JP2004201500A - Power conversion apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the power conversion apparatus which realizes miniaturization and lightening of weight, while making a cooling configuration in size of necessary minimum limit, by making the leveling of allotment for a heat loss applied to a plurality of coolers. <P>SOLUTION: In the power conversion apparatus for storing a plurality of groups of power conversion circuits converting AC power into DC power or DC power into AC power by switching operation of a plurality of semiconductor elements, the semiconductor devices (8), connected in parallel to constitute a plurality of groups of the power conversion circuits, each being capable of independent operation are mounted in a common cooling unit (30) having a heat receiving part (31) and a heat-radiating part (32). <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to a power conversion device containing a plurality of sets of power conversion circuits.

  There are various types of power conversion circuits composed of semiconductor elements, and there are inverter circuits for converting DC to AC and converter circuits for converting AC to DC. The inverter circuit includes a variable voltage variable frequency inverter (hereinafter, referred to as a VVVF inverter) circuit for variably controlling the voltage and frequency of the AC output, and a constant voltage constant frequency inverter for controlling the voltage and frequency of the AC output to be constant. (Hereinafter, referred to as CVCF inverter), and these constitute a power conversion system.

  Taking a railway vehicle system as an example, a power conversion device in which a plurality of groups of VVVF inverter circuits for controlling an induction motor for driving a vehicle are housed for each control unit is attached to the vehicle. For example, a power converter in which a VVVF inverter circuit for individually controlling one induction motor for one vehicle, that is, four groups, is widely used. This power conversion device is a system having excellent redundancy such that operation can be continued by disconnecting a failed VVVF inverter circuit in the event of a failure. In addition, a CVCF inverter circuit is used in the auxiliary power supply system. Recently, a plurality of groups of VVVF inverter circuits and CVCF inverter circuits are housed in one power conversion device, and when the CVCF inverter circuit fails, the VVVF inverter circuit is used. There is also a system in which a group of circuits is switched to a CVCF inverter circuit to improve the redundancy as a railway vehicle system.

  AC electric vehicles generally use a system that drives an induction motor by controlling the output voltage and output frequency by combining a converter circuit that converts AC to DC and an inverter circuit that converts DC to AC. I have. Conventionally, these various power conversion systems have been installed in a vehicle as separate devices, but recently, installation space has been reduced, and devices have been consolidated to reduce the number of wirings connecting the devices. There is a tendency to accommodate various conversion circuits in one power conversion device. In a power conversion device in which a plurality of groups of power conversion circuits are housed in one device, for example, a device is provided for each electrical function such as a converter conversion circuit unit, an inverter conversion circuit unit, a control board unit, and a control power supply unit. In many cases, they are mounted in areas that define the inside, and each is configured as a unit.

  In a conversion circuit section using a semiconductor element, a cooler for discharging heat generated by the semiconductor element (hereinafter, referred to as loss heat) to the outside of the apparatus and using the semiconductor element at a temperature equal to or lower than an allowable value is required. The basic structure of the cooler consists of a heat receiving part to which the semiconductor element is attached and a heat radiating part that dissipates heat to the outside air.The heat receiving part is placed in the closed chamber of the power converter, and the heat radiating part is an open chamber that communicates with the outside air. Placed on a piece. The open room part where the heat radiating part is placed is slightly projected from the housing of the device to make it easier to dissipate heat to the outside air, as a cooling wind tunnel where cooling air is forced to flow by an electric blower, or installed under the floor of a railway vehicle The device is provided at a location that is likely to receive traveling wind that flows relatively on the outer surface of the device when the vehicle is traveling.

  A conventional power converter that houses a plurality of groups of conversion circuits as described above will be described below. FIG. 11 is a circuit diagram of a power conversion device for driving a railway vehicle. FIG. 11 is a circuit diagram of a power conversion device containing one group of motors, that is, four groups of VVVF inverter circuits that individually control four induction motors. is there. In FIG. 1, a positive input terminal of a VVVF inverter circuit 4 is connected to a pantograph 1 via a circuit breaker 2 and a filter reactor 3, and a negative input terminal thereof is grounded through wheels. A filter capacitor 5 is connected between the positive and negative input terminals of the VVVF inverter circuit 4, and an output motor is connected to an induction motor 6. As described above, the four groups of circuits are connected in parallel, and the four groups of VVVF inverter circuits 4 individually control the four induction motors 6 for one vehicle. Among the electric components shown in this circuit diagram, four groups of VVVF inverter circuits 4 and filter capacitors 5 are housed in one box to constitute a power conversion device 7A, and the other electric components are used alone or separately. These are housed in a box of the device, and are electrically connected to each other by a vehicle body wiring to constitute a railway vehicle drive system.

  FIG. 12A is a perspective view showing a state in which the above-described power conversion device 7A is mounted under the floor of a railway vehicle, and FIG. 12B is a side view seen from the traveling direction of the vehicle. 13) is a plan view of the power conversion device 7A viewed from the direction in which the power conversion device is attached to the bottom surface of the vehicle, and FIG. 13B is a bottom view thereof. In each of these figures, the power converter 7A includes four coolers 9 for cooling a semiconductor element (for example, a IGBT in which snubber diodes are connected in parallel) 8. One cooler 9 accommodates a group of semiconductor elements 8 of the VVVF inverter circuit collectively, and the filter capacitor 5 is accommodated in one box.

  Note that the one group of VVVF inverter circuits is a three-phase inverter circuit of U, V, and W. In some cases, one phase of each of the four groups of VVVF inverter circuits is collectively attached to one cooler 9, In some cases, three of them are arranged. This is because if the semiconductor elements 8 for one phase constituting the VVVF inverter circuits of each group are arranged collectively, the peripheral components can be easily arranged and electrically connected, and the power converter 7A can be functionally divided. As a result, a unit configuration for each function becomes possible, so that the cooler 9 is also formed by such a group of conversion circuits.

