JP2860850B2 - Cooling device for power converter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for a power converter such as an inverter or a converter, which is constituted by using semiconductor switching elements.

[0002]

2. Description of the Related Art Generally, a power converter using a semiconductor switching element is employed as a power converter, and such a power converter is provided with a cooling device for cooling the semiconductor switching element.

Generally, a gate turn-off thyristor (GTO thyristor) is used as a semiconductor switch element of a main circuit of a large-capacity inverter or converter. This is because there is a feature that the voltage and the current capacity are relatively large as compared with a semiconductor switching element such as a bipolar transistor or a gate insulating bipolar transistor.

The GTO thyristor is suitable for a large current, but has a large loss (calorific value). Therefore, in order to increase the cooling efficiency, a GTO thyristor is disclosed in Japanese Utility Model Laid-Open Publication No. 2-753838. A thyristor is formed in a disk shape, and both surfaces thereof are used as main electrodes, and conductive cooling blocks are pressed against the main electrodes, respectively, and a heat pipe through which a boiling refrigerant flows is communicated inside the cooling block, A cooling method is adopted in which heat radiating fins are attached to the heat pipe to cool the heat pipe with outside air.

In the case of such a cooling system, it is not possible to provide insulation between the main electrode of the GTO thyristor and the cooling block. Therefore, between the cooling block and the heat pipe condensing section (ground potential) or on both sides. In order to ensure electrical insulation between the cooling blocks, insulation between the cooling block and the heat pipe is provided by an insulating pipe, and a refrigerant having excellent cooling performance and insulating properties is used as a boiling refrigerant.

[0006]

However, since CFCs are harmful substances, there is a demand for the use of an alternative cooling method which does not use CFCs and has excellent cooling performance.

In order to satisfy such a demand, it is conceivable to insulate the GTO thyristor from the cooling block. However, a decrease in cooling efficiency due to the insulating material is inevitable. Therefore, in order to sufficiently cool the GTO thyristor having a large loss, the cooling system becomes large.

Therefore, a semiconductor switch element having a smaller loss than a GTO thyristor, for example, a bipolar transistor, a gate-insulated bipolar transistor (IG)
BT), a thyristor controlled by a MOS gate, or the like may be used to reduce the size of the cooling system.

However, since a low-loss semiconductor switch element such as an IGBT generally has a small current capacity and a low withstand voltage, a large-capacity inverter device for an electric vehicle or the like (for example, for driving a motor having a single unit capacity of 200 kW or more). In this case, the number of semiconductor switch elements connected in parallel and in series increases, and as a result, there is a problem that a device including a cooling system becomes large.

An object of the present invention is to provide a cooling device for a power converter that can be downsized as a whole including a cooler system.

[0011]

A cooling device for a power converter according to the present invention achieves the above object by the following means.

Basically, at least a semiconductor switch of a main circuit of a power converter is mounted on one surface of a heat receiving plate, and one straight portion of an L-shaped bent heat pipe is mounted on the other surface of the heat receiving plate. The cooling device is characterized by being embedded along the plate surface of the heat receiving plate, and radiating fins attached to the other straight portion of the heat pipe.

[0013]

According to the present invention, the above objects can be achieved by the following operations.

First, the semiconductor switch having the positive arm and the semiconductor switch having the negative arm which constitute the power converter do not turn on at the same time. Therefore, by mounting them on the same heat receiving plate, the heat input amount of the heat receiving plate is made uniform and the heat load of the cooling device is made uniform, so that the cooling device including the heat receiving plate and the radiation fins can be downsized. .

One straight portion of the heat pipe embedded in the heat receiving plate functions as a refrigerant liquid evaporating portion. In the present invention, since the evaporating portion is embedded along the plate surface of the heat receiving plate, the heat transfer area between them can be made sufficiently large, and the heat collecting efficiency can be increased.

Further, since the heat pipe is formed by bending the heat pipe into an L shape, the external dimensions of the cooling device including the heat radiation fins can be easily accommodated within the height or width of the housing. As a result, the space utilization rate (space integration degree) of the entire apparatus including the power converter is improved.

In particular, if the heat receiving plate forms a part of the outer wall surface of the housing, one surface of the heat receiving plate is exposed to the outside air,
Since it acts as a heat radiating surface, the temperature rise inside the housing can be suppressed by that much, and the heat radiating capacity of the cooler can be reduced.

