Switching measurement (double pulse)
A large part of the total losses of an inverter are caused by the switching losses of the semiconductors. The exact determination of these losses is important in order to determine effects of different switching frequencies in the simulation. For the characterization a buck converter circuit in double pulse operation is usually used.
Example: Switching behavior of an IGBT in a 3-level NPC1 phase module 300A/650V with inductive load
Switch-on: Uce=400V, Ic=300A, T=150°CX: 200ns/divUce: 100V/div Ic: 80A/div Uge: 5V/div P: 5kW/div Eon: 6,23mJ
Switch-off: Uce=400V, Ic=300A, T=150°CX: 200ns/divDue to the parasitic inductance in the module, the Uce voltage mustUce: 100V/div Ic: 50A/div Uge: 5V/div P: 20kW/div Eoff: 33,79mJbe limited to 600V by means of "active clampling".
Example: Switching behavior of an IGBT in a 2-level phase module 300A/1200V with inductive load
Switch-on: Uce=800V, Ic=300A, T=150°CX: 200ns/divUce: 200V/div Ic: 80A/div Uge: 5V/div P: 50kW/div Eon: 77,83mJ
Switch-off: Uce=800V, Ic=300A, T=150°C
X: 200ns/divUce: 200V/div Ic: 60A/div Uge: 5V/div P: 50kW/div Eoff: 56,33mJ