JP3735165B2 - Power converter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power converter such as an oil-cooled inverter or a DC-DC converter.
[0002]
[Prior art]
As an electrical configuration of a power conversion device such as an inverter or a DC-DC converter, there are mainly a transformer body and a semiconductor element, and the transformer body is composed of an input transformer body and an output transformer body. Since these generate heat during use, it is necessary to cool them. Moreover, when using at a high voltage, it is necessary to electrically insulate. FIG. 5 is a longitudinal sectional view showing a conventional power converter. In the figure, 1 is a tank, 2 is a radiator provided on the side wall of the tank 1, 3 is an insulating oil filled in the tank 1, 4a is an input transformer body, 4b is an output transformer body, and 5 is a semiconductor. An element 61 is an element radiator to which the semiconductor element 5 is detachably attached. Note that the control device and the electrical connection are omitted.
[0003]
In this conventional example, the input transformer body 4a, the output transformer body 4b, the semiconductor element 5 and the element radiator 61 are immersed in the insulating oil 3. Therefore, the input transformer body 4a and the output transformer body 4a are used. The transformer body 4 b and the semiconductor element 5 are cooled by natural convection of the insulating oil 3.
[0004]
FIG. 6 is a longitudinal sectional view showing another example of a conventional power converter. In the figure, 1 is a tank, 2 is a radiator, 3 is insulating oil, 4a is an input transformer body, 4b is an output transformer body, 5 semiconductor elements, and 61 is an element radiator. 7 is attached to the outside of the side wall of the tank 1, and a box cover for accommodating the semiconductor element 5 and the element radiator 61 outside the tank 1, and 7 c and 7 d are provided at the lower and upper parts of the box 7, respectively. A suction port and a discharge port 8 are cooling fans provided in the upper portion of the box 7. Note that the control device and the electrical connection are omitted.
[0005]
In this conventional example, the input transformer body 4 a and the output transformer body 4 b are cooled by natural convection of the insulating oil 3, while the semiconductor element 5 has a cooling air sucked by the cooling fan 8 for suction. It is cooled by being discharged to the outside through 7c, element radiator 61 and discharge port 7d.
[0006]
[Problems to be solved by the invention]
In the conventional oil-cooled power conversion apparatus shown in FIG. 5, when the semiconductor element 5 fails or when periodic inspection is performed, a cover (not shown) attached by screwing to the upper part of the tank 1 is removed, Since the semiconductor element 5 must be taken out from the oil, there is a problem that workability is poor.
[0007]
Therefore, as shown in FIG. 6 as another conventional example, a power conversion device adopting two methods of an oil cooling type for a transformer body and a forced air cooling type for a semiconductor element can be considered. Since each of them is configured separately and has a cooling function, the cooling fan 8 is required, and a space volume of an appropriate size for installing the cooling fan 8 is required. In addition, there is a problem that becomes expensive. Furthermore, the life of the cooling fan 8 is significantly smaller than that of the input transformer body 4a and the output transformer body 4b, and is usually 3 to 5 years. Therefore, it is necessary to replace it regularly and check it before it breaks down. There is a problem that must be done. In particular, when installed outdoors, there is a problem that the life of the cooling fan is further shortened.
[0008]
An object of the present invention is to provide a power conversion device that eliminates complicated operations at the time of failure or inspection of a semiconductor element and does not reduce the cooling of the semiconductor element without using a cooling fan.
[0009]
[Means for Solving the Problems]
The present invention relates to a power conversion device that includes an input transformer body, an output transformer body, and a semiconductor element, and the semiconductor element is mounted on an element radiator.
[0010]
According to the first aspect of the present invention, the input transformer body and the output transformer body are accommodated in a tank filled with insulating oil, the element radiator is disposed outside the tank, and the element radiator is oiled. provided the road, is disposed an upper communication oil pipe and the lower communication oil pipe connecting the upper and lower oil path of the tank, respectively, attached to the side wall outside of the tank, along with housing a radiator element, failure of the semiconductor devices A cover having a door that is opened and closed at the time of inspection or inspection is provided .
[0011]
As a result, the semiconductor element remains attached to the element radiator and is exposed to the air, and the oil in the tank flows through the oil passage of the element radiator.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a longitudinal sectional view showing an embodiment of a power converter according to the present invention, and shows an example in which an element radiator is cooled using oil in one tank. In the same figure, 1 is a tank, 2 is a radiator, 3 is insulating oil, 4a is an input transformer body, 4b is an output transformer body, and 5 is a semiconductor element. It is the same. 6 is an element radiator having an oil passage 6 c formed therein, 10 is an upper oil passage pipe, 11 is a lower oil passage pipe, 14 is attached to the outside of the side wall of the tank 1, and the element radiator 6 having the semiconductor element 5 mounted thereon. Is a box-shaped cover that houses a door (not shown). This door is opened and closed when the semiconductor element 5 is broken or inspected.
