Mitsubishi Electric Corporation

Hiroshi Kurushima

Masato Matsubara

Hitoshi Kidokoro

Akihiro Suzuki

Toshiki Koshimae

Hiroyasu Iwabuki

Naoki Nishikawa

A power supply apparatus includes an inverter having output terminals; a first transformer that transforms AC output from the output terminals; a second transformer that is connected to the output terminals in parallel to the first transformer, arranged on an opposite side of the first transformer with respect to a straight line passing through a center of the output terminals and extending perpendicularly to a plane including the output terminals, and transforms AC power output from the output terminals; first conductive lines that connect the output terminals to both ends of the first transformer; and second conductive lines that connect the output terminals to both ends of the second transformer. An area of a first loop formed by the inverter, the first conductive lines, and the first transformer is equal to an area of a second loop formed by the inverter, the second conductive lines, and the second transformer.

Power supply apparatus

A three-phase rectification circuit rectifies output voltage of a three-phase AC power supply, a step-up converter circuit steps up the output voltage, and a smoothing device smoothes the stepped-up output voltage. A voltage detection circuit detects output voltage Voof the smoothing device, and an AC current component detection circuit extracts AC component included in output current of the three-phase rectification circuit and outputs a detection signal Vicorresponding to the AC component. A control circuit calculates a deviation &#x394;Vdc(=Vs&#x2212;Vo&#x2212;Vi) among an output voltage instruction Vs for output voltage of the step-up converter circuit and detection signals Voand Viobtained by the detection circuits, and generates a pulse signal for suppressing the deviation &#x394;Vdcto zero, thereby performing PWM control for a switching device of the step-up converter circuit.

Power conversion apparatus

Included are: a circuit-specific printed circuit board to be a circuit board that generates a power supply voltage; a first diode that is connected in antiparallel with the transistor and is configured so as to be capable of passing a current through a path to circumvent the transistor; a second diode that is connected in series to the transistor and prevents a current flow through a parasitic diode formed on the transistor; a protection circuit that is connected in parallel with the second diode to protect the second diode from a high voltage breakdown, and is formed on a substrate different from the circuit-specific printed circuit board; and a cooling unit that is joined to the protection circuit outside the circuit-specific printed circuit board and cools the protection circuit.

A switching power supply device includes: a chopper circuit that adjusts a DC voltage input through a reactor to a desired DC voltage by performing an on/off operation of a switching element; an inverter circuit that converts an output of the chopper circuit into a desired AC voltage; a first capacitor that is provided on a side of the inverter circuit relative to the switching element; a second capacitor that is provided on a side of the inverter circuit relative to the switching element; and a resistor that is in a resonant loop formed by three constituent elements that are the first capacitor, the second capacitor, and a wiring inductance between the chopper circuit and the inverter circuit, where the resistor is connected in series to the second capacitor and inserted between the DC bus-bars.

Switching power supply device

A pressure of a laser gas in an enclosure () is detected by a gas pressure sensor (), and a pressure comparison circuit () determines whether the thus-detected pressure is normal or anomalous. An electric current output from an inverter () that drives a blower () to cause a laser gas to flow back, is detected by a current detection circuit (). A current comparison circuit () determines whether or not the output current is normal or anomalous. A result of a pressure comparison circuit () and a result of the current comparison circuit () are sent to an AND circuit () and performed AND processing. A result of the AND circuit (), a result of the current detection circuit (), and a result of the gas pressure sensor () are sent to a comparison operation section () in a controller (). A determination is made as to whether or not the blower is anomalous. When the blower is determined to be anomalous, a signal is output to an oscillator and a machine control section (), to thus stop the oscillator and the machine. Thereby, an anomaly in the blower () can be detected regardless of fluctuations in the pressure of the laser gas.

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Tokyo, Japan

Hiroshi Kurushima