JP2000232288A - Power conversion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively cool a heating part built in a power conversion device, to lessen time and labor required for assembly, maintenance, and inspection of the power conversion device, and quickly form a protective structure for preventing foreign objects and dust from infiltrating into the power conversion device. SOLUTION: A power conversion device is composed of a main circuit block 36 equipped with a semiconductor device, cooling fins, smoothing capacitor 37 and the like which are mounted on a mounting plate and connected with a conductor, a printed board block composed of printed boards and their cases, a cooling fan block 34 composed of cooling fans and their mounting pads, a terminal pad block 35, and a box block. These blocks are combined and assembled into the power conversion device. The box block has a structure where a protective cover which has a gap that blocks foreign objects larger than prescribed dimensions can be additionally provided to the upper or lower part of the box block, an L-shaped mounting piece can be provided along a boundary between a cooling fin housing section and an equipment housing section, and a back cover can be mounted on the L-shaped mounting piece.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power converter in which a semiconductor element for power conversion and its accessories are housed in a box.

[0002]

2. Description of the Related Art In the following, an inverter device connected to a commercial power supply and outputting AC power of a desired voltage and frequency will be described as an example of a power converter.

There are the following devices constituting the inverter device. That is, the main circuit includes a rectifier obtained by bridge-connecting a plurality of diodes as a semiconductor element, an inverter obtained by bridge-connecting a plurality of sets of an anti-parallel connection of an IGBT (insulated gate bipolar transistor) and a diode serving as a semiconductor element, It is a smoothing capacitor connected to a DC intermediate circuit that connects the DC side of these rectifiers and the DC side of the inverter, and the AC power from the commercial power supply is supplied with a desired voltage by these rectifiers, the smoothing capacitor, and the IGBT. It is converted into AC power of the frequency. However, in this power conversion operation, in addition to these main circuit devices, a control circuit for sequentially turning on and off the IGBT at appropriate times, various printed boards on which the power supply circuit is mounted, and the heat generated by the rectifier and the IGBT. Cooling fins for dissipating, cooling fans for discharging the heat of the cooling fins and the smoothing condenser out of the device, various terminals for connecting wires for inputting and outputting main circuit power and control signals, and these devices A box or the like for storing is required.

FIG. 6 is an exploded view showing the components constituting the conventional power conversion device in an exploded manner. Reference numeral 1 denotes a front cover, reference numeral 2 denotes a control printed board, reference numeral 3 denotes a gate drive printed board, Reference numeral 4 denotes a power supply printed board, reference numeral 5 denotes a control panel, reference numeral 6 denotes a cooling fan for cooling fins, reference numeral 7
Reference numeral 8 denotes a terminal block, reference numeral 9 denotes a semiconductor element (such as a diode or IGBT), reference numeral 10 denotes a cooling fin of the semiconductor element, reference numeral 11 denotes a smoothing capacitor,
Reference numeral 12 denotes a lower surface cover, and reference numeral 13 denotes a right side cover. In addition, there are parts that make up the box body other than the illustration,
The description is omitted.

[0005]

In the conventional power converter, the priority has been given to storing necessary various devices in a small box as much as possible, so that the devices are grouped by function. I didn't. For example, in the conventional example of FIG. 6, since the control printed board 2, the gate drive printed board 3, and the power supply printed board 4 are separately mounted, separate connectors are mounted on each printed board, and each connector is connected by a flat cable. Are connected. However, a flat cable requires a large bending radius, which wastes space, and noise may be picked up at this cable part, so noise countermeasures must be taken, and extra work and cost are required for the cable and its wiring work. Is occurring. Further, since the cooling fin cooling fan 6 for cooling the cooling fins 10 and the apparatus internal cooling fan 7 for removing heat generated inside the apparatus such as a control circuit are installed at different places, The power supply wiring becomes complicated, maintenance and inspection are inconvenient, and the smoothing capacitor 11, which generates a large amount of heat, is not installed at a position suitable for cooling. There is a problem that is done.