The total heat generation of the semiconductor switch element is 1
In consideration of the cooling capacity of the heat pipe, it is preferable to reduce the volume occupied by the radiating fins by dividing the heat pipe into a plurality and providing the heat pipe on the heat receiving plate. In particular,
It is preferable to miniaturize the apparatus that a plurality of heat pipes are arranged in at least two rows (for example, upper and lower two rows) with respect to the heat receiving plate. In this case, by dividing the heat receiving plate in accordance with the division of the heat pipe, the handling work at the time of manufacturing and assembling becomes easy.

The heat receiving plate and the heat pipe are joined by forming a heat pipe insertion hole in the heat receiving plate from one side end to the other side end, and inserting a straight portion of the heat pipe into the insertion hole. However, this can be achieved by filling the gap with a filler having thermal conductivity. When arranging the heat pipes in two rows, the heat pipe insertion holes are formed by shifting the position in the arrangement direction for each row, and the heat pipe insertion holes are inserted except for the portion where the straight portion of the heat pipe is embedded. Forming a part of the side in an open groove shape facilitates the joining operation.

The heat receiving plate can be formed by overlapping the first and second heat receiving plates. In this case, when the semiconductor switch element is mounted on the first heat receiving plate side and the heat pipe is embedded in the second heat receiving plate side, the handling work during manufacture and assembly is facilitated.

Further, by covering the boundary between the embedded portion and the exposed portion of the heat pipe with a resin, both materials are used, for example, when the heat pipe is formed of copper and the heat receiving plate is formed of aluminum. It is possible to prevent electrolytic corrosion that occurs in different cases.

On the other hand, the above-mentioned heat receiving plate is attached so as to form a part of a vertical outer wall surface of a housing for housing the components of the power converter, and one straight portion of the heat pipe faces downward. If the straight part of the heat pipe provided with the radiation fin is inclined upward from the horizontal, the refrigerant liquid condensed at the radiation fin is embedded in the heat reception plate along the inclination. Since the heat is smoothly returned to the evaporating portion of the heat pipe by gravity, the heat transfer effect of the heat pipe is sufficiently exhibited, and the cooling capacity is improved. On the other hand, if the refrigerant liquid is inclined parallel or downward, the reflux of the condensed refrigerant liquid by gravity is prevented, and the cooling capacity is reduced.

Further, water can be used as the refrigerant liquid of the heat pipe. In this case, it is preferable to lower the boiling temperature by forming the inside at a negative pressure. According to this, excellent cooling performance can be exhibited without using Freon.

When water is used as the refrigerant liquid, the initial water level of the water is preferably set at least on the embedded portion side of the boundary between the embedded portion and the exposed portion of the heat pipe embedded in the heat receiving plate. According to this, even if the water inside freezes during cold weather such as winter, it is embedded in the heat receiving plate, so that the semiconductor switch is quickly melted by the heat generated by the semiconductor switch, so that there is no problem. In this respect, if the water is filled up to the position exposed to the outside, there is a problem that the pressure of the evaporating part abnormally rises because the water frozen at the exposed part is delayed in melting.

Further, if the radiating fins are provided so as to be eccentric downward with respect to the heat pipe, the dimension in the height direction can be suppressed correspondingly.

In the case where the heat receiving plate is formed using a conductive material, the semiconductor switch element is electrically insulated and mounted on the heat receiving plate, so that the semiconductor switch elements are interposed between the semiconductor switch elements and the semiconductor switch and the heat receiving plate. Since the insulation between the heat pipe and the heat pipe is ensured, the insulation property of the refrigerant liquid of the heat pipe is not limited, and a refrigerant liquid having excellent cooling performance other than chlorofluorocarbon such as water can be used. Solvable.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. As an embodiment of the cooling device of the power converter of the present invention,
A cooling device applied to a train inverter device will be described with reference to FIGS. Figure 1 shows a train inverter 1
FIG. 2 is a configuration diagram of a main part of a phase and a cooling device.
FIG. 2 is a configuration diagram viewed from I-II. FIG. 3 is a configuration diagram of an inverter main circuit for one phase. FIG. 4 is a rear view of the overall appearance of the train inverter device. FIG. 5 is a cross-sectional view taken along arrow VV in FIG. FIG. 6 is an enlarged view showing the arrangement of the semiconductor switch module and the clamp diode on the heat receiving plate and their electrical connection. FIG. 7 is a perspective view showing the structure of the semiconductor switch module with a part thereof cut away. FIG. 8 is a cross-sectional view showing a state where the heat pipe is embedded in the heat receiving plate.

