Abstract: A load abnormality detecting circuit for an inverter to detect abnormality of a load during an operation of the inverter which has a self-arc-extinguishing element as a switching element and a phase synchronizing loop controlling an output frequency to be a resonance frequency of the load, the load abnormality detecting circuit includes a phase shift detection part that detects a phase shift between a gate voltage signal controlling ON/OFF of the self-arc-extinguishing element and an output current of the inverter which is applied to the load, and that sends a first abnormal load signal based on the phase shift.

Abstract: A load abnormality detecting circuit for an inverter to detect abnormality of a load during an operation of the inverter which has a switching element and a phase synchronizing loop controlling an output frequency to be a resonance frequency of the load, the load abnormality detecting circuit includes a phase shift detection part that detects a phase shift between an output voltage and an output current which are applied from the inverter to the load and sends an abnormal load signal based on the detected phase shift. The switching element including a self-arc-extinguishing element and a reflux diode connected in reversely parallel to the self-arc-extinguishing element. The phase shift detection part detects advance and delay of a phase of the output current with respect to the output voltage.

Abstract: A power supply device includes a first output unit that outputs a first alternating current, a second output unit that outputs a second alternating current, and a current combining unit that combines the first alternating current and the second alternating current. The current combining unit includes a first bus bar, a second bus bar, a first conductive member welded to a first surface of the first bus bar and connected to the first output unit, a second conductive member that is welded to a second surface of the first bus bar, penetrates the second bus bar, and is connected to the second output unit, a third conductive member welded to a first surface of the second bus bar and connected to the second output unit, and a fourth conductive member that is welded to a second surface of the second bus bar, penetrates the first bus bar, and is connected to the first output unit. The second surface of the first bus bar faces the second surface of the second bus bar.

Abstract: A power conversion apparatus includes a rectifier to convert AC power into constant-current DC power, a resonant inverter to convert the DC power into AC power to be output to a load, and a control unit to receive settings of an output current value of the inverter, a current-supplying time of the inverter, an operation rate defined by dividing the current-supplying time by a sum of the current-supplying time and a non-current-supplying time, and a resonance frequency of the load. The control unit operates the rectifier and the inverter only when it determines that it is operable to perform an output in accordance with the set conditions, based on data in which the output frequency, the current-supplying time and the operation rate are associated with an allowable output current value of the inverter at a temperature equal to or lower than a maximum operable temperature of a switching device.

Abstract: A power conversion apparatus includes a rectifier to convert AC power into constant-current DC power, a resonant inverter to convert the DC power into AC power to be output to a load, and a control unit to receive settings of an output current value of the inverter, a current-supplying time of the inverter, an operation rate defined by dividing the current-supplying time by a sum of the current-supplying time and a non-current-supplying time, and a resonance frequency of the load. The control unit operates the rectifier and the inverter only when it determines that it is operable to perform an output in accordance with the set conditions, based on data in which the output frequency, the current-supplying time and the operation rate are associated with an allowable output current value of the inverter at a temperature equal to or lower than a maximum operable temperature of a switching device.

Abstract: A power supply device includes a first output unit that outputs a first alternating current, a second output unit that outputs a second alternating current, and a current combining unit that combines the first alternating current and the second alternating current. The current combining unit includes a first bus bar, a second bus bar, a first conductive member welded to a first surface of the first bus bar and connected to the first output unit, a second conductive member that is welded to a second surface of the first bus bar, penetrates the second bus bar, and is connected to the second output unit, a third conductive member welded to a first surface of the second bus bar and connected to the second output unit, and a fourth conductive member that is welded to a second surface of the second bus bar, penetrates the first bus bar, and is connected to the first output unit. The second surface of the first bus bar faces the second surface of the second bus bar.

