JP2004087711A - Forced air-cooled power conversion apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a forced air-cooled power conversion apparatus which improves the cooling efficiency by housing a plurality of groups of independent power converter circuits in a single apparatus housing, and incorporating a suitable margin without waste in a plurality of semiconductor element cooling units which improves an apparatus performance and which can realize reduction in size. <P>SOLUTION: Semiconductor element cooling units 7, 8 are constituted of one group of independently operable inverter circuits 5 and converter circuits 4, and arrangements and dispositions of different groups of semiconductor element cooling units 7, 8 are devised in a cooling air tunnel 10. Even if a certain group is disconnected from a system due to a fault, cooling air is effectively supplied to the rest of the cooling units as continuously operating group for effectively cooling without waste of the cooling air. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a forced air-cooled power converter.
[0002]
[Prior art]
The power conversion device performs power conversion by switching operation of the semiconductor element, and in order to dissipate heat generated by the switching loss, the semiconductor element constituting the power conversion device and electric components of peripheral circuits thereof are attached to a cooler so that the semiconductor element is cooled. A cooling unit is configured, and the semiconductor element cooling unit is housed in the apparatus.
[0003]
The semiconductor element cooling unit efficiently discharges the heat loss generated from the semiconductor element to the outside air and cools the semiconductor element temperature below the allowable temperature.A semiconductor element is attached to the heat receiving part of the cooler, and the heat radiation part of the cooler is cooled. The heat is dissipated outside the device by placing it in the open chamber (portion that communicates with the outside air) provided outside or inside the device.
[0004]
In order to improve the heat transfer coefficient of the heat radiating portion of the semiconductor element cooling unit, it is effective to increase the flow velocity of the cooling air passing through the heat radiating portion. For this purpose, a cooling wind tunnel is generally provided in the apparatus, in which the electric blower forcibly ventilates the air, and the radiator of the semiconductor element cooling unit is housed therein.
[0005]
Generally, the semiconductor element cooling units are grouped into units for each phase of the power conversion circuit, or grouped into units for each conversion circuit so as not to become too large in consideration of the handling of the unit. For example, in a power conversion circuit in which a converter circuit for converting an AC power supply to DC and an inverter circuit for converting the AC power to AC again are paired, a group of components constituting the converter circuit is configured as one unit to configure the inverter circuit. In many cases, the component group is combined into another unit, and each of them constitutes a semiconductor element cooling unit. When there are a plurality of groups of power conversion circuits including the converter circuits and the inverter circuits, more semiconductor element cooling units are housed in the apparatus.
[0006]
The circuit diagram of FIG. 13 shows a conventional AC motor drive system for an AC overhead line railway vehicle. The AC power collected from the pantograph 1 is supplied to the primary winding of the main transformer 2, and the AC transformed by the main transformer 2 is input to the power conversion circuit 3 from the secondary winding. The power conversion circuit 3 includes a converter circuit 4 and an inverter circuit 5. The alternating current input to the power conversion circuit 3 is converted to direct current by the converter circuit 4 in the power conversion circuit 3, and is converted again to the desired voltage and current by the inverter circuit 5. The AC from the inverter circuit 5 drives an AC motor 6 for driving a railway vehicle.
[0007]
FIG. 14 is a front view of a power conversion device including the conventional power conversion circuit. FIG. 14 shows a state in which the front cover is removed to show the internal device arrangement. FIG. 15 is a sectional view taken along line AA in FIG.
[0008]
As the semiconductor element cooling unit, there are a converter unit 7 in which a group of components constituting the converter circuit 4 is integrated, and an inverter unit 8 in which a group of components constituting the inverter circuit 5 are integrated, and a cooling wind tunnel 10 forcedly ventilated by an electric blower 9. The heat loss generated from the semiconductor element is discharged inside. The cooling wind tunnel 10 is configured to penetrate vertically through the inside of the device housing 11. The upper and lower end surfaces of the cooling wind tunnel 10 are opened for taking in and discharging outside air, and the outside air is sucked in from below and discharged upward by an electric blower 9 provided in an upper portion of the cooling wind tunnel 10. The area other than the cooling wind tunnel 10 in the device housing 11 is a closed chamber. There is another electrical component storage area 12 in the closed chamber in the device housing 11.
[0009]
The semiconductor element cooling unit of the converter unit 7 and the inverter unit 8 has a semiconductor element and an electric component group 13 of its peripheral circuit mounted on the front side (the front side when the device is stored), and has a radiator 14 of a cooler on the rear side. Is provided. The radiator 14 is accommodated in the cooling wind tunnel 10 and is cooled by forced ventilation.
