Electric power conversion device
AssigneeToyota Jidosha Kabushiki Kaisha
InventorsKaoru TORII, Kazunari YAMAMOTO, Kosuke KAJI, Taiki KATO, Takashi KOJIMA, Katsuya NOMURA, Yoshiyuki HATTORI
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Abstract
If the capacitance of a snubber capacitor, the inductance of a coil and the magnitude of a resistor are specified such that the resonance frequency of the snubber circuit coincides with the ringing frequency of the transistor, and the impedance of the first loop at the resonance frequency becomes smaller than the impedance of the second loop at the resonance frequency, a current component due to ringing flows in the snubber circuit, and energy is consumed by the resistor. Therefore, it is possible to quickly converge ringing.
Claims3
An electric power conversion device comprising:
- a transistor for electric power conversion;
- a diode connected in series with the transistor;
- a smoothing capacitor connected in parallel with the transistor and the diode, the smoothing capacitor being configured to suppress ripples generated by the transistor;
- and
- a snubber circuit including a snubber capacitor, an inductor element and a resistor, the snubber capacitor, the inductor element and the resistor being connected to each other in series, the snubber circuit being connected in parallel with the smoothing capacitor,
- capacitance of the snubber capacitor, inductance of the inductor element and magnitude of the resistor being set such that a resonance frequency of the snubber circuit coincides with a ringing frequency of the transistor, and being set such that impedance of a first loop at the resonance frequency becomes smaller than impedance of a second loop at the resonance frequency,
- the first loop includes of the snubber circuit and the smoothing capacitor, and the second loop includes of the transistor and the smoothing capacitor.
Dependencies are inferred from the claim text.