FIG. 7 is a main circuit connection diagram showing a conventional example when DC power is input to an inverter device. A commercial power supply is connected to the terminals 21A, 21B, 21C of the inverter device 20, and this commercial power is converted into DC power by a rectifier 22 composed of a diode and output to a DC intermediate circuit. The smoothing capacitor 11 connected to the DC intermediate circuit absorbs and removes the pulsating component included in the DC power, and supplies the smoothed DC power to the inverter 23 which is an anti-parallel connection of the IGBT and the diode. The inverter 23 converts the DC power into AC power having a desired voltage and frequency, and rotates an induction motor 24 as a load. At this time, terminals 25A and 2
Short-circuit with 5P. Since the cooling fan 51 (hereinafter, the cooling fin cooling fan 6 and the device internal cooling fan 7 are collectively expressed as described above) is generally operated with commercial AC power, as shown in the drawing, the cooling fan 51 is connected via terminals 25A, 25B, and 25C. The commercial AC power introduced into the power converter 20 is branched inside the power converter 20 and supplied to the cooling fan 51.

If the inverter 23 outputs AC power of a variable voltage and a variable frequency, the induction motor 24 can be operated at a variable speed. At the time of deceleration of the induction motor 24, its kinetic energy is converted to electric power and is regenerated to the DC intermediate circuit via the inverter 23. In order to effectively use the regenerated electric power,
Recently, instead of the rectifier 22 composed of a diode, I
A converter 26 composed of a semiconductor switch element such as a GBT is used. In this case, the short circuit between the terminals 25A and 25P is released, the terminals 27P and 25P are connected, and the terminals 27N and 25N are connected. . With such a circuit configuration, electric power generated when the induction motor 24 decelerates is
Induction motor 24 → Inverter 23 → Terminals 25P, 25N
→ Terminal 27P, 27N → Converter 26 → Regeneration can be performed on the path of commercial power supply.

Further, the box housing the inverter device is usually open, and if foreign matter enters, a short circuit accident or a ground accident may occur. Therefore, when installing the inverter device 20 in a place where foreign matter may enter or where there is a lot of dust, a box having a structure capable of preventing entry of foreign matter or dust is required. Must be manufactured separately because it is different from the standard product. Therefore, it takes a long time to complete and has the disadvantage of being expensive.

Accordingly, an object of the present invention is to make it possible to effectively cool a heat-generating component incorporated in a power converter, to reduce the time required for assembling, maintaining and inspecting the power converter, and to reduce the amount of foreign matter and dust. A protection structure for preventing intrusion can be easily and quickly formed.

[0010]

In order to achieve the above object, in the power converter of the present invention, the power converter is divided into a plurality of blocks. That is, the main circuit block is composed of a semiconductor element and its cooling fins, a main circuit switching device, a smoothing capacitor, a resistor, etc., a main circuit device mounting plate for mounting these components, and a conductor for connecting the devices to each other. The board block is composed of a plurality of printed boards for controlling the semiconductor elements, a printed board mounting case for mounting each of the printed boards, and a connector for connecting the printed boards to each other. It consists of a cooling fan that sends cooling air to each device including the board and its mounting base,
The terminal block is configured by integrating a main circuit terminal block, a control circuit terminal block, and a main circuit conductor from the main circuit terminal block to the main circuit block, which connect electric wires to be introduced into the power converter, and a box. The body block has a strong frame structure on the lower surface and upper surface to accommodate these blocks, and the left and right side plates, the front plate, and the rear plate are attached to the upper and lower frames, and a power converter is formed by combining these blocks Shall be able to do so.

The box block has a gap for preventing foreign substances exceeding a predetermined size from entering, and the total area of the gap is sufficient to allow the air flow required by the cooling fan block to pass. The protective cover is provided with a mounting structure that can be added to the lower portion or the upper portion of the box block as required. Or, if necessary, an attachment structure for adding an L-shaped attachment around the box along a boundary between a portion for accommodating the cooling fins of the semiconductor element and a portion for accommodating other devices. Prepare. Alternatively, an attachment plate or a back cover is attached to this L-shaped attachment via a packing.

