| 摘要 |
PROBLEM TO BE SOLVED: To provide an inverter that suppresses higher harmonics in the input current of commercial power supply, and rush current that occurs when power is turned on, and is suitable for downsizing. SOLUTION: The inverter is constructed as a neutral point-type step-down inverter that reduces and chops the positive and negative voltages obtained by half-wave rectifying commercial power supply Vi at Q1, Q2, and L1 without smoothing, charges capacitors C1 and C2 with them, and smooths them at a smoothing capacitor C4 to generate direct-current voltage. Thus, rush current to the smoothing capacitor is suppressed. A charging/discharging capacitor C3 that performs charge pump operation is provided between the junction point (neutral point) between the capacitors C1 and C2 and the power supply. Thus, even when the input voltage of the power supply is lower than the voltages of the capacitors C1 and C2 and the capacitors are not charged, a current flows from the power supply. The input current of the commercial power supply is thereby prevented from having intermittent waveform that causes the production of higher harmonics. COPYRIGHT: (C)2006,JPO&NCIPI |
