Abstract: A common mode choke coil includes: a magnetic core; and a pair of coils wound on a winding portion of the magnetic core, wherein the pair of coils include a first pole coil and a second pole coil which are each wound on the winding portion in a spiral shape by N turns, and wherein the first pole coil and the second pole coil are arranged on the winding portion so that one or more turns of the N turns are adjacent to each other, and each include a parallel running portion and a non-parallel running portion, the first pole coil and the second pole coil overlapping each other in the parallel running portion, and separating from each other in the non-parallel running portion in at least one turn of the adjacent first pole coil and second pole coil as viewed from the length direction of the winding portion.

Abstract: A common mode choke coil includes: a magnetic core; and a pair of coils wound on a winding portion of the magnetic core, wherein the pair of coils include a first pole coil and a second pole coil which are each wound on the winding portion in a spiral shape by N turns, and wherein the first pole coil and the second pole coil are arranged on the winding portion so that one or more turns of the N turns are adjacent to each other, and each include a parallel running portion and a non-parallel running portion, the first pole coil and the second pole coil overlapping each other in the parallel running portion, and separating from each other in the non-parallel running portion in at least one turn of the adjacent first pole coil and second pole coil as viewed from the length direction of the winding portion.

Abstract: A capacitor has a parasitic inductance component and is electrically connected between a positive line and a negative line. A converter includes a reactor provided in the positive line and performs voltage conversion of a DC voltage smoothed by a capacitor. An inverter performs DC-AC conversion between the converter and an AC motor by switching control. A path of the positive line which connects a DC power supply and the capacitor has an inductance smaller than an inductance of a path of the negative line which connects the DC power supply and the capacitor. A difference between the inductance of the path and the inductance of the path is less than twice the parasitic inductance component.

Abstract: A capacitor has a parasitic inductance component and is electrically connected between a positive line and a negative line. A converter includes a reactor provided in the positive line and performs voltage conversion of a DC voltage smoothed by a capacitor. An inverter performs DC-AC conversion between the converter and an AC motor by switching control. A path of the positive line which connects a DC power supply and the capacitor has an inductance smaller than an inductance of a path of the negative line which connects the DC power supply and the capacitor. A difference between the inductance of the path and the inductance of the path is less than twice the parasitic inductance component.

Abstract: A power converter includes: a base conductor, an electrically heating member which is provided on the base conductor, a noise reduction capacitor of flat plate-shape in which via an insulator, a plurality of first electrodes and second electrodes are alternately layered, on one surface, the first electrode in an outermost layer is exposed and on another surface, the second electrode in an outermost layer is exposed, a relay conductor which is electrically connected to other members from the electrically heating member via the noise reduction capacitor, and the second electrode in an outermost layer of the noise reduction capacitor is face-joined to a face of the base conductor at a side where the electrically heating member is provided and the first electrode in an outermost layer and the relay conductor are face-joined.

Abstract: A power converter includes: a base conductor, an electrically heating member which is provided on the base conductor, a noise reduction capacitor of flat plate-shape in which via an insulator, a plurality of first electrodes and second electrodes are alternately layered, on one surface, the first electrode in an outermost layer is exposed and on another surface, the second electrode in an outermost layer is exposed, a relay conductor which is electrically connected to other members from the electrically heating member via the noise reduction capacitor, and the second electrode in an outermost layer of the noise reduction capacitor is face-joined to a face of the base conductor at a side where the electrically heating member is provided and the first electrode in an outermost layer and the relay conductor are face-joined.

Abstract: A power conversion device 300 includes: an AC/DC converter section 10 which has an initial charging circuit 36 that initially charges a smoothing capacitor 22 provided at an output portion, and converts alternating current power into direct current power; a DC/DC converter section 11 which performs voltage conversion of direct current power supplied from the smoothing capacitor 22; and a control unit 5 which controls output of the AC/DC converter section 10 and output supplied from the DC/DC converter section 11. The control unit 5 performs a predetermined charging from the initial charging circuit 36 to the smoothing capacitor 22 at start-up of the AC/DC converter section 10, and starts the operation of the DC/DC converter section 11 after completion of charging, whereby the circuit can be protected from an inrush current at start-up.