[0010]
The arrangement of the converter unit 7 and the inverter unit 8 depends on the size of the device housing 11, the cooling wind tunnel 10 formed therein, the converter unit 7 and the inverter unit 8, and the like. In many cases, they are arranged in series with respect to the flow of the cooling air so that they can be simply configured. When a larger number of semiconductor element cooling units are accommodated in the device housing 11, the cooling units are often arranged in series with respect to the flow of cooling air in the cooling wind tunnel 10 and also arranged in parallel. .
[0011]
So far, the power converter having one set of power converters 3 in which the converter circuit 4 and the inverter circuit 5 are paired has been described. However, there is a power converter including a plurality of groups of power converters. This will also be described briefly.
[0012]
FIG. 16 is a circuit diagram of an AC motor driving system for an AC overhead line railway vehicle, similar to FIG. 13, but a system in which a power conversion circuit 3 in which a converter circuit 4 and an inverter circuit 5 are paired is configured in two groups. It is.
[0013]
In such a power conversion device including a plurality of groups of power conversion circuits 3, by allowing each of the power conversion circuits to be independently operable, in the event of a failure, only the group in which a failure has occurred is separated from the system. The operation can be continued with only the remaining healthy groups, and a highly redundant power converter can be realized.
[0014]
The converter circuit 4 of one group is called “converter 1”, the inverter circuit is called “inverter 1”, the converter circuit 4 of the other group is called “converter 2”, and the inverter circuit is called “inverter 2”. That is, when the "converter 1" or the "inverter 1" fails, this group is disconnected from the system, and the remaining "converter 2" and "inverter 2" sides are continuously operated, so that the redundancy as a railway vehicle system is obtained. Is a high system.
[0015]
A power converter that realizes this system requires two sets of power converters similar to those shown in FIGS. 14 and 15, but two sets are combined in a single device housing, which is appropriate for the motor control capacity. Innovative measures such as reviewing the rated components and reducing the size have been made so far, and have been used as a plurality of groups of power conversion circuits to compensate for the increase in the number of components.
[0016]
[Problems to be solved by the invention]
As described above, in the forced air cooling type power converter in which the heat radiating portion of the semiconductor element cooling unit is arranged in the cooling air tunnel forcibly ventilated by the electric blower or the like, the cooling air flow is arranged in series with the flow of the cooling air in the cooling air tunnel. There is a problem that the temperature of the cooling air sucked into the heat radiating portion of the semiconductor element cooling unit varies.
[0017]
In the power converter shown in FIGS. 14 and 15, when the inside of the cooling wind tunnel 10 is forcibly ventilated by the electric blower 9, the heat is dissipated in the inverter unit 8 arranged on the windward side (the inlet side). Air having a temperature substantially equal to the outside air temperature is sent to the section 14, but passes through the heat radiating section 14 of the inverter unit 8 with respect to the heat radiating section 14 of the converter unit 7 arranged on the leeward side (the exhaust side). Since the cooling air that has passed through is passed, the temperature of the ventilation air is higher than the outside air temperature due to the exhaust heat from the inverter unit 8. Therefore, cooling conditions become severe in the heat radiating portion on the converter unit 7 side arranged on the leeward side.
[0018]
That is, the cooling wind tunnel 10 in which the heat radiating portion 14 is placed is forcibly ventilated from below to above by the electric blower 9, and heat exchange is performed by passing the forced air through the heat radiating portion 14. The air sucked into the cooling wind tunnel 10 is substantially equal to the outside air temperature, and heat is discharged to the ventilation air side by the heat dissipating portion 14 arranged on the windward side due to the temperature difference between the air temperature substantially equal to the outside air temperature and the heat dissipating portion 14. . The temperature of the air passing through the radiator 14 on the leeward side increases due to the heat loss discharged on the leeward side, and then goes to the radiator 14 located on the leeward side.
[0019]
Similarly, heat is discharged to the air side by the temperature difference between the heat radiation part 14 and the air temperature of the ventilation to the heat radiation part 14 on the leeward side. Cooling is disadvantageous. For example, if the same heat loss as that of the radiator 14 on the leeward side is discharged, the temperature of the radiator 14 on the leeward side will increase unnecessarily by the rise in the air temperature on the inlet side. As a result, it is inevitable that the temperature of the semiconductor element on the leeward side becomes higher than that on the leeward side.
