Power converter and method for assembling a power converter

Abstract

To provide a power converter and a power converter assembly method capable of improving the workability of assembling a power converter by eliminating the work of reversing a case by a worker when assembling the power converter.SOLUTION: A power converter 1000 includes a first case 107 in which a first main circuit portion 103 is provided, a second case 108 that is provided in parallel with the first case in a first horizontal direction, which is one of the horizontal directions, and in which a second main circuit portion 104 is provided, a ventilation passage 119 provided between the first case 107 and the second case 108 and arranged in the first horizontal direction, and a base portion 112 to which the lower end of the first case 107 and the lower end of the second case 108 are attached.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a power conversion device and a method for assembling a power conversion device, and more particularly, to a power conversion device including a case having a main circuit section provided therein and a method for assembling the power conversion device.

Background Art

[0002] Conventionally, a power conversion device including a case having a main circuit section provided therein is known (see, for example, Patent Document 1).

[0003] Patent Document 1 discloses a power conversion device including a housing having a main circuit section provided therein. The main circuit section of this power conversion device includes a first main circuit section and a second main circuit section. The first main circuit section converts DC power output from a DC power source outside the device into AC power. The second main circuit section converts the AC power from the first main circuit section into DC.

[0004] The housing of the power conversion device of Patent Document 1 includes an upper housing, a lower housing, an inner housing, upper heat radiating fins, and lower heat radiating fins.

[0005] The upper housing of Patent Document 1 is attached to the upper end of the lower housing. The first main circuit section is attached inside the upper housing. The inner housing is attached inside the lower housing. The inner housing is attached to the bottom surface of the inner surface of the lower housing. An opening for inserting the inner housing is formed on the upper surface of the lower housing. The second main circuit section is attached inside the inner housing. An opening for inserting the second main circuit section is formed on the lower surface of the inner housing.

[0006] The upper heat dissipation fin described in Patent Document 1 above is configured to dissipate heat generated in the first main circuit section. The upper heat dissipation fin is attached to the lower surface of the upper housing section in contact with the first main circuit section. The lower heat dissipation fin is configured to dissipate heat generated in the second main circuit section. The lower heat dissipation fin is attached to the upper surface of the inner housing section in contact with the second main circuit section. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2021-158847 [Overview of the project] [Problems that the invention aims to solve]

[0008] Here, although not explicitly stated in Patent Document 1, in the power converter described in Patent Document 1, when an operator assembles the power converter, in order to facilitate the installation work of attaching the second main circuit to the inside of the inner housing, the opening on the bottom surface of the inner housing is turned upward, the second main circuit is inserted into the inner housing from above through the opening on the bottom surface of the inner housing, and then the second main circuit is installed inside the inner housing. Alternatively, with the opening on the bottom surface of the inner housing still facing upward, the operator can invert the lower housing so that the opening on the top surface of the lower housing is facing downward, and then insert the inner housing into the lower housing through the opening on the top surface of the lower housing to attach the inner housing to the bottom surface of the lower housing. Finally, since the operator needs to attach the upper housing to the upper end of the lower housing, the operator can invert the lower housing again to its original position so that the bottom surface of the lower housing is facing upward, and then attach the upper housing to the upper end of the lower housing.

[0009] However, in this case, the lower casing needs to be inverted, and then inverted again to return it to its original position, which is a cumbersome process. Therefore, it is desirable to improve the workability of assembling the power converter by eliminating the need for the worker to invert the lower casing (case) when assembling the power converter.

[0010] This invention was made to solve the above-mentioned problems, and one objective of this invention is to provide a power converter and a method for assembling a power converter that can improve the work efficiency of the assembly work of the device by eliminating the need for the worker to invert the case when assembling the power converter. [Means for solving the problem]

[0011] A power conversion device according to the first aspect of this invention comprises a first case containing a first main circuit section that converts DC power output from a DC power source into AC power, a second case provided alongside the first case in a first horizontal direction (one of the horizontal directions) and containing a second main circuit section that converts the AC power converted by the first main circuit section into DC power, a ventilation passage provided between the first case and the second case which are aligned in the first horizontal direction, and a base portion to which the lower end of the first case and the lower end of the second case are attached. The base portion forms the lower surface of the power converter body. .

[0012] In the power conversion device according to the first aspect of this invention, as described above, a base portion is provided to which the lower ends of the first case and the lower ends of the second case are attached. This allows the worker to complete the installation of the first and second cases to the base portion by attaching the lower ends of the first and second cases to the base portion after separately performing the tasks of installing the first main circuit portion in the first case and installing the second main circuit portion in the second case. This allows the first and second cases to be installed to the base portion without inverting the second case. As a result, the work efficiency of the assembly of the power conversion device can be improved by eliminating the need for the worker to invert the first or second case when assembling the device.

[0013] The power conversion device according to the first aspect described above further includes a first heat dissipation section arranged in the ventilation passage to dissipate heat generated in the first main circuit section. The first case has a first insertion opening provided on the side opposite to the ventilation passage side in the first horizontal direction, into which the first main circuit section can be inserted, and a first ventilation passage side wall section to which the first heat dissipation section is attached on the ventilation passage side. With this configuration, the first main circuit section can be installed in the first case by attaching the first heat dissipation section to the ventilation passage side of the first ventilation passage side wall section and then inserting the first main circuit section through the first insertion opening. As a result, the first heat dissipation section and the first main circuit section can be easily attached to the first case.

[0014] In this case, preferably, the second case further includes a second heat dissipation section arranged in the ventilation passage to dissipate heat generated in the second main circuit section, and the second case has a second insertion opening provided on the side opposite to the ventilation passage side in the first horizontal direction into which the second main circuit section can be inserted, and a second ventilation passage side wall section to which the second heat dissipation section is attached on the ventilation passage side. With this configuration, the first main circuit section can be installed in the second case by attaching the second heat dissipation section to the ventilation passage side of the second ventilation passage side wall section and then inserting the second main circuit section through the second insertion opening. As a result, the second heat dissipation section and the second main circuit section can be easily installed in the second case.

[0015] In a power conversion device equipped with the above-described second heat dissipation section, preferably, the device further includes a blower that blows air into the air passage along a second horizontal direction perpendicular to a first horizontal direction, and an airflow direction changing section that changes the direction of the air blown from the blower towards the first and second heat dissipation sections in the air passage by narrowing the air passage from both the upper and lower sides in a cross section along the vertical direction of the air passage, from the upstream side to the downstream side of the air blown from the blower. With this configuration, the air can be concentrated toward the first and second heat dissipation sections, making it easier for the air to hit the entire first and second heat dissipation sections. As a result, heat dissipation becomes easier throughout the entire first and second heat dissipation sections, thereby improving the heat dissipation performance of the first and second heat dissipation sections.

[0016] In a power conversion device equipped with the above-described wind direction changing unit, preferably, the device further comprises a transformer that converts voltage between a first main circuit unit and a second main circuit unit, and a reactor to which the power converted in the second main circuit unit is input. The wind direction changing unit has a base-side projection that protrudes upward from the base unit, and the base-side projection has a mounting base unit to which the transformer and reactor are attached, and a base-side wind direction changing inclined unit that is inclined upward as the airflow from the blower unit moves from the upstream side to the downstream side, thereby changing the direction of the airflow from the blower unit upward. With this configuration, the base-side wind direction changing inclined unit can concentrate airflow not only towards the first heat dissipation unit and the second heat dissipation unit, but also towards the transformer and reactor, making it easier for air to hit the entire first heat dissipation unit, the second heat dissipation unit, the transformer, and the reactor. As a result, heat can be easily dissipated in the first heat dissipation unit, the second heat dissipation unit, the transformer, and the reactor.