First, with reference to FIGS. 3 to 5, the overall configuration of the train inverter device of this embodiment and the inverter main circuit will be described. As shown in FIG. 4, the entirety of the inverter device for a train according to the present embodiment includes inverters having the same configuration on both sides, centering on control units CU-A and B and auxiliary devices AU-A and B in a common housing 6. apparatus 1A, and the power module PU ₁ to PU ₃ of B is configured by symmetrically arranged. As shown in the cross-sectional view of FIG. 5, the coolers 53 and 54 are provided so as to protrude outside the front side of the housing 6. The train inverter device configured as described above has its longitudinal direction aligned with the running direction of the train, and is suspended under the floor at the center of the train vehicle via a plurality of suspension fittings 7 provided at the upper part of the housing 6. It can be mounted down. In addition, cooler 5
The 3, 54 side is attached to the outside of the vehicle. This allows the coolers 53 and 54 to be exposed to traveling wind in a direction perpendicular to the plane of the drawing.

The inverter device for a train according to the present embodiment drives four induction motors, and the four induction motors are driven by the inverter devices 1A and 2B, two by two. . Each of the power modules PU _{1 to} PU ₃ of each of the inverter devices 1A and 1B is configured by dividing a three-phase inverter main circuit for each phase.

As shown in FIG. 3, a so-called three-level inverter circuit is applied to the main circuit of each of the power modules PU _{1 to} PU ₃ . FIG. 3 shows a main circuit for one phase of the inverter. Among a pair of DC input terminals P and N, P is connected to a pantograph (not shown) via a DC line, and N is grounded. A series circuit of _two filter capacitors CF ₁ and CF ₂ is connected to the pair of DC input terminals P and N, and a connection point between the filter capacitors CF ₁ and CF ₂ is a neutral point of the DC power source and a neutral point. Connected to terminal O. A series circuit of _four semiconductor switch modules SM _{1 to} SM ₄ is connected between a pair of DC input terminals P and N. Each semiconductor switch module SM _{1 to} SM
₄ are each composed by inverse parallel connection of the IGBT Q ₁ to Q ₄ and the freewheeling diode DF ₁ ~DF _4. Connection point of the semiconductor switch modules SM ₁ and SM connection point and the semiconductor switch modules SM _{3 2} and SM ₄ are respectively connected to the neutral point terminal O through clamp diodes DC ₁ and DC _2. The connection point of the semiconductor switch modules SM ₂ and SM ₃ is connected to the AC output terminal M. The snubber circuit is a snubber capacitor CS
And a _1, CS ₂ and snubber diodes DS ₁ to DS ₄ and snubber resistor RS ₁ to RS ₃ Prefecture. The snubber capacitors CS ₁ and CS ₂ are respectively three capacitors C _{11 to} C ₁₃ ,
C _{21 to} C ₂₃ are connected in a delta type. The snubber capacitors CS ₁ and CS ₂ can be equivalently configured by connecting three capacitors in a star configuration. The gate pulses amplified are input by the gate driver GD to the gates of the semiconductor switch modules SM ₁ to SM _4.

Next, a specific structure of the power module PU will be described with reference to FIGS. FIG. 1 is a configuration diagram of a main part when one power module is viewed from the side.
FIG. 2 is a configuration diagram viewed from an arrow II-II in FIG.

As shown in these figures, each of the semiconductor switch modules SM _{1 to} SM ₄ has two semiconductor switch modules connected in parallel, and these semiconductor switch modules are arranged side by side. The semiconductor switch modules SM ₁ and SM ₂ of the positive arm are mounted vertically on the surface of the first heat receiving plate 31, and the semiconductor switch modules SM ₃ and SM ₄ of the negative arm are mounted on the surface of the second heat receiving plate 32. Mounted vertically. Also,
A clamp diode DC is provided on the surface of each heat receiving plate 31, 32.
₁ and DC ₂ are installed. Clamp diode D
C ₁ and DC ₂ are also configured by connecting two diodes in parallel.