[0020]
The top and bottom arrangement suitable for the difference in heat loss generated by each semiconductor element cooling unit is devised, and the size of the cooler itself is changed between the upper and lower heat radiating parts so that the temperature rise value of the semiconductor element does not extremely differ Although considerations such as are taken into account, the temperature rise on the side of the semiconductor element cooling unit arranged on the leeward side as described above is generally higher, so that the temperature rise allowable value on the windward side is not sufficient. Generally, there is a margin and there is little margin on the leeward side.
[0021]
Furthermore, in a power conversion device including a plurality of groups of power conversion circuits, when one group is disconnected from the system due to a failure, the current value of the remaining group is smaller than that of the normal group in which all the groups operate normally. , Etc., and the generated heat loss increases. In the design of the cooling capacity, the cooling capacity is set in consideration of such a case, so that there is a sufficient margin for the allowable temperature rise during the normal operation.
[0022]
As described above, in the conventional forced air cooling type power converter, the difference in temperature rise between the two semiconductor element cooling units arranged in series in the cooling air channel along the flow of the cooling air, There is a difference in the temperature rise that occurs between the operation and the operation of only one group, and not all of them have the same margin for the temperature rise allowable value of the semiconductor element. This is a factor that hinders miniaturization of the entire device.
[0023]
The present invention has been made in view of such a conventional technical problem, and a plurality of groups of independent power conversion circuits are housed in a single device housing, and each of the plurality of semiconductor element cooling units is wasted. It is an object of the present invention to provide a forced-air-cooling type power converter capable of improving cooling efficiency, improving device performance, and realizing downsizing by providing a proper margin without any problem.
[0024]
[Means for Solving the Problems]
The invention according to claim 1 is a forced air cooling type power converter in which a heat radiating portion of a semiconductor element cooling unit is disposed in a cooling wind tunnel forcibly ventilated by an electric blower or the like, wherein a plurality of groups of independently operable power are provided. The conversion circuit is housed in a single device housing, each group of the power conversion circuit is constituted by a plurality of the semiconductor element cooling units, and the plurality of the semiconductor element cooling units are arranged in the cooling wind tunnel. Are arranged in a plurality of rows with respect to the flow of the cooling air, and the plurality of semiconductor element cooling units arranged in series in the cooling air channel along the flow of the cooling air have at least two groups. And a semiconductor element cooling unit constituting each of the power conversion circuits.
[0025]
The invention according to claim 2 is a forced air cooling type power converter in which a heat radiating portion of a semiconductor element cooling unit is disposed in a cooling wind tunnel forcibly ventilated by an electric blower or the like, and a converter circuit for converting an AC power supply to a DC. A plurality of groups of power conversion circuits, which are paired with inverter circuits for converting converted DC to AC again, are housed in a single device housing, and each group of converter circuits can be operated independently. Alternatively, the semiconductor element cooling unit is configured for each divided phase, and the semiconductor element cooling unit is configured for each of a group of inverter circuits that can be operated independently or for each divided phase, and Wherein the semiconductor element cooling unit on the converter circuit side and the semiconductor element cooling unit on the inverter circuit side are arranged in series along the flow of cooling air in the cooling wind tunnel. It is an.
[0026]
The invention according to claim 3 is a forced air cooling type power converter in which a heat radiating portion of a semiconductor element cooling unit is disposed in a cooling wind tunnel forcibly ventilated by an electric blower or the like, and a converter circuit for converting an AC power supply to a DC. A plurality of groups of power conversion circuits, which are paired with inverter circuits for converting converted DC to AC again, are housed in a single device housing, and each group of converter circuits can be operated independently. Alternatively, the semiconductor element cooling unit is configured for each divided phase, and the semiconductor element cooling unit is configured for each of a group of inverter circuits that can be operated independently or for each divided phase, and The semiconductor element cooling units constituting the converter circuits are arranged in series along the flow of the cooling air in the cooling wind tunnel, and the semiconductor element cooling units constituting different groups of inverter circuits are arranged. It is characterized in that arranged in series along a knit together with the flow of the cooling air.
[0027]
The invention according to claim 4 is a forced air cooling type power converter in which a heat radiating portion of a semiconductor element cooling unit is arranged in a cooling wind tunnel forcibly ventilated by an electric blower or the like, wherein a plurality of groups for converting DC power to AC are provided. An inverter circuit is housed in a single device housing, and the semiconductor element cooling unit is configured for each phase constituting each group of inverter circuits that can operate independently, and the semiconductor element cooling unit belonging to a different group of inverter circuits is provided. The units are arranged in series along the flow of cooling air.
