JP2014207845A - Power converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power converter having a switch element cooling structure.SOLUTION: The power converter includes a switch element attached to the inner side face of a housing 10 and a molded first recess 11 for housing an AC reactor. The power converter further includes: a first fin F1 on the outer side face of the housing 10 corresponding to the switch element; a second fin F2 on the outer side face of the housing 10 corresponding to the first recess 11; a first wall 13 extending from between the first fin F1 and the second fin F2; and a fan FAN, disposed on the first fin F1 side of the first wall 13, for making an air flow to the first fin F1. Further, the power converters includes a molded first air channel (A) for leading an air flow to the first fin by the fan FAN disposed on the first fin F1 side of the first wall 13, and a molded second air channel (B) through which natural convection of air is made to the second fin F2 side of the first wall 13.

Description

  The present invention relates to a power conversion device.

2. Description of the Related Art Conventionally, there has been provided a power conversion device that converts DC power from renewable energy such as a solar battery or wind power generation, a storage battery, or a fuel cell into AC power and supplies it to a load or system. The power converter includes a booster circuit having a DC reactor, and converts the boosted DC power into AC power by an inverter circuit having a switching element. The AC power includes a high frequency component, and the high frequency component is attenuated by a filter circuit having an AC reactor.

Since these DC reactor, AC reactor, and switch element generate heat, it is necessary to cool them using a cooling fin, a blower fan, or the like. Patent Document 1 and Patent Document 2 describe this cooling structure.

In Patent Document 1, a plurality of switch elements are arranged in a case having heat dissipating fins through which air flows in the vertical direction, and a capacitor arrangement hole is provided to the right of the plurality of switch elements in the case. Since the capacitor is disposed through the hole, the capacitor is disposed in the air flow along with the heat dissipating fins. Moreover, the common ventilation fan which ventilates air toward a radiation fin and a capacitor | condenser is provided. As a result, the blown air flows along the radiation fins from the lower side to the upper side of the radiation fins, the radiation fins are cooled to cool the plurality of switch elements, and air is directly blown to the capacitors to cool the capacitors. The As described above, the plurality of switch elements that generate particularly high heat are cooled by the cooling fin and the blower fan, and then the heat-generating component (condenser) that generates high heat is cooled by the blower fan.

In Patent Document 2, a heat dissipating fin is provided on the back surface of the housing, and the heat dissipating fin is divided into three air passages to cool the corresponding heat generating components provided inside the housing.

Japanese Patent Laid-Open No. 10-295087 US Pat. No. 7,715,195

However, in the thing of patent document 1, the blown air hits a capacitor | condenser and raise | generates a turbulent air current, There existed a problem which obstructs the flow of the air which flows into a radiation fin, and inhibits cooling of a switch element. Moreover, in the thing of patent document 2, the cooling capacity by each air path depended on the cross-sectional area of the air path, and there existed a problem that it was difficult to respond | correspond optimally for every calorific value of each heat-emitting component.

The present invention has been made in view of such problems, and an object of the present invention is to provide a power conversion device that can ensure a cooling effect of a switch element.

In order to achieve the above object, a power converter according to the present invention includes an inverter circuit that converts DC power into AC power using a switching element, a filter circuit that attenuates high-frequency components of AC power through a first reactor, and an inverter circuit. And a single housing containing the filter circuit;
The first fin on the outer surface of the housing corresponding to the mounting position of the switch element, the switch element is mounted on the inner surface of the housing, the first recess for storing the first reactor is formed, A second fin on the outer surface of the housing corresponding to the first recess, a first wall extending from between the first fin and the second fin, and a first fin provided on the first fin side of the first wall. A fan that blows air to the fin, and a first air passage that guides air from the fan to the first fin and a second air passage that naturally convects air to the second fin side of the first wall are provided. It is characterized by this.

In addition, the power conversion device of the present invention uses at least the first wall and the second wall to form a wind path in which air naturally convects from the bottom to the top and has radiating fins on the back surface of the die-cast casing. 1st to 3rd air paths are provided, and air is blown from the fan in the first air path, and the first heat generating component is attached to the inner surface of the housing corresponding to the air path, and the housing corresponds to the second air path. A second heat generating component having a smaller amount of heat generation than the first heat generating component is attached to the inner surface of the first heat generating component, and a third heat generating component having a smaller heat generation amount than the second heat generating component is attached to the inner surface of the housing corresponding to the third air path Is.