Semiconductor switch modules SM _{1 to} SM
Reference numeral ₄ denotes the same configuration, which is formed as a so-called single-sided cooling type having a structure as shown in a perspective view partially broken away in FIG. That is, an insulating plate 62 such as alumina is placed on a substrate 61 formed of a material having excellent heat conductivity such as copper, and a first copper plate or the like having conductivity is placed on the insulating plate 62.
Is placed, and a plurality of thermal stress relaxation plates 64 made of conductive molybdenum or the like are placed on the main electrode 63,
An IGBT element 65 is placed on each thermal stress relaxation plate 64,
Further, a second main electrode 66 such as a conductive copper plate is placed on the first main electrode 63, and the whole of them is placed in an insulating case 67.
It has a structure covered by. A pair of main electrode terminals 68 and a gate terminal 69 are provided on the outer surface of the insulating case 67 so as to be exposed. Although not shown, a freewheeling diode DF connected in anti-parallel to the IGBT element (Q) 65 is also mounted on the first main electrode 63.
Then, the first heat receiving plates 31 and 32 are attached in close contact with the first and second heat receiving plates 31 and 32 by bolt holes 70 provided in the substrate 61. As shown in FIG. 6, semiconductor switch modules SM _{1 to} SM ₄ and clamp diodes DC ₁ and DC ₂ are arranged on heat receiving plates 31 and 32, and conductors 11 to 16 are arranged according to the circuit configuration of FIG. It is connected.

The first and second heat receiving plates 31, 32 are formed of a material having excellent heat conductivity such as aluminum. Each of the heat receiving plates 31 and 32 is fixedly attached to a power module support frame 33 formed in a rectangular frame shape by bolts 34.

A flange 35 is provided around the power module support frame 33. A frame-shaped mounting seat 37 is formed around an opening formed on the side surface of the housing 6. Then, the flange 35 of the power module support frame is fixed to the mounting seat 37 via a packing 39 with bolts 38, and the power module support frame 33 is mounted on the housing 6. That is, a part of the side surface of the housing 6 is formed by the heat receiving plates 31 and 32 and the power module support frame 33, and airtightness is secured by the packing 39.

A component support member 40 is provided at a position sandwiching the semiconductor switch modules SM _{1 to} SM ₄ with respect to the heat receiving plates 31 and 32. The component support member 40 is fixed to the power module support frame 33 by an arm member 41. Snubber capacitors CS ₁ and CS ₂ and snubber diodes DS _{1 to} DS ₄ are attached to the component support member 40 so as to face the semiconductor switch modules SM _{1 to} SM ₄ , and are arranged so that the terminals to be connected are brought close to each other. . Thereby, the wiring of the snubber circuit is mounted with the shortest distance.

At a position opposite to the component support member 40,
Terminal blocks 42 to 45 made of an insulating material such as epoxy resin are attached, and the DC input terminals P and N, the neutral point terminal O, and the AC output terminal M are supported on these terminal blocks 42 to 45. A current transformer CT and a gate driver GD (GD ₁ , GD ₂ ) are provided beside the terminal blocks 42 to 45 by the component supporting members 40.
Attached to. In the space below these CT and GD, filter capacitors CF ₁ and CF ₂ are arranged. The gate drivers GD ₁ and GD ₂ correspond to the positive side and the negative side of the semiconductor switch module, respectively.

The heat receiving plates 31 and 32 are thermally attached with coolers 53 and 54 each comprising a plurality of heat pipes 51 and radiating fins 52 attached to the heat pipes 51. The heat pipe 51 is formed of a material having excellent heat conductivity and workability such as copper, and water as a boiling refrigerant is sealed inside the pipe to facilitate boiling at a low temperature, and to use a non-condensable gas. Is adjusted to a negative pressure in order to prevent mixing.

In the case of this embodiment, the heat pipe 51 is
It is bent into a mold, and one of the straight pipe portions is embedded in the heat receiving plates 31 and 32 and thermally connected to form the evaporating portion 51a, and the heat pipe 51 is supported by the heat receiving plate. The other straight pipe portion is provided at a slight upward angle to the horizontal plane at an angle θ, and a plurality of radiating fins 52 are attached to this portion to form a condensing portion 51.
b. The inclination θ is set to an angle at which the inclination of the evaporating section 51b can be maintained at least above the horizontal plane, in consideration of the maximum inclination angle of the train caused by the curve of the track.

Further, the tip of the condensing portion 51 b is
This is fixed to the heat receiving plate 31 via the support member 56, and the vibration of the heat pipe 51 is made the same vibration system as the inverter device main body. Further, as shown in FIG. 5, the whole of the coolers 53 and 54 is covered with a protective cover 57 having a large number of ventilation holes.

