Abstract: A power converter has one set of two semiconductor switches performing switching actions, each of which is formed of an FET and a free wheel diode connected in anti-parallel to the FET, and a smoothing capacitor, and convers power by complementary switching actions of the FETs in the semiconductor switches. The power converter is provided with a current sensor that detects a direction of a current flowing through the semiconductor switches and a gate generation portion that skips ON signals of PWM gate signals of the semiconductor switches when the direction of the current flowing through the semiconductor switches is negative.

Abstract: Disclosed is a DC-DC power conversion apparatus (10) including two or more switching units (SU1, SU2) each of which further includes two semiconductor switching elements (Sa, Sb), and wherein each of the semiconductor switching elements (S1a, S1b, S2a, S2b) of each of the switching units are all connected in series, and which also includes an energy transition capacitor (C1) for conducting charging/discharging, and an inductor (L). The DC-DC power conversion apparatus (10) is also provided with a control unit that makes the semiconductor elements execute operations in four types of switching modes, according to the ratio (V2/V0) of the input/output voltages of the power conversion apparatus and the direction of the power transmission, and that also makes the elements carry out a current-discontinuing operation wherein the inductor current will become zero during switching operation, upon low load.

Abstract: In a DC/DC converter, a first operation section calculates a first operation value, based on a difference voltage between an instruction value for a high-voltage-side voltage and a detected value of a high-voltage-side voltage, a second operation section calculates a second operation value, based on a difference voltage between a voltage instruction value for a charge-discharge capacitor and a voltage detected value of the charge-discharge capacitor, and a switching control section obtains a conduction ratio, based on the first operation value and the second operation value, and controls, based on the conduction ratio, switching operations of first to fourth semiconductor circuits, thereby controlling the high-voltage-side voltage, and the voltage of the charge-discharge capacitor.

Abstract: A power module includes at least two pairs of two power semiconductor units (PSUs), each of which includes a switch element and a rectifier element connected in anti-parallel. One of two PSUs in one pair and one of two PSUs in another pair are connected in series between primary and secondary positive terminals of a DC/DC voltage converter. Another of two PSUs in the one pair and another of two PSUs in the another pair are connected in series between the primary positive terminal and a secondary negative terminal in a direction reverse to a direction of the ones of two PSUs. Control is performed to suppress transient voltage fluctuations that occur in switching between the state where the polarity of a reactor current is only one of positive and negative and the state where the polarity remains one of positive and negative.

Abstract: An object of the present invention is to provide a DC/DC power conversion apparatus that can reduce the average power consumption over a wide range of DC voltage ratios. A control circuit (120) changes a switching frequency f at which IGBTs S1 to S4 perform ON/OFF operation, in accordance with a voltage ratio k (k=V2/V1) for DC voltage conversion, based on the following expressions, such that a magnitude ?I of a current ripple flowing in a reactor Lc is a predetermined constant value irrespective of the voltage ratio k.

Abstract: A power module includes at least two pairs of two power semiconductor units (PSUs), each of which includes a switch element and a rectifier element connected in anti-parallel. One of two PSUs in one pair and one of two PSUs in another pair are connected in series between primary and secondary positive terminals of a DC/DC voltage converter. Another of two PSUs in the one pair and another of two PSUs in the another pair are connected in series between the primary positive terminal and a secondary negative terminal in a direction reverse to a direction of the ones of two PSUs. Control is performed to suppress transient voltage fluctuations that occur in switching between the state where the polarity of a reactor current is only one of positive and negative and the state where the polarity remains one of positive and negative.

Abstract: The invention provides a reactor to be built in a power converter. In the reactor, an induction component composed of a coil being a winding of a conductor wire, a core in which interior a magnetic path is formed and an insulation bobbin positioning and engaging a wire wound part of the coil is housed in a case to be soaked with a mold resin. Inner bottom face of the case has a plurality of surfaces having not less than two different heights letting the outside bottom of the case a reference surface, and the lower end face of the core is in contact with any of the case inner bottom surfaces excluding the lowest inner bottom surface. As a result, the reactor is suitable for on-vehicle applications to achieve reduced article variation as well as a longer service life, a shorter operation time and decreased cost.

