JPH113971A - Semiconductor power conversion unit for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize a vehicle semiconductor power conversion unit, without deteriorating the capacity and the functions of a semiconductor switch element and the attachments, so as to store it in a prescribed fitting space. SOLUTION: The block of clean cooling air and the block of cooling air which is not clean are divided by a partition fitting board 11. IGBT(insulated gate bipolar transistor) 2 as a semiconductor switch element, a cooling body, a phase capacitor 6, a snubber circuit 7 and a control circuit 9 are installed in the block of a clean cooling air side. A condenser 5 and a snubber resistor 8 are installed in the block of cooling air which is not clean. IGBT 2 and the phase capacitor 6 are arranged in such a way that wiring between them becomes shortest and are connected by a sheet-like conductor 12. IGBT 2 and the snubber circuit 7 are arranged so that the wiring of them becomes the shortest and are connected by a sheet-like conductor 13. IGBT 2 and the control circuit are arranged so that the wiring of them becomes the shortest. Consequently, inductance is reduced, the electrostatic capacity of the respective capacitors is reduced, mis-ignition is reduced, and reliability is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicular semiconductor power conversion unit that converts power using a semiconductor switch element mounted on a vehicle.

[0002]

2. Description of the Related Art Since a DC series motor has advantages such as easy speed control and a large torque at a low speed, a DC series motor has conventionally been adopted as a motor for driving a vehicle. There were many. Therefore, the power supplied from the overhead wire to the vehicle is also DC power. However, a DC motor has a commutator and a brush, so that it must be constantly maintained and inspected, and the brush is worn and must be replaced periodically. Therefore, there is a drawback that maintenance and inspection are troublesome, and in order to avoid occurrence of a large accident such as flashover, it is necessary to take care not to apply a large current exceeding a predetermined value to the DC motor. On the other hand, an induction motor driven by AC power has the advantage that the structure is simple and sturdy, and there are no commutators or brushes, so that maintenance and inspection work can be simplified, but speed control and torque control cannot be easily performed. There were drawbacks.

In recent years, however, the speed and torque of an induction motor of several hundred kilowatts can be freely controlled due to the increase in the capacity of semiconductor switch elements and the remarkable progress in the technology for controlling these semiconductor switch elements. Therefore,
For example, if a rectifier comprising a semiconductor switching element and an inverter are mounted on a Shinkansen vehicle, the inverter can output AC power of a desired voltage and frequency to operate the induction motor at a variable speed. If the junction temperature of the semiconductor switch element exceeds an allowable value when performing the above-described power conversion, the semiconductor switch element is thermally destroyed and loses its function. Therefore, the heat generated by the semiconductor switch element is quickly removed by a boiling cooling device.

[0004] Boiling cooling encloses a refrigerant having a low boiling temperature in a closed container in which a storage portion for storing a liquid refrigerant is on the lower side and a condensing portion for returning the vaporized refrigerant to the original liquid is on the upper side. When the high temperature portion of the object to be cooled is brought into contact with the storage section, the heat evaporates the refrigerant in the closed vessel, and at that time, the temperature of the object decreases. This is a cooling system in which the vaporized refrigerant moves to the upper condensing section, where it is cooled, returns to liquid again, and descends to the storage section.

[0005]

Since a vehicle is equipped with various electric components (drive motors, air conditioners, lighting communication devices, etc.), the above-described semiconductor switch uses AC power or DC power taken from overhead lines. The device converts it to the appropriate power. The electric component is operated using the semiconductor switch element as a power source. However, the semiconductor switch element requires various accessories. The main components are cooling devices for semiconductor switching elements (effective cooling devices such as air-cooling type, liquid-cooling type immersed in liquid, and boiling-cooling type described above are necessary because semiconductor switching elements have small heat capacity). A protection device for a semiconductor switching element (a snubber circuit for suppressing an overvoltage, a phase capacitor, etc.), and a control circuit for quickly turning on and off the semiconductor switching element at an appropriate time.

[0006] By the way, the original purpose of a vehicle is to carry people and cargo, and in order to achieve this purpose quickly and comfortably, the above-mentioned various electric components are mounted on the vehicle. . However, there is a limit to the space that can be provided for a semiconductor switch element serving as a power supply for these electrical components and its accessories. Particularly in the case of a train, these are often hung under the floor, so that the space restrictions are even more severe.

Attempting to store the semiconductor switch element and its accessories in such a limited space causes various difficulties. For example, a device that generates a large amount of heat and a device that generates a small amount of heat may be housed in the same box, or an installation location of devices to be installed close to each other may be separated. For this reason, in the former, a cooling device having an unnecessarily large cooling capacity is installed, and in the latter, not only an extra conductor is required due to a large wiring length between devices,
Problems such as an increase in wiring inductance occur.
All of these increase the size and weight of the equipment,
Storage in a restricted space becomes more difficult. As a result, each device is placed in a more and more dispersed arrangement, resulting in a vicious circle in which the conductor size becomes longer. Alternatively, the capacity of the device is reduced to accommodate the limited space,
This degrades the running performance of the vehicle.

