Electric-power conversion system including single-phase inverter

摘要

The number of constituent components is reduced so as to provide a small-size and inexpensive electric-power conversion system. The electric-power conversion system is provided with an inverter circuit (14) connected with the rear stage of an AC power source, a smoothing capacitor (22) connected with the rear stage of the inverter circuit (14) by way of a rectifying device (20), a charging switch (2) that is connected with the front stage of the inverter circuit (14), that inputs an electric quantity based on an output of the AC power source (1) to the inverter circuit (14) when being turned on, and that cuts off an input of the electric quantity to the inverter circuit (14) when being turned off, and an inrush current prevention circuit (7) having an inrush current prevention switch (3) and an inrush current prevention resistor (4) that is connected in series with the rear stage of the inrush current prevention switch (3); the electric-power conversion system is characterized in that the inrush current prevention circuit (7) is connected in parallel with the charging switch (2).

主权项

1. An electric-power conversion system comprising:
an inverter circuit connected with a rear stage of an AC power source; a smoothing capacitor connected with a rear stage of the inverter circuit via a rectifying device; a charging switch that is connected with a front stage of the inverter circuit, that inputs an electric quantity based on an output of the AC power source to the inverter circuit when being turned on, and that cuts off an input of the electric quantity to the inverter circuit when being turned off; an inrush current prevention circuit having an inrush current prevention switch and an inrush current prevention resistor that is connected in series with a rear stage of the inrush current prevention switch; and a discharging switch, one terminal of which is connected to the inrush current prevention resistor and other terminal of which is connected to one terminal of the smoothing capacitor, and which is configured to connect and disconnect the smoothing capacitor to and from the inrush current prevention resistor, wherein: the inrush current prevention circuit is connected in parallel with the charging switch; one terminal of the charging switch is connected with one terminal of the AC power source; the inverter circuit is formed of a single-phase inverter including a first serial circuit in which a first semiconductor switching device and a third semiconductor switching device are connected in series with each other, a second serial circuit in which a second semiconductor switching device and a fourth semiconductor switching device are connected in series with each other, and a DC voltage source; the first serial circuit and the second serial circuit are connected in parallel with each other; and the DC voltage source is connected between the parallel connection points of the first serial circuit and the second serial circuit.