An object of the present invention is to provide a power conversion device that can ensure cooling of a switch element.

It is a front view of the power converter of this embodiment. It is a perspective view of the back of the power converter of this embodiment. It is an electric circuit diagram of the power converter of this embodiment.

As shown in FIG. 3, for example, the power conversion device converts a direct current output of a solar cell, a fuel cell, or the like (which may be an output from renewable energy such as wind power generation into direct current power) into a direct current reactor DCL (second reactor). ), The inverter circuit 32 that converts the DC power output from the booster circuit 31 into AC power using a plurality of switch elements IPM, and the AC power output from the inverter circuit 32. The filter circuit 33 which removes a high frequency component using AC reactor ACL (1st reactor) and a capacitor | condenser, and the housing | casing 10 which accommodates these booster circuits 31, the inverter circuit 32, and the filter circuit 33 are provided.

As shown in FIG. 3, there are a plurality of solar cells (strings) 34a to 34e (here, a maximum of 5).
One string can be supported, but the number of connected strings can be changed)
There are provided boosting circuits 31a to 31e for boosting the outputs of the five solar cells 34, respectively. For this reason, the DC reactor DCL (or booster circuit) is also a solar cell (string)
DCLa to DCLe (not shown) are required for several minutes. Regarding the circuit configuration of the booster circuit 31, the inverter circuit 32, and the filter circuit 33, the configuration of an existing DC / DC switching type booster circuit, a conversion circuit based on PWM of DC / AC, and a low-pass filter having a boundary of 50 Hz / 60 Hz. Since it can be used, details are omitted. As shown in FIG. 1, the DC power output from the solar cells 34a to 34e is wirings L1 to L5, respectively, and the housing 10
The wiring lid 15 is drawn in through a wiring hole (not shown) and connected to the switches S1 to S5, respectively. The switches S <b> 1 to S <b> 5 are manually opened by an operator when performing maintenance or the like, and are closed by an operator when taking the output of the solar cell into the power conversion device 2.

The housing 10 has a substantially cubic shape having an opening in a front surface portion obtained by die-casting an aluminum alloy. On the inner side of the housing 10 (inner surface of the housing 10), an AC reactor ACL (
The first recess 11 and the second recess 12 in which the second heat generating component) and the DC reactors DCLa to DCLe (third heat generating component) are arranged are integrally formed on the left and right. In the first dent 11 and the second dent 12, a resin having high thermal conductivity and electrical insulation is poured after the arrangement of the reactor, and these reactors are fixed to the dents 11 and 12. The hollow 11 is a DC reactor DCL
DC reactor DCLb in order from the bottom to the top of housing 10 starting from a
, DC reactor DCLc is arranged, then DC reactor DCLd, DC reactor D
CLe is arranged. When the number of connected solar cells (strings) decreases, the direct current reactor DCLe is reduced in the reverse order from the direct current reactor DCLe to the direct current reactor DCLd.
Is the last thing left.

On the inner surface of the housing 10 between the first recess 11 and the second recess 12, a plurality of switch elements IPM (
A first heat generating component) is arranged. The amount of heat generated during normal operation of the first heat generating component to the third heat generating component has a relationship of first heat generating component> second heat generating component> third heat generating component. Also, a plurality of switch elements I
On the opening side of PM, DC reactors DCLa to DCLe, and AC reactor ACL,
The electrical circuit board 17 which comprises the booster circuit 31, the inverter circuit 32, and the filter circuit 33 is arrange | positioned (refer the dotted line of FIG. 1). Further, a terminal block 16 is provided below the AC reactor ACL, and wiring extending from the terminal block 16 is wired to the outside through the wiring hole of the wiring lid 15 and supplies AC power. The power conversion device 1 is used by closing the opening of the front portion with a lid (not shown) and attaching it to the wall surface of a house.

