(2) Reduce the number of turns, but it will increase the magnetic flux density of the magnetic core and increase the iron loss. When the copper loss is significantly higher than the iron loss, use with caution;
(3) Changing the transformer process to reduce the AC resistance of the winding can be achieved by reducing the diameter of the copper wire (without reducing the total cross-sectional area), increasing the adjacent faces of the primary stage (which will increase the distributed capacitance of the primary stage), reducing the distance between the primary stages (which will increase the distributed capacitance of the primary stage), and loosening the coil;
(4) Changing circuit operation parameters to reduce AC resistance, such as lowering switching frequency, can increase the magnetic flux density of the magnetic core and increase iron loss. When copper loss is significantly higher than iron loss, use with caution;
(5) Using wires with lower resistivity (not very practical).
2. Reduce iron loss
(1) Switch to magnetic core materials with better power consumption parameters, such as using TDK's PC50 material to replace PC40 material;
(2) Reduce magnetic flux density, but it will increase the number of coil turns, leading to increased copper loss. Use with caution;
(3) Changing the circuit parameters, such as lowering the switching frequency, will also increase the magnetic flux density. Use with caution and adjust the number of turns of the cooperative winding if necessary;
(4) Reasonable thermal planning, utilizing the valley values in the temperature loss curve of magnetic core materials.
Summary
Methods for reducing transformer losses in switching power supplies
(1) Reasonably allocate the share of copper loss and iron loss based on their respective heat dissipation conditions;
(2) Reasonably plan the magnetic flux density and operating frequency of the magnetic core to work in the optimal FB combination condition.