[0028]
In the forced air-cooling type power converter according to the first to fourth aspects of the present invention, a semiconductor element cooling unit is configured for each of a group of independently operable inverter circuits, converter circuits, or phases obtained by dividing the groups. By arranging the arrangement and arrangement of the semiconductor element cooling units in the cooling air tunnel, even if one group is disconnected from the system due to a failure, the cooling air is supplied to the remaining semiconductor element cooling units in the continuously operating group. And effectively use the cooling air without wasting it.
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0030]
(First Embodiment)
(Structure) A forced air cooling type power converter according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a circuit configuration of an AC motor drive system for an AC overhead line railway vehicle to which the forced air cooling type power converter according to the first embodiment is applied. FIG. 2 is a front view of the power conversion device according to the first embodiment (however, a state in which a front cover is removed to show an internal device arrangement). FIG. 3 is a sectional view taken along the line BB in FIG. 2 and shows a cooling wind tunnel portion viewed from the side. FIG. 4 is a cross-sectional view taken along the line CC in FIG. 3, showing a cross section inside the cooling wind tunnel at the back of the device, and showing a state in which the heat radiating portion of the semiconductor element cooling unit is housed in the cooling wind tunnel.
[0031]
As shown in FIG. 1, the power conversion device 3 of the present embodiment is composed of two groups of power conversion circuits in which a converter circuit 4 and an inverter circuit 5 are paired, similarly to the conventional device shown in FIG. However, they are housed in a single device housing. Other circuit configurations are common to the conventional example.
[0032]
In the power converter 3 of the present embodiment, in each group, the AC power collected from the pantograph 1 is supplied to the primary winding of the main transformer 2 and is transformed by the main transformer 2. The AC that is transformed by the main transformer 2 and output from the secondary winding is converted to DC by the converter circuit 4, which is again converted to AC by the inverter circuit 5, and supplied to the AC motor 6 for driving the railway vehicle. The AC motor 6 is driven.
[0033]
The two groups of power conversion circuits, which constitute one group by the set of the converter circuit 4 and the inverter circuit 5, can operate independently, and in the event of a failure, only the group in which the failure has occurred is transmitted from the system. Disconnect and continue operation with the remaining group.
[0034]
In the following description, one group of converter circuits 4 is called "converter 1", the inverter circuit is called "inverter 1", the other group of converter circuits 4 is called "converter 2", and the inverter circuit is called "inverter 2". I do.
[0035]
Next, a mechanical configuration of the power converter according to the first embodiment will be described with reference to FIGS. A cooling wind tunnel 10 is provided in the device housing 11, and the cooling wind tunnel 10 is forcibly ventilated by the electric blower 9.
[0036]
The cooling wind tunnel 10 is configured to penetrate vertically through the inside of the device housing 11, and the upper and lower end surfaces of the cooling wind tunnel 10 are opened for taking in and discharging outside air, and are provided at the upper part in the cooling wind tunnel 10. Outside air is taken in from the lower opening by the electric blower 9 and is discharged from the upper opening. The area other than the cooling wind tunnel 10 in the device housing 11 is a closed chamber. This closed chamber in the device housing 11 is an electric component storage area 12 other than the semiconductor element cooling unit.
[0037]
As the semiconductor element cooling unit, there are a converter unit 7 in which a group of components constituting the converter circuit 4 is aggregated and an inverter unit 8 in which a group of components constituting the inverter circuit 5 are aggregated. Two units are accommodated each, for a total of four units.
[0038]
In these semiconductor element cooling units, a semiconductor element and an electric component group 13 of peripheral circuits are mounted on the front side of the unit (on the front side when the device is stored), and a radiator 14 of a cooler is formed on the back side of the unit. The heat radiating portion 14 is housed in the cooling wind tunnel 10.
[0039]
The arrangement of four semiconductor element cooling units (two converter units 7 and two inverter units 8) is arranged in series with respect to the flow of cooling air in the cooling wind tunnel 10, and two sets are arranged in parallel again. There is a configuration. Then, the two combinations arranged in series are, on the one hand, a combination in which “converter 1” is arranged on the leeward side and “inverter 2” is arranged on the leeward side, and conversely, the “converter 2” is arranged on the leeward side. On the windward side, "inverter 1" is arranged in a combination, and the units of the other groups are arranged in series.