  The cooling unit shown in FIGS. 11 to 13 is provided with a cooling unit including a heat receiving unit to which the semiconductor element 8 is attached and a heat radiating unit for dissipating heat to the outside air. The heat radiating part is placed in an open room part that communicates with the outside air. The open chamber part where the heat radiating part is placed is slightly protruded from the housing so that heat can be easily dissipated to the outside air, and furthermore, it is configured to be easy to receive running wind that relatively flows on the outer surface of the device when the vehicle is running .

  During operation of the power converter 7A, heat loss is generated from the semiconductor element 8, which is transmitted by heat conduction to the heat receiving portion of the cooling unit mounted in the cooler 9, and dissipates heat from the heat radiating portion of the cooling unit to the outside air. The semiconductor element 8 is cooled, and can be used at a temperature lower than the allowable temperature.

  By the way, during the operation in which all the four groups of VVVF inverters constituting the power converter 7A are healthy, the four groups of VVVF inverters are individually controlled, but the heat loss generated from each group is substantially equal. In each of the coolers 9, substantially the same heat loss is dissipated. However, when the power conversion device 7A fails, the group of failed VVVF inverter circuits is separated by the circuit breaker 2 and the system is provided with redundancy so that operation can be continued with the remaining group of VVVF inverter circuits. This is a feature of the power converter 7A.

  When the operation of the remaining three groups of VVVF inverter circuits is continued due to the failure of one group of VVVF inverter circuits, all of the four groups of VVVF inverter circuits are included in the semiconductor element 8 constituting the VVVF inverter circuit that continues the operation. It is necessary to pass a large current compared to when it is healthy. For this reason, the heat loss generated by the semiconductor element 8 is larger than in the normal state, and the heat dissipation capability of the cooler 9 is required to be higher than that in the normal state. Therefore, each of the coolers 9 can dissipate not only heat loss when all of the four groups of VVVF inverter circuits are operating properly, but also heat loss at the time of failure which is increased compared to the normal state. It is necessary to secure the ability. In other words, each cooler 9 has sufficient cooling capacity at the time of soundness, and at the time of failure, the cooler 9 to which the semiconductor element 8 of the VVVF inverter circuit separated due to the failure is attached does not perform any heat radiation processing and operates. Only the cooler 9 to which the semiconductor element 8 of the remaining VVVF inverter circuit is mounted performs the heat radiation processing.

  As a result, the coolers 9 must be individually increased in size, which has been a factor that hinders the reduction in size and weight of the power converter 7A.

  Another conventional power conversion device containing a plurality of groups of power conversion circuits will be described below. FIG. 14 is a circuit diagram of a power conversion device 7B in which two groups of VVVF inverter circuits for driving a vehicle and one group of CVCF inverter circuits 17 for a vehicle power supply are configured as the same system. Elements have the same reference characters allotted, and description thereof will not be repeated. Here, one of the two groups of VVVF inverter circuits is configured to be able to operate by switching from the VVVF inverter circuit to the CVCF inverter circuit when the CVCF inverter circuit fails, and to secure the vehicle power supply by securing the vehicle power supply. This is to increase the redundancy of the system.

  FIG. 15A is a perspective view showing a state in which the power converter shown in FIG. 14 is mounted under the floor of a railway vehicle, and FIG. 14B is a side view seen from the traveling direction of the vehicle. 16A is a plan view of the power conversion device 7 as viewed from a direction in which the power conversion device is attached to the bottom surface of the vehicle, and FIG. 16B is a bottom view thereof. This is provided with two coolers 9 for the VVVF inverter circuit and one cooler 9 for the CVCF inverter circuit, as in the conventional device shown in FIGS. Have been.

  Here, although details of the switching operation are omitted, when the CVCF inverter circuit fails, the cooler 9 to which the semiconductor element 8 of the CVCF inverter circuit is attached does not perform the heat radiation processing, and the VVVF inverter circuit is not used. The two coolers that have been performing the heat radiation processing work for the VVVF inverter circuit and the CVCF inverter circuit. The cooler 9 to which the group of semiconductor elements 8 that continue to operate as a VVVF inverter circuit is required to have a higher heat radiation capacity than in the normal state, as in the conventional apparatus shown in FIGS. It is necessary to make the outer shape of the cooler 9 suitable for the heat radiation capacity. Further, it is required that the VVVF inverter circuit and the CVCF inverter circuit be configured in common, but the heat loss generated from the semiconductor element 8 is not always equal between the VVVF inverter circuit and the CVCF inverter circuit depending on the applied vehicle system. Nevertheless, since the coolers 9 having the same shape are used, it is difficult to say that all the coolers 9 take charge of the heat radiation process even during the normal operation. This is a factor that hinders the small size and light weight of 7B.

  Further, another conventional power conversion device accommodating a plurality of groups of conversion circuits will be described below with reference to FIGS. FIG. 17 is a circuit diagram of the power conversion device 7C. The converter circuit 18 for substantially two sets of converting an alternating current into a direct current by using an alternating current as an input and a direct current converted by the converter circuit 18 into a variable voltage, An inverter circuit 19 that converts the alternating current into a variable-frequency controlled alternating current is configured to drive the four induction motors 6 of the railway vehicle. 18A is a plan view of the power conversion device 7C as viewed from the side where the power conversion device 7C is mounted on the vehicle bottom, FIG. 18B is a side view of the power conversion device 7C as viewed from the traveling direction of the vehicle, and FIG. 3 is a sectional view taken along the line AA of FIG. The power conversion device 7C includes two cooling units 9a and 9b. Among them, the cooling unit 9a includes a semiconductor element 8 that forms a converter circuit, and the cooling unit 9b includes a semiconductor element 8 that forms an inverter circuit. It is attached and is configured to be forcedly blown by the electric blower 14 to dissipate heat.