Abstract: A power supply apparatus includes: an AC generator including an AC generating section, and a rectifier for rectifying an AC voltage generated in the AC generating section, and outputting a DC voltage; and a DC/DC converter for converting the output voltage of the rectifier into a DC voltage having a different voltage value, wherein the output voltage of the rectifier is set to be larger than the output voltage of the DC/DC converter in accordance with the rotation speed of the AC generating section and the amount of power supply to an electrical load connected to the DC/DC converter, and is stepped down and outputted by using the DC/DC converter. The power supply apparatus is capable of increasing an output power efficiently.

Abstract: In the present invention, when a power module is soldered to a heatsink, steam which is temperature-adjusted to at least the melting point of a solder is introduced from a steam generating tank into the flow path provided in the heatsink, the heatsink is heated and the solder is melted. Inert gas is introduced into a soldering tank from another route so as not to mix with the steam supplied to the heatsink. Voids in the solder are reduced and condensed by pressure regulation and as a result the negative impact of voids is eliminated.

Abstract: In a DC/DC converter, a first operation section calculates a first operation value, based on a difference voltage between an instruction value for a high-voltage-side voltage and a detected value of a high-voltage-side voltage, a second operation section calculates a second operation value, based on a difference voltage between a voltage instruction value for a charge-discharge capacitor and a voltage detected value of the charge-discharge capacitor, and a switching control section obtains a conduction ratio, based on the first operation value and the second operation value, and controls, based on the conduction ratio, switching operations of first to fourth semiconductor circuits, thereby controlling the high-voltage-side voltage, and the voltage of the charge-discharge capacitor.

Abstract: A power converter has one set of two semiconductor switches performing switching actions, each of which is formed of an FET and a free wheel diode connected in anti-parallel to the FET, and a smoothing capacitor, and convers power by complementary switching actions of the FETs in the semiconductor switches. The power converter is provided with a current sensor that detects a direction of a current flowing through the semiconductor switches and a gate generation portion that skips ON signals of PWM gate signals of the semiconductor switches when the direction of the current flowing through the semiconductor switches is negative.

Abstract: Disclosed is a DC-DC power conversion apparatus (10) including two or more switching units (SU1, SU2) each of which further includes two semiconductor switching elements (Sa, Sb), and wherein each of the semiconductor switching elements (S1a, S1b, S2a, S2b) of each of the switching units are all connected in series, and which also includes an energy transition capacitor (C1) for conducting charging/discharging, and an inductor (L). The DC-DC power conversion apparatus (10) is also provided with a control unit that makes the semiconductor elements execute operations in four types of switching modes, according to the ratio (V2/V0) of the input/output voltages of the power conversion apparatus and the direction of the power transmission, and that also makes the elements carry out a current-discontinuing operation wherein the inductor current will become zero during switching operation, upon low load.

Abstract: The invention provides a reactor to be built in a power converter. In the reactor, an induction component composed of a coil being a winding of a conductor wire, a core in which interior a magnetic path is formed and an insulation bobbin positioning and engaging a wire wound part of the coil is housed in a case to be soaked with a mold resin. Inner bottom face of the case has a plurality of surfaces having not less than two different heights letting the outside bottom of the case a reference surface, and the lower end face of the core is in contact with any of the case inner bottom surfaces excluding the lowest inner bottom surface. As a result, the reactor is suitable for on-vehicle applications to achieve reduced article variation as well as a longer service life, a shorter operation time and decreased cost.

