U_2}{U_1}=\frac{N_2}{N_1}
U
1
​
U
2
​
​
=
N
1
​
N
2
​
​
Transformation factor
U
1
I
1
η
=
U
2
I
2
U_1I_1\eta=U_2I_2
U
1
​
I
1
​
η
=
U
2
​
I
2
​
power balance
Review of the situation
The voltage is increased prior to transmission to reduce current and loss of I2R in wires.
04
Links and application
In the real world
The voltage is increased prior to transmission to reduce current and loss of I2R in wires.
Model verification
Compare the prediction with observation, evaluate the units, the order of magnitude and the influence of the factors not taken into account. Disparity does not always mean an error of law: often idealization is no longer sufficient.
C
What needs to be understood
Outcome 1
Explain the physical meaning of the "transformer" topic through the model, not just through the formula.
Outcome 2
Distinguish and correctly use terms: transformer, primary wrapping, heart.
Outcome 3
Indicate the conditions for the applicability of the law, verify units and limit cases.
T
Terms of the topic
The definition should indicate the physical meaning, not a substitute for a domestic synonym.
transformer
Electromagnetic device to modify variable voltage and current by induction.
Primary wrapping
Transformer wrapping connected to variable voltage source.
Heart
Magnetic conductive element that reinforces and directs the magnetic flow of a coil or transformer.
Transmission line
A system of conductors and equipment for the transmission of electrical energy over a distance.
F
Origin and conclusion of the formulas
The fundamental law cannot be "proven" by algebras: for each record, it is stated whether it is a definition, an experimental law, or a model effect.
U
2
U
1
=
N
2
N
1
\frac{U_2}{U_1}=\frac{N_2}{N_1}
U
1
​
U
2
​
​
=
N
1
​
N
2
​
​
model effect
Transformation rate.
The following is an indication of the definition, experience or law from which this entry arises and where it is applicable.
E
1
=
−
N
1
d
Φ
d
t
,
E
2
=
−
N
2
d
Φ
d
t
\mathcal{E}_1=-N_1\frac{d\Phi}{dt},\qquad\mathcal{E}_2=-N_2\frac{d\Phi}{dt}
E
1
​
=
−
N
1
​
d
t
d
Φ
​
,
E
2
​
=
−
N
2
​
d
t
d
Φ
​
The total variable heart flow creates the FADS in both windshields.
E
2
E
1
=
N
2
N
1
\frac{\mathcal{E}_2}{\mathcal{E}_1}=\frac{N_2}{N_1}
E
1
​
E
2
​
​
=
N
1
​
N
2
​
​
The same flow rate is reduced for EDS.
U
1
≈
E
1
,
U
2
≈
E
2
U_1\approx\mathcal{E}_1,\ U_2\approx\mathcal{E}_2
U
1
​
≈
E
1
​
,
U
2
​
≈
E
2
​
In an ideal transformer, stress drops in the winding system are neglected.
Conditions:
The perfect transformer, sinusoidal mode, the total flow for all turns, the negligible small curling resistance, and the scattering streams.
Monitoring:
The dimensions of both parts shall coincide; the result shall be checked for sign, order and limit case.
U
1
I
1
η
=
U
2
I
2
U_1I_1\eta=U_2I_2
U
1
​
I
1
​
η
=
U
2
​
I
2
​
model effect
Power balance.
The following is an indication of the definition, experience or law from which this entry arises and where it is applicable.
P
1
=
U
1
I
1
,
P
2
=
U
2
I
2
P_1=U_1I_1,\qquad P_2=U_2I_2
P
1
​
=
U
1
​
I
1
​
,
P
2
​
=
U
2
​
I
2
​
For the loading mode, the input and output active power shall be expressed through the operating voltages and currents.
η
:
=
P
2
P
1
\eta:=\frac{P_2}{P_1}
η
:=
P
1
​
P
2
​
​
The AAC is defined as the ratio of the net output power to the input.
P
2
=
η
P
1
⇒
U
1
I
1
η
=
U
2
I
2
P_2=\eta P_1\quad\Rightarrow\quad U_1I_1\eta=U_2I_2
P
2
​
=
η
P
1
​
⇒
U
1
​
I
1
​
η
=
U
2
​
I
2
​
Capacity setting provides a balance to take into account losses.
Conditions:
The installed transformer mode; U and I are the operating values, the power ratios of both sides are taken as one or are already accounted for.
Monitoring:
The dimensions of both parts shall coincide; the result shall be checked for sign, order and limit case.
!
Model boundaries and typical errors
Error: Forget model condition
You can't move the formula to any situation just because it's a coincidence of letters. The key condition of this topic is that the transformer doesn't work with a strict current.
How to Check the Mind
Increases in voltage at the same power reduce current and losses in lines. Then check the units, vector orientation and result behaviour at zero or very large parameter.
Σ
Conclusion on the topic
Transformer
The variable flux in the heart creates the EDS in the secondary winding. The stress ratio is approximately equal to the number of turns.
The transformer doesn't work with a strictly constant current.
Increased voltage at the same power reduces current and losses in lines.
Any numerical result shall be accompanied by a unit, a sign and an explanation of its physical meaning.
The content is consistent with the FRP on Physics of the OS/OSS 2025 and the subject matter of the current lines of the PNP: I. M. Peryškin and co-authors (7–9), G. J. Mäkishev and coauthors (10–11), and with the lines "Engineers of the Future" and V. A. Kasyanov. The original texts are not reproduced, the text of the textbooks is not reproduced.