As shown in FIG. 2, the outside of the housing 10 (the back surface of the housing 10) is subjected to die casting.
A plurality of first fins F1 provided corresponding to the arrangement locations of the plurality of switch elements IPM, a plurality of second fins F2 provided corresponding to the first depressions 11, and provided corresponding to the second depressions 12. A plurality of third fins F3 are integrally formed. The first to third fans F1 to F3 are formed in the vertical direction. Further, walls 19A and 19B are provided on both sides of the rear surface of the housing 10 to restrict the first fin F1 to the third fin F3 from being easily touched by a user or the like.

A fan FAN that blows air to the first fins F <b> 1 is disposed outside the housing 10.
A first wall 13 provided to extend from between the fin F1 and the second fin F2 to the fan FAN.
There is. The fan FAN is disposed below the first recess 11 (on the wiring lid 15) on the AC reactor ACL side of the housing 10 and on the side of the housing 10. Therefore, the first wall 13 is the first
It is bent to the dent side. The wall 19A is provided slightly above the fan FAN and forms a suction port on the side of the housing 10. The fan FAN can take in air from the suction port 17. The air taken in from the suction port 17 and blown from the fan FAN is guided to the first fin F1 through the first air passage A on the first fin F1 side of the first wall 13 constituted by the first wall. In addition, on the second fin F2 side of the first wall 13, a second air passage B that guides air naturally convected by the heat of the first recess 11 to the second fin is constituted by the first wall. Fan F
An opening 18 for guiding a part of the air flowing from the suction port 17 into the second air passage B is formed on the second air passage side across the first wall 13 of the AN. The suction port 17 may be provided with a mesh member or the like so that the user does not touch the fins F1 to F3.

Between the first fin F1 and the third fin F3, a second wall 14 provided in parallel with the fins F1 and F3 is provided in the housing 10, and the second wall 14 is more than the place where the fan FAN is disposed. It extends down. The first fin F <b> 1 is a housing 10 between the first recess 11 and the second recess 12.
The second fin protrudes from the back surface of the housing 10 corresponding to the first recess, and the third fin protrudes from the back surface of the housing 10 corresponding to the second recess. The tips of the fins are configured to contact substantially the same virtual plane (a plane having a certain distance from the wall surface when the power converter is attached to the wall surface). Therefore, the height of the fin from the back surface of the housing | casing 10 changes with the depth of a hollow, and the height of each fin is comprised by 1st fin> 2nd fin> 3rd fin.

As described above, according to the power conversion device 1 of the present embodiment, the first wall 1 is formed by the first wall 13.
The first air flow A that guides the air blown from the fan FAN to the first fin F1 on the first fin F1 side of the third air and the second air that naturally convects on the second fin F2 side of the first wall 13 A second air passage B leading to the fin F2 is configured. For this reason, since the first air path A and the second air path B are separated by the first wall 13, the air flow interferes with the second fin F2 and the third fin F3, and the fan FAN.
From the air to the first fin F1 is not obstructed, and a plurality of switch elements IPM
Can be ensured.

In addition, since the AC reactor ACL generates less heat than the plurality of switch elements IPM, the AC reactor ACL can be sufficiently cooled even by the cooling by the second fin F2 provided in the first recess 11 (even if there is no ventilation from the fan FAN). it can.

Moreover, according to the power converter device 1 of this embodiment, since the 1st wall 13 is bent to the 1st hollow 11 side, the air which flows in from the opening 18 can reach the 1st hollow 11 in a short distance. it can. Thereby, since cooler air can be sent to the 1st hollow 11, the cooling effect improves. Since the air flowing through the second air passage B has a slower flow velocity than the air passing through the first air passage A, the first wall 13 is moved to the first recess 11 rather than bending the first wall 13 toward the first fin F1. The cooling effect can be expected to bend to the side (second fin side).

Moreover, according to the power converter device 1 of this embodiment, the 2nd wall 14 provided in parallel with these fins F1 and F3 is provided between the 1st fin F1 and the 3rd fin F3, and this 2nd wall. 14 is extended below the position where the fan FAN is disposed. For this reason, since the air blown from the fan FAN hits the second wall 14 and leads to the first fin, the cooling effect is improved.

As mentioned above, although one Embodiment of this invention was described, the above description is for making an understanding of this invention easy, and does not limit this invention. It goes without saying that the present invention can be changed and improved without departing from the gist thereof, and that the present invention includes equivalents thereof.