Abstract: An object of the present invention is to provide a DC/DC power conversion apparatus that can reduce the average power consumption over a wide range of DC voltage ratios. A control circuit (120) changes a switching frequency f at which IGBTs S1 to S4 perform ON/OFF operation, in accordance with a voltage ratio k (k=V2/V1) for DC voltage conversion, based on the following expressions, such that a magnitude ?I of a current ripple flowing in a reactor Lc is a predetermined constant value irrespective of the voltage ratio k.

Abstract: A cooling structure includes a heat dissipation structure having a heat generator and a heatsink that is adhered through an insulating adhesive layer to at least a surface of the heat generator that faces a cooling fluid and made of a metal foil having the flexibility. A fluid flow path is disposed outside of the heat dissipation structure so that the cooling fluid flowing inside thereof and the heatsink may directly come into contact. Further, a fine recess is disposed on a surface of the heatsink that directly comes into contact with the cooling fluid.

Abstract: A cooling structure includes a heat dissipation structure having a heat generator and a heatsink that is adhered through an insulating adhesive layer to at least a surface of the heat generator that faces a cooling fluid and made of a metal foil having the flexibility; and a fluid flow path that is disposed outside of the heat dissipation structure so that the cooling fluid flowing inside thereof and the heatsink may directly come into contact. Furthermore, on a surface of the heatsink that directly comes into contact with the cooling fluid, a fine recess is disposed.

Abstract: Three or more circuits, in which series-connected low-voltage and high-voltage side switches including MOSFETs including parasitic diodes are connected across positive and negative terminals of each of smoothing capacitors, are connected in series. One of elementary series circuits, each including a capacitor and an inductor, is disposed between any adjacent two of the circuits with the elementary series circuits set to have the same period of resonance. The MOSFETs of rectifier circuits are brought into an ON state simultaneously with the MOSFETs of a driving inverter circuit and brought into an OFF state earlier than the MOSFETs of the driving inverter circuit by a period of time not exceeding a time period equal to (period of resonance)/2. A resonance phenomenon of the capacitor and the inductor is used and conduction loss in the rectifier circuits is reduced in DC/DC power conversion performed through charging and discharging operation of the capacitor.

Abstract: Three or more circuits including a driving inverter circuit and rectifier circuits are connected in series, each of the circuits including a high-voltage side MOSFET and a low-voltage side MOSFET connected in series as well as a smoothing capacitor having positive and negative terminals between which the MOSFETs are connected. LC series circuits, each including a capacitor and an inductor, are disposed individually between one specific circuit and the other circuits with periods of resonance of the LC series circuits made equal to one another. In performing DC/DC power conversion through charging and discharging operation of the capacitors, a resonance phenomenon of the LC series circuits is used to improve conversion efficiency and achieve a reduction in size of the apparatus structure.

Abstract: A power conversion apparatus comprising a base 110 which includes a first fixation portion 110a and a second fixation portion 110b that are coupled to each other at a desired angle, wherein power modules IPM1, IPM2 and IPM3 are fixed on the first fixation portion 110a of the base 110, a control circuit board 10 is fixed with its first principal surface 10a held in direct or indirect touch with the second fixation portion 110b of the base 110, and components constituting a control circuit are packaged on the second principal surface 10b of the control circuit board 10. Owing to the configuration, a versatility for the installation of the power conversion apparatus on a vehicle becomes high, the vibration-proofness of the control circuit board is enhanced, and heats generated by the electronic components, etc. packaged on the control circuit board are sufficiently emitted.

Abstract: A power supply apparatus includes: an AC generator including an AC generating section, and a rectifier for rectifying an AC voltage generated in the AC generating section, and outputting a DC voltage; and a DC/DC converter for converting the output voltage of the rectifier into a DC voltage having a different voltage value, wherein the output voltage of the rectifier is set to be larger than the output voltage of the DC/DC converter in accordance with the rotation speed of the AC generating section and the amount of power supply to an electrical load connected to the DC/DC converter, and is stepped down and outputted by using the DC/DC converter. The power supply apparatus is capable of increasing an output power efficiently.