As shown in FIG. 8, the heat pipe 51 and the heat receiving plates 31, 32 are joined by forming a heat pipe insertion hole from the upper end to the lower end of the heat reception plate 31, and inserting the heat pipe into the insertion hole. Is inserted, and the gap is filled with a filler material such as solder having thermal conductivity to perform thermal and mechanical bonding. The boundary between the embedded portion and the exposed portion of the heat pipe 51 is covered with a resin 58 such as an epoxy resin adhesive. Thus, even if moisture such as rainwater adheres to that portion, it is possible to prevent electrolytic corrosion between the copper of the heat pipe 51 and the aluminum of the heat receiving plate 31.

The semiconductor switch module SM is mounted on the heat receiving plate 31 (32) by means of a buried bolt 59. The heat pipe insertion hole is formed at a position that does not contact the bolt 59.

With respect to the operation of the train inverter device and the cooling operation of the semiconductor switch element thus configured,
The following describes mainly the features of the present invention.

The gate pulse for driving and controlling the train inverter device of the present embodiment is generated by a PWM control device (not shown) of the control unit CU in accordance with the well-known basic operation of a three-level inverter (reference: New Neutral point clamped PWM inverter (AN
ew Neutral-Point-Clamped PWM Inverter, IEEE Tra
nsactions on industry applications, vol.1A-17, No.
5, september / october1981)). That is, the basic operation of the three-level inverter is the semiconductor switch module SM
The ₁ to SM Q ₁ to Q ₄ of ₄ are turned on and off in accordance with the conduction mode the following three, the 3-level voltage selectively outputs to the AC output terminal M. Here, the total DC voltage is indicated as Ed, and the neutral point voltage is indicated as Ed / 2v.

Q ₁ Q ₂ Q ₃ Q ₄ Output voltage First conduction mode On On Off Off Ed Second conduction mode Off On On Off Ed / 2 Third conduction mode Off Off On On 0 Next, the present embodiment The characteristic operation of the cooling system for cooling the example semiconductor switch module will be described.

The PWM control device generates a gate pulse according to the above three conduction modes and the specified target speed and traveling mode of the train, performs PWM control on each semiconductor switch module via a gate driver, and outputs the output voltage of the inverter device and the output voltage of the inverter device. In addition to variably controlling the frequency, the inverter device is controlled in accordance with the running mode (powering, coasting, braking) of the train.

The semiconductor switch modules SM _{1 to} SM ₄ generate heat due to the loss during the ON operation. In this embodiment, the heat is radiated by the cooling system including the heat receiving plates 31 and 32 and the coolers 53 and 54, and is maintained at a predetermined allowable temperature or lower. That is, first, the heat of the semiconductor switch modules SM _{1 to} SM ₄ is transferred to the heat receiving plate 3 via the substrate 21.
1, 32, the temperature of the heat receiving plates 31, 32 rises.
Next, the water in the evaporating section 51a of the heat pipe 51 boils and evaporates due to the temperature rise of the heat receiving plates 31, 32, and the heat receiving plates 31, 32 are cooled by the heat of evaporation. The evaporated water in the heat pipe 51 is guided to the condensing portion 51b, and exchanges heat with the traveling wind of the train (basically, the wind in a direction perpendicular to the plane of FIG. 1 or FIG. 5) through the radiation fins to condense. I do. The condensed water travels along the inner wall of the heat pipe 51 and evaporates.
Then, the cooling operation is repeated. In addition,
A plurality of grooves are formed on the inner wall of the heat pipe 51 along the longitudinal direction, and the condensed water is returned to the evaporating section 51a along these grooves.

On the other hand, loss (heat generation) of semiconductor switch modules SM _{1 to} SM ₄ forming a three-level inverter
Has been found to be related to the running mode (powering, coasting, braking) of the electric vehicle, as in the semiconductor element heat cycle shown in FIGS. 9 (a) and 9 (b). In other words, the loss of the semiconductor switch modules SM ₁ and SM ₄ has a peak during power running, the loss of the semiconductor switch modules SM ₂ and SM ₃ is a peak during braking.

In view of this, as shown in FIG.
In this embodiment, the loss peaks of SM ₁ and SM ₂ are shifted.
Are mounted on the same heat receiving plate 31, and SM ₃ and SM ₄
Are mounted on the same heat receiving plate 32. This allows
It is heat input equalization of the heat receiving plate at the time of braking and power running, than the case of providing separately cooler the semiconductor switch modules SM ₁ to SM _4, the heat load of the cooler 53, 54 Mean Therefore, the size of the cooler can be reduced.