  The heat loss generated by each conversion circuit does not increase and decrease at the same timing, but increases and decreases at different timings. When a railway vehicle is running at a relatively low speed, that is, during acceleration / deceleration, the heat loss generated by the inverter circuit is large, and when the vehicle is operating at a relatively high speed, the heat loss generated by the converter circuit is large. Therefore, when the heat dissipation from the cooling unit 9a is large, the heat dissipation from the cooling unit 9b is relatively small, and when the heat dissipation from the cooling unit 9b is large, the heat dissipation from the cooling unit 9a is relatively small. Will be small. In addition, since the heat radiation side of the cooling units 9a and 9b is cooled by forced air in the present apparatus, the thermal time constant is small, and the size of each cooling unit 9a and 9b is determined by the maximum heat loss. I will. That is, since the temperature of the cooler follows in a short time in accordance with the increase or decrease in the heat loss, when the heat loss changes with time, it is necessary to enable cooling with the maximum heat loss in a short time.

  In the power converter shown in FIGS. 17 to 19, similarly to the power converter shown in FIGS. 11 to 13 or FIGS. In many cases, the heat load applied to the vessel becomes unbalanced, and as a result, the size of the cooler becomes large, which hinders the reduction in size and weight of the apparatus.

  The present invention has been made in order to solve the above-mentioned problem, and makes it possible to provide a cooling structure having a minimum necessary size by leveling the sharing of the loss heat applied to a plurality of coolers. It is another object of the present invention to provide a power conversion device that can be reduced in size and weight.

In order to achieve the above object, the invention according to claim 1 is:
In a power converter that houses a plurality of groups of power conversion circuits that convert AC to DC or DC to AC by switching operation of a plurality of semiconductor elements,
Semiconductor devices that are connected in parallel and constitute a plurality of groups of power conversion circuits each of which can operate independently are mounted on a common cooling unit having a heat receiving unit and a heat radiating unit.

The invention according to claim 2 is
In a power converter including a plurality of groups of inverter circuits, each output of which is connected to a different load by a switching operation of a plurality of semiconductor elements,
Semiconductor devices that are connected in parallel and constitute a plurality of groups of inverter circuits that can operate independently are attached to a common cooling unit having a heat receiving unit and a heat radiating unit.

The invention according to claim 3 is:
A plurality of groups of variable voltage variable frequency inverter circuits for converting direct current to variable voltage and variable frequency alternating current by switching operation of a plurality of semiconductor elements, and a constant voltage constant frequency inverter circuit for converting direct current to constant voltage and constant frequency alternating current; Are connected in parallel and housed,
A semiconductor device, which is connected in parallel and forms each inverter circuit that can operate independently, is attached to a common cooling unit having a heat receiving unit and a heat radiating unit.

  According to a fourth aspect of the present invention, in the power conversion device according to any one of the first to third aspects, a plurality of semiconductor elements are divided for each phase or for the positive side and the negative side, and the divided semiconductor element group Are attached to coolers provided corresponding to these semiconductor element groups.

  According to a fifth aspect of the present invention, in the power conversion device according to any one of the first to fourth aspects, heat for mutually transporting heat of the mounting portions of the semiconductor elements of different circuits to the heat receiving portion of the cooling unit is provided. It is characterized by having a pipe.

  According to a sixth aspect of the present invention, in the power conversion device according to any one of the first to fourth aspects, the heat receiving portion of the cooling unit has a box shape, and a refrigerant is sealed therein.

  According to a seventh aspect of the present invention, in the power converter according to any one of the first to fourth aspects, the heat receiving portion of the cooling unit is configured such that a semiconductor element can be attached to a front surface and a back surface, and one surface is provided. A semiconductor element group forming one group of power conversion circuits is mounted, and a semiconductor element group forming another group of power conversion circuits is mounted on the other surface.

  According to an eighth aspect of the present invention, in the power conversion device according to any one of the first to fourth aspects, semiconductor element groups of different power conversion circuits are alternately arranged for each phase on one surface of the cooling unit. It is characterized by the following.

  According to a ninth aspect of the present invention, in the power converter according to the eighth aspect, when the height of the semiconductor element is different for each power conversion circuit, the height of the electrical connection terminals of the semiconductor element is equal. In addition, a step is provided on the semiconductor element mounting surface of the cooling unit.

The invention according to claim 10 is
In a power converter that is connected to different loads, and accommodates a plurality of groups of power conversion circuits that convert AC to DC or DC to AC by switching operation of a plurality of semiconductor elements,
Semiconductor devices connected in parallel and constituting a plurality of groups of power conversion circuits are mounted on a common cooling unit having a heat receiving section and a heat radiating section.

The invention according to claim 11 is
In a power converter having a plurality of groups of inverter circuits each connected to a different load and each output connected to a different load by a switching operation of a plurality of semiconductor elements,
Semiconductor devices connected in parallel and constituting a plurality of groups of inverter circuits are mounted on a common cooling unit having a heat receiving portion and a heat radiating portion.

The invention according to claim 12 is
A plurality of groups of variable voltage variable frequency inverter circuits for converting direct current to variable voltage and variable frequency alternating current by switching operation of a plurality of semiconductor elements, and a constant voltage constant frequency inverter circuit for converting direct current to constant voltage and constant frequency alternating current; Are connected in parallel and housed,
The semiconductor device constituting each inverter circuit connected in parallel and connected to a different load is attached to a common cooling unit having a heat receiving unit and a heat radiating unit.

  According to a thirteenth aspect of the present invention, in the power converter according to any one of the tenth to twelfth aspects, a plurality of semiconductor elements are divided for each phase or for the positive side and the negative side, and the divided semiconductor element group Are attached to coolers provided corresponding to these semiconductor element groups.