[0017] In a power converter equipped with a wind direction changing section including the base-side protrusion described above, preferably, the wind direction changing section has an upper-side protrusion that faces the base-side protrusion in the vertical direction and protrudes downward, and the upper-side protrusion is provided at an inclination downward as the airflow from the blower unit moves from the upstream side to the downstream side, and has an upper-side wind direction changing inclined section that changes the direction of the airflow from the blower unit downward. With this configuration, the upper-side wind direction changing inclined section and the base-side wind direction changing inclined section can concentrate the airflow not only towards the first heat dissipation section and the second heat dissipation section but also towards the transformer and reactor, so that the airflow can more easily reach the entire first heat dissipation section, the second heat dissipation section, the transformer and reactor. As a result, heat can be more easily dissipated in the first heat dissipation section, the second heat dissipation section, the transformer and reactor.

[0018] In a power converter equipped with a wind direction changing section including the base-side protrusion described above, the mounting base is preferably formed to extend in a second horizontal direction. With this configuration, the air passage on the mounting base can be formed in a straight line, allowing air to flow smoothly through the air passage.

[0019] In a power conversion device equipped with the above-described airflow direction changing section, preferably, a blower section is provided, further comprising: an upstream end cover section that covers the upstream end portion of the airflow from the blower section in the first case, second case, and air passage; a downstream end cover section that covers the downstream end portion of the airflow from the blower section in the first case, second case, and air passage; a first side cover section that covers the side of the first case opposite to the air passage; a second side cover section that covers the side of the second case opposite to the air passage; and an upper cover section that covers the upper side of the first case, second case, and air passage in the upward direction. With this configuration, the base section, upstream end cover section, downstream end cover section, first side cover section, second side cover section, and upper cover section can cover the first case and the second case, thereby preventing water and dust from entering the first case and the second case.

[0020] In the power conversion device according to the first aspect described above, preferably, the wiring and equipment constituting the main circuit for power conversion, including the first main circuit section and the second main circuit section, are arranged in a substantially U-shape in plan view, sequentially from the input side to the output side of the main circuit, following the order of electrical connections of the main circuit. With this configuration, even though the space inside the power conversion device is relatively narrow, the U-shaped arrangement makes effective use of the space and prevents the current flowing through the wiring and equipment constituting the main circuit from returning to the input side. As a result, the length of the wiring constituting the main circuit can be made relatively short, thus suppressing the increase in device weight caused by an increase in wiring length and the number of wires.

[0021] A method for assembling a power converter according to a second aspect of this invention comprises the steps of: installing a first main circuit section, which converts DC power output from a DC power source into AC power, inside a first case; installing a second main circuit section, which converts the AC power converted by the first main circuit section into DC power, inside a second case; and attaching the lower end of the first case and the lower end of the second case to a base section, aligned in a first horizontal direction, so as to provide a ventilation passage between the first case and the second case. The step of attaching the lower end of the first case and the lower end of the second case to the base portion includes the step of forming the lower surface portion of the power converter body with the base portion. .

[0022] In the assembly method of the power converter according to the second aspect of this invention, as described above, a step is provided in which the lower ends of the first case and the lower ends of the second case are attached to the base in a horizontal direction. This allows the worker to complete the work of attaching the first and second cases to the base by attaching the lower ends of the first and second cases to the base after the worker has separately performed the work of installing the first main circuit in the first case and the second main circuit in the second case. This allows the first and second cases to be attached to the base without inverting the second case. As a result, an assembly method for a power converter can be obtained that improves the work efficiency of the assembly work of the device by eliminating the work of the worker having to invert the first or second case when assembling the power converter.

[0023] In the assembly method of the power converter according to the second aspect described above, preferably, the step of installing the first main circuit section inside the first case includes the step of attaching the first ventilation passage side wall of the first case on the ventilation passage side to the first heat dissipation section that dissipates heat generated in the first main circuit section from above, and the step of inserting the first main circuit section through a first insertion opening provided on the side of the first case opposite to the ventilation passage side, and attaching the first main circuit section to the first case from above while it is in contact with the first heat dissipation section. With this configuration, the first case can be assembled by attaching the first ventilation passage side wall and the first main circuit section in that order to the upper side of the first heat dissipation section, so the first case can be easily assembled.

[0024] In the method for assembling the power conversion device according to the second aspect, preferably, the step of attaching the second main circuit unit inside the second case includes attaching the second ventilation path side wall portion on the ventilation path side of the second case from above to the second heat radiating portion that radiates heat generated in the second main circuit unit, and inserting the second main circuit unit from the second insertion opening provided on the surface opposite to the ventilation path side of the second case, and attaching the second main circuit unit to the second case from above in a state of being in contact with the second heat radiating portion. With this configuration, the second case can be assembled by attaching the second ventilation path side wall portion and the second main circuit unit in this order above the second heat radiating portion, so that the second case can be easily assembled.

Advantages of the Invention

[0025] According to the present invention, as described above, when assembling the power conversion device, the workability of the device assembly work can be improved by eliminating the operation of the operator reversing the case.

Brief Description of the Drawings

[0026] [Figure 1] It is a perspective view of the power conversion device of this embodiment. [Figure 2] It is a plan view of the power conversion device of this embodiment with the upper surface cover portion removed. [Figure 3] It is a block diagram showing the first main circuit unit and the second main circuit unit in the power conversion device of this embodiment. [Figure 4] It is a perspective view showing a state where the first case and the second case are attached to the base portion in the power conversion device of this embodiment. [Figure 5] It is a cross-sectional view taken along the line V-V of FIG. 2. [Figure 6] It is a cross-sectional view taken along the line VI-VI of FIG. 5. [Figure 7] It is a perspective view of the upper surface cover portion of the power conversion device of this embodiment as viewed from below. [Figure 8]This is a perspective view showing the power converter of this embodiment with the rear cover, first side cover, second side cover, and top cover removed. [Figure 9] This is a flowchart showing the first part of the assembly method for the power converter of this embodiment. [Figure 10] This flowchart shows the latter part of the assembly method for the power converter of this embodiment. [Figure 11] This is a perspective view showing the state in which the first main circuit section is installed inside the first case in the assembly method of the power conversion device of this embodiment. [Figure 12] This is a perspective view showing the assembly method of the power converter according to this embodiment, with the second main circuit section installed inside the second case. [Figure 13] This is a perspective view showing the assembly method of the power converter according to this embodiment, with the blower unit, input connector unit, and output connector unit attached to the front cover. [Figure 14] This is a perspective view showing the assembly method of the power converter according to this embodiment, with the first case, reactor, and transformer attached to the front cover and base. [Figure 15] This is a perspective view showing the state in which the second case is attached to the front cover and base in the assembly method of the power converter of this embodiment. [Figure 16] This is a perspective view showing the assembly method of the power converter according to this embodiment, with the second case attached to the front cover and base. [Modes for carrying out the invention]

[0027] Embodiments of the present invention will be described below with reference to the drawings.