[0040]
(Operation) In the forced air cooling type power converter having the above-described configuration, heat loss is generated from the semiconductor element during operation, and the heat loss is dissipated to the outside air from the radiator 14 of each of the semiconductor element cooling units 7 and 8. Thereby, the semiconductor element is cooled. The cooling wind tunnel 10 in which the heat radiating portions 14 are placed is forcibly ventilated from below to above by the electric blower 9, and the forcedly ventilated air passes through each of the heat radiating portions 14 to exchange heat. The air flowing into the cooling wind tunnel 10 is substantially equal to the outside air temperature, and the heat is radiated to the air side in the heat radiating portion 14 arranged on the windward side due to the temperature difference between the incoming air temperature and the heat radiating portion 14 substantially equal to the outside air temperature. Heat is dissipated. The air that has passed through the radiator 14 on the leeward side moves toward the radiator 14 placed on the leeward side in a state where the temperature is increased by the heat received from the radiator 14 on the leeward side.
[0041]
Similarly, heat is radiated to the air side by the temperature difference between the heat radiating portion 14 and the temperature of the incoming air to the radiating portion 14 on the leeward side. Is disadvantaged.
[0042]
Here, the operation when one of the two groups of power conversion circuits is separated from the system will be described. Now, assuming that the first group of the "converter 1" and the "inverter 1" is separated from the system, only the remaining "converter 2" and the "inverter 2" are operated. As for the cooling of the semiconductor element, only the “converter 2” and the “inverter 2” may be considered. When the heat radiating portion 14 in the cooling wind tunnel 10 is the “converter 2” located on the leeward side, no heat loss occurs from the “inverter 1” located on the leeward side. Air equal to the outside air temperature will be blown in. On the other hand, the condition of the incoming air temperature is not changed in the “inverter 2”, but the rise in the temperature of the air passing through the heat radiating portion 14 of the “inverter 2” affects the “converter 1” which is arranged next in series. Will not give.
[0043]
Due to the above forced air cooling function, the semiconductor element cooling units arranged in series with respect to the flow of cooling air are in a combination of different groups. Therefore, when operating only one group, the semiconductor element cooling units are arranged in two rows in series. The cooling air flowing to both sides remains and is effectively sent to the group-side semiconductor element cooling unit that is operated.
[0044]
Compared to when both groups are operating normally, when only one group is operated, the units on the other side arranged in series are not operated, so that cooling becomes easier. That is, in the "converter 2", the temperature rise of the semiconductor element is reduced, and the heat loss in the "converter 2" can be further increased. In the “inverter 2” as well, it is not necessary to consider an increase in the temperature of the incoming air to the heat radiating portion 14 of the semiconductor element cooling unit placed on the leeward side of the “inverter 2”.
[0045]
When one group is separated from the system and operation is continued with the remaining group, the load on the group that continues operation increases, and it becomes necessary to increase the current, etc. compared to when all the groups are in healthy operation. It is possible to cope with an increase in heat loss due to cooling by the heat radiating portion, and the system performance is improved. In addition, since it is not necessary to increase the size of the heat radiating portion in consideration of the single-group operation, it is possible to reduce the size of the heat radiating portion of the semiconductor element cooling unit, thereby reducing the size and weight of the entire power converter.
[0046]
(Second embodiment)
A forced air-cooled power converter according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a front view of the power converter according to the second embodiment (however, a state where a front cover is removed) is shown. FIG. 6 is a sectional view taken along line DD in FIG. 5 and shows a cooling wind tunnel portion viewed from the side. FIG. 7 is a cross-sectional view taken along the line EE in FIG. 6, showing a cross section of the inside of the cooling wind tunnel on the back surface of the device, and shows a state where the heat radiating portion of the semiconductor element cooling unit is housed in the cooling wind tunnel.
[0047]
The configuration of a system circuit to which the second embodiment is applied is the same as that of the first embodiment shown in FIG. 1, and includes two groups of power conversion circuits. However, in the case of the second embodiment, the arrangement of the four semiconductor element cooling units differs from that of the first embodiment.
[0048]
In the following description, similarly to the first embodiment, the converter circuit 4 and the inverter circuit 5 belonging to the first group of power conversion circuits are referred to as “converter 1” and “inverter 1,” respectively, and the second group of power conversion circuits The converter circuit 4 and the inverter circuit 5 belonging to the circuit are referred to as “converter 2” and “inverter 2”, respectively.
[0049]
In the present embodiment, as in the first embodiment, two semiconductor element cooling units of different groups are arranged in series with respect to the flow of cooling air, but “converter 1” and “converter 2” Are arranged in series, two “inverter 1” and “inverter 2” are also arranged in series, and these two sets are arranged in parallel.
