| 摘要 |
PROBLEM TO BE SOLVED: To obtain an inverter in which low breakdown strength elements can be employed by employing partial smoothing circuitry in the output circuitry of a booster chopper circuit, thereby applying a voltage lower than the output voltage of a chopper to the switching element at an inverter section. SOLUTION: For example, a smoothing circuit section is a one half smoothing circuit constituted by connecting two field capacitors C11, C12 in series through a charging diode D5 and connecting them in parallel through discharge diodes D6, D4, respectively. Since that circuit is a booster chopper, the voltage sum Vdc of the capacitors C11, C12 is equal to about two times of the peak value of AC power supply voltage Vs. For example, a switching element Q2 has an interval when the peak value of DC power supply voltage Vdc is applied but a switching element Q1 is only applied with a voltage equal to about one half of Vdc. Consequently, the switching element Q1 requires breakdown strength equal to about one half of the output voltage of a chopper. |