[0012]

FIG. 1 is an exploded view showing a first embodiment of the present invention by disassembling and illustrating a power converter. In FIG. 1, a diode as a semiconductor element and an IGBT are mounted on the main circuit block 36, and cooling fins for these semiconductor elements are provided on the back side (invisible portion) of the main circuit block 36. It can be seen that the smoothing capacitor 37 is mounted on the lower part. A cooling fan block 34 is inserted into a box-shaped portion on the upper side (right side in the figure) of the main circuit block 36. The cooling fan block 34 is provided with one cooling fan inside the apparatus at the upper part and two cooling fin cooling fans at the lower part. The cooling air sucked through the lower case adapter 38 by the induced draft first sucks the smoothing condenser. After cooling the cooling fins and cooling the cooling fins, the cooling fins are discharged out of the box via the upper case adapter 39. Terminal block 35 is main circuit block 3
6 are stacked on the lower part. Control panel 4
The printed circuit board block is formed by stacking the control printed circuit board 32 to which the “0” is mounted and the power / gate printed circuit board 33 and attaching them integrally to a printed board storage case (not shown). By this stacking, the connector mounted on the control printed board 32 and the connector mounted on the power supply / gate printed board 33 come into direct contact to connect both printed boards, so that it is not necessary to use a flat cable.

The lower and upper sides of the box use a lower case adapter 38 and an upper case adapter 39 formed by die-casting of a light alloy. A strong box can be formed by screwing the screw.

FIG. 2 is a structural view showing a second embodiment of the present invention. By attaching a lower protective cover 71 to a lower portion of an inverter device 70, a foreign matter larger than a predetermined size (for example, IEC) is used. 12 for protection class IP20
A solid foreign object exceeding mm) can be prevented from entering the inside of the inverter device 70.

FIG. 3 is a structural view showing a third embodiment of the present invention. A lower protective cover 71 is attached to a lower portion of an inverter device 70, and an upper protective cover 72 is attached to an upper portion.
By attaching the, the degree of protection required by the NEMA 1 can be cleared.

FIG. 4 is a structural view showing a fourth embodiment of the present invention, in which a lower protective cover 71 is attached to a lower portion of an inverter device 70, and cooling fins for semiconductor elements are provided on both left and right sides. An L-shaped fitting 81 having an L-shape along the boundary between the storage portion and the other device storage portion
And the packing 82, the degree of protection required by the NEMA 12 can be cleared.

FIG. 5 is a structural view showing a fifth embodiment of the present invention, in which a lower protective cover 71 is attached to a lower portion of an inverter device 70, and cooling fins of semiconductor elements are provided on both left and right sides. An L-shaped fitting 81 having an L-shape along the boundary between the storage portion and the other device storage portion
Is provided. The L-shaped fitting 81 has a packing 83.
The mounting plate 84 is mounted via the cover 70, and the rear surface of the inverter device 70 is covered with a rear cover 85. The back cover 85 can prevent water drops from falling into the cooling fins 10 and entering the inside. Also, a mounting plate 84 is attached to the L-shaped mounting tool 81 via a packing 83.
By attaching, the dust floating on the cooling fin 10 portion can be prevented from entering the control circuit portion to be cleaned, and it can correspond to the protection class IP54 defined by IEC.

[0018]

According to the conventional power converter, since each device contained therein is housed separately without being grouped by function, for example, it takes much time for assembling, maintenance and inspection, and the generation of heat-generating parts. Although there were various inconveniences such as cooling not being performed effectively and the length of wiring between devices becoming longer, noise, danger, and time and labor required for wiring, in the present invention,
Since the built-in devices are grouped into separate blocks for each function, for example, the printed circuit boards are connected by direct contact of the connector, so that the effect of eliminating the wiring is obtained. Wiring and maintenance
The effect that inspection becomes easy is obtained. Furthermore, the effect of extending the life can be obtained by arranging the smoothing capacitor so that it can be cooled efficiently. In addition, it is possible to easily respond to requests to improve the degree of protection of the device by taking measures such as processing the mounting parts such as protective covers on the box in advance, so that non-standard protective structures can be quickly supplied in a short period of time. can get.

