The advantages and disadvantages of the primary average winding method of transformer

2019-01-02 17:02:58 JUKE CHINA ODM OEM Transformer factory Read

The advantages and disadvantages of the primary average winding method of transformer
The advantages and disadvantages of the primary average winding method of transformer

As shown above, the order is Np/2-Ns-Np/2-Nb, and this kind of winding method has a large advantage.
This is beneficial to the coupling of the primary and secondary, reducing the leakage inductance; it is also conducive to the smoothness of the winding; the last advantage is that the voltage variation of the power supply winding is less affected and more stable by the secondary load.

By increasing the effective coupling area of the primary and secondary, the leakage inductance of the transformer can be greatly reduced, and the benefit of reducing the leakage inductance is obvious: the voltage spike caused by the leakage inductance is lowered, which lowers the voltage stress of the MOSFET. At the same time, the common mode interference current caused by the MOSFET and the heat sink can also be reduced, thereby improving EMI;

Since a secondary winding is added in the middle of the primary stage, the interlayer capacitance of the transformer primary is reduced, and the reduction of the interlayer capacitance reduces the parasitic oscillation in the circuit, and the voltage and current of the MOSFET and the secondary rectifier can also be reduced. Stress, improve EMI.

Disadvantages: Since the primary and secondary have two contact faces, the winding coupling capacitance is relatively large, so EMI is more difficult.