The power transformer is composed of an iron core (or a magnetic core) and a coil. The coil has two or more windings, among which the windings connected to the power supply are called primary windings and the rest are called secondary windings. It can vary AC voltage, current and impedance. The simplest core transformer consists of a core of soft magnetic material and two coils of unequal turns. However, it is difficult to avoid transformer failure in daily work.

The Function of The Power Transformer

Regulating Voltage
Usually, we use a variety of voltage, such as 220V household appliances, 36V industrial safety lighting, welding machine voltage regulation, which are inseparable from the transformer. Through the principle of primary and secondary coil electromagnetic mutual inductance, the transformer can reduce the voltage to a certain extent which we need. In addition, in the process of long-distance voltage transmission, we need to raise the voltage to a very high level to reduce the voltage loss, which usually rises to several kilowatts or even tens of kilowatts. This is the role of the transformer.

Impedance Matching
In the electronic circuit, in order to make the signal unimpeded, the transformer is usually used for impedance matching in the connection between the output and the input. For example, in the old broadcasting system, the loudspeakers are all high-impedance loudspeakers with constant voltage output, so only the output transformer can be used for matching. Therefore, daily life and industrial production are inseparable from the transformer.

In view of the actual situation of malfunctions of the power transformer, OUGE will give you an insight into the the leakage inductance and capacitance.

Leakage Inductance
The leakage inductance is the magnetic flux that is missed in the coupling process of the first stage of the motor. The leakage inductance of the transformer is caused by the magnetic field lines generated by the coil. Leakage inductance is an essential index of switching transformer, which has a significant influence on the performance index of switching power supply. In the presence of leakage inductance, when the switching device is cut off, the reverse electromotive force will be generated, which is easy to over-voltage the switching device. The leakage inductance can also form an oscillation circuit with the distributed capacitance in the circuit and the distributed capacitance in the transformer coil, so that the circuit will oscillate and radiate electromagnetic energy outwards, causing electromagnetic interference.

Causes
- Uneven or not tight distribution of the arrangement lines and no siding, resulting in the incomplete coupling of the inter-turn magnetic flux

- Too much dielectric thickness between layers of different windings

- Unreasonable distribution structure of primary and secondary windings

- Unreasonable magnetic core structure size

- The shielding layer of the leakage package or the beginning and end of the shielding layer do not overlap

2)Improvement Measures

- Evenly distribute the lines and keep them to the side

- Reduce the thickness of the winding and increase the width of the winding

- Reduce the insulation thickness between windings

- The primary and secondary windings are layered and cross-wound

- Select magnetic cores with high saturation magnetic induction and low loss

- Add shielding layer between primary and secondary;

- In case of short circuit, the wire and PIN shall be in close contact and the wire with smaller diameter shall be used as far as possible

Non-standard Distributed Capacitance
Causes
- The winding amplitude is too wide;

- Insulation material thickness. (paint leather thickness, covering of interlayer insulation tape)

- Magnetic core material. (high saturation magnetic induction strength)

2) Improvement measures

- Adjust the winding and amplitude of the winding (increase the diameter of the winding and reduce the height of the winding)

- Reduce the paint film thickness of the paint leather line;

- Loose insulation tape between layers

- Select the magnetic core with low saturation magnetic induction intensity