JP-7854964-B2 - Power converter

JP7854964B2JP 7854964 B2JP7854964 B2JP 7854964B2JP-7854964-B2

Inventors

早瀬佳

Assignees

三菱電機株式会社

Dates

Publication Date: 20260507
Application Date: 20230515

Claims (13)

The iron core that forms the magnetic circuit, The primary coil wound around the aforementioned iron core, The primary coil is magnetically coupled to the secondary coil wound around the iron core, The system comprises a smoothing coil electrically connected to the secondary coil and wound around the iron core, The iron core comprises a first iron core, a second iron core facing the first iron core and spaced apart from it, a central leg connecting the opposing central portions of the first and second iron cores, and a plurality of side legs spaced apart from the central leg and connecting the opposing end portions of the first and second iron cores. The primary coil and the secondary coil are wound around the first side leg. The smoothing coil is wound around the second side leg, A common magnetic path is formed in the central leg for the primary coil, the secondary coil, and the smoothing coil . The aforementioned central leg does not have a spaced gap portion in the central leg portion. The first side leg is a power conversion device in which there is no spaced gap portion in the first side leg portion .
The power conversion device according to claim 1, wherein each of the primary coil, the secondary coil, and the smoothing coil is formed in the shape of a curved plate on a flat surface.
It further comprises a power conversion circuit that has multiple semiconductor switching elements and converts between DC power and AC power, The primary coil is electrically connected to the output side of the power conversion circuit. The power conversion device according to claim 1, wherein the power conversion circuit is a circuit that uses a hard switching method to adjust the output power by changing the on-off duty cycle of the plurality of semiconductor switching elements.
The power conversion device according to claim 1, wherein the cross-sectional area of the central leg is smaller than the sum of the cross-sectional areas of the plurality of side legs.
The central leg is positioned with a gap between it and the adjacent primary coil, secondary coil, and smoothing coil, The power conversion device according to claim 1, wherein the side surface of the central leg has a shape that conforms to the respective side shapes of the primary coil, the secondary coil, and the smoothing coil that are facing the side surface of the central leg.
The power conversion device according to claim 1, wherein the thickness of one or both portions of the first core and the second core, in which the magnetic flux of the smoothing coil is linked, is greater than the respective thicknesses of the first core and the second core, in which the magnetic flux of the primary coil and the secondary coil are linked.
The power conversion device according to claim 1, wherein the iron core is made of ferrite.
The rectifier circuit further comprises multiple rectifier elements and is electrically connected to the secondary coil, The power conversion device according to claim 1, wherein the anode terminal of each of the plurality of rectifier elements is grounded.
The power conversion device according to claim 8 , wherein the secondary coil and the smoothing coil are arranged side by side and are electrically and mechanically coupled by an integrated portion to form an integrated coil member.
The power conversion device according to claim 1, wherein the number of turns of the secondary coil is less than the number of turns of the primary coil.
Any portion of the central leg and any of the multiple side legs around which the primary coil, the secondary coil, and the smoothing coil are wound, and which does not form a common magnetic path for the primary coil, the secondary coil, and the smoothing coil, has a spaced gap. The power conversion device according to claim 1, wherein a spacer member is inserted into the gap portion.
The cooler further comprises a recessed section, The portion of the second core opposite to the first core is thermally connected to the bottom of the recess. The power conversion device according to claim 1, wherein the primary coil or the secondary coil and the smoothing coil are thermally connected to the portion of the cooler surrounding the opening of the recess.
The iron core that forms the magnetic circuit, The primary coil wound around the aforementioned iron core, The primary coil is magnetically coupled to the secondary coil wound around the iron core, The system comprises a smoothing coil electrically connected to the secondary coil and wound around the iron core, The iron core comprises a first iron core, a second iron core facing the first iron core and spaced apart from it, a central leg connecting the opposing central portions of the first and second iron cores, and a plurality of side legs spaced apart from the central leg and connecting the opposing end portions of the first and second iron cores. The primary coil and the secondary coil are wound around the first side leg. The smoothing coil is wound around the second side leg, A common magnetic path is formed in the central leg for the primary coil, the secondary coil, and the smoothing coil. The plurality of side legs, a third side leg and a fourth side leg, are provided. Each of the first, second, third, and fourth side legs is spaced apart from the central leg and arranged to surround it. The primary coil and the secondary coil are wound around the third side leg. The smoothing coil is a power conversion device wound around the fourth side leg.