Abstract: An inverter circuit is connected in series to an AC power supply, and at the subsequent stage, a smoothing capacitor is connected via a converter circuit including semiconductor switching devices. A control circuit controls the converter circuit by providing a short-circuit period for bypassing the smoothing capacitor in each cycle, and controls the inverter circuit to improve the power factor of the AC power supply by using a current instruction such that the voltage of the smoothing capacitor becomes a target voltage. When the voltage of a DC voltage source of the inverter circuit has exceeded a predetermined upper limit, the control circuit increases the current instruction to control the inverter circuit, thereby increasing the discharge amount of the DC voltage source. Thus, even if the voltage variation of the DC voltage source of the inverter circuit increases, it is possible to stably continue the control.

Abstract: A power conversion apparatus includes a high-power-factor converter section converting an AC voltage to a DC voltage, a smoothing capacitor, a DC/DC converter section, and a control circuit. The control circuit controls the high-power-factor converter section such that the power factor of AC is controlled and a DC voltage follows a target value, and performs duty control for semiconductor switching devices such that a DC voltage from the DC/DC converter section to a load follows an instruction value. In accordance with the DC voltage, the control circuit adjusts the DC voltage target value of the high-power-factor converter section such that the duty ratio of the semiconductor switching devices approaches a set value, thereby optimizing the duty ratio of the semiconductor switching devices and reducing power loss.

Abstract: A DC-DC converter in which a primary side and a secondary side are insulated by a transformer, includes: two diodes having anodes respectively connected to both ends of a secondary winding of the transformer and cathodes connected to each other; a series circuit composed of a resistor and a capacitor connected in series; and a snubber circuit formed by connecting the cathodes of the diodes to the connection point between the resistor and the capacitor. Surge voltage caused on the secondary side of the transformer is clamped at the voltage of the capacitor, and surge energy stored in the capacitor is regenerated to a load via the resistor. Thus, surge voltage caused on the secondary side of the transformer is suppressed with a simple configuration, and effective use of surge energy is ensured.

Abstract: A power conversion device 300 includes: an AC/DC converter section 10 which has an initial charging circuit 36 that initially charges a smoothing capacitor 22 provided at an output portion, and converts alternating current power into direct current power; a DC/DC converter section 11 which performs voltage conversion of direct current power supplied from the smoothing capacitor 22; and a control unit 5 which controls output of the AC/DC converter section 10 and output supplied from the DC/DC converter section 11. The control unit 5 performs a predetermined charging from the initial charging circuit 36 to the smoothing capacitor 22 at start-up of the AC/DC converter section 10, and starts the operation of the DC/DC converter section 11 after completion of charging, whereby the circuit can be protected from an inrush current at start-up.

Abstract: A DC-DC converter in which a primary side and a secondary side are insulated by a transformer, includes: two diodes having anodes respectively connected to both ends of a secondary winding of the transformer and cathodes connected to each other; a series circuit composed of a resistor and a capacitor connected in series; and a snubber circuit formed by connecting the cathodes of the diodes to the connection point between the resistor and the capacitor. Surge voltage caused on the secondary side of the transformer is clamped at the voltage of the capacitor, and surge energy stored in the capacitor is regenerated to a load via the resistor. Thus, surge voltage caused on the secondary side of the transformer is suppressed with a simple configuration, and effective use of surge energy is ensured.

