Measures to Reduce the Leakage Inductance

Leakage Inductance

Under high frequency conditions, leakage inductance is an important parameter that can not be ignored by the transformer. The amount of leakage inductance directly affects the efficiency of the high frequency transformer. Then what is the leakage inductance, and how to solve the problem of leakage inductance to improve the efficiency of the transformer?

When there are two self-inductances in the relationship of the magnetic circuit, the magnetic flux is not fully coupled, and the leakage flux is generated, which causes a leakage inductance. That is to say, the primary winding and the secondary winding cannot be fully coupled, and there is a leakage inductance. The existence of the leakage inductance can form an oscillation circuit with the distributed capacitance between the capacitor in the circuit or the transformer winding, and it will bring a self-oscillation after satisfying the oscillation condition. Then, radiating electromagnetic energy outward, causing electromagnetic interference, making other components of the electronic system can not work properly. The existence of a leakage inductance produces a spike voltage. Therefore, the influence of leakage inductance on circuit performance and conversion efficiency is particularly important. When designing a transformer, the leakage inductance of the transformer should be minimized.

Measures to reduce the leakage inductance:

1. Choose a suitable core to reduce leakage

2, increase the width-to-thickness ratio of the winding, reduce the insulation between the windings

3. increase the degree of coupling between the windings

4. Reduce the average perimeter between the two coils

5. the primary winding cross-transformed winding