Abstract: A snubber circuit unit for a power semiconductor module including an arm having two power semiconductor elements capable of switching which are connected in series, the power semiconductor module including a positive DC input terminal, a negative input terminal, and an output terminal which are electrically connected to the arm, the positive DC input terminal, the negative DC input terminal, and the output terminal being provided on an upper surface opposite to an installation surface of the power semiconductor module, the snubber circuit unit includes a circuit board, and a plurality of electronic components mounted on the circuit board.

Abstract: An output current synthesizer that synthesizes output currents output from a plurality of power inverter circuits converting direct current power to alternating current power and outputs the synthesized output currents as synthesized current having a predetermined frequency, the output current synthesizer includes a pair of conductors which is provided with each of the power inverter circuits and to which the output currents of the power inverter circuits flow, a reactor which is provided on each of the pairs of conductors and generates magnetic flux corresponding to a difference between values of currents flowing to the pairs of conductors to reduce the difference between the values of currents, a pair of conductive members to which the pairs of conductors are connected in parallel, and a pair of output terminals which is provided on the pair of conductive members and output the synthesized currents.

Abstract: An induction heating power supply apparatus includes a smoothing section to smooth pulsating current of DC power output from a DC power supply section, and an inverter to convert the DC power smoothed by the smoothing section to AC power. The smoothing section includes a pair of bus bars connected to the inverter and a capacitor connected to the pair of bus bars. Each of the bus bars has an external surface extending in a current flow direction, the external surface including a flat face having a larger surface dimension than another face of the external surface in a direction perpendicular to the current flow direction. The bus bars are arranged in a layered manner such that the flat faces of the bus bars are opposed to each other and such that an insulator is sandwiched between the flat faces of the bus bars.

Abstract: A power conversion apparatus and a power conversion method are provided. The power conversion apparatus includes a rectifier configured to convert AC power to DC power, a smoothing filter configured to control the DC power received from the rectifier to be constant, an inverter configured to convert the DC power received from the smoothing filter into high-frequency power by turning the DC power on and off using a switching device, and a control unit configured to control the rectifier and the inverter. A rating of output power from the inverter is determined in accordance with a frequency of the high-frequency power output from the inverter, a current-applying time, and an operation rate obtained by dividing the current-applying time by a sum of the current-applying time and a non-current-applying time.

Abstract: An induction heating power supply apparatus includes a smoothing section to smooth DC power and an inverter section to convert the smoothed DC power into AC power. The inverter section has first and second modules, each having serially connected switching devices. Output bus bars are interposed between the first and second modules. The smoothing section has first bus bars connected to a DC power supply section and the first module, a capacitor connected to the first bus bars, second bus bars connected to the DC power supply section and the second module, and another capacitor connected to the second bus bars. The first and second bus bars extend parallel to the output bus bars. The first module is interposed between the first bus bars and the output bus bars. The second module is interposed between the second bus bars and the output bus bars.

Abstract: A power conversion apparatus includes a rectifier to convert AC power into constant-current DC power, a resonant inverter to convert the DC power into AC power to be output to a load, and a control unit to receive settings of an output current value of the inverter, a current-supplying time of the inverter, an operation rate defined by dividing the current-supplying time by a sum of the current-supplying time and a non-current-supplying time, and a resonance frequency of the load. The control unit operates the rectifier and the inverter only when it determines that it is operable to perform an output in accordance with the set conditions, based on data in which the output frequency, the current-supplying time and the operation rate are associated with an allowable output current value of the inverter at a temperature equal to or lower than a maximum operable temperature of a switching device.

Abstract: A load abnormality detecting circuit for an inverter to detect abnormality of a load during an operation of the inverter which has a switching element and a phase synchronizing loop controlling an output frequency to be a resonance frequency of the load, the load abnormality detecting circuit includes a phase shift detection part that detects a phase shift between an output voltage and an output current which are applied from the inverter to the load and sends an abnormal load signal based on the detected phase shift. The switching element including a self-arc-extinguishing element and a reflux diode connected in reversely parallel to the self-arc-extinguishing element. The phase shift detection part detects advance and delay of a phase of the output current with respect to the output voltage.