[0028] Referring to Figures 1 to 16, the configuration of the power converter 1000 of this embodiment will be described.

[0029] The power converter 1000 is configured in a railway vehicle to convert DC power output from an external DC power source into AC power, then convert the converted AC power back into DC power, and finally supply the converted DC power to an external load. The power converter 1000 is located in the space above (or below) the passenger compartment of the railway vehicle.

[0030] As shown in Figures 1 and 2, the power converter 1000 comprises an input connector section 101, an output connector section 102, a first main circuit section 103, a second main circuit section 104, a transformer 105, a reactor 106, a first case 107, and a second case 108. Figure 2 is a view of the power converter 1000 from the Z1 direction side with the top cover section 113 (described later) removed.

[0031] Here, the vertical direction is defined as the Z direction, the upward direction of the Z direction is defined as the Z1 direction, and the downward direction of the Z direction is defined as the Z2 direction. The direction in which the first case 107 and the second case 108 are aligned in the horizontal direction is defined as the X direction, the direction toward the first case 107 in the X direction is defined as the X1 direction, and the direction toward the second case 108 in the X direction is defined as the X2 direction. The direction perpendicular to the X direction in the horizontal direction is defined as the Y direction, one direction is defined as the Y1 direction, and the other direction is defined as the Y2 direction. Note that the X2 direction is an example of the "first horizontal direction" in the claims. The Y1 direction is an example of the "second horizontal direction" in the claims.

[0032] The input connector section 101 is electrically connected to an external DC power supply via wiring (not shown) and is configured to input DC power from the wiring to the first main circuit section 103. The output connector section 102 is electrically connected to an external load (not shown) via wiring and is configured to output DC power converted in the second main circuit section 104 to the load. The input connector section 101 and the output connector section 102 are arranged side by side in the X direction. The input connector section 101 is located on the X1 side. The output connector section 102 is located on the X2 side.

[0033] As shown in Figures 2 and 3, the first main circuit 103 is configured to convert DC power output from a DC power supply into AC power. The first main circuit 103 is an inverter. Specifically, the first main circuit 103 includes a circuit board 103a, a circuit board 103b, a filter unit 103c, a DC / AC conversion unit 103d, and a control unit 103e.

[0034] Substrate 103a is a printed circuit board (PCB) with a conductor pattern formed on it. Substrate 103a is provided with a filter section 103c and a DC / AC conversion section 103d. Substrate 103b is a printed circuit board with a conductor pattern formed on it. Substrate 103b is provided with a control section 103e.

[0035] The filter section 103c is configured to remove noise contained in the DC power output from the DC power supply. In other words, the filter section 103c is a filter circuit for extracting specific (intended) frequency components, for example, composed of an inductor and a capacitor. The input connector section 101 and the filter section 103c are electrically connected by wires, copper bars (busbars), or conductive patterns formed on the substrate 103a.

[0036] The DC / AC conversion unit 103d is configured to convert the DC power output from the filter unit 103c into AC power. The DC / AC conversion unit 103d has a plurality of semiconductor switching elements 131. The control unit 103e is configured to control the ON or OFF state of each of the plurality of semiconductor switching elements 131 of the DC / AC conversion unit 103d.

[0037] The DC / AC conversion unit 103d and the filter unit 103c are electrically connected by electric wires, busbars, or conductor patterns formed on the substrate 103a. The DC / AC conversion unit 103d and the control unit 103e are electrically connected by electric wires. The DC / AC conversion unit 103d and the transformer 105 are electrically connected by electric wires via terminal blocks or the like. In this way, the semiconductor switching elements 131 of the filter unit 103c and the DC / AC conversion unit 103d are electrically connected to the transformer 105 in a state where they are arranged sequentially in the Y1 direction.

[0038] The second main circuit section 104 is configured to convert the AC power converted by the first main circuit section 103 into DC power. The second main circuit section 104 is a rectifier section. Specifically, the second main circuit section 104 includes a circuit board 104a, an AC / DC conversion section 104b, and a smoothing capacitor section 104c.

[0039] The substrate 104a is a printed circuit board on which a conductor pattern is formed. The substrate 104a is provided with an AC / DC conversion unit 104b and a smoothing capacitor unit 104c.

[0040] The AC / DC converter 104b is configured to convert the AC power output from the transformer 105 into DC power. The AC / DC converter 104b has multiple diodes. The smoothing capacitor 104c is configured to smooth the DC power output from the reactor 106.

[0041] The transformer 105 and the AC / DC converter 104b are electrically connected by wires via a terminal block or the like. The AC / DC converter 104b and the reactor 106 are electrically connected by wires, busbars, or conductor patterns formed on the substrate 103a. The reactor 106 and the smoothing capacitor 104c are electrically connected by wires, busbars, or conductor patterns formed on the substrate 103a. The smoothing capacitor 104c and the output connector 102 are electrically connected by wires, busbars, or conductor patterns formed on the substrate 103a. In this way, the diodes of the AC / DC converter 104b and the smoothing capacitor 104c are arranged sequentially in the Y2 direction.

[0042] The transformer 105 is configured to convert voltage between the first main circuit section 103 and the second main circuit section 104. The reactor 106 is configured to smooth the DC power converted in the AC / DC conversion section 104b.

[0043] Furthermore, the wiring and equipment constituting the main circuit for power conversion, including the first main circuit section 103 and the second main circuit section 104, are arranged in a roughly U-shape in plan view, sequentially following the order of electrical connections of the main circuit from the input side to the output side. Here, the wiring and equipment constituting the main circuit include the filter section 103c, the multiple semiconductor switching elements 131 of the DC / AC conversion section 103d, the transformer 105, the diodes and reactors 106 of the AC / DC conversion section 104b, and the smoothing capacitor section 104c.

[0044] Specifically, the first main circuit section 103 is configured to supply AC power to the transformer 105 by allowing current supplied from the input connector section 101 to flow in the Y1 direction. That is, in the first main circuit section 103, current flows in the Y1 direction in the order of the filter section 103c and the DC / AC conversion section 103d. The second main circuit section 104 is configured to allow current to flow in the Y2 direction to convert the AC power supplied from the transformer 105 into DC power and output it to the output connector section 102. That is, in the second main circuit section 104, current flows in the Y2 direction in the order of the AC / DC conversion section 104b, the reactor 106, and the smoothing capacitor section 104c.

[0045] (cooling structure) As shown in Figures 4 and 5, the power converter 1000 has a cooling structure that cools the heat-generating semiconductor switching element 131 and the diode of the AC / DC conversion unit 104b by circulating air inside.

[0046] The power converter 1000 comprises the first case 107, the second case 108, the first heat dissipation section 109, the second heat dissipation section 110, the air blower section 111, the base section 112, the top cover section 113, the air direction changing section 114, the front cover section 115, the rear cover section 116 (see Figure 8), the first side cover section 117 (see Figure 8), the second side cover section 118 (see Figure 8), and the air passage 119. The front cover section 115 is an example of the "upstream end cover section" in the claims. The rear cover section 116 is an example of the "downstream end cover section" in the claims.

[0047] Figure 4 is a perspective view showing the power converter 1000 with the top cover 113, rear cover 116, first side cover 117, and second side cover 118 removed, and the first case 107 and second case 108 installed.

