| 摘要 |
PROBLEM TO BE SOLVED: To inhibit switching loss depending on carrier frequency and hence reduce the size of an electric power conversion system, while ensuring the followability of control for DC voltage pulsation.SOLUTION: The waveform of a DC voltage Vdc is gentle in a phase area T02 than that in a phase area T01, and its change is small. Therefore, even if the frequency Fc2 of switching carrier employed in the phase area T02 is made lower than the frequency Fc1 of switching carrier employed in the phase area T01, the followability of switching control is not significantly degraded. By controlling the frequency of the switching carrier in such a manner, switching loss depending on the carrier frequency of the electric power conversion system can be decreased. This makes it possible to simplify a cooling device, or the like, for a switching element, and hence reduce the size of the electric power conversion system. |