Abstract: An inverter of a power supply apparatus includes a smoothing circuit. The smoothing circuit includes a circuit body having a positive-side output terminal and a negative-side output terminal, and a plurality of capacitors mounted on the circuit body and connected in parallel between the positive-side output terminal and the negative-side output terminal. A difference between the maximum value and the minimum value among positive-negative electrical path lengths lnPNi=lnPi+lnNi (i=1, 2, and 3) for the respective capacitors is equal to or smaller than 30% of the minimum value.

Abstract: A load abnormality detecting circuit for an inverter to detect abnormality of a load during an operation of the inverter which has a self-arc-extinguishing element as a switching element and a phase synchronizing loop controlling an output frequency to be a resonance frequency of the load, the load abnormality detecting circuit includes a phase shift detection part that detects a phase shift between a gate voltage signal controlling ON/OFF of the self-arc-extinguishing element and an output current of the inverter which is applied to the load, and that sends a first abnormal load signal based on the phase shift.

Abstract: A power supply apparatus for induction heating is provided. The power supply apparatus includes a smoothing filter configured to smooth a pulsating current of DC power output from a DC power supply, and an inverter configured to convert the DC power that has been smoothed by the smoothing filter into AC power. The smoothing filter includes a plurality of capacitors having different internal inductances and connected to each other in parallel between input terminals of the inverter, each of the capacitors being connected to the input terminals of the inverter directly or through a pair of bus bars. The plurality of capacitors includes a first capacitor and a second capacitor, the first capacitor having smaller internal inductance than the second capacitor and a shorter conductive path between the input terminals of the inverter than the second capacitor.

Abstract: An output current synthesizer that synthesizes output currents output from a plurality of power inverter circuits converting direct current power to alternating current power and outputs the synthesized output currents as synthesized current having a predetermined frequency, the output current synthesizer includes a pair of conductors which is provided with each of the power inverter circuits and to which the output currents of the power inverter circuits flow, a reactor which is provided on each of the pairs of conductors and generates magnetic flux corresponding to a difference between values of currents flowing to the pairs of conductors to reduce the difference between the values of currents, a pair of conductive members to which the pairs of conductors are connected in parallel, and a pair of output terminals which is provided on the pair of conductive members and output the synthesized currents.

Abstract: A power conversion apparatus and a power conversion method are provided. The power conversion apparatus includes a rectifier configured to convert AC power to DC power, a smoothing filter configured to control the DC power received from the rectifier to be constant, an inverter configured to convert the DC power received from the smoothing filter into high-frequency power by turning the DC power on and off using a switching device, and a control unit configured to control the rectifier and the inverter. A rating of output power from the inverter is determined in accordance with a frequency of the high-frequency power output from the inverter, a current-applying time, and an operation rate obtained by dividing the current-applying time by a sum of the current-applying time and a non-current-applying time.

Abstract: A power conversion apparatus and a power conversion method are provided. The power conversion apparatus includes a rectifier configured to convert AC power to DC power, a smoothing filter configured to control the DC power received from the rectifier to be constant, an inverter configured to convert the DC power received from the smoothing filter into high-frequency power by turning the DC power on and off using a switching device, and a control unit configured to control the rectifier and the inverter. A rating of output power from the inverter is determined in accordance with a frequency of the high-frequency power output from the inverter, a current-applying time, and an operation rate obtained by dividing the current-applying time by a sum of the current-applying time and a non-current-applying time.

Abstract: A power semiconductor module, a snubber circuit for the power semiconductor module, and induction heating power supply apparatus having the power semiconductor module are provided. The power semiconductor module includes a power semiconductor device configured to perform a switching operation, a casing inside which the power semiconductor device is provided, a control circuit board provided on top of an upper surface of the casing, a control terminal for the power semiconductor device being provided on the upper surface of the casing and connected to the control circuit board, and a shield plate disposed between the control circuit board and the upper surface of the casing to cover the upper surface of the casing and to cover at least one side surface of the casing.