[0048] (Case 1) The first case 107 contains the first main circuit section 103. That is, the first case 107 is configured to house the first main circuit section 103. Specifically, the first case 107 includes a first insertion opening 171, a front opening 172, a rear opening 173, a bottom opening 174, a top opening 175, and a first ventilation passage side wall section 176.

[0049] The first insertion opening 171 is provided on the X1-direction side of the first case 107. The first insertion opening 171 has dimensions in the X direction and Y direction that allow the first main circuit section 103 to be inserted. The first insertion opening 171 has a rectangular shape when viewed from the X1 direction side. The front opening 172 is provided on the Y2-direction side of the first case 107. The front opening 172 has a rectangular shape when viewed from the Y2 direction side. The rear opening 173 is provided on the Y1-direction side of the first case 107. The rear opening 173 has a rectangular shape when viewed from the Y1 direction side. The bottom opening 174 is provided on the Z2-direction side of the first case 107. The bottom opening 174 has a rectangular shape when viewed from the Z2 direction side. The top opening 175 is provided on the Z1-direction side of the first case 107. The top opening 175 has a rectangular shape when viewed from the Z1 direction.

[0050] The first ventilation passage side wall portion 176 is a wall provided on the X2 direction side (ventilation passage 119 side) of the first case 107. The first ventilation passage side wall portion 176 has an opening (not shown) into which the semiconductor switching element 131 is inserted in order to bring the semiconductor switching element 131 into contact with the first heat dissipation portion 109. The semiconductor switching element 131 is attached to the first heat dissipation portion 109 and is in contact with the first heat dissipation portion 109 through the opening.

[0051] In the first case 107, the substrate 103a is attached to the first case 107 by soldering multiple pins (not shown) that protrude in the X1 direction from the X1 direction side surface of the first ventilation passage side wall portion 176 into the substrate 103a. In the first case 107, the substrate 103b is attached to the first case 107 via the substrate 103a by attaching the substrate 103b to the tip of a spacer that protrudes from the substrate 103a in the X1 direction. The substrate 103b may also be attached to a stay provided on the first case 107.

[0052] (Case 2) The second case 108 contains the second main circuit section 104. In other words, the second case 108 is configured to house the second main circuit section 104. Specifically, the second case 108 includes a second insertion opening 181, a front opening 182, a rear opening 183, a bottom opening 184, a top opening 185, and a second ventilation passage side wall section 186.

[0053] The second insertion opening 181 is provided on the X2 side (ventilation passage 119 side) of the second case 108. The second insertion opening 181 has dimensions in the X direction and Y direction that allow the second main circuit section 104 to be inserted. The second insertion opening 181 has a rectangular shape when viewed from the X2 side. The front opening 182 is provided on the Y2 side of the second case 108. The front opening 182 has a rectangular shape when viewed from the Y2 side. The rear opening 183 is provided on the Y1 side of the second case 108. The rear opening 183 has a rectangular shape when viewed from the Y1 side. The bottom opening 184 is provided on the Z2 side of the second case 108. The bottom opening 184 has a rectangular shape when viewed from the Z2 side. The top opening 185 is provided on the Z1 side of the second case 108. The upper opening 185 has a rectangular shape when viewed from the Z1 direction.

[0054] The second ventilation passage side wall portion 186 is a wall provided on the X1 direction side of the second case 108. The second ventilation passage side wall portion 186 has an opening (not shown) into which the diode of the AC / DC conversion unit 104b is inserted, in order to bring the diode of the AC / DC conversion unit 104b into contact with the second heat dissipation unit 110. The diode of the AC / DC conversion unit 104b is attached to the second heat dissipation unit 110 and is in contact with the second heat dissipation unit 110 through the opening.

[0055] In the second case 108, the substrate 104a is attached to the second case 108 by soldering multiple pins (not shown) that protrude in the X2 direction from the X2 direction side surface of the second ventilation passage side wall portion 186 into the substrate 104a. At this time, the diode of the second main circuit portion 104 and the second heat dissipation portion 110 are in contact.

[0056] The second case 108 is installed alongside the first case 107 in the X2 direction. In the X direction, the dimensions of the second case 108 and the first case 107 are approximately the same. In the Y direction, the dimensions of the second case 108 and the first case 107 are approximately the same. In the Z direction, the dimensions of the second case 108 and the first case 107 are approximately the same.

[0057] (First heat dissipation section and second heat dissipation section) The first heat dissipation section 109 is configured to dissipate heat generated in the first main circuit section 103. The first heat dissipation section 109 is configured to cool the semiconductor switching element 131 by dissipating heat from the semiconductor switching element 131. Specifically, the first heat dissipation section 109 has a plurality of fins that protrude toward the X2 direction from the surface of the first heat dissipation section 109 toward the X2 direction. The first heat dissipation section 109 is attached to the ventilation passage 119 side of the first ventilation passage side wall section 176. Thus, the first heat dissipation section 109 is located in the ventilation passage 119. In other words, the entire first heat dissipation section 109 is located inside the ventilation passage 119. That is, the entire first heat dissipation section 109 is exposed inside the ventilation passage 119. The first heat dissipation section 109 located in the ventilation passage 119 and the first main circuit section 103 inside the first case 107 are arranged in order along the X1 direction.

[0058] The second heat dissipation section 110 is configured to dissipate the heat generated in the second main circuit section 104. The second heat dissipation section 110 is configured to cool the diodes of the AC / DC conversion section 104b by dissipating the heat from the diodes of the AC / DC conversion section 104b. Specifically, the second heat dissipation section 110 has a plurality of fins that protrude toward the X1 direction from the surface of the second heat dissipation section 110 toward the X1 direction. The second heat dissipation section 110 is attached to the ventilation passage 119 side of the second ventilation passage side wall section 186. Thus, the second heat dissipation section 110 is located within the ventilation passage 119. That is, the entire second heat dissipation section 110 is exposed within the ventilation passage 119. The second heat dissipation section 110 located in the ventilation passage 119 and the second main circuit section 104 in the second case 108 are arranged in order along the X2 direction.

[0059] Here, each of the multiple fins of the first heat dissipation section 109 and each of the multiple fins of the second heat dissipation section 110 face each other. That is, each of the multiple fins of the first heat dissipation section 109 and each of the multiple fins of the second heat dissipation section 110 are not positioned at offset positions in the Z direction, so the space between adjacent fins of the first heat dissipation section 109 and the space between adjacent fins of the second heat dissipation section 110 coincide in the X direction. As a result, the combined space between adjacent fins of the first heat dissipation section 109 and the space between adjacent fins of the second heat dissipation section 110 becomes a linear space extending in the Y1 direction, allowing air to flow smoothly.

[0060] (Air blower unit) As shown in Figure 6, the air blower 111 is configured to blow air into the air passage 119 along the Y1 direction. The air blower 111 is an electric fan. Multiple (three) air blowers 111 are arranged in the Z direction. Note that there may be one, two, or four or more air blowers 111.

[0061] (Base section) As shown in Figures 5 and 6, the base portion 112 constitutes the lower surface of the power converter 1000. The lower ends of the first case 107 and the second case 108 are attached to the base portion 112. In the base portion 112, the first case 107 is located in region A1 on the X1 direction side. In the base portion 112, the second case 108 is located in region A2 on the X2 direction side. In the base portion 112, a ventilation passage 119 is formed in region A3 between region A1 on the X1 direction side and region A2 on the X2 direction side.