For example, the first wall 13 is bent toward the first recess 13 (second fin side), and the fan FAN is provided under the first recess 13, but the second wall 14 is connected to the second recess 12 (third fin). The fan FAN may be provided under the second recess 14 by bending the second fan 14 to the side. In this case, the second wall 14 is changed by the second wall 14.
First air that is blown from the fan FAN to the first fin F1 is guided to the first fin F1.
An air path A and a third air path that guides convection air to the third fin F3 (second recess 14) are configured on the third fin F3 side of the second wall 14.

DESCRIPTION OF SYMBOLS 1 Power converter device 10 Housing | casing 11 1st hollow 12 2nd hollow 13 1st wall 1
4 Second wall 15 Wiring hole 16 Terminal block 17 Suction port 18 Opening 19 Wall A
First air path B Second air path ACL AC reactor (first reactor) DCLa to e DC reactor (second reactor) IPM Multiple switch elements S1 to S5 Switches L1 to L5 Wiring FAN Fan F1 First fin F2 Second Fin F3 3rd fin

Claims (13)

An inverter circuit that converts DC power into AC power using a switch element; a filter circuit that attenuates high-frequency components of the AC power through a first reactor; a single housing that houses the inverter circuit and the filter circuit; In the power conversion device, the switch element is attached to the inner surface of the housing, and a first recess for housing the first reactor is formed, and the outer surface of the casing corresponding to the attachment position of the switch element is formed. 1 fin,
A second fin on the outer surface of the housing corresponding to the first depression, a first wall extending from between the first fin and the second fin, and a first fin provided on the first fin side of the first wall. A first air passage that guides air flow from the fan to the first fin, and a second air passage that naturally convects air to the second fin side of the first wall. A power converter characterized by being provided. The power converter according to claim 1, further comprising an opening connected to the first air path and the second air path. The power converter according to claim 2, wherein the first wall is bent toward the first depression. A second recess for accommodating the second reactor forming the DC power boosting circuit is formed on the inner surface of the casing, and the switch element is attached to the inner surface of the casing between the first recess and the second recess. And a second fin extending from between the first fin and the third fin on the outside of the housing corresponding to the second recess, and the second wall is blown from the fan. The first air
A power converter characterized by being guided to a fin. The power converter according to claim 4, wherein the casing is formed by die casting. At least the first wall and the third air path are formed by using at least the first wall and the second wall in the air channel in which air is naturally convected from the bottom to the top and the heat dissipating fins are formed on the rear surface of the die-cast casing. The first air passage is provided with air from the fan, and a first heat generating component is attached to the inner surface of the housing corresponding to the air passage, and the first heat generating component is attached to the inner surface of the housing corresponding to the second air passage. A power converter, wherein a second heat generating component having a smaller heat generation amount is attached, and a third heat generating component having a heat generation amount smaller than that of the second heat generating component is attached to the inner surface of the housing corresponding to the third air path. The power conversion device according to claim 6, wherein at least one of the first heat generating component and the third heat generating component is provided in a recess in the inner surface of the housing. The height of the radiating fin of the first air passage from the outer surface of the housing is higher than the height of the radiating fin of the second air passage and the height of the radiating fin of the third air passage. 8. The power conversion device according to 7. The first heat generating component is a switching element that forms an inverter circuit that converts DC power into AC power, the second heat generating component is a first reactor that forms a filter circuit that attenuates high frequency components, and the third heat generating component receives DC power. The power converter according to claim 8, wherein the power converter is a second reactor that forms a step-up circuit. The power converter according to claim 9, wherein the circuit for boosting the DC power includes a plurality of booster circuits corresponding to a plurality of DC power inputs, and each booster circuit includes a second reactor. 11. The power converter according to claim 10, wherein the second reactor has a number of three or more, and the lower reactor is attached in a divergent shape from the lower side to the upper side of the housing in the recess. The power converter according to claim 11, wherein the second heat generating component and the third heat generating component are molded with a member having thermal conductivity and electrical insulation in each recess. 2. The DC power input to the booster circuit is generated power of a solar cell.
2. The power conversion device according to 2.

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