摘要 |
An inverter apparatus can lengthen a lift span and improve efficiency. Instead of a conventional electrolytic capacitor, only a noise absorption film capacitor is provided in a DC intermediate circuit between rectifying and inverter circuits. In a voltage command generating unit, when a frequency set by a frequency setting unit is within a predetermined range including the frequency of an AC input power supply, PLL control is performed to make the frequency set by an output voltage command signal equal to the frequency of the AC input power supply voltage, and to substantially synchronize the peak value of an output voltage from the inverter circuit with the peak value of a voltage formed between both ends of the film capacitor. Accordingly, output voltage amplitude is generated when the frequency set by the output voltage command signal equals the frequency of the voltage of the AC input power supply.
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