Power Electronics and Motor Drive Systems

7.10. Switching Power Losses of a Power Semiconductor Switch and Electromagnetic Interference

A semiconductor device is subjected to switching power stresses, when the device goes from an off state to an on state and vice versa. Moreover, the semiconductor devices are subjected to power losses when they are in conduction state. In high switching frequencies the parasitic circuit elements make their undesirable presence remarkable. Because of the junction capacitances of semiconductor elements and leakage self-inductance of transformers, oscillations are generated as soon as semiconductor elements turn on or turn off. Leakage magnetic fields are also generated from inductors and transformers. Finally, the closed current loops of the converter behave ...