  According to a fourteenth aspect of the present invention, in the power conversion device according to any one of the tenth to thirteenth aspects, heat for transporting heat of the mounting portions of the semiconductor elements of different circuits to each other to the heat receiving portion of the cooling unit. It is characterized by having a pipe.

  According to a fifteenth aspect of the present invention, in the power converter according to any one of the tenth to thirteenth aspects, the heat receiving portion of the cooling unit has a box shape, and a refrigerant is sealed therein.

  According to a sixteenth aspect of the present invention, in the power converter according to any one of the tenth to thirteenth aspects, the heat receiving portion of the cooling unit is configured such that a semiconductor element can be attached to a front surface and a back surface, and one side has a heat receiving portion. A semiconductor element group forming one group of power conversion circuits is mounted, and a semiconductor element group forming another group of power conversion circuits is mounted on the other surface.

  According to a seventeenth aspect of the present invention, in the power converter according to any one of the tenth to thirteenth aspects, semiconductor element groups of different power conversion circuits are alternately arranged for each phase on one surface of the cooling unit. It is characterized by the following.

  According to an eighteenth aspect of the present invention, in the power converter according to the seventeenth aspect, when the height of the semiconductor element is different for each power conversion circuit, the height of the electrical connection terminals of the semiconductor element is equal. In addition, a step is provided on the semiconductor element mounting surface of the cooling unit.

  According to the present invention, as described above, the distribution of heat loss applied to a plurality of coolers is leveled, thereby enabling a cooling configuration having a minimum necessary size, and at the same time, small and lightweight. It is possible to provide a power conversion device capable of realizing power conversion.

  Hereinafter, the present invention will be described in detail based on preferred embodiments shown in the drawings.

  FIG. 1 shows a configuration of a first embodiment of a power conversion device according to the present invention, in which (a) is a plan view seen from a direction in which the power conversion device is mounted on a bottom surface of a vehicle, and (b) is a bottom view thereof. It is. The power converter 7D shown here is applied to four groups of VVVF inverter circuits whose circuit diagram is shown in FIG. 11 as a conventional device, and the components of each group include three coolers 9U, 9V, and 9W. It is configured to be stored separately for each phase. That is, of the four groups of VVVF inverter circuits, the U-phase semiconductor elements 8 of each group are housed in the cooler 9U, the V-phase semiconductor elements 8 of each group are housed in the cooler 9V, and the W-phase Semiconductor element 8 is stored in cooler 9W. The power converter 7D further houses four control units 15, each of which is configured to individually control four groups of VVVF inverter circuits.

  Here, when the four groups of VVVF inverter circuits are operating normally, the heat loss generated from the semiconductor elements 8 is released to the outside air by the coolers 9U, 9V, 9W, and all the semiconductor elements 8 are below the allowable temperature. Is cooled. At this time, substantially the same amount of heat loss is applied to each of the coolers 9U, 9V, and 9W, and the semiconductor element 8 is cooled below the allowable temperature.

  On the other hand, when one of the four groups of VVVF inverter circuits is out of order and the one group is operated separately from the system due to a failure, a current larger than usual is supplied to the remaining VVVF inverter circuits that continue to operate. It is necessary to prevent performance degradation of the system. At this time, the heat loss of the semiconductor element 8 constituting the VVVF inverter circuit increases. However, the heat loss is applied to all three coolers 9U, 9V, 9W almost equally, and the coolers 9U, 9V, 9W are originally provided with the ability to cool the heat loss of four groups. Therefore, even if the heat loss of the three groups increases more than usual, sufficient cooling is performed.

  Thus, not only during normal operation when all the VVVF inverter circuits are in a healthy state, but also when the one group of VVVF inverter circuits is disconnected due to a failure and the remaining group of VVVF inverter circuits is operated, the efficiency of the plurality of coolers as a whole is improved. Demonstrate good cooling performance. Generally, the ratio of the size of the cooler to the outer shape of the power converter is large, and according to the present invention, the cooling system efficiently performs the cooling operation. It is possible to reduce the size and weight of the entire conversion device.

  FIGS. 2A and 2B show the configuration of a second embodiment of the power converter according to the present invention, wherein FIG. 2A is a plan view seen from a direction in which the power converter is mounted on the bottom surface of a vehicle, and FIG. 2B is a bottom view thereof. . In the power converter 7E shown here, the semiconductor elements 8 constituting the two groups of VVVF inverter circuits and the one group of CVCF inverter circuits shown in the circuit diagram of FIG. 14 are separately housed for each phase. That is, of the three coolers 9U, 9V, and 9W, the cooler 9U includes the semiconductor elements 8 for two groups of the U phase of the VVVF inverter circuit and the semiconductor elements 8 for one group of the U phase of the CVCF inverter circuit. Are stored in the cooler 9V, and the semiconductor elements 8 for two groups of the V phase of the VVVF inverter circuit and the semiconductor elements 8 for one group of the V phase of the CVCF inverter circuit are stored in the cooler 9W, and the VVVF inverter is stored in the cooler 9W. Two groups of semiconductor elements 8 of the W phase of the circuit and one group of semiconductor elements 8 of the W phase of the CVCF inverter circuit are housed. The power converter 7E also houses three control units 15, and is configured to individually control two groups of VVVF inverter circuits and one group of CVCF inverter circuits.

  Here, when all the circuits of the two groups of VVVF inverter circuits and one group of CVCF inverter circuits are in a healthy state, substantially the same amount of heat loss is applied to each of the coolers 9U, 9V and 9W, and all the semiconductor elements The heat loss generated from 8 is released to the outside air by coolers 9U, 9V, and 9W, and semiconductor element 8 is cooled to below the allowable temperature.

