Power supply unit for press machine
AssigneeAida Engineering, Ltd.
InventorKazuhiro Kuboe
Life of this patent
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Abstract
A power supply unit for a press machine having a converter (converter circuit) connected to a commercial AC power supply, and an inverter (inverter circuit) connected to a press motor, includes an electrical energy bank, an inrush prevention circuit, an inrush prevention instruction signal generation section, and a contactor switch section, wherein contactors of the inrush prevention circuit are switched from on ON state to an OFF state and inrush prevention resistors of the inrush prevention circuit are connected to AC phase current paths on condition that the inrush prevention instruction signal generation section has generated and output an inrush prevention instruction signal (Sres) during press operation.
Claims9
A power supply unit for a press machine having a converter connected to a commercial AC power supply, and an inverter connected to a press motor, and generating and outputting a motor drive power for driving the press motor,
- an electrical capacity of the converter during power-running operation being smaller than an electrical capacity of the inverter during power-running operation,
- the converter being formed by a converter circuit, and the inverter being formed by an inverter circuit that implements a regeneration operation, and
- the power supply unit comprising:
- an electrical energy bank that is provided in a DC current path and stores electrical energy, the DC current path connecting the converter circuit and the inverter circuit;
- an inrush prevention circuit that includes inrush prevention resistors and contactors that are respectively connected in parallel to AC phase current paths that connect the commercial AC power supply and the converter circuit;
- an inrush prevention instruction signal generation section that generates an inrush prevention instruction signal when a detected actual DC voltage of the DC current path is lower than a comparison reference voltage;
- and
- a contactor switch section that switches the contactors of the inrush prevention circuit from an ON state to an OFF state on condition that the inrush prevention instruction signal generation section has generated and output the inrush prevention instruction signal.
A power supply unit for a press machine having a converter connected to a commercial AC power supply, and an inverter connected to a press motor, and generating and outputting a motor drive power for driving the press motor,
- an electrical capacity of the converter during power-running operation being smaller than an electrical capacity of the inverter during power-running operation,
- the converter being formed by a rectifier circuit, and the inverter being formed by an inverter circuit that implements a regeneration operation, and
- the power supply unit comprising:
- an electrical energy bank that is provided in a DC current path and stores electrical energy, the DC current path connecting the rectifier circuit and the inverter circuit;
- an inrush prevention circuit that includes inrush prevention resistors and contactors that are respectively connected in parallel to AC phase current paths that connect the commercial AC power supply and the rectifier circuit;
- an inrush prevention instruction signal generation section that generates an inrush prevention instruction signal when a detected actual DC voltage of the DC current path is lower than a comparison reference voltage;
- and
- a contactor switch section that switches the contactors of the inrush prevention circuit from an ON state to an OFF state on condition that the inrush prevention instruction signal generation section has generated and output the inrush prevention instruction signal.
Dependencies are inferred from the claim text.