Description

This application relates to a power conversion device. Due to recent environmental regulations surrounding automobiles and technological advancements, electric vehicles and hybrid vehicles have been developed and are becoming increasingly popular across various vehicle classes. Electrified vehicles, such as hybrid or electric vehicles, which use motors as their drive source, are equipped with multiple power conversion devices. A power conversion device is a device that converts input current from direct current (DC) to alternating current (AC), from AC to DC, or input voltage to a different voltage. Power conversion devices utilize multiple magnetic components, each comprising an iron core and windings. Specific examples of power conversion devices installed in electrified vehicles include chargers that convert commercial AC power to DC power to charge high-voltage batteries, DC/DC converters that convert DC power from high-voltage batteries to DC power of a different voltage, and inverters that convert DC power from high-voltage batteries to AC power for the motor. DC/DC converters are installed in electric vehicles, for example, to charge low-voltage lead-acid batteries from high-voltage lithium-ion batteries. To protect the surroundings from high voltage, high-voltage lithium-ion batteries are isolated from the chassis and low-voltage systems. Similarly, in DC/DC converters, isolation transformers are generally required to isolate the high-voltage input side from the low-voltage output side. In a DC/DC converter, the DC input voltage is switched using semiconductor elements to convert it into an AC signal, which is then input to the primary side of the isolation transformer. The output of the secondary side of the isolation transformer is rectified using semiconductor elements, smoothed by a smoothing reactor, and then output as a DC output voltage from the DC/DC converter. Isolated DC/DC converters installed in electric or hybrid vehicles are typically in the kW class or higher. Therefore, isolation transformers and smoothing reactors are large and prone to overheating. Furthermore, isolated DC/DC converters with multiple magnetic components such as isolation transformers and smoothing reactors require fixing parts to secure each component, resulting in a high number of parts. A power conversion device configuration that reduces the number of parts has been disclosed (for example, Patent Document 1). In Patent Document 1, the iron core has a central leg and side legs, with the smoothing reactor winding wound around the central leg which has a gap, and the isolation transformer winding wound around the side legs. By integrating the isolation transformer and smoothing reactor, the power conversion device is miniaturized, and the number of parts in the power conversion device is reduced. Patent No. 6198994 This figure shows the circuit configuration of the power conversion device according to Embodiment 1.This diagram shows the configuration of the magnetic components of the power converter according to Embodiment 1.This diagram shows the operation of the circuit of the power converter according to Embodiment 1.This figure shows the magnetic flux generated in the magnetic components of the power converter according to Embodiment 1.This diagram shows the operation of the circuit of the power converter according to Embodiment 1.This diagram shows the operation of the circuit of the power converter according to Embodiment 1.This figure shows the magnetic flux generated in the magnetic components of the power converter according to Embodiment 1.This is an exploded perspective view showing a schematic representation of the magnetic components of the power converter according to Embodiment 1.This diagram shows a schematic representation of the magnetic components and cooler of the power converter according to Embodiment 1.This diagram shows the operation of the circuit of the power converter according to Embodiment 1.This diagram shows the operation of the circuit of the power converter according to Embodiment 1.This figure shows the operating waveform of the power converter circuit according to Embodiment 1.This is a plan view showing a schematic of the main parts of the power conversion device according to Embodiment 2.This figure shows a schematic diagram of the main parts of the power conversion device according to Embodiment 3.This diagram shows a schematic representation of the magnetic components of the power converter according to Embodiment 4.This figure shows a schematic diagram of the main parts of the power conversion device according to Embodiment 5.This diagram shows the configuration of the magnetic components of the power converter according to Embodiment 6.This diagram shows the configuration of another magnetic component of the power converter according to Embodiment 6.This diagram shows the configuration of the magnetic components of the power converter according to Embodiment 7. The power con