| 摘要 |
PROBLEM TO BE SOLVED: To keep constant the clamp voltage of IGBT for alleviating the loss thereof. SOLUTION: This semiconductor power converter is formed into a circuit structure, such that a voltage for a wiring 13N, having a constant potential difference with respect to the collector and the emitter of the IGBT1, is divided with a high-potential side resistor 3 and a low-potential side resistor 4 and also has a function to protect the IGBT from an overcurrent application to the collector by controlling the gate potential of the IGBT to the potential of a voltage-dividing point 9 via the buffer circuit 6. In this semiconductor power converter, a capacitor 5 is connected in parallel with the low potential side resistor, and the capacitance Cl of the capacitor C5 is set to obtain the relation (1) Cl=Ch×Rh/Rl, when a resistance value of the high potential side resistor 3 is Rh, a parasitic capacitance value is Ch, a resistance value of the low potential side resistor 4 is Rl and a capacitance of the capacitor 5 is Cl. Thereby, a clamp voltage level can be held at the constant value, without relation to a voltage variation coefficient (dv/dt) of the collector voltage. |
