Power conversion apparatus
AssigneeMitsubishi Electric Corporation
InventorsMasaki Yamada, Akihiko Iwata
Life of this patent
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Abstract
In a power conversion apparatus that converts AC power to DC power, an inverter circuit including one or more single-phase inverters connected in series with each other is connected in series at the subsequent stage of a rectification of an AC input. At the subsequent stage of the inverter circuit, a smoothing capacitor connected via a rectification diode, and a short-circuiting switch for bypassing the smoothing capacitor are provided. The short-circuiting switch is subjected to ON/OFF control by PWM control such that a voltage of the DC voltage supply of the inverter circuit follows a target voltage. The inverter circuit is subjected to output control such that a DC voltage of the smoothing capacitor follows a target voltage and an input power factor is improved.
Claims12
A power conversion apparatus comprising:
- a rectification circuit for rectifying an input from an AC input power supply;
- an inverter circuit including one or more single-phase inverters each of which has a plurality of semiconductor switch devices and a DC voltage supply, AC sides of the one or more single-phase inverters being connected in series with each other and being connected in series with an output of the rectification circuit, which inverter circuit superimposes the sum of outputs of the one or more single-phase inverters onto the output of the rectification circuit;
- a smoothing capacitor for smoothing an output of the inverter circuit, the smoothing capacitor being connected via a rectification diode to the inverter circuit at a subsequent stage of the inverter circuit;
- and
- a short-circuiting switch for bypassing the smoothing capacitor, one end of the short-circuiting switch being connected to the inverter circuit and the other end being connected to one end of the smoothing capacitor,
- wherein
- the inverter circuit is subjected to output control by using a current instruction such that a voltage of the smoothing capacitor follows a first target voltage and an input power factor from the AC input power supply is improved, and
- the short-circuiting switch is subjected to ON/OFF control such that a voltage of the DC voltage supply of the inverter circuit follows a second target voltage.
Dependencies are inferred from the claim text.