[0050]
In this configuration, when the first group of the "converter 1" and the "inverter 1" is disconnected from the system, only the remaining "converter 2" and the "inverter 2" are operated. Heat loss and cooling of the semiconductor element may be considered only for "converter 2" and "inverter 2". Therefore, in the “converter 2”, since heat loss does not occur from the “converter 1” located on the windward side, air almost equal to the outside air temperature enters the radiator 14 of the “converter 2”. Become. Similarly, in the “inverter 2”, no heat loss is generated from the “inverter 1” on the windward side, so that air having substantially the same outside air temperature enters the radiator 14 of the “inverter 2”. Become.
[0051]
On the other hand, when the second group of the “converter 2” and the “inverter 2” is disconnected from the system, only the “converter 1” and the “inverter 1” are operated, and the cooling of the semiconductor element cooling units arranged on the leeward side thereof is performed. There is no need to consider the rise in the temperature of air entering the heat radiating section 14.
[0052]
As described above, the same effects as those of the first embodiment can be obtained also in the power conversion device of the second embodiment. In addition, in the case of the second embodiment, since the converter circuits and the inverter circuits of the same group are arranged side by side in parallel, there is an advantage that the electrical connection between these circuits is relatively easy. .
[0053]
(Third embodiment)
A forced air-cooled power converter according to a third embodiment of the present invention will be described with reference to FIGS. FIG. 8 is a plan view of a power converter according to the third embodiment. FIG. 9 is a sectional view taken along the line FF in FIG. 8 and shows a cooling wind tunnel portion.
[0054]
Although the forced air-cooled power converters of the first and second embodiments are power converters installed on the floor of a railway vehicle, the forced air-cooled power converters of the third embodiment are , A power conversion device installed under the floor of a railway vehicle.
[0055]
The system circuit to which this embodiment is applied is the same as that of the first embodiment shown in FIG. 1, and is composed of two groups of power conversion circuits. However, the device housing 11a is installed under the floor of the body 15 of the railway vehicle, and inside the device housing 11a, there is a cooling wind tunnel 10a that is forcibly ventilated by the electric blower 9, and each of the four semiconductor element cooling units is provided. Are mounted in such a manner that the heat radiating portions 14 are housed in the cooling wind tunnel 10a. In the closed part other than the cooling wind tunnel 10a in the device housing 11a, the electric component group 13 of the semiconductor element cooling unit is accommodated, and there are other electric component storage areas 12a, 12b.
[0056]
As in the first embodiment, the four semiconductor element cooling units each include two converter units 7 and two inverter units 8. In the following description, the first group side of the converter circuit 4 and the inverter circuit 5 is referred to as “converter 1” and “inverter 1”, and the second group side is referred to as “converter 2”, as in the previous embodiment. , "Inverter 2".
[0057]
In the cooling wind tunnel 10a, two sets are arranged in series with respect to the flow of the cooling air, and two sets are arranged in parallel. This is also the same as in the first embodiment. The semiconductor element cooling units are combined in different groups. That is, two “converter 1” and “inverter 2” are arranged in series, and two “converter 2” and “inverter 1” are arranged in series on the other side.
[0058]
This is a device installed under the floor of a railway vehicle 15, and a cooling air flows horizontally in a cooling air tunnel 10 a installed in the device housing 11 a. The relationship is the same as that described in the first embodiment, and the same effect can be obtained.
[0059]
As shown in the third embodiment, the present invention can be applied not only to a plate-shaped device installed on the floor of a railway vehicle but also to a device installed under the floor.
[0060]
(Fourth embodiment)
Next, a forced air-cooled power converter according to a fourth embodiment of the present invention will be described with reference to FIGS. FIG. 10 is a circuit diagram of an AC motor drive system for a DC overhead line railway vehicle to which the fourth embodiment is applied. FIG. 11 is a front view of the power conversion device according to the present embodiment (however, a state where a front cover is removed is shown to show the internal device arrangement).
[0061]
As shown in FIG. 10, the power conversion device 3a of the present embodiment includes two groups of inverter circuits 5 for converting a DC power supply taken from the pantograph 1 into an AC power supply, and the inverter circuit 5 is connected to one device housing. It is characterized by being stored in.
[0062]
In the AC motor drive system to which the power converter 3a according to the present embodiment is applied, DC power collected from the pantograph 1 is converted into AC by each inverter circuit 5 and supplied to each AC motor 6 for driving a railway vehicle. Each AC motor 6 is driven by this AC.
