Flyback energy storage

How does a flyback converter work?

In a traditional flyback converter, the transformer acts as an energy storage element resulting in a larger transformer compared to forward topologies. This limits the maximum achievable power density. Over the years, increasing the switching frequency has been used to reduce the transformer size.

What happens if a flyback transformer needs more energy?

If the load requires more energy at this point, the energy storage capability of the transformer will be exceeded and the load will not receive the required energy. This will lead to loss of regulation, therefore the peak primary current (Ipk) or primary saturation current (Isat) of a flyback transformer is a critical parameter.

How does a flyback transformer work?

During each cycle, when the input voltage is applied to the primary winding, energy is stored in the gap of the core. It is then transferred to the secondary winding to provide energy to the load. Flyback transformers are used to provide voltage transformation and circuit isolation in flyback converters.

What is a flyback circuit?

The flyback topology is based on a buck-boost topology, with the transformer providing isolation and, if needed, voltage transformation by turns ratio. The schematic shown in Figure 1 represents a typical flyback circuit.

How does a flyback controller work?

The flyback controller opens and closes the switch with the appropriate duty cycle to achieve the required output voltage. The duty cycle of flyback transformers typically does not exceed 0.5. Various combinations of turns ratios and duty cycles can be used to achieve the required output voltage according to this equation:

What is the difference between a flyback converter and ACF converter?

This is different behavior compared to a standard flyback converter or an ACF converter where the transformer is the only element storing the energy. Here, the frequency decreases with lower input voltages and the transformer is forced to store more energy leading to higher core flux and losses. 3.5. Magnetizing Current Displacement