SUMMARY OF THE INVENTION It is an object of the present invention to reduce the size and the capacity of a semiconductor switch element and its accessories without reducing the capacity and function thereof, and to accommodate the semiconductor switch element in a predetermined mounting space.

[0009]

According to a first aspect of the present invention, there is provided a semiconductor power conversion unit for a vehicle, which converts a power introduced into a vehicle into a desired power. And a cooling body which is in close contact with the semiconductor switch element and removes heat generated by boiling cooling, a snubber circuit for protecting the semiconductor switch element, a phase capacitor, and a medium inside the cooling body. In a vehicular semiconductor power conversion unit comprising a condenser for condensing and a control circuit for controlling the semiconductor switching element, the element / cooling body, the snubber circuit, the phase capacitor, and the control circuit are cleaned. It is installed in a section cooled by air, and only the condenser is installed in the same section as a device that cools with cooling air separate from the clean cooling air. The semiconductor switch element and its snubber circuit are arranged at the position where the length of the conductor connecting them is shortest, and the semiconductor switch element and the phase capacitor are located at the position where the length of the conductor connecting them is shortest. And the semiconductor switch element and its control circuit are arranged at a position where the length of the conductor connecting them is the shortest.

According to a second aspect of the present invention, the semiconductor switch element and its snubber circuit are connected by a plate-shaped conductor, and the semiconductor switch element and its phase capacitor are connected by a plate-shaped conductor. According to a third invention, the snubber circuit according to the first invention or the second invention comprises at least a snubber capacitor and a snubber resistor, and the snubber resistor is provided outside the snubber circuit box and with the same cooling air as the condenser. This is a device arrangement for cooling.

A condenser for boiling cooling, which is a device that generates a large amount of heat and is insensitive to dirt, is installed in a place where it is cooled by a large amount of outside air. On the other hand, devices such as a semiconductor switch element control circuit, a snubber circuit, and a phase capacitor, which generate a small amount of heat but do not like to be contaminated, are installed in a section cooled with clean air. Here, the semiconductor switching element is configured so as to remove heat generated by being in close contact with a cooling body for boiling cooling, so that cooling air is not required. However, a control circuit, a snubber circuit, a phase capacitor, and the like are in close contact with the semiconductor switching element. Have a relationship. Therefore, the semiconductor switch element is also installed in the same section as these. Further, if the length of the wiring between the snubber circuit and the semiconductor switch element is reduced, the wiring inductance is reduced, so that the capacitance of the snubber capacitor constituting the snubber circuit can be reduced accordingly. Similarly, if the length of the conductor connecting the semiconductor switch element and the phase capacitor is reduced, the capacity of the phase capacitor can be reduced.

If a plate-like conductor is used instead of an electric wire for connecting the semiconductor switch element and the snubber circuit, and a plate-like conductor is used instead of the electric wire for connection between the semiconductor switch element and the phase capacitor, the space of the terminal portion is increased. In addition, the plate-like conductor can be used as a snubber circuit, a phase capacitor, and a reinforcing material for preventing vibration. The snubber resistor constituting the snubber circuit generates a larger amount of heat than other devices, but the function is less likely to be deteriorated even if it is soiled. Therefore, only the snubber resistor from the snubber circuit installed close to the semiconductor switch element is installed outside the section cooled by clean air, and the influence of the heat generation on other devices is eliminated.

[0013]

FIG. 1 is a front view of a configuration of a semiconductor power conversion unit for a vehicle according to a first embodiment of the present invention, and corresponds to claim 1 or claim 2. In FIG. 1, the shape of an IGBT (insulated gate bipolar transistor) 2 as a semiconductor switch element is a disk shape. The boiling cooling device is formed of a closed container in which the cooling body 3, the refrigerant passage 4 and the condenser 5 are integrated, and a liquid which is liquid at normal temperature and has a low boiling temperature is sealed in the closed container. If the portion of the cooling body 3 of the boiling cooling device is inserted into each appropriate portion of the power conversion device configured by stacking the IGBTs 2, heat generated by the operation of the IGBT 2 vaporizes the refrigerant inside the cooling body 3, The temperature of the IGBT 2 is lowered by the heat of vaporization at that time. The vaporized refrigerant rises to the condenser 5 through the refrigerant passage 4, and if liquefied by cooling here, descends the refrigerant passage 4 and returns to the cooling body 3. A large amount of cooling air must be sent to the condenser 5, but this cooling air does not need to be clean.
Therefore, the partition mounting plate 11 also serving as the mounting plate prevents the unclean cooling air from flowing to the lower side of the partition mounting plate 11.

A phase condenser 6, a snubber circuit 7, a control circuit 9 and the like which require clean cooling air are mounted below the partition mounting plate 11 so that the cooling air does not enter the condenser 5 described above. I have. For equipment that requires clean cooling air, take measures such as internal cooling, in which the cooling air is circulated by sealing this part, or introducing cooling air from outside through a filter to this sealed part. However, since this part is not related to the present invention, the illustration is omitted.