  On the other hand, if the CVCF inverter circuit fails, one group of VVVF inverter circuits is switched to the CVCF inverter circuit. At this time, it is necessary to supply a larger current than usual to the remaining one group of VVVF inverter circuits that continue the operation to prevent the system performance from deteriorating. Therefore, it is necessary to prevent the performance of the system from deteriorating by flowing a larger current than usual in the remaining VVVF inverter circuit that continues the operation. As a result, the heat loss generated from one semiconductor element 8 becomes larger than that in the normal operation. However, all three coolers 9U, 9V, and 9W are almost uniformly loaded with the loss heat, and the coolers 9U, 9V, and 9W originally have two groups of VVVF inverter circuits and one group. The CVCF inverter circuit has a capability of dissipating the heat loss of each semiconductor element 8, so that even if the heat loss of one group that continues the operation increases more than usual, sufficient cooling is performed.

  Thus, according to the second embodiment, even if one group of CVCF inverter circuits fails, all the coolers function to dissipate the heat loss of the semiconductor elements, and the cooling system is efficient and efficient. A simple cooling system can be realized. As a result, the size of the entire cooler can be reduced, and the size and weight of the entire power converter can be reduced.

  3A and 3B show the configuration of a third embodiment of the power converter according to the present invention, in which FIG. 3A is a plan view seen from the direction in which the power converter is mounted on the bottom surface of the vehicle, and FIG. It is the side view seen from the direction. The power conversion device 7F shown here is a conventional device applied to the device shown in the circuit diagram of FIG. 17, and in the drawing, the same elements as those of FIG. 18 are denoted by the same reference numerals and description thereof is omitted. I do. Here, the power conversion device 7F includes a cooling unit 9c mounted on a blowing path of the electric blower 14. On the cooling unit 9c, the semiconductor elements 8 constituting the inverter circuit are accommodated for each of U, V, and W phases, and are mounted by being divided into three in the width direction of the air flow path, so that the semiconductor elements 8 constituting the converter circuit are correct. It is divided into a side and a negative side, and is mounted on the rear of the semiconductor element 8 constituting the inverter circuit when viewed from the electric blower 14, divided into two parts in the width direction of the blower path.

  The operation of this embodiment will be described below. At low speed, that is, during acceleration / deceleration, heat loss mainly occurs from the semiconductor element 8 of the inverter circuit, and heat loss from the converter circuit is small. During high-speed operation, heat loss mainly occurs from the semiconductor element 8 of the converter circuit, and heat loss from the semiconductor element of the inverter circuit is small. As described above, the heat loss generated by the converter circuit and the heat loss generated by the inverter circuit do not increase and decrease at the same timing, but increase and decrease at different timings. In the cooling unit, the converter circuit and the inverter circuit are equally divided and arranged in the width direction, respectively, and are arranged before and after the blowing path, so that almost equal heat loss can be processed in all the speed ranges.

  In this way, by arranging the converter circuit and the inverter circuit that generate different heat loss depending on the speed range in the front-rear direction of the airflow path, the cooling unit is loaded with substantially uniform heat loss in each speed range, The cooling performance is efficiently exhibited as a whole, and an efficient cooling system with no waste in the cooling system can be realized.

  Thus, according to the third embodiment as well, the size of the entire cooler can be reduced, and the size and weight of the entire power converter can be reduced.

FIG. 4 shows a fourth embodiment of the power converter according to the present invention, in which each semiconductor element 8 of the four groups of inverter circuits 4 shown in FIG. 11 is attached to a common cooling unit. It is a top view which shows a detailed structure, (b) is the sectional view. In each of these drawings, the cooling unit 30 includes a heat receiving portion 31 having a flat surface, and a heat radiating portion 32 formed of a number of heat radiating fins formed on the back surface. The semiconductor elements 8 constituting four groups of inverter circuits are mounted on the surface of the heat receiving unit 31 in two rows and two columns for each group. Further, four heat pipes 33 are embedded in the heat receiving portion 31 in parallel at appropriate intervals so as to equalize the temperature of the heat receiving portion 31.
Here, the heat pipe 33 buried in the heat receiving section 31 of the cooling unit 30 has an effect of thermally leveling the entire heat receiving section 31, but as described in the first and second embodiments, the heat pipe 33 may fail. Since the heat is also transferred to the mounting portion of the semiconductor element to which the lost heat is no longer applied due to the separation, the lost heat of the semiconductor element 8 which continues the operation is transferred to the entire heat receiving portion 31 to be cooled.

  Thus, the heat pipe 33 buried in the heat receiving section 31 of the cooling unit 30 equalizes the temperature of the heat receiving section 31 during the normal operation as well as the operation at the time of failure. The heat loss of the semiconductor element 8 of the circuit is dissipated, and an efficient cooling system with no waste in the cooling system can be realized. Thus, the size of the entire cooler can be reduced, and the size and weight of the entire power conversion device can be reduced.

  FIG. 5 shows a fifth embodiment of the power converter according to the present invention, in which each semiconductor element 8 of the four groups of inverter circuits 4 shown in FIG. 11 is attached to a common cooling unit. It is a top view which shows a detailed structure, (b) is the sectional view. In each of these drawings, a cooling unit 40 has a flat box-shaped heat receiving portion 41 and a heat radiating portion in which a large number of cooling fins are continuously formed on one outer peripheral portion obtained by dividing the heat receiving portion 41 into substantially half. 42, and the semiconductor elements 8 constituting four groups of inverter circuits are mounted on the other half surface in two rows and two columns for each group. A refrigerant 43 made of florinate or water is sealed in the heat receiving section 41.

  The cooler unit 40 is a boiling cooling type, and the temperature of the mounting surface of the semiconductor element 8 can be efficiently leveled by the refrigerant 43. Thus, the size of the entire cooler can be reduced, and the size and weight of the entire power conversion device can be reduced.