[0063]
Each inverter circuit 5 is a three-phase inverter. In the following description, the U phase of the first group of inverter circuits 5 is “U1”, the V phase is “V1”, the W phase is “W1”, and similarly, the phases of the second group are “U2” and “V2”. , "W2".
[0064]
Each of the power conversion circuits composed of these two groups of inverter circuits 5 can be operated independently. In the event of a failure, only the group in which the failure occurred is separated from the system, and the remaining groups are operated. Can be continued.
[0065]
Next, the forced air cooling operation of the power converter 3a having such a circuit configuration will be described with reference to FIG. A cooling wind tunnel 10 is provided in the device housing 11, and the inside of the cooling wind tunnel 10 is forcibly ventilated by the electric blower 9.
[0066]
The semiconductor element cooling unit has a configuration in which the U, V, and W phases of the inverter circuit 5 are grouped for each phase, and three inverter circuits 5 for one group and six phase unit units 16 for two groups are provided. Are housed in a single device housing 11.
[0067]
The arrangement of these phase unit units 16 is such that three units are arranged in series with respect to the flow of the cooling air, and two sets are arranged in parallel. In the three combinations arranged vertically in series, not only the phase unit units 16 of one group of the inverter circuit 5 are arranged but also “U1”, “V2”, “W1” and “U2” as shown in FIG. , "V1", "W2", the combination of the V-phase unit units 16 is alternated with the other group.
[0068]
With such an arrangement configuration of the phase unit units 16, when the first group is disconnected from the system due to a failure, the three phase unit units 16 constituting the second group of inverter circuits 5 that continue to operate are The arrangement is distributed in parallel with the flow of the cooling air, and the cooling air can be used effectively. As a result, the same effects as those described in the first and second embodiments can be obtained.
[0069]
In the present embodiment, in addition to the arrangement shown in FIG. 11, a combination in which the U-phase unit is replaced with that of another unit group, or the W-phase unit is replaced by another unit It is also possible to use a combination in which the locations of the units of the group are replaced with those of the units, and the same effect can be obtained.
[0070]
Next, a fifth embodiment of the present invention will be described with reference to FIG. The forced air cooling type power converter according to the fifth embodiment has a circuit configuration similar to that of the fourth embodiment shown in FIG. 10, but a phase unit constituting each group of inverter circuits 5. The arrangement of 16 is different from that of the fourth embodiment.
[0071]
That is, as shown in FIG. 12, a first group of inverter circuits 5 is provided on the lower side of a semiconductor element cooling unit group in which three units are arranged in series in the direction of the flow of the cooling air, and two units are arranged in parallel. "U2", "V2", which constitutes the second group of inverter circuits 5 by arranging three phase unit units 16 of "U1", "V1", and "W1" over two rows and constituting the second group of inverter circuits 5 on the upper side , “W2” are also arranged in two rows. Even in the arrangement of the fifth embodiment, the same effects as those of the arrangement of the fourth embodiment can be obtained.
[0072]
As described above, the same effect can be obtained by combining a plurality of semiconductor element cooling units arranged in series in the flow of the cooling air with units constituting different power conversion circuits.
[0073]
【The invention's effect】
As described above, according to the present invention, even if one of a plurality of groups of independently operable power conversion circuits is disconnected from the system due to a failure, the remaining group of semiconductor elements that are continuously operated The cooling air always hits the cooling unit, so that the cooling can be effectively performed without wasting and the temperature rise can be reduced.
[0074]
Further, even if the heat loss is increased as compared with the normal operation due to the increase in current, the cooling air having substantially the same temperature as the outside air always hits the semiconductor element cooling units in the continuously operating group, thereby increasing the cooling capacity for the unit. It is possible to reduce the difference in the temperature rise of each semiconductor element between the normal operation of all groups and the operation of opening a certain group. Sometimes it is not necessary to have a design with extra space, and a well-balanced cooling can be realized. Furthermore, as a result, it is possible to design with an appropriate cooling margin, so that the semiconductor element cooling unit can be downsized and the device can be downsized. Is also possible.
[Brief description of the drawings]
FIG. 1 is a circuit diagram of an AC motor drive system for an AC overhead line railway vehicle to which a forced air cooling type power converter according to a first embodiment of the present invention is applied.
FIG. 2 is a front view of the forced air-cooled power converter according to the first embodiment.
FIG. 3 is a sectional view taken along line BB in FIG. 2;
FIG. 4 is a sectional view taken along line CC in FIG. 3;
FIG. 5 is a front view of a forced air-cooled power converter according to a second embodiment of the present invention.