Further, as shown in FIG. 7, a freewheeling diode DF is mounted on the same substrate as the IGBT to form a semiconductor switch module SM, and a semiconductor element generating heat and its cooling system are integrated. This contributes to downsizing of the entire device.

In this case, the snubber diode DS can also be formed integrally with the semiconductor switch module SM, which can further consolidate the cooling system and contribute to downsizing of the device.

Similarly, clamp diodes DC ₁ and DC ₂
Are the same heat receiving plate 31, as the semiconductor switch module SM,
32, the heat generating semiconductor element and its cooling system can be further integrated, which contributes to downsizing of the entire apparatus. Further, since the loss of the clamp diodes DC ₁ and DC ₂ changes as shown in FIG. 9C according to the traveling mode of the train,
The heat load of the cooler can be averaged to some extent as compared with the case where the coolers are individually provided.

Further, since the evaporating portion 51a of the heat pipe is embedded along the plate surfaces of the heat receiving plates 31, 32, the heat transfer area between them can be made sufficiently large, and the heat collecting efficiency can be increased.

Further, since the heat pipe 51 is formed by bending the heat pipe 51 into an L shape, the outer dimensions of the coolers 53 and 54 including the radiation fins can be easily accommodated within the height of the housing. This makes it possible to easily satisfy the restriction on the device height required for the inverter device that is mounted to be hung below the floor of the train. Moreover, the heat pipe 51 provided with the radiation fins is provided for the housing mounted under the floor of the vehicle.
Because the straight part of was provided extending in the width direction of the train,
The running wind of the train is sufficiently passed through the radiating fins, and a large cooling effect is obtained.

In particular, since one surface of the heat receiving plates 31 and 32 is exposed to the outside air and acts as a heat radiating surface, the rise in temperature inside the housing can be suppressed by that much, and the coolers 53 and 54 can be suppressed.
Can reduce the heat radiation capacity.

Further, since the heat pipe 51 is divided into a plurality of parts and provided on the heat receiving plates 31 and 32, the volume occupied by the radiation fins can be reduced. In particular, since the heat pipes 51 are arranged in two stages above and below the heat receiving plate,
The device can be further miniaturized.

In this embodiment, the heat receiving plates 31 and 32 are divided into upper and lower portions, and the heat pipes 51a and 51b are
Is divided and embedded, so that the handling operation during production and assembly is facilitated.

Further, the radiation fins 52 are connected to the heat pipe 51.
Eccentrically downward, the size in the height direction can be suppressed by that much, and a sufficient heat radiation area can be secured.

On the other hand, as shown in FIG. 7, the IGBT and the freewheeling diode DF constituting the semiconductor switch module SM are connected to the substrate 61 via the insulating plate 62.
The heat-receiving plate 3 having conductivity has been configured such that the ground insulation of the semiconductor element is secured inside the module.
1, 32 can be set to the ground potential.

This eliminates the necessity of insulating the heat receiving plates 31 and 32 and the coolers 53 and 54 from the ground, so that the configuration of the cooling system can be simplified, which contributes to the downsizing of the entire apparatus and the heat receiving plates 31 and 32. A heat pipe using a non-insulating coolant such as water can be applied as a heat transfer member for thermally connecting the cooling devices 53 and 54 to each other. Therefore, it is possible to realize a cooling system that does not use harmful CFCs without impairing the cooling capacity.

When water is used as the refrigerant liquid, it is preferable that the initial water level of the water to be injected into the embedded portion of the heat pipe 51 be set closer to the embedded portion than the boundary between the embedded portion and the exposed portion. If the initial water level is set to a position reaching the exposed portion, the water in the exposed portion freezes in winter, and the pressure in the evaporating portion 51a may abnormally increase at the start of the inverter operation.

Since the heat receiving plates 31 and 32 can be set to the ground potential, they can be directly attached to the housing 6. Therefore, in the present embodiment, as shown in FIGS.
Since the heat receiving plates 31 and 32 are attached to the openings formed in the vertical outer wall of the housing 6 with the semiconductor switch module SM inside, one surface of the heat receiving plates 31 and 32 is exposed to the outside of the housing 6. I do. As a result, the exposed heat receiving plate 31 and the exposed heat receiving plate 31,
Since the surface of 32 also effectively acts as a heat dissipation surface, the temperature rise inside the housing can be suppressed by the amount of heat dissipation,
In addition, the heat radiation capacity of the cooler can be reduced and the size can be reduced.