  FIG. 6 shows a sixth embodiment of the power converter according to the present invention, and is a configuration example of a cooling unit in which the semiconductor elements 8 constituting the four groups of inverter circuits shown in FIG. 11 are commonly mounted. It is a top view which shows a detailed structure, (b) is the sectional view. In each of these figures, a cooling unit 50 has a flat box-shaped heat receiving portion 51 and a heat radiating portion 52 in which a large number of cooling fins are continuously formed on one outer peripheral portion obtained by dividing the heat receiving portion 51 into substantially half. And six semiconductor elements 8 (corresponding to those constituting the two groups of inverters shown in FIG. 11) are mounted in two rows and three columns on the other half surface, and six semiconductor elements 8 are also mounted on the rear surface. (Corresponding to those constituting the two groups of inverters shown in FIG. 11) are mounted in the same manner as the front surface. Further, a refrigerant 53 is sealed inside the heat receiving section 51.

  The cooling unit 50 is also a boiling cooling type, and the temperature of the mounting surface of the semiconductor element 8 can be efficiently leveled by the refrigerant 53. In this case, since the semiconductor elements 8 are dispersedly arranged on the front surface and the rear surface of the heat receiving portion 51, the cooling efficiency is further improved as compared with the cooling unit 40 shown in FIG. The effect of simplifying the arrangement of the conductors to be connected is also obtained.

  FIG. 7 shows a seventh embodiment of the power converter according to the present invention, in which each of the semiconductor elements 8 of the four groups of inverter circuits 4 shown in FIG. 11 is attached to a common cooling unit. 1 is a plan view showing a detailed configuration, and FIG. 1B is a cross-sectional view thereof. In each of these drawings, a cooling unit 60 has a flat box-shaped heat receiving portion 61 and a heat radiating portion in which a large number of cooling fins are continuously formed on one outer peripheral portion obtained by dividing the heat receiving portion 61 into substantially half. 62, and the semiconductor elements 8a and 8b of each phase are mounted on the surface of the other half in two rows and six columns in the width direction of the heat receiving portion 61, that is, for each phase. A refrigerant 63 is sealed inside the heat receiving section 61.

  In this embodiment, of the four groups of inverter circuits shown in FIG. 11, two groups of inverter circuits and the remaining inverter circuits correspond to two types of semiconductor elements having different types or ratings. The semiconductor elements 8a of the inverter circuit are arranged at intervals in the order of the U phase, the V phase, and the W phase, and the semiconductor elements 8b of the other two groups of inverter circuits are arranged for the U phase, the V phase, and the W phase. Are arranged adjacent to the semiconductor element 8a.

  In this cooling unit 60 as well, the temperature of the heat receiving portion 61 at the time of failure is leveled without any bias, and a more efficient cooling system than the cooler shown in FIG. 5 or 6 can be realized.

  FIG. 8 shows an eighth embodiment of the power converter according to the present invention, in which each semiconductor element 8 of the four groups of inverter circuits 4 shown in FIG. 11 is attached to a common cooling unit. 1 is a plan view showing a detailed configuration, and FIG. 1B is a side view thereof. In each of these figures, a cooling unit 70 has a flat box-shaped heat receiving portion 71 and a heat radiating portion in which a large number of cooling fins are continuously formed on one outer peripheral portion obtained by dividing the heat receiving portion 71 into substantially half. 72, and the semiconductor elements 8a and 8b of each phase described above are arranged in two rows and six columns in the width direction of the heat receiving portion 61 on the other half surface. A refrigerant 63 is sealed inside the heat receiving section 61.

  The cooling unit 70 shown here is arranged such that the mounting surface of the semiconductor element 8a is changed by the height difference ΔH in order to align the height positions when the heights of the electrical connection terminals of the semiconductor element are different from each other. Irregularities are formed on the surface of the heat receiving section 71 so as to be lower than that. As a result, the heights of the electrical connection terminals of the semiconductor elements 8a and 8b are made uniform, and they can be directly connected by the linear connection conductor 21, so that electrical connection between the semiconductor elements is facilitated and the configuration is simplified. The effect of being performed is also obtained.

  FIG. 9 shows a ninth embodiment of the power converter according to the present invention, and particularly shows a modification of the cooling unit constituting the third embodiment shown in FIG. FIG. 2A is a plan view showing a detailed configuration of a cooling unit and a mounting state of a semiconductor element, and FIG. 2B is a side view thereof. Here, the cooling unit 80 includes a flat heat receiving portion 81. The heat receiving portion 81 may have a heat pipe buried therein, or may have a structure in which the heat pipe 81 is formed in a box shape and seals the refrigerant inside. A semiconductor element 8a forming an inverter and a semiconductor element 8b forming a converter are mounted on the front surface of the heat receiving portion 81, and a large number of cooling fins are arranged on the rear surface of the heat receiving portion 81 in parallel in the direction of air flow. A portion 82 is formed.

  The semiconductor element 8a attached to the surface of the heat receiving portion 81 of the cooling unit 80 includes three sets of semiconductor elements U1, U2, and U3 for the U phase and three sets of semiconductors for the V phase, which constitute three groups of inverter circuits. Elements V1, V2, V3 and three sets of semiconductor elements W1, W2, W3 for the W phase are included, and semiconductor element 8b includes three sets of semiconductor elements Q1, Q2, Q3 forming three groups of converter circuits. In.

  These semiconductor elements are, when viewed in a direction in which wind passes through the heat radiating section 82, semiconductor elements U1, U2, U3 for the U phase, semiconductor elements V1, V2, V3 for the V phase, and W phase. Semiconductor elements W1, W2, and W3 are sequentially arranged in a row, and semiconductor elements Q1, Q2, and Q3 of the converter circuit are arranged in a row beside the semiconductor elements W1, W2, and W3. The feature of this embodiment is that the semiconductor elements for the U phase are arranged in the order of U1, U2, U3 in the direction in which the wind flows, whereas the semiconductor elements for the V phase are arranged in the order of V3, V1, V2. The point is that the semiconductor elements for the W phase are arranged in the order of W2, W3, and W1.