[0062] The base portion 112 has a base-side projection 1121. The base-side projection 1121 protrudes in the Z1 direction from the surface of the base portion 112 other than the base-side projection 1121. The base-side projection 1121 has a mounting base portion 1121a and a base-side wind direction changing inclined portion 1121b.

[0063] The mounting base portion 1121a is a flat surface on which the transformer 105 and reactor 106 are mounted. The mounting base portion 1121a is formed to extend in the Y1 direction. The transformer 105 is positioned on the mounting base portion 1121a downstream of the airflow from the blower portion 111 relative to the first heat dissipation portion 109 and the second heat dissipation portion 110. The reactor 106 is positioned on the mounting base portion 1121a upstream of the airflow from the blower portion 111 relative to the first heat dissipation portion 109 and the second heat dissipation portion 110. Thus, the transformer 105, which has a larger dimension in the Z direction than the reactor 106, is positioned downstream of the airflow from the blower portion 111.

[0064] The base-side wind direction changing inclined section 1121b is configured to change the direction of the airflow from the blower section 111 upwards. The base-side wind direction changing inclined section 1121b is inclined toward the Z1 direction as the airflow from the blower section 111 moves from the upstream side to the downstream side. In other words, the base-side wind direction changing inclined section 1121b is an inclined surface that moves toward the Z1 direction as the airflow moves toward the Y1 direction.

[0065] The first case 107 is positioned in the X2 direction by contacting the base-side projection 1121, which has the configuration described above, from the X1 direction side. The second case 108 is positioned in the X1 direction by contacting the base-side projection 1121, which has the configuration described above, from the X2 direction side.

[0066] (Top cover section) The top cover portion 113 covers the first case 107, the second case 108, and the ventilation passage 119 in the Z1 direction. As shown in Figures 6 and 7, the top cover portion 113 has an upper side projection 1131 and a plurality (four) of projection ends 1132.

[0067] The upper projection 1131 faces the base projection 1121 in the Z direction. The upper projection 1131 protrudes in the Z2 direction from the surface of the upper cover portion 113 other than the upper projection 1131. The upper projection 1131 has a flat portion 1131a and an upper airflow direction changing inclined portion 1131b.

[0068] The planar section 1131a is a flat surface. The planar section 1131a is formed to extend in the Y1 direction. The upper side airflow direction changing inclined section 1131b is configured to change the direction of the airflow from the blower section 111 downwards. The upper side airflow direction changing inclined section 1131b is inclined towards the Z2 direction as the airflow from the blower section 111 moves from the upstream side to the downstream side. The upper side airflow direction changing inclined section 1131b is an inclined surface that moves towards the Z2 direction as the airflow moves towards the Y1 direction.

[0069] The first case 107 is positioned in the X2 direction by contacting the upper protrusion 1131 with the above configuration from the X1 direction side. The second case 108 is positioned in the X1 direction by contacting the upper protrusion 1131 with the above configuration from the X2 direction side.

[0070] The multiple protruding ends 1132 are provided at the X1 direction end of the top cover portion 113, the X2 direction end of the top cover portion 113, the Y1 direction end of the top cover portion 113, and the Y2 direction end of the top cover portion 113. The multiple protruding ends 1132 protrude in the Z2 direction from the surface of the top cover portion 113 other than the top surface protruding portion 1131. Here, the protruding ends 1132 at the X1 direction end of the top cover portion 113 and the protruding ends 1132 at the X2 direction end of the top cover portion 113 sandwich the first case 107, the second case 108, the base side protruding portion 1121, the top side protruding portion 1131, the first side cover portion 117, and the second side cover portion 118 in the X direction. In the Y direction, the first case 107, the second case 108, the front cover portion 115, and the rear cover portion 116 are sandwiched between the protruding end 1132 of the upper cover portion 113 on the Y1 direction side and the protruding end 1132 of the upper cover portion 113 on the Y2 direction side.

[0071] (Wind direction change section) The airflow direction changing section 114 is configured to change the direction of the airflow from the blower section 111 toward the first heat dissipation section 109 and the second heat dissipation section 110 within the airflow section 119 by narrowing the airflow section 119 from both the upper and lower sides in a cross-section along the vertical direction of the airflow passage 119, from the upstream side toward the downstream side. The airflow direction changing section 114 includes the base-side projection 1121 and the upper surface projection 1131.

[0072] The base-side protrusion 1121 is configured to change the direction of airflow from the blower unit 111 toward the first heat dissipation unit 109 and the second heat dissipation unit 110 within the air passage 119 by narrowing the air passage 119 from below. The upper-side protrusion 1131 is configured to change the direction of airflow from the blower unit 111 toward the first heat dissipation unit 109 and the second heat dissipation unit 110 within the air passage 119 by narrowing the air passage 119 from above.

[0073] (Front cover section) The front cover portion 115 covers the upstream end of the airflow from the first case 107, the second case 108, and the air supply portion 111 of the ventilation passage 119. The front cover portion 115 is a wall that protrudes from the Y2 direction end of the base portion 112 toward the Z1 direction. The front cover portion 115 and the base portion 112 are integrally provided. The front cover portion 115 and the base portion 112 are combined in a roughly L-shape when viewed from the X2 direction.

[0074] The first case 107 and the second case 108 come into contact with the front cover portion 115, which has the configuration described above, from the Y1 direction side, thereby positioning the first case 107 and the second case 108 in the Y2 direction.

[0075] The front cover portion 115 has an opening in the area where multiple air blowers 111 are located. Air blown from the multiple air blowers 111 flows into the ventilation passage 119 through this opening.

[0076] (Rear cover section) The rear cover portion 116 covers the first case 107, the second case 108, and the downstream end portion of the airflow from the blower portion 111 of the ventilation passage 119. The rear cover portion 116 is a wall that protrudes in the Z1 direction from the Y2 direction end of the base portion 112. The rear cover portion 116 has a plurality (9) of exhaust ports 116a. The plurality of exhaust ports 116a are configured to exhaust the air that has been sent from the plurality of blower portions 111 and flowed into the ventilation passage 119 to the outside of the device. Each of the plurality of exhaust ports 116a is a slit formed in the rear cover portion 116. Each of the plurality of exhaust ports 116a penetrates the rear cover portion 116 in the Y direction. The plurality of exhaust ports 116a are formed at positions aligned with the ventilation passage 119. The number of exhaust ports 116a may be 1 to 8, or 10 or more.

[0077] (First side cover section) The first side cover portion 117 covers the side of the first case 107 opposite to the ventilation passage 119. The first side cover portion 117 is a wall that protrudes in the Z1 direction from the X1 direction end of the base portion 112.

[0078] (Second side cover section) The second side cover portion 118 covers the side of the second case 108 opposite to the ventilation passage 119. The second side cover portion 118 is a wall that protrudes in the Z1 direction from the X2 direction end of the base portion 112.