Abstract: In order to widen an operational input voltage range of a power conversion apparatus and obtain a maximum efficiency value comparable to that in a case where the operational input voltage range is not widened by changing software but not hardware, provided is a power conversion apparatus, in which a control section (5) controls a current input to an inverter circuit (14) to cause a DC output voltage from an AC/DC converter section (10) which is a voltage across a smoothing capacitor (22) to follow a target voltage and to cause an input power factor from an AC power supply (1) to approach one, to thereby maintain a DC voltage from a single-phase inverter (14a), and adjusts the target voltage for the DC output voltage from the AC/DC converter section (10) in accordance with a voltage of the AC power supply (1).

Abstract: An inverter circuit is connected in series to an AC power supply, and at the subsequent stage, a smoothing capacitor is connected via a converter circuit including semiconductor switching devices. A control circuit controls the converter circuit by providing a short-circuit period for bypassing the smoothing capacitor in each cycle, and controls the inverter circuit to improve the power factor of the AC power supply by using a current instruction such that the voltage of the smoothing capacitor becomes a target voltage. When the voltage of a DC voltage source of the inverter circuit has exceeded a predetermined upper limit, the control circuit increases the current instruction to control the inverter circuit, thereby increasing the discharge amount of the DC voltage source. Thus, even if the voltage variation of the DC voltage source of the inverter circuit increases, it is possible to stably continue the control.

Abstract: A power conversion apparatus includes a high-power-factor converter section converting an AC voltage to a DC voltage, a smoothing capacitor, a DC/DC converter section, and a control circuit. The control circuit controls the high-power-factor converter section such that the power factor of AC is controlled and a DC voltage follows a target value, and performs duty control for semiconductor switching devices such that a DC voltage from the DC/DC converter section to a load follows an instruction value. In accordance with the DC voltage, the control circuit adjusts the DC voltage target value of the high-power-factor converter section such that the duty ratio of the semiconductor switching devices approaches a set value, thereby optimizing the duty ratio of the semiconductor switching devices and reducing power loss.

Abstract: A power converter includes an inverter circuit for superimposing a generated voltage on an AC input voltage, a diode bridge full-wave rectifying circuit connected to the inverter circuit, smoothing capacitors connected between DC output terminals of the rectifying circuit, short-circuit switches connected to the rectifying circuit, a rectification mode changing circuit connected to the rectifying circuit, a short-circuit switch control circuit for maintaining the short-circuit switches in an on state in a short-circuit phase range, a rectification mode control circuit for maintaining the rectification mode changing circuit in an off state in the short-circuit phase range and an inverter control circuit for PWM-controlling the inverter circuit so that an output voltage of the rectifying circuit follows a target output voltage when the rectification mode changing circuit is in the off state.

Abstract: In order to widen an operational input voltage range of a power conversion apparatus and obtain a maximum efficiency value comparable to that in a case where the operational input voltage range is not widened by changing software but not hardware, provided is a power conversion apparatus, in which a control section (5) controls a current input to an inverter circuit (14) to cause a DC output voltage from an AC/DC converter section (10) which is a voltage across a smoothing capacitor (22) to follow a target voltage and to cause an input power factor from an AC power supply (1) to approach one, to thereby maintain a DC voltage from a single-phase inverter (14a), and adjusts the target voltage for the DC output voltage from the AC/DC converter section (10) in accordance with a voltage of the AC power supply (1).

Abstract: A power converter includes an inverter circuit for superimposing a generated voltage on an AC input voltage, a diode bridge full-wave rectifying circuit connected to the inverter circuit, smoothing capacitors connected between DC output terminals of the rectifying circuit, short-circuit switches connected to the rectifying circuit, a rectification mode changing circuit connected to the rectifying circuit, a short-circuit switch control circuit for maintaining the short-circuit switches in an on state in a short-circuit phase range, a rectification mode control circuit for maintaining the rectification mode changing circuit in an off state in the short-circuit phase range and an inverter control circuit for PWM-controlling the inverter circuit so that an output voltage of the rectifying circuit follows a target output voltage when the rectification mode changing circuit is in the off state.