For example, by mounting the phase capacitor 6 upside down, the length of the plate-shaped conductor 12 connecting the phase capacitor 6 and the IGBT 2 is minimized, and the wiring inductance of the plate-shaped conductor 12 is minimized. I have. Further, the plate-shaped conductor 12 plays a role as a reinforcing material when the phase capacitor 6 is mounted. Note that a conductor from the IGBT 2 is drawn out from between the IGBT 2 and the cooling body 3. Similarly, the snubber circuit 7 is connected so that the length of the plate-shaped conductor 13 connecting the snubber circuit 7 and the IGBT 2 is minimized.
Are arranged to minimize the wiring inductance of the plate-shaped conductor 13. Further, the wiring distance between the control circuit 9 and the IGBT 2 is also minimized to minimize the possibility that noise is superimposed on the ignition signal given to the IGBT 2 by the control circuit 9.

FIG. 2 is a side view of the configuration of a semiconductor power conversion unit for a vehicle according to a first embodiment of the present invention. FIG. 1 is viewed from the left side (the direction of the arrow on the left side of FIG. 1). It represents a place. As shown in FIG. 2, the cooling air 21 flows in the direction of the arrow above the partition mounting plate 11, and the cooling air 20 flows in the direction of the arrow below the partition mounting plate 11. Here, the cooling air 20 is a wind of clean air, and the cooling air 20 and the cooling air 21 do not mix due to the presence of the partition mounting plate 11.

FIG. 3 is a front view of a semiconductor power conversion unit for a vehicle according to a second embodiment of the present invention. FIG. 3 is different from FIG. 1 described above in that the snubber resistor 8 is provided above the partition mounting plate 11, and the rest is the same as FIG. 1. Therefore, description of the same part is omitted. In the second embodiment shown in FIG. 3, there is a snubber resistor 8 as a component that has a large amount of heat generation and does not require clean cooling air among the devices mounted below the partition mounting plate 11. Therefore, the amount of clean cooling air used can be reduced by transferring the snubber resistor 8 above the partition mounting plate 11.

[0018]

Since the power conversion device for a vehicle has a limited installation space, it must be reduced in size and weight. In the present invention, the wiring inductance of the conductor is reduced by arranging each device so that the length of the conductor connecting the semiconductor switch element, which is a main component of the power conversion device, and the protection device is minimized. . If the wiring inductance is reduced, the capacitance of the snubber capacitor and the phase capacitor can be reduced, so that the effect of reducing the size of the entire device can be obtained. Further, since the wiring length between the control circuit and the semiconductor switch element is shortened, the possibility of erroneous firing is reduced, and the effect of improving the reliability of the device is obtained. Furthermore, cooling efficiency is improved by putting together components that do not require clean cooling air and generate a large amount of heat and reducing components that require clean cooling air. In addition, the space between the terminals is reduced by connecting each device with a plate-shaped conductor, and the plate-shaped conductor also serves to reinforce the attachment of the device, thereby further promoting the downsizing and weight reduction of the device. Obtained.

[Brief description of the drawings]

FIG. 1 is a front view of a configuration of a vehicle semiconductor power conversion unit according to a first embodiment of the present invention.

FIG. 2 is a side view of a configuration of a vehicle semiconductor power conversion unit according to a first embodiment of the present invention.

FIG. 3 is a front view of a configuration of a vehicle semiconductor power conversion unit according to a second embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 2 IGBT as semiconductor switch element 3 Cooling body 4 Refrigerant passage 5 Condenser 6 Phase capacitor 7 Snubber circuit 8 Snubber resistor 9 Control circuit 11 Partition mounting plate 12 Plate conductor 13 Plate conductor 20 Cooling air (clean) 21 Cooling air (cleaning) Not clean)

Claims (3)

[Claims] An element comprising a semiconductor switch element for converting electric power taken into a vehicle through a current collector into a desired electric power, and a cooling body which is in close contact with the semiconductor switch element and removes heat generated by boiling cooling. A vehicle semiconductor comprising: a cooling body, a snubber circuit that protects the semiconductor switch element, a phase capacitor, a condenser that condenses a refrigerant inside the cooling body, and a control circuit that controls the semiconductor switch element. In the power conversion unit, the element / cooling element, the snubber circuit, the phase capacitor, and the control circuit are installed in a section for cooling with clean air, and the semiconductor switch element and the snubber circuit have a length of a conductor connecting the two. And the semiconductor switch element and its phase capacitor are arranged such that the length of the conductor connecting them is shortest. A semiconductor power conversion unit for a vehicle, wherein the switching element and its control circuit are arranged so that the length of a conductor connecting them is the shortest. 2. The semiconductor power conversion unit according to claim 1, wherein said semiconductor switch element and its snubber circuit are connected by a plate conductor, and said semiconductor switch element and its phase capacitor are plate conductors. A semiconductor power conversion unit for a vehicle, which is connected. 3. The semiconductor power conversion unit according to claim 1, wherein said snubber circuit includes at least a snubber capacitor and a snubber resistor, and said snubber resistor is cooled by said clean air. A semiconductor power conversion unit for a vehicle, which is installed in a place different from the above.