[0079] (Ventilation path) As described above, the ventilation passage 119 is a space provided between the first case 107 and the second case 108, which are aligned in the X2 direction. Air flowing into the ventilation passage 119 from multiple air blowers 111 through the openings in the front cover portion 115 flows toward multiple exhaust ports 116a of the rear cover portion 116 (towards the Y1 direction). The ventilation passage 119 is a space enclosed by the first ventilation passage side wall portion 176 of the first case 107, the second ventilation passage side wall portion 186 of the second case 108, the base portion 112, the top cover portion 113, the front cover portion 115, and the rear cover portion 116. Here, the portion of the ventilation passage 119 between the flat surface portion 1131a and the flat surface mounting base portion 1121a is provided in a straight line along the Y1 direction.

[0080] (Assembly method for power converters) The assembly method of the power converter 1000 will be described below with reference to Figures 8 to 16.

[0081] First, as shown in Figures 9 and 11, in step S1, the worker attaches the Z2-direction side surface of the first ventilation passage side wall 176 of the first case 107 to the Z1-direction side surface of the first heat dissipation section 109. In step S2, the worker inserts the first main circuit section 103 through the first insertion opening 171 and attaches the first main circuit section 103 to the first case 107 from the Z1 direction while it is in contact with the first heat dissipation section 109.

[0082] Specifically, the worker attaches the first case 107 to the Z1-direction side of the first heat dissipation section 109. The worker attaches the semiconductor switching element 131 to the Z1-direction side of the first heat dissipation section 109. After attaching the semiconductor switching element 131 to the substrate 103a, the worker attaches the substrate 103a to the first case 107 by soldering it while the substrate 103a is inserted into a plurality of pins (not shown) protruding from the surface of the first ventilation passage side wall 176. In this way, the semiconductor switching element 131 of the first main circuit section 103 and the first heat dissipation section 109 come into contact. Then, the worker attaches the substrate 103b to the tip of the spacer protruding from the substrate 103a.

[0083] Thus, steps S1 and S2 are steps in which the worker installs the first main circuit unit 103 inside the first case 107.

[0084] As shown in Figures 9 and 12, in step S3, the worker attaches the Z2-direction side surface of the second ventilation passage side wall 186 of the second case 108 to the Z1-direction side surface of the second heat dissipation section 110. In step S4, the worker inserts the second main circuit section 104 through the second insertion opening 181 and attaches the second main circuit section 104 to the second case 108 from the Z1 direction while it is in contact with the second heat dissipation section 110.

[0085] Specifically, the worker attaches the second case 108 to the Z1-direction side of the second heat dissipation section 110. The worker attaches the diode of the AC / DC conversion section 104b to the Z1-direction side of the second heat dissipation section 110. After attaching the diode of the AC / DC conversion section 104b to the substrate 104a, the worker attaches the substrate 104a to the second case 108 by soldering it to a plurality of pins (not shown) protruding from the surface of the second ventilation passage side wall section 186 while the substrate 104a is inserted into them. In this way, the diode of the AC / DC conversion section 104b of the second main circuit section 104 and the second heat dissipation section 110 come into contact.

[0086] Thus, steps S3 and S4 are steps in which the worker installs the second main circuit unit 104 inside the second case 108.

[0087] As shown in Figures 9 and 13, in step S5, the worker attaches multiple air blowers 111, an input connector 101, and an output connector 102 to the front cover 115.

[0088] As shown in Figures 9 and 14, in step S6, the worker attaches the first case 107 to the front cover portion 115 and the base portion 112. In step S7, the worker attaches the transformer 105 and the reactor 106 to the mounting base portion 1121a from the Z1 direction side. The process proceeds to step S8 via point A in Figure 9 and point A in Figure 10.

[0089] As shown in Figures 10, 15, and 16, in step S8, the worker attaches the second case 108 to the front cover portion 115 and the base portion 112. Thus, steps S6 to S8 are steps in which the lower ends of the first case 107 and the second case 108 are attached to the base portion 112 side by side in the X2 direction so as to provide a ventilation passage 119 between the first case 107 and the second case 108.

[0090] As shown in Figures 8 and 10, in step S9, the worker attaches the rear cover portion 116, the first side cover portion 117, the second side cover portion 118, and the top cover portion 113 to the front cover portion 115 and the base portion 112 of the first case 107 and the second case 108 in that order (see Figure 8). Specifically, the worker attaches the rear cover portion 116 to the Y1 direction end of the first case 107 and the second case 108. The worker attaches the first side cover portion 117 to the X1 direction end of the first case 107. The worker attaches the second side cover portion 118 to the X2 direction end of the second case 108. The worker places the top cover portion 113 over the first case 107 and the second case 108 from the Z1 direction side, and then attaches it to the Z2 direction end of the first case 107 and the second case 108.

[0091] This completes the assembly method for the power converter 1000.

[0092] (Effects of this embodiment) In this embodiment, the following effects can be obtained.

[0093] In this embodiment, as described above, the power converter 1000 is equipped with a base portion 112 to which the lower ends of the first case 107 and the second case 108 are attached. This allows the worker to separately perform the tasks of installing the first main circuit portion 103 in the first case 107 and installing the second main circuit portion 104 in the second case 108, and then attach the lower ends of the first case 107 and the second case 108 to the base portion 112, thereby completing the installation of the first case 107 and the second case 108 to the base portion 112. This allows the first case 107 and the second case 108 to be attached to the base portion 112 without inverting the second case 108. As a result, the work efficiency of assembling the power converter 1000 can be improved by eliminating the need for the worker to invert the first case 107 or the second case 108.

[0094] Furthermore, in this embodiment, as described above, the power converter 1000 is provided with a first heat dissipation unit 109 located in the ventilation passage 119 and which dissipates heat generated in the first main circuit unit 103. The first case 107 is provided on the side opposite to the ventilation passage 119 in the X2 direction and has a first insertion opening 171 into which the first main circuit unit 103 can be inserted, and a first ventilation passage side wall 176 to which the first heat dissipation unit 109 is attached on the ventilation passage 119 side. As a result, the first main circuit unit 103 can be installed inside the first case 107 by attaching the first heat dissipation unit 109 to the ventilation passage 119 side of the first ventilation passage side wall 176 and then inserting the first main circuit unit 103 through the first insertion opening 171. As a result, the first heat dissipation unit 109 and the first main circuit unit 103 can be easily installed in the first case 107.

[0095] Furthermore, in this embodiment, as described above, the power converter 1000 is provided with a second heat dissipation unit 110 located in the ventilation passage 119 and which dissipates heat generated in the second main circuit section 104. The second case 108 is provided on the side opposite to the ventilation passage 119 in the X2 direction and has a second insertion opening 181 into which the second main circuit section 104 can be inserted, and a second ventilation passage side wall 186 to which the second heat dissipation unit 110 is attached on the ventilation passage 119 side. As a result, the first main circuit section 103 can be installed inside the second case 108 by attaching the second heat dissipation unit 110 to the ventilation passage 119 side of the second ventilation passage side wall 186 and then inserting the second main circuit section 104 through the second insertion opening 181. In this way, the second heat dissipation unit 110 and the second main circuit section 104 can be easily installed in the second case 108.

