1: Formula in the transformer:
1) v = N * b * ae / t.
V is the voltage at both ends of the coil;
N is the number of turns of the coil;
B is the magnetic flux density of the core;
AE is a cross-sectional area of the wound of the core
T is time.
The meaning of the formula is that in time t, the change in the wound N turcy is in the case of the magnetic flux is N * b * ae, and the generated inductive voltage is V.
Ampere, N1 * I1 + N2 * I2 ... = H1 * L1 + H2 * L2. In a steady magnetic field, the magnetic induction strength B is along any closing path line, equal to the algebra of each current surrounded by this closed path, and multiplied by the magnetic permeability.
N1 is the number of turns of coil 1 on the core winding.
I1 is the current on the coil 1.
H1 is the magnetic field intensity = B / U0 * UR, U0 is a vacuum magnetore, and the UR is the relative magnetic permeability of the core.
L1 is the length of the magnetic field loop in the magnetic core.
H2 is the magnetic field strength of the air gap of the core = B / U0
L2 is the length of the magnetic core air gap.
B = u0 * (N1 * I1 + N2 * I2 + ...) / (L1 / UR + L2).
2: orthogonal transformer
Maximum power waveform
Waveform of magnetic flux density relative to time T
Equation 1 (V = N * B * AE / T), the more the number of turns is, the larger the loss, the larger the required core, therefore, selecting the number of turns, select B = Bmax. V = N * BMAX * AE / T1, finds N, N to take a number of Ni as the wound turns.
After selecting Ni, the BI = V * T1 / (Ni * AE) at this time can be obtained.
Paper 2:
Bi = u0 * (N1 * I1-N2 * I2) / (L1 / UR + L2).
In the transformer, the current direction of the same name is opposite, so the symbol is opposite.
When the power is equal to P, I2 is determined, and I1 = bi * (L1 / UR + L2) / (U0 * N1) + N2 * I2 / N1 can be calculated.
Transformer input power = i1 * v * d = 0.5 * bi * (L1 / UR + L2) / (u0 * n1) * v * d + n2 * i2 / n1 * v * t * d = 0.5 * bi * ( L1 / UR + L2) / (u0 * n1) * v * d +p. It is possible to meet the power requirements. Therefore, the transducer transformer does not need to adjust the value of L2 to meet the power requirements.
3: Fast transformer (discontinuous)
Waveform of magnetic flux density relative to time T
Equation 1 (V = N * B * AE / T), the more the number of turns is, the larger the loss, the larger the required core, therefore, selecting the number of turns, select B = Bmax. V = N * BMAX * AE / T1, finds N, N to take a number of Ni as the wound turns.
After selecting Ni, the BI = V * T1 / (Ni * AE) at this time can be obtained.
Paper 2:
Bi = u0 * (N1 * I1) / (L1 / UR + L2).
In the flyback transformer, I1 has a current, and I2 is not current.
I1 = BI * (L1 / UR + L2) / (U0 * N1) can be calculated.
The maximum input power P1 = I1 * V * T * D * 0.5 = 0.5 * bi * (L1 / UR + L2) / (u0 * n1) * v * d. If the power of the transformer is required to be P0, the maximum power of the transformer at this time is found to be P1.
4: Four transformer (continuous)
Waveform of magnetic flux density relative to time T
Select B = Br. V = N * br * AE / T1, finds N, N to take a number of Ni, as the number of windings.
After selecting Ni, the BI = V * T1 / (Ni * AE) at this time can be obtained.
Paper 2:
Bi = u0 * (N1 * I1) / (L1 / UR + L2).
BMAX = U0 * (N1 * IMAX) / (L1 / UR + L2).
In the flyback transformer, I1 has a current, and I2 is not current.
I1 = BI * (L1 / UR + L2) / (U0 * N1) can be calculated. IMAX = BMAX * (L1 / UR + L2) / (U0 * N1)
Maximum input power P1 = (IMAX-0.5 * I1) * V * D = 0.5 * (BMAX-0.5Br) * (L1 / UR + L2) / (U0 * N1) * V * D. If the power of the transformer is required to be P0, the maximum power of the transformer at this time is found to be P1.
5 Conclusion
The reverse transformer can increase the maximum output power of the transformer by increasing the air gap. The maximum power and air gap of the ortholistor transformer are independent.
Editor in charge: xj
Original title: Transformer formula - air gap calculation!
Article Source: [WeChat public number: Power Alliance] Welcome to add attention! Please indicate the source of the article. Read more
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