[0013]
In this embodiment, holes 1c1 and 1c2 are provided in the upper and lower portions of the side wall of the tank 1 in the cover 14, and the upper oil passage pipe 10 and the lower oil passage pipe 11 are attached to these holes by welding or the like. A flange (not shown) is attached to the other ends of the upper oil passage pipe 10 and the lower oil passage pipe 11, and the upper oil passage pipe 10 and the lower oil passage pipe 11 are respectively an oil passage outlet 6c1 and an oil passage inlet 6c2 of the element radiator 6. The tank 1 and the element radiator 6 are connected to each other.
[0014]
FIG. 2 is a schematic configuration diagram of an element heat radiator applied to the present invention. The element radiator 6 is made of aluminum, copper, or the like, is formed with a heat absorbing portion 6e that absorbs heat by mounting the semiconductor element 5, and an oil passage 6c that becomes a heat radiating portion is formed so as to penetrate in the vertical direction, for example. The oil passage 6c has an oil passage outlet 6c1 and an oil passage inlet 6c2.
[0015]
In the present embodiment, since the semiconductor element 5 remains attached to the element heatsink 6 and is exposed to the air, complicated work at the time of failure or inspection of the semiconductor element 5 becomes unnecessary. Only the operation of attaching and detaching the element 5 is performed. The heat generated in the semiconductor element 5 is transferred to the oil in the oil passage 6 via the element radiator 6, and the warmed oil goes out of the oil passage outlet 6c1 and rises in the upper oil passage pipe 10 to the tank. 1 flows into the tank 1 through a hole 1c1 provided in the upper part of 1. The oil heated by the semiconductor element 5 moves downward in the radiator 2 while being cooled by the radiator 2 together with the oil heated by the heat generated by the input transformer body 4a and the output transformer body 4b. It flows into the tank 1 from the lower part of the tank 1. Part of the cooled oil exits through a hole 1c2 provided in the lower portion of the tank 1, rises in the lower oil passage 11 and flows into the oil passage 6 from the oil passage inlet 6c2. Since the oil naturally convects in this way, the semiconductor element 5 is cooled as in the conventional case.
[0016]
FIG. 3 is a longitudinal sectional view showing another embodiment of the power conversion device according to the present invention, and shows an example in which the element radiator is cooled using oil in two tanks. In the same figure, 2 is a heat radiator, 3 is insulating oil, 5 is a semiconductor element, which is the same as in FIGS. 5 and 6 showing the conventional example. 1a is a first tank, 1b is a second tank, 4a is an input transformer body housed in the first tank 1a, 4b is an output transformer body housed in the second tank 1b, 6 is For example, element radiators having oil passages 6c and 6d formed therein, 10 and 12 are upper oil passage pipes, 11 and 13 are lower oil passage pipes, and 14 is attached to the outside of the side wall between both tanks 1a and 1b. Is a box-shaped common cover for housing the element heatsink 6 to which is attached, and has a door (not shown). This door is opened and closed when the semiconductor element 5 is broken or inspected.
[0017]
In the present embodiment, holes 1c1 and 1c2 are respectively provided in the upper and lower portions of the side wall of the first tank 1a in the cover 14, and the upper oil passage pipe 10 and the lower oil passage pipe 11 are attached to these holes by welding or the like. A flange (not shown) is attached to the other ends of the upper oil passage pipe 10 and the lower oil passage pipe 11, and the upper oil passage pipe 10 and the lower oil passage pipe 11 are respectively an oil passage outlet 6c1 and an oil passage inlet 6c2 of the element radiator 6. The first tank 1a and the element radiator 6 are connected to each other.
[0018]
Similarly, holes 1d1 and 1d2 are provided in the upper and lower portions of the side wall of the second tank 1b in the cover 14, and the upper oil passage pipe 12 and the lower oil passage pipe 13 are attached to these holes by welding or the like. A flange (not shown) is attached to the other ends of the upper oil passage 12 and the lower oil passage 13. The upper oil passage 12 and the lower oil passage 13 are respectively connected to the oil passage outlet 6 d 1 and the oil passage inlet 6 d 2 of the element radiator 6. The second tank 1b and the element radiator 6 are connected to each other.
[0019]
FIG. 4 is a schematic configuration diagram of another element heat radiator applied to the present invention. A heat absorbing portion 6e that absorbs heat by mounting the semiconductor element 5 is formed, and oil passages 6c and 6d that serve as heat radiating portions are formed so as to penetrate, for example, in the vertical direction. The oil passage 6c includes the oil passage outlet 6c1 and the oil passage. The oil inlet 6c2 and the oil passage 6d have an oil passage outlet 6d1 and an oil passage inlet 6d2.