[0096] Furthermore, in this embodiment, as described above, the power converter 1000 includes a blower 111 that blows air into the air passage 119 along the Y1 direction, which is perpendicular to the X2 direction in the horizontal direction. The power converter 1000 includes a wind direction changing unit 114 that changes the direction of the air blown from the blower 111 toward the first heat dissipation section 109 and the second heat dissipation section 110 in the air passage 119 by narrowing the air passage 119 from both the upper and lower sides in a cross section along the vertical direction of the air passage 119 from the upstream side toward the downstream side of the air blown from the blower 111. As a result, the air can be concentrated toward the first heat dissipation section 109 and the second heat dissipation section 110, making it easier for the air to hit the entire first heat dissipation section 109 and the second heat dissipation section 110. As a result, heat dissipation becomes easier throughout the first heat dissipation section 109 and the second heat dissipation section 110, thereby improving the heat dissipation performance of the first heat dissipation section 109 and the second heat dissipation section 110.

[0097] Furthermore, in this embodiment, as described above, the power conversion device 1000 includes a transformer 105 that converts voltage between the first main circuit section 103 and the second main circuit section 104, and a reactor 106 to which the power converted in the second main circuit section 104 is input. The wind direction changing section 114 has a base-side projection 1121 that protrudes upward from the base section 112. The base-side projection 1121 has a mounting base section 1121a to which the transformer 105 and the reactor 106 are attached, and a base-side wind direction changing inclined section 1121b that is inclined upward as the airflow from the blower section 111 moves from the upstream side to the downstream side, and changes the direction of the airflow from the blower section 111 upward. As a result, the base-side airflow direction changing inclined section 1121b can concentrate airflow not only towards the first heat dissipation section 109 and the second heat dissipation section 110, but also towards the transformer 105 and the reactor 106, making it easier for air to reach the entire first heat dissipation section 109, the second heat dissipation section 110, the transformer 105, and the reactor 106. Consequently, heat dissipation can be made easier in the first heat dissipation section 109, the second heat dissipation section 110, the transformer 105, and the reactor 106.

[0098] Furthermore, in this embodiment, as described above, the power converter 1000 has an upper surface projection 1131 that faces the base surface projection 1121 in the vertical direction and protrudes downward. The upper surface projection 1131 is provided at an inclination downward as the airflow from the blower 111 moves from the upstream to the downstream side, and has an upper surface airflow direction changing inclined section 1131b that changes the direction of the airflow from the blower 111 downward. As a result, the upper surface airflow direction changing inclined section 1131b and the base surface airflow direction changing inclined section 1121b can concentrate the airflow not only towards the first heat dissipation section 109 and the second heat dissipation section 110, but also towards the transformer 105 and the reactor 106, so that the airflow can more easily reach the entire first heat dissipation section 109, the second heat dissipation section 110, the transformer 105 and the reactor 106. As a result, heat can be dissipated more efficiently in the first heat dissipation section 109, the second heat dissipation section 110, the transformer 105, and the reactor 106.

[0099] Furthermore, in this embodiment, as described above, the mounting base portion 1121a of the power converter 1000 is formed to extend in the Y1 direction. This allows the ventilation passage 119 on the mounting base portion 1121a to be formed in a straight line, so that air can flow smoothly through the ventilation passage 119.

[0100] Furthermore, in this embodiment, as described above, the power converter 1000 is provided with a blower 111 and a front cover portion 115 that covers the upstream end portion of the air blown from the blower 111 in the first case 107, the second case 108, and the air passage 119. The power converter 1000 is provided with a rear cover portion 116 that covers the downstream end portion of the air blown from the blower 111 in the first case 107, the second case 108, and the air passage 119. The power converter 1000 is provided with a first side cover portion 117 that covers the side of the first case 107 opposite to the air passage 119, and a second side cover portion 118 that covers the side of the second case 108 opposite to the air passage 119. The power converter 1000 is provided with an upper cover portion 113 that covers the upper side of the first case 107, the second case 108, and the air passage 119 in the upward direction. As a result, the base portion 112, front cover portion 115, rear cover portion 116, first side cover portion 117, second side cover portion 118, and top cover portion 113 can cover the first case 107 and the second case 108, thereby preventing water and dust from entering the first case 107 and the second case 108.

[0101] Furthermore, in this embodiment, as described above, the wiring and equipment constituting the main circuit for power conversion, including the first main circuit section 103 and the second main circuit section 104, are arranged in a roughly U-shape in plan view, sequentially from the input side to the output side of the main circuit, following the order of electrical connections of the main circuit. As a result, the U-shaped arrangement allows for effective use of the space, even in the relatively narrow space inside the power converter 1000, to prevent the current flowing through the wiring and equipment constituting the main circuit from returning to the input side. Consequently, the length of the wiring constituting the main circuit can be made relatively short, thereby suppressing the increase in device weight caused by an increase in wiring length and the number of wires.

[0102] Furthermore, in this embodiment, as described above, the assembly method for the power converter 1000 includes steps S1 to S4, in which the lower ends of the first case 107 and the second case 108 are attached to the base portion 112 in the horizontal X2 direction. This allows the worker to separately perform the tasks of installing the first main circuit section 103 in the first case 107 and installing the second main circuit section 104 in the second case 108, and then attach the lower ends of the first case 107 and the second case 108 to the base portion 112, thereby completing the installation of the first case 107 and the second case 108 to the base portion 112. This allows the first case 107 and the second case 108 to be attached to the base portion 112 without inverting the second case 108. As a result, a method for assembling the power converter 1000 can be obtained that improves the work efficiency of the assembly work of the power converter 1000 by eliminating the need for the worker to invert the first case 107 or the second case 108 when assembling the power converter 1000.

[0103] Furthermore, in this embodiment, as described above, steps S1 and S2 for installing the first main circuit section 103 inside the first case 107 include step S1, which involves attaching the first ventilation passage side wall 176 on the ventilation passage 119 side of the first case 107 to the first heat dissipation section 109 that dissipates heat generated in the first main circuit section 103 from above, and step S2, which involves inserting the first main circuit section 103 through the first insertion opening 171 provided on the side of the first case 107 opposite to the ventilation passage 119 side, and installing the first main circuit section 103 to the first case 107 from above while it is in contact with the first heat dissipation section 109. As a result, the first case 107 can be assembled by attaching the first ventilation passage side wall 176 and the first main circuit section 103 in that order to the upper side of the first heat dissipation section 109, thus making the first case 107 easy to assemble.

[0104] Furthermore, in this embodiment, as described above, steps S3 and S4 for installing the second main circuit section 104 inside the second case 108 include step S3, which involves attaching the second ventilation passage side wall 186 on the ventilation passage 119 side of the second case 108 to the second heat dissipation section 110, which dissipates heat generated in the second main circuit section 104, from above, and step S4, which involves inserting the second main circuit section 104 through the second insertion opening 181 provided on the side of the second case 108 opposite to the ventilation passage 119 side, and installing the second main circuit section 104 to the second case 108 from above while it is in contact with the second heat dissipation section 110. As a result, the second case 108 can be assembled by attaching the second ventilation passage side wall 186 and the second main circuit section 104 in that order to the upper side of the second heat dissipation section 110, thus making the second case 108 easy to assemble.

[0105] [Differentiation] It should be noted that the embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims rather than by the description of the embodiments above, and further includes all modifications (exceptions) within the meaning and scope equivalent to the claims.

[0106] For example, in the above embodiment, an example was shown in which a plurality of air blowers 111 are arranged in the front cover portion 115, but the present invention is not limited to this. In the present invention, a plurality of air blowers may be arranged in the rear cover portion.