In the above embodiment, an example in which an IGBT is applied as a semiconductor switch element of an inverter main circuit has been described. However, the present invention is not limited to this.
The same effect can be obtained by applying a thyristor controlled by an OS gate.

In the above embodiment, a three-level inverter has been described as an example. However, the present invention is not limited to this and can be applied to a two-level inverter or a cooling device for a power converter such as a converter. In other words, a power converter is generally configured by connecting a semiconductor switch having a positive arm and a semiconductor switch having a negative arm in a bridge manner, and these positive and negative semiconductor switches do not turn on at the same time. Therefore, by mounting them on the same heat receiving plate, the heat input amount of the heat receiving plate is made uniform and the heat load of the cooling device is made uniform, so that the cooling device including the heat receiving plate and the radiation fins can be downsized. .

In the above embodiments, the inverter device for an electric vehicle has been described as an example. However, the present invention is not limited to this and can be applied to a general-purpose power conversion device, and the same effect can be obtained.

In the above embodiment, the heat receiving plate is
1 and 32, and the coolers 53 and 54 are attached to each of them. As shown in FIG.
The above effect does not change even if the

In this case, the heat pipe 51 and the heat receiving plate 48
As shown in FIGS. 11A and 11B, the heat pipe insertion holes 49a and 49b for the upper stage and the lower stage are formed by shifting the position in the arrangement direction for each stage.
Except for the portions where the straight portions 1a and 51b are respectively buried, a part of the heat pipe insertion holes 49a and 49b on the insertion side is formed in an open groove shape. Thereby, the heat pipe 51
And the heat receiving plate 48 can be easily joined.

Further, as shown in FIG.
(32) is the heat receiving plate 3 on the semiconductor switch module SM side.
1a (32a) and a heat receiving plate 32b on the heat pipe 51 side
(32b) and a two-layer structure in which they are joined together. According to this, manufacture and assembly are further facilitated. In addition, as shown in FIG. 13, the heat receiving plate 50 on the semiconductor switch module SM side may be configured not to be divided. However, according to these, the cooling effect may be reduced due to the heat transfer resistance of the joining surface of the two layers of the heat receiving plate.

In the above embodiment, a combination of a heat pipe and a radiation fin is shown as a cooler. However, the present invention is not limited to this, and a configuration in which the radiation fin is directly thermally joined to the outer surface of the heat receiving plate, or A configuration in which the radiation fins are integrally formed with the heat receiving plate can be adopted. Further, in the embodiment shown in FIG. 5, the example in which the snubber resistors RS _{1 to} RS ₃ are arranged on the upper part of the cooler 53 is shown, but as shown in FIG. The vacant surface may be attached via an electric insulating material 71 having high thermal conductivity. According to this, the heat generated by the snubber resistors RS _{1 to} RS ₃ is absorbed by the heat receiving plate 48 via the electric insulating material 71, and
2 is efficiently released into the air. As a result, by increasing the current density of the snubber resistor RS ₁ to RS _3, it can be small.

[0070]

As described above, according to the present invention,
The entire cooling device of the power converter can be downsized.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a main part including a cooling device of an inverter device for an electric vehicle according to an embodiment to which the present invention is applied.

FIG. 2 is a configuration diagram of the embodiment of FIG. 1 as viewed from an arrow II-II.

FIG. 3 is a main circuit configuration diagram of one phase of a three-level inverter according to the present invention.

FIG. 4 is an overall external view of a train inverter device according to the present invention.

FIG. 5 is a view as viewed from an arrow VV in FIG. 4;

FIG. 6 is an enlarged view showing an arrangement relationship of semiconductor switch modules and the like on a heat receiving plate.

FIG. 7 is a perspective view showing a configuration of a semiconductor switch module according to an embodiment of the present invention, with a part thereof cut away.

FIG. 8 is a cross-sectional view showing a joint between a heat receiving plate and a heat pipe.

FIG. 9 is a diagram showing a loss of a semiconductor switch module and a clamp diode corresponding to an operation mode of an inverter.

FIG. 10 is a view showing another embodiment of the heat receiving plate.

FIG. 11 is a detailed view of a heat pipe insertion hole of the heat receiving plate of the embodiment in FIG. 10;

FIG. 12 is a sectional view of an embodiment in which the heat receiving plate has a two-layer structure.