[Brief description of the drawings]

FIG. 1 is an exploded view showing a first embodiment of the present invention by disassembling and illustrating a power converter.

FIG. 2 is a structural diagram showing a second embodiment of the present invention.

FIG. 3 is a structural diagram showing a third embodiment of the present invention.

FIG. 4 is a structural diagram showing a fourth embodiment of the present invention.

FIG. 5 is a structural view showing a fifth embodiment of the present invention.

FIG. 6 is an exploded view showing a device constituting a conventional power converter in an exploded manner.

FIG. 7 is a main circuit connection diagram showing a conventional example when DC power is input to an inverter device.

[Explanation of symbols]

 2, 32 Control printed board 3 Gate drive printed board 4 Power supply printed board 5, 40 Control panel 6 Cooling fin cooling fan 7 Internal cooling fan 8 Terminal block 9 Semiconductor element 10 Cooling fin 11, 37 Smoothing capacitor 12 Bottom cover 13 Right side Front cover 20, 70 Inverter device 21A, B, C terminal 22 Rectifier 23 Inverter 24 Induction motor 25P, N terminal 26 Converter 27P, N terminal 31 Front cover 33 Power supply / gate printed board 34 Cooling fan block 35 Terminal block block 36 Main circuit Block 38 Lower case adapter 39 Upper case adapter 51 Cooling fan 71 Lower protective cover 72 Upper protective cover 81 L-shaped mounting 82,83 Packing 84 Mounting plate 85 Back cover

Claims (5)

[Claims] 1. A semiconductor device and its accessories are housed in a box,
A power converter that converts input power into power different from the power by the operation of the semiconductor element and outputs the converted power. The power converter includes the semiconductor element and its cooling fin, a main circuit switching device, a smoothing capacitor, and a resistor. A main circuit block composed of a device, a main circuit device mounting plate for mounting these components, a conductor mounted on the main circuit device mounting plate for connecting the devices, and a plurality of prints for controlling the semiconductor element. Board, a printed board mounting case for mounting the plurality of printed boards, a printed board block including a connector for connecting the printed boards mounted on the printed board mounting case, and each device including the cooling fins and the printed boards. A cooling fan that feeds cooling air and a cooling fan block consisting of its mounting base, and an electric wire introduced to the power converter The main circuit terminal block to be connected, the control circuit terminal block, the terminal block block integrating the main circuit conductors from the main circuit terminal block to the main circuit block, and the lower surface and the upper surface for storing these blocks are A power conversion device characterized by having a strong frame structure, dividing the upper and lower frames into a left and right side plate, a front plate and a back plate, and combining these blocks. 2. The power converter according to claim 1, wherein the box block has a gap for preventing intrusion of foreign matter exceeding a predetermined size, and the gap has a ventilation amount required by the cooling fan block. A power conversion device comprising a mounting structure for adding a lower protective cover having an area that can pass therethrough to a lower portion of the box block as necessary. 3. The power converter according to claim 1, wherein the box block has a gap for preventing the intrusion of foreign matter exceeding a predetermined size, and the gap has a ventilation volume required by the cooling fan block. A power converter, comprising: a mounting structure for adding a lower protective cover and an upper protective cover having an area that can pass therethrough to lower and upper portions of the box block as required. 4. The power converter according to claim 1, wherein the box block is provided along a boundary between a portion where a cooling fin of a semiconductor element is stored and a portion where other devices are stored. A power conversion device comprising a mounting structure for adding an L-shaped mounting tool around the box. 5. The power converter according to claim 1, wherein the box block is provided along a boundary between a portion where a cooling fin of a semiconductor element is stored and a portion where other devices are stored. A mounting structure for attaching an L-shaped mounting tool around the box body is provided. A mounting plate is mounted on the L-shaped mounting tool via packing, and a dropping part is attached to a rear surface of the power converter. A back cover for blocking water droplets is provided, and a gap is provided for preventing foreign matter exceeding a predetermined size from entering. The gap is provided with a lower protective cover and an upper protective cover having an area capable of passing a ventilation volume required by the cooling fan block. And a mounting structure for adding to the lower portion or the upper portion of the box block as required.