  As is well known, the temperature of the cooling air gradually increases due to heat loss of the semiconductor element while the cooling air passes between the cooling fins 82 of the cooling unit 80. Therefore, the cooling efficiency of the semiconductor element arranged upstream is high, and the cooling efficiency of the semiconductor element arranged downstream is low. Therefore, as described above, the temperature rise of the semiconductor elements can be leveled for each group of the inverters by regularly changing the position of the semiconductor elements in each group of the inverters in the direction in which the cooling air passes. An efficient cooling system can be realized.

  Further, when a group of inverters is separated and operated due to a failure, heat loss from the semiconductor elements of the inverter circuit is eliminated, and heat loss of the semiconductor elements of the remaining inverters increases, but there is a margin in cooling capacity. Therefore, a system having excellent redundancy at the time of failure can be configured.

  FIG. 10 shows a tenth embodiment of the power converter according to the present invention, in which an electric blower is arranged in an open chamber portion arranged adjacent to a closed chamber portion, and two sets of cooling units and related units are provided. In this configuration, two sets of peripheral circuits are arranged side by side in the direction in which the wind flows, (a) showing a plan view thereof, and (b) showing a side view thereof. In each of these figures, two sets of cooling units 90a and 90b have the same shape as the cooling unit shown in FIG. 4, and six semiconductor elements 8a are mounted on the surface of the heat receiving portion of the cooling unit 90a. Six semiconductor elements 8b are mounted on the surface of the heat receiving portion 90b. These cooling units 90a and 90b are mounted such that the semiconductor elements 8a and 8b are housed in the closed chamber portion 12 side, and a heat radiating portion composed of cooling fins is located in the open chamber portion 13 side. In this case, the cooling units 90a and 90b are arranged side by side in a direction orthogonal to the direction in which the air is blown by the electric blower 14. On the other hand, the peripheral circuit 22a related to the semiconductor element 8a mounted on the cooling unit 90a is mounted in the open chamber portion on the downstream side of the cooling unit 90b when viewed in the direction of the wind, and conversely, mounted on the cooling unit 90b. A peripheral circuit 22b related to the semiconductor element 8b is mounted in an open chamber portion on the downstream side of the cooling unit 90a when viewed in the direction in which the wind flows. That is, the cooling unit and the peripheral circuit related to each other are mounted with their positions interchanged with each other.

  By arranging the peripheral circuits 22a and 22b downstream of the other group in this manner, a plurality of groups of conversion circuits are shared with the flow of the cooling air, and the temperature rise of the cooling air is leveled. Further, as in the case of the ninth embodiment shown in FIG. 9, when a group is separated due to a failure, the heat loss of the cooling units 90b, 90a to which the upstream semiconductor elements 8a, 8b are mounted as the peripheral circuits 22a, 22b. As the number of heat generations decreases due to the operation of the remaining groups, there is a margin in the cooling capacity even if the amount of generated heat increases, so that a system with excellent redundancy at the time of failure can be configured.

FIG. 1 is a plan view and a bottom view of a first embodiment of a power conversion device according to the present invention as viewed from a direction in which the power conversion device is mounted on a bottom surface of a vehicle. FIG. 2 is a plan view and a bottom view of a power conversion device according to a second embodiment of the present invention when viewed from a direction in which the power conversion device is mounted on a bottom surface of a vehicle. The top view and the side view which looked at the 3rd Example of the power converter concerning the present invention from the direction attached to the bottom of the vehicle. FIG. 9 is a plan view showing a cooling unit and a semiconductor element of a fourth embodiment of the power converter according to the present invention, and FIGS. FIG. 11 is a plan view showing a state where a cooling unit and a semiconductor element constituting a fifth embodiment of the power converter according to the present invention are mounted, and a sectional view thereof. FIG. 14 is a plan view and a sectional view showing a mounting state of a cooling unit and a semiconductor element constituting a sixth embodiment of the power converter according to the present invention. FIG. 14 is a plan view and a sectional view showing an attachment state of a cooling unit and a semiconductor element constituting a seventh embodiment of the power converter according to the present invention. The top view and its side view which show the attachment condition of the cooling unit and the semiconductor element which comprise 8th Example of the power converter concerning this invention. The top view and its side view which show the attachment condition of the cooling unit and semiconductor element which comprise the 9th Example of the power converter concerning this invention. The top view and its side view which show the attachment state of the cooling unit and semiconductor element which comprise 10th Example of the power converter concerning this invention. The circuit diagram which shows the structure of the power converter for driving a railway vehicle which has four groups of VVVF inverter circuits as a conventional power converter. FIG. 12 is a perspective view showing a state in which the power conversion device shown in FIG. 11 is mounted under the floor of a railway vehicle, and a side view seen from the traveling direction of the vehicle. FIG. 12 is a plan view and a bottom view of the power conversion device illustrated in FIG. 11 as viewed from a direction in which the power conversion device is mounted on a bottom surface of the vehicle. FIG. 9 is a circuit diagram showing a configuration of another conventional power converter for driving a railway vehicle including two groups of VVVF inverter circuits and one group of CVCF inverter circuits. The perspective view which shows the state which mounted the power converter shown in FIG. 14 under the floor of the railway vehicle, and the side view seen from the traveling direction of the vehicle. The top view and bottom view which looked at the electric power converter shown in Drawing 14 from the direction attached to the bottom of vehicles. FIG. 9 is a circuit diagram of a power conversion device for driving a vehicle in which a plurality of groups of conversion circuits are housed as another conventional power conversion device. FIG. 18 is a plan view as seen from a side where the power converter shown in FIG. 17 is mounted on the vehicle bottom, and a side view as seen from the traveling direction of the vehicle. FIG. 18 is a longitudinal sectional view of the power converter shown in FIG. 17.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Pantograph 2 Circuit breaker 3 Filter reactor 4 VVVF inverter circuit 5 Filter capacitor 6 Induction motors 7A to 7F Power conversion devices 8, 8a, 8b Semiconductor elements 9, 9U, 9V, 9W Coolers 9a, 9b, 9c Cooling unit 12 Closed room Part 13 Open room part 14 Electric blower 15 Control part 17 CVCF inverter circuit 18 Converter circuit 19 Inverter circuit 21 Connection conductors 22a, 22b Peripheral circuits 30, 40, 50, 60, 70, 80, 90a, 90b Cooling units 31, 41, 51, 61, 71, 81 Heat receiving part 32, 42, 52, 62, 72, 82 Heat radiating part 33 Heat pipe
43, 53, 63 refrigerant