[0020]
In this embodiment, the heat generated in the semiconductor element 5 is transmitted to the oil in the oil passage 6c via the element radiator 6, and the warmed oil exits the oil passage outlet 6c1 and passes through the upper oil passage pipe 10. It rises and flows into the tank 1 through the hole 1c1 provided in the upper part of the tank 1a. The oil warmed by the semiconductor element 5 moves downward in the radiator 2 while being cooled by the radiator 2 together with the oil warmed by the heat generated by the input transformer body 4a, and from the lower part of the tank 1a to the tank 1a Flows in. Part of the cooled oil exits the hole 1c2 provided in the lower part of the tank 1a, rises in the lower oil passage pipe 11, and flows into the oil passage 6c from the oil passage inlet 6c2. Since the oil naturally convects in this way, the semiconductor element 5 is cooled.
[0021]
Similarly, the heat generated in the semiconductor element 5 is transmitted to the oil in the oil passage 6d through the element radiator 6, and the warmed oil exits the oil passage outlet 6d1 and rises in the upper oil passage 12. Then, it flows into the tank 1b through the hole 1d1 provided in the upper part of the tank 1b. The oil heated by the semiconductor element 5 moves downward in the radiator 2 while being cooled by the radiator 2 together with the oil heated by the heat generated in the output transformer body 4b, and from the lower part of the tank 1b to the tank 1b. Flows in. Part of the cooled oil exits the hole 1d2 provided in the lower portion of the tank 1b, rises in the lower oil passage 13 and flows into the oil passage 6d from the oil passage inlet 6d2.
[0022]
The element radiator 6 is provided between the tanks 1a and 1b. The cover 14 is attached so that both tanks are close to each other and the side walls of both tanks are provided, and the element radiator is provided in the cover. In this case, the size can be further reduced.
[0023]
The element radiator 6 used in each of the above embodiments may be provided with fins on the outside, fins may be provided on the oil passages 6c and 6d, and the oil passage 6c may be formed in a honeycomb shape. Furthermore, instead of forming an oil passage inside, an oil passage tubular oil passage made of aluminum, copper, or the like may be attached to the outside. Further, the number of oil passages may be increased. In this case, the number of the pair of upper oil passage pipes and lower oil passage pipes is made to correspond to the number of oil passages. If it does in this way, cooling efficiency can be raised. Further, the structure, dimensions, and number of the radiator 2 are optimally designed according to the degree of cooling. Furthermore, forced cooling may be performed using an oil feed pump having a life much longer than that of the cooling fan used in the conventional example.
[0024]
The semiconductor element 5 used in each of the above embodiments is called an IGBT, and is modularized so that the inside thereof and the metal heat dissipating part are electrically insulated. Even if the semiconductor element 5 is directly attached to the heat absorbing portion 6e of the element radiator 6 which is in conduction with the tank 1 or 1a, 1b, no problem occurs.
[0025]
The semiconductor element 5 is not limited to the IGBT, and an element that is not electrically insulated from the inside may be used. In this case, the upper oil passage pipe and the lower oil passage pipes 10, 11, 12, 13 are used. Can be made insulative.
[0026]
【The invention's effect】
As described above, according to the present invention, a complicated operation at the time of a failure or inspection of a semiconductor element is not required, and the enlargement of the apparatus can be prevented and the cost can be prevented. Furthermore, a cooling fan can be made unnecessary without reducing the cooling of the semiconductor element. Further, since no cooling fan is used, the inspection work for the cooling fan becomes unnecessary, and the life can be extended even when installed outdoors.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an embodiment of a power converter according to the present invention.
FIG. 2 is a schematic configuration diagram of an element heat radiator applied to the present invention.
FIG. 3 is a longitudinal sectional view showing another embodiment of the power conversion device according to the present invention.
FIG. 4 is a schematic configuration diagram of another element heat radiator applied to the present invention.
FIG. 5 is a longitudinal sectional view showing a conventional power converter.
FIG. 6 is a longitudinal sectional view showing another example of a conventional power converter.
[Explanation of symbols]
1, 1a, 1b Tank 3 Insulating oil 4a Input transformer body 4b Output transformer body 5 Semiconductor element 6 Element radiator 6c, 6d Oil passage 10, 12 Upper oil passage pipe 11, 13 Lower oil passage pipe

Claims (1)

In a power conversion device comprising an input transformer body, an output transformer body, and a semiconductor element, and mounting the semiconductor element on an element radiator,
The input transformer body and the output transformer body are housed in a tank filled with insulating oil,
The element radiator is disposed outside the tank, and an oil passage is provided in the element radiator, and an upper oil passage pipe and a lower oil passage pipe are provided to connect the upper and lower parts of the tank and the oil passage, respectively. and,
A power converter provided with a cover that is attached to the outside of the side wall of the tank, accommodates the element radiator, and has a door that is opened and closed when the semiconductor element fails or is inspected .

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