FIG. 6 is a sectional view taken along line DD in FIG. 5;
FIG. 7 is a sectional view taken along line EE in FIG. 6;
FIG. 8 is a plan view of a forced air-cooled power converter according to a third embodiment of the present invention.
FIG. 9 is a sectional view taken along line FF in FIG. 8;
FIG. 10 is a circuit diagram of an AC motor drive system for a DC overhead line railway vehicle to which a forced air cooling type power converter according to a fourth embodiment of the present invention is applied.
FIG. 11 is a front view of a forced air-cooled power converter according to the fourth embodiment.
FIG. 12 is a front view of a forced air-cooled power converter according to a fifth embodiment of the present invention.
FIG. 13 is a circuit diagram of an AC motor drive system for an AC overhead line railway vehicle to which a conventional power converter is applied.
FIG. 14 is a front view of a conventional forced air cooling type power converter.
FIG. 15 is a sectional view taken along line AA in FIG. 14;
FIG. 16 is a circuit diagram of an AC motor drive system for an AC overhead line railway vehicle to which another conventional forced air cooling type power converter is applied.
[Explanation of symbols]
1 Pantograph
2 Main transformer
3,3a power converter
4 Converter circuit
5 Inverter circuit
6 AC motor
7 Converter unit (as semiconductor element cooling unit)
8 Inverter unit (as semiconductor element cooling unit)
9 Electric blower
10,10a cooling wind tunnel
11, 11a Device housing
14 Heat radiating part
16 Phase unit unit (as semiconductor element cooling unit)

Claims (4)

A forced air-cooled power converter in which a heat radiating portion of a semiconductor element cooling unit is arranged in a cooling wind tunnel forcibly ventilated by an electric blower or the like,
A plurality of groups of independently operable power conversion circuits are housed in a single device housing,
Each group of the power conversion circuit is composed of a plurality of the semiconductor element cooling units,
Arranging the plurality of semiconductor element cooling units in the cooling wind tunnel such that their heat radiating portions are arranged in a plurality of rows with respect to the flow of the cooling air,
The plurality of semiconductor element cooling units arranged in series along the flow of the cooling air in the cooling wind tunnel include semiconductor element cooling units constituting at least two groups of the power conversion circuits. Forced air-cooled power converter. A forced air-cooled power converter in which a heat radiating portion of a semiconductor element cooling unit is arranged in a cooling wind tunnel forcibly ventilated by an electric blower or the like,
A plurality of groups of power conversion circuits in which a converter circuit for converting an AC power supply to DC and an inverter circuit for converting converted DC to AC again are housed in a single device housing,
The semiconductor element cooling unit is configured for each of a group of converter circuits that can be operated independently or for each of the divided phases,
The semiconductor element cooling unit is configured for each of a group of inverter circuits that can be operated independently or for each divided phase thereof,
A forced air cooling type power supply, wherein the semiconductor element cooling unit on the converter circuit side and the semiconductor element cooling unit on the inverter circuit side belonging to different groups are arranged in series along the flow of cooling air in the cooling wind tunnel. Conversion device. A forced air-cooled power converter in which a heat radiating portion of a semiconductor element cooling unit is arranged in a cooling wind tunnel forcibly ventilated by an electric blower or the like,
A plurality of groups of power conversion circuits in which a converter circuit for converting an AC power supply to DC and an inverter circuit for converting converted DC to AC again are housed in a single device housing,
The semiconductor element cooling unit is configured for each of a group of converter circuits that can be operated independently or for each of the divided phases,
The semiconductor element cooling unit is configured for each of a group of inverter circuits that can be operated independently or for each divided phase thereof,
The semiconductor element cooling units constituting different groups of converter circuits are arranged in series along the flow of the cooling air in the cooling wind tunnel, and the semiconductor element cooling units constituting different groups of inverter circuits are separated from each other by the cooling air. A forced air-cooled power converter, which is arranged in series along the flow. A forced air-cooled power converter in which a heat radiating portion of a semiconductor element cooling unit is arranged in a cooling wind tunnel forcibly ventilated by an electric blower or the like,
A plurality of groups of inverter circuits for converting DC power to AC are housed in a single device housing,
Configuring the semiconductor element cooling unit for each phase constituting an inverter circuit of each group operable independently,
A forced-air-cooled power converter, wherein the semiconductor element cooling units belonging to different groups of inverter circuits are arranged in series along a flow of cooling air.

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