Claims (18)

In a power converter that houses a plurality of groups of power conversion circuits that convert AC to DC or DC to AC by switching operation of a plurality of semiconductor elements,
A power converter, wherein a plurality of semiconductor elements which are connected in parallel and constitute a plurality of groups of power conversion circuits each of which can operate independently are mounted on a common cooling unit having a heat receiving portion and a heat radiating portion. In a power converter including a plurality of groups of inverter circuits, each output of which is connected to a different load by a switching operation of a plurality of semiconductor elements,
A power converter wherein a plurality of semiconductor elements connected in parallel and constituting a plurality of groups of the inverter circuits each of which can operate independently are mounted on a common cooling unit having a heat receiving portion and a heat radiating portion. A plurality of groups of variable voltage variable frequency inverter circuits for converting direct current to variable voltage and variable frequency alternating current by switching operation of a plurality of semiconductor elements, and a constant voltage constant frequency inverter circuit for converting direct current to constant voltage and constant frequency alternating current; Are connected in parallel and housed,
A power converter, wherein semiconductor elements constituting each of the inverter circuits connected in parallel and each of which can operate independently are mounted on a common cooling unit having a heat receiving unit and a heat radiating unit.   The plurality of semiconductor elements are divided for each phase or for the positive side and the negative side, and the divided semiconductor element groups are attached to coolers provided corresponding to these semiconductor element groups. The power converter according to any one of claims 1 to 3.   The power converter according to any one of claims 1 to 4, wherein the heat receiving unit of the cooling unit includes a heat pipe for mutually transferring heat of a mounting portion of a semiconductor element of a different circuit. .   The power converter according to any one of claims 1 to 4, wherein the heat receiving unit of the cooling unit has a box shape and a refrigerant is sealed therein.   The heat receiving portion of the cooling unit is configured such that semiconductor elements can be attached to the front and back surfaces, a semiconductor element group constituting one group of the power conversion circuits is attached to one surface, and another group is attached to the other surface. The power conversion device according to any one of claims 1 to 4, wherein a semiconductor element group constituting the power conversion circuit is mounted.   The power conversion device according to any one of claims 1 to 4, wherein semiconductor element groups of different power conversion circuits are alternately arranged for each phase and mounted on one surface of the cooling unit.   When the semiconductor element has a different height for each power conversion circuit, a step is provided on the semiconductor element mounting surface of the cooling unit so that the height of the electrical connection terminals of the semiconductor element is equal. The power converter according to claim 8, wherein In a power converter that is connected to different loads, and accommodates a plurality of groups of power conversion circuits that convert AC to DC or DC to AC by switching operation of a plurality of semiconductor elements,
A power converter, wherein semiconductor elements connected in parallel and forming a plurality of groups of the power conversion circuits are mounted on a common cooling unit having a heat receiving section and a heat radiating section. In a power converter having a plurality of groups of inverter circuits each connected to a different load and each output connected to a different load by a switching operation of a plurality of semiconductor elements,
A power converter, wherein semiconductor elements connected in parallel and forming a plurality of groups of the inverter circuits are mounted on a common cooling unit having a heat receiving unit and a heat radiating unit. A plurality of groups of variable voltage variable frequency inverter circuits for converting direct current to variable voltage and variable frequency alternating current by switching operation of a plurality of semiconductor elements, and a constant voltage constant frequency inverter circuit for converting direct current to constant voltage and constant frequency alternating current; Are connected in parallel and housed,
A power converter, wherein semiconductor elements constituting each of the inverter circuits connected in parallel and connected to different loads are mounted on a common cooling unit having a heat receiving section and a heat radiating section.   The plurality of semiconductor elements are divided for each phase or for the positive side and the negative side, and the divided semiconductor element groups are attached to coolers provided corresponding to these semiconductor element groups. The power converter according to any one of claims 10 to 12.   The power converter according to any one of claims 10 to 13, wherein the heat receiving unit of the cooling unit is provided with a heat pipe for mutually transferring heat of a mounting portion of a semiconductor element of a different circuit. .   The power converter according to any one of claims 10 to 13, wherein the heat receiving unit of the cooling unit has a box shape and a refrigerant is sealed therein.   The heat receiving portion of the cooling unit is configured such that semiconductor elements can be attached to the front and back surfaces, a semiconductor element group constituting one group of the power conversion circuits is attached to one surface, and another group is attached to the other surface. The power converter according to any one of claims 10 to 13, wherein a semiconductor element group constituting the power conversion circuit is mounted.   The power converter according to any one of claims 10 to 13, wherein semiconductor element groups of different power conversion circuits are alternately arranged for each phase and mounted on one surface of the cooling unit.   When the semiconductor element has a different height for each power conversion circuit, a step is provided on the semiconductor element mounting surface of the cooling unit so that the height of the electrical connection terminals of the semiconductor element is equal. The power converter according to claim 17, characterized in that:

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