Design SpecificationsPower: 5kW
Input Voltage: 400V Output Voltage: ~230V (grid voltage) Switching Frequency: 16kHz Inductance: 3mH ModelingBecause the positive and negative half cycles are complementary, only the positive half cycle was simulated. Additional modeling can be performed by adjusting the voltage pulse control in the SPICE deck.
The initial simulation of the inverter to the right didn't correctly match the voltages at two the common mode voltage nodes (second and third plot from bottom). Despite this, the common voltage was quite accurate (fourth plot from bottom). To increase accuracy, component parasitics were taken into consideration. ParasiticsLooking through the datasheets for the components below, there were several recommendations for the parasitics of these components and for SPICE components in general. The following parasitic elements and values were used to realistically model the inverter.
Input source: R_series = 100mΩ, L_series = 1nH Input capacitor: L_series = 1nH Output inductor: C_par = 1nF Output source: R_series = 100mΩ ComponentsThe original topology calls for several Si devices, listed below.
IGBT: S1, S2, S3, S4 : Mitsubishi CM100DY-24NF 1200 V IGBT S5, S6 : IR G4PSC71UG 600V IGBT D7, D8 : IR HFA26TB60 600V Diodes Recently, there have been advancements in SiC (Silicon Carbide) technology, which is supposed to have better conduction and switching losses due to zero reverse recovery. Using this assumption, we researched potential SiC devices. SiC: S1 - S6 : Cree C2M0025120D 1200V 90A 25mΩ SiC FET D7, D8 : Rohm SCS230AE2 650V 30A SiC Schottky Barrier Diode Rohm and Cree are two of the major Silicon-Carbide device manufacturers. The SiC components above were chosen to match the original component voltage and current characteristics as closely as possible. It is important to note that although the chosen devices have much higher performance, they are quite costly due to manufacturability and demand. |
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