FIG. 13 is a sectional view of another embodiment in which the heat receiving plate has a two-layer structure.

[Explanation of symbols]

1A, B Inverter device 6 Housing 11 to 23 Conductor 31, 32 Heat receiving plate 33 Power module support frame 35 Flange 37 Mounting seat 39 Packing 40 Component support member 41 Arm member 42 to 45 Terminal block 48 Heat receiving plate 49a, b Heat pipe Insertion hole 50 Heat receiving plate 51 Heat pipe 52 Radiation fins 53, 54 Cooler 55 Sway stopper 56 Support member 61 Substrate 62 Insulating plate 63 Main electrode 64 Thermal stress relieving plate 65 IBGT element 67 Insulating case 68 Main electrode terminal 69 Gate terminal 71 Electricity Insulation material PU _{1 to} PU ₃ Power module SM _{1 to} SM ₄ Semiconductor switch module Q _{1 to} Q ₄ IGBT DF _{1 to} DF ₄ Free wheeling diode CS _{1 to} CS ₂ Snubber capacitor DS _{1 to} DS ₄ Snubber diode RS ₁ to RS ₃ snubber resistance DC _1, DC ₂ Kuranpuda Eau CF _1, CF ₂ filter capacitor CT current transformer

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takeshi Ando 1070 Ma, Katsuta-shi, Ibaraki Hitachi, Ltd. Mito Plant (72) Inventor Eiichi Toyoda 1070 Ma, Katsuta-shi, Ibaraki Hitachi, Ltd.Mito Inside the plant (72) Inventor Takayuki Matsui 1070 Ma, Katsuta-shi, Ibaraki Pref. Inside the Mito Plant, Hitachi, Ltd. (72) Inventor ▲ Toshihiko Taka ▼ Hisashi 832. Within Engineering Co., Ltd. (72) Inventor Kiyoshi Nakamura 7-1-1, Omika, Hitachi, Ibaraki Pref. Hitachi, Ltd. Inside Hitachi Research Laboratory (72) Inventor Kiyoshi Nakata 7-1-1, Omika 7-chome, Hitachi, Ibaraki, Japan Hitachi, Ltd.Hitachi Research Laboratories (72) Inventor Hirayoshi Kuwahara 502, Kandatecho, Tsuchiura-shi, Ibaraki Pref. Stand Works machine in the Laboratory (72) inventor Koichi Isaka Tsuchiura, Ibaraki Prefecture Kidamari-cho, 3550 address Hitachi Electric Wire Co., Ltd. Tsuchiura in the factory

Claims (4)

(57) [Claims] 1. A straight part of a heat pipe is embedded along a plate surface of a heat receiving plate on which a heating element of a power converter is mounted, and the other straight portion of the heat pipe protruding from the heat receiving plate. in the cooling apparatus of power converter comprising attaching a heat radiation fin part, and characterized by being filled with a filler having a thermal conductivity in the gap portion between the embedded portion and the heat receiving plate of the heat pipe Power converter cooling device. 2. A heating element of a power converter is mounted on a plate surface.
Fill one straight part of the heat pipe along the surface of the heat receiving plate.
Other than the heat pipe protruding from the heat receiving plate.
Of the power converter with the radiation fin attached to the
In the cooling device, the heat pipe embedded straight
A refrigerant liquid is sealed in the section to form an evaporating section, and all of the evaporating section is
Embedded in the heat receiving plate so as not to touch the outside air, and
All of the refrigerant liquid is positioned correspondingly in the heat receiving plate.
A power converter, wherein the power converter is enclosed in the evaporator.
Cooling system. 3. A heating element of a power converter is mounted on a plate surface.
Fill one straight part of the heat pipe along the surface of the heat receiving plate.
Other than the heat pipe protruding from the heat receiving plate.
Of the power converter with the radiation fin attached to the
In the cooling device, the heat pipe embedded straight
A refrigerant liquid is sealed in the section to form an evaporating section, and all of the evaporating section is
Embedded in the heat receiving plate so as not to touch the outside air, and
All of the refrigerant liquid is positioned correspondingly in the heat receiving plate.
Into the evaporating part, and the embedded part of the heat pipe
Filler having thermal conductivity in the gap between the heat receiving plate
A cooling device for a power converter, wherein the cooling device is filled. 4. A claim 1, the cooling device for a power converter characterized by comprising a boundary portion of the exposed portion and the embedded portion of the heat pipe coated with a resin.