[0107] In the above embodiment, the power converter 1000 is shown to include a wind direction changing unit 114, but the present invention is not limited to this. In the present invention, the power converter does not need to include a wind direction changing unit.

[0108] In the above embodiment, the base-side projection 1121 was shown to include a mounting base portion 1121a to which the transformer 105 and reactor 106 are attached, but the present invention is not limited thereto. In the present invention, the transformer and reactor may be attached to a location other than the mounting base portion of the base.

[0109] In the above embodiment, the transformer 105 is positioned downstream of the airflow from the air blower 111 of the first heat dissipation section 109 and the second heat dissipation section 110, and the reactor 106 is positioned upstream of the airflow from the air blower 111 of the first heat dissipation section 109 and the second heat dissipation section 110. However, the present invention is not limited to this. In the present invention, the transformer may be positioned upstream of the airflow from the air blower of the first heat dissipation section and the second heat dissipation section, and the reactor may be positioned downstream of the airflow from the air blower of the first heat dissipation section and the second heat dissipation section.

[0110] In the above embodiment, the wiring and equipment constituting the main circuit for power conversion, including the first main circuit section 103 and the second main circuit section 104, are shown to be arranged in a substantially U-shape in plan view, sequentially from the input side to the output side of the main circuit, in accordance with the order of the electrical connections of the main circuit. However, the present invention is not limited to this. In the present invention, the wiring and equipment constituting the main circuit for power conversion, including the first main circuit section and the second main circuit section, may be arranged in a shape other than a substantially U-shape in plan view, sequentially from the input side to the output side of the main circuit, in accordance with the order of the electrical connections of the main circuit. [Explanation of symbols]

[0111] 103 1st main circuit section 104 2nd main circuit section 105 Transformer 106 Reactor 107 Case 1 108 Case 2 109 1st heat dissipation section 110 Second heat dissipation section 111 Air blower 112 Base section 113 Top cover section 114 Wind direction changing section 115 Front cover section (upstream end cover section) 116 Rear cover section (downstream end cover section) 117 First side cover section 118 Second side cover section 119 Ventilation duct 171 First insertion opening 176 1st ventilation duct side wall 181 Second insertion opening 186 2nd ventilation duct side wall 1000 Power converter 1121 Base side protrusion 1121a Mounting base 1121b Base-side wind direction changing inclined section 1131 Top side protrusion 1131b Upper side wind direction changing inclined section

Claims

1. A first case containing a first main circuit section that converts DC power output from a DC power supply into AC power, A second case is provided alongside the first case in a first horizontal direction, which is one of the horizontal directions, and contains a second main circuit that converts the AC power converted by the first main circuit into DC power. A ventilation passage is provided between the first case and the second case, which are arranged in the first horizontal direction, The system comprises a base portion to which the lower end of the first case and the lower end of the second case are attached, A power converter in which the base portion forms the lower surface of the power converter body.

2. The ventilation passage is further provided with a first heat dissipation section that dissipates heat generated in the first main circuit section, The first case mentioned above is, A first insertion opening is provided on the side opposite to the ventilation passage side in the first horizontal direction, into which the first main circuit section can be inserted, The power conversion device according to claim 1, wherein the first heat dissipation section has a first ventilation passage side wall section attached to the ventilation passage side.

3. The ventilation passage is further provided with a second heat dissipation section that dissipates heat generated in the second main circuit section, The two cases mentioned above are: A second insertion opening is provided on the side opposite to the ventilation passage side in the first horizontal direction, into which the second main circuit section can be inserted, The power conversion device according to claim 2, wherein the second heat dissipation section has a second ventilation passage side wall section attached to the ventilation passage side.

4. A blower unit that blows air into the ventilation passage along a second horizontal direction perpendicular to the first horizontal direction, The power conversion device according to claim 3, further comprising a wind direction changing unit that changes the direction of the air blown from the air blowing unit toward the first heat dissipation unit and the second heat dissipation unit in the air blowing unit by narrowing the air blowing unit from both the upper and lower sides in a cross section along the vertical direction of the air blowing unit toward the downstream side from the upstream side of the air blowing unit toward the first heat dissipation unit and the second heat dissipation unit in the air blowing unit.

5. A transformer for converting voltage between the first main circuit section and the second main circuit section, The circuit further comprises a reactor to which the power converted in the second main circuit is input, The wind direction changing section has a base-side projection that protrudes upward from the base section. The base-side protrusion is, A mounting base portion to which the transformer and the reactor are attached, The power conversion device according to claim 4, further comprising a base-side airflow direction changing inclined section which is provided at an upward inclination from the upstream side to the downstream side of the airflow from the air blowing section, and which changes the direction of the airflow from the air blowing section upward.

6. The wind direction changing section has an upper surface projection that faces the base side projection in the vertical direction and protrudes downward, The power conversion device according to claim 5, wherein the upper protrusion is provided at an inclination downward as the airflow from the blower unit is directed from the upstream side to the downstream side, and has an upper airflow direction changing inclination portion that changes the direction of the airflow from the blower unit downward.

7. The power conversion device according to claim 5, wherein the mounting base portion is formed to extend in the second horizontal direction.

8. The aforementioned air blowing section is provided, and an upstream end cover section covers the upstream end portion of the air blown from the air blowing section in the first case, the second case, and the ventilation passage, A downstream end cover portion that covers the downstream end portion of the air blown from the air blowing section in the first case, the second case, and the air passage, A first side cover portion that covers the side opposite to the ventilation passage in the first case, A second side cover portion that covers the side opposite to the ventilation passage in the second case, The power conversion device according to claim 4, further comprising an upper cover portion that covers the upper side of the first case, the second case, and the ventilation passage in the upward direction.

9. The power conversion device according to claim 1, wherein the wiring and equipment constituting the main circuit for power conversion, including the first main circuit section and the second main circuit section, are arranged in a substantially U-shape in plan view, sequentially from the input side to the output side of the main circuit, in accordance with the order of the electrical connections of the main circuit.

10. The first main circuit section, which converts DC power output from a DC power supply into AC power, is installed inside the first case. The steps include installing a second main circuit unit, which converts the AC power converted by the first main circuit unit into DC power, inside the second case, The process includes the step of attaching the lower end of the first case and the lower end of the second case to the base portion in a horizontal direction, so as to provide an air passage between the first case and the second case, A method for assembling a power converter, comprising the step of attaching the lower end of the first case and the lower end of the second case to a base portion, wherein the base portion forms the lower surface of the power converter body.

11. The step of mounting the first main circuit section inside the first case is: The first step of attaching the first ventilation passage side wall portion of the first case on the ventilation passage side to the first heat dissipation portion that dissipates the heat generated in the first main circuit portion from above, A method for assembling a power converter according to claim 10, comprising the step of inserting the first main circuit section through a first insertion opening provided on the side of the first case opposite to the ventilation passage side, and attaching the first main circuit section to the first case from above while it is in contact with the first heat dissipation section.

12. The step of installing the second main circuit section inside the second case is: The steps include attaching the second ventilation side wall portion of the second case on the ventilation side to the second heat dissipation portion that dissipates the heat generated in the second main circuit portion from above, A method for assembling a power converter according to claim 10, comprising the step of inserting the second main circuit section through a second insertion opening provided on the side of the second case opposite to the ventilation passage side, and attaching the second main circuit section to the second case from above while it is in contact with the second heat dissipation section.

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