JP5703343B2 - Power converter - Google Patents

Description

  The present invention relates to a power conversion device.

  Inverters, which are power conversion devices, are widely used as speed control devices for electric motors in industry and home appliances. However, power semiconductors for power conversion such as IGBTs used in power converters generate heat due to electrical loss during power conversion, and usually these power semiconductors have an operating limit temperature. If the power semiconductor is still heated even if it exceeds the operating limit temperature of the power semiconductor, there is a risk that the power semiconductor will not operate. Therefore, it is necessary to employ a structure for cooling the power semiconductor in the power conversion device. That is, a cooling fin and a cooling fan are provided, heat from a power semiconductor as a heating element is conducted to the cooling fin, air is sent to the cooling fin by the cooling fan, heat is exchanged, and heat is radiated by an air cooling method.

  The paragraph (0019) of Patent Document 1 states that “a shielding plate 7 as a shielding member is provided between the main circuit portion 4 and the logic portion 5 so as to minimize gaps and prevent mutual air from flowing in and shielding. In order to make the plate 7 have a heat insulating effect and a magnetic shielding effect, the main circuit side is composed of the insulating material 9 and the logic portion side is composed of the iron plate 8 or the like, and a refrigerant passage is formed between them as a wind tunnel, and air is flown In addition, the main circuit portion 4 and the logic portion 5 are provided in a room independent from each other. ”

Japanese Patent Laid-Open No. 9-237992

  The above prior art cannot be said that sufficient consideration is given to the efficiency of the cooling action by natural air cooling, and there is a problem that it is not possible to sufficiently achieve both suppression of temperature rise and downsizing. In other words, when the mounting density of elements on the circuit board is increased in order to reduce the size of the device, the cooling action by the cooling fan is not sufficiently obtained in the conventional technology, and the element rises due to the temperature rise inside the device. There was a possibility that the life of the product would be shortened.

  In the above prior art, a shielding member is provided between the main circuit unit and the logic unit so that the heat of the main circuit unit does not flow to the logic unit weak against heat, and the logic unit itself is generated. There was a problem that the cooling action was not sufficient for heat.

  An object of the present invention is to improve cooling capacity while reducing the size of a power converter.

  One aspect of the present invention for solving the above object includes a power semiconductor, a cooling fin for cooling the power semiconductor, a casing including the cooling fin, a main circuit board including a driver circuit, and the main circuit board. A cover for covering, a vent that is provided below the cooling fin in a use state of the power converter, and allows air from the main circuit board to flow into the casing, It is a power converter device provided with the cooling fan which flows the air from the said vent to the said cooling fin.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to improve cooling capacity, aiming at size reduction of a power converter device.

(A) The perspective view at the time of installing the power converter device which demonstrates Example 1 in this invention (b) An exploded view. The side view (figure seen from the direction of the arrow of Drawing 1) of the power converter of Example 1 in the present invention. The disassembled perspective view of the power converter device of Example 1 in this invention. The figure explaining the attachment state of the circuit component with respect to the cooling fin of Example 1 in this invention. The figure explaining the external appearance of the power converter device of Example 1 in this invention. FIG. 3 is a diagram illustrating the arrangement of main components of the main circuit board according to the first embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS The figure explaining the outline of the main circuit board of Example 1 in this invention. The figure explaining the example of a simulation of the flow velocity distribution inside the apparatus of Example 1 in this invention. The main circuit block diagram explaining the power converter device explaining Example 1 in this invention.

  Specific examples of the present invention will be described below with reference to FIGS.

  Example 1 of the power converter device by this invention is demonstrated.

  FIG. 1 is a schematic diagram of a perspective view (a) of the power conversion device and an exploded view (b) of the device in this embodiment. FIG. 1A is a perspective view when the apparatus is installed, and is configured by connecting a main body cover 3 (cover) on the front side and a main body case 2 (casing) on the back side. FIG. 1B shows an exploded view of the apparatus, and the cover 3 covers the main circuit board 7 and is connected to the casing 2. As shown in FIG. 1 (b), the cover 3 has a vent hole slit A2 (intake port) on its side surface, the main circuit board 7 has a cutout through hole 22 (first vent port), and the front of the casing. Notch vent holes A3 (second vent holes) are provided respectively.

  Cooling fins 1 (fins) are provided inside the casing 2, and a power semiconductor module 11 (not shown) is installed on the fins, thereby serving to radiate heat from the power semiconductor module 11.

  FIG. 2 is a side view of the power converter as viewed from the direction of the arrow in FIG. The internal air flow in this embodiment will be described. A cooling fan 6 (fan) is provided at the upper part of the casing 2 and operates to suck out the air inside the casing, whereby the air from the cooling fins 1 flows to the cooling fan, and heat dissipation of the power semiconductor module 11 (not shown). Is done. Moreover, the arrow of FIG. 2 has shown the flow of the air inside the power converter device in a present Example. That is, the fan 6 provided in the upper part of the casing 2 performs a suction operation, and the air (air in the space between the cover 3 and the main circuit board) that has entered the air inlet A2 from the outside is the main circuit board 22. After passing through the first vent 22 and passing through the space between the main circuit board and the casing 2, it passes through the second vent of the casing 2 and is sucked out by the cooling fan. The positional relationship between these vents and air intakes and the function of air flow will be described in detail later.

  FIG. 3 is a detailed exploded perspective view of the power conversion device according to this embodiment. FIG. 1 shows a perspective view when the power conversion device is installed, but FIG. 3 shows a drawing in the manufacturing process, and shows a perspective view when the power conversion device is turned sideways. . That is, in FIG. 1, the cover 3 disposed on the front side is disposed on the upper side in FIG. 3, and the casing 2 disposed on the back side is disposed on the lower side. The detailed arrangement inside the power conversion apparatus will be described with reference to FIG.

  In FIG. 3, 1 is a cooling fin, 2 is a main body case (casing), 3 is a main body cover (cover), 4 is a wire drawing plate, 5 is a cooling fan mounting plate, and 6 is a cooling fan (fan). 7 is a main circuit board composed of a driver circuit, a power circuit, etc., 8 is a board on which the main circuit electrolytic capacitor CB is mounted, 9 is a control board, and 10 is a conductor copper bar. A composite module 11 (power semiconductor module) as a power element is mounted on the cooling fin 1 (fin).

  Since the composite module 11 configured as an assembly of power semiconductors generates a large loss, heat generated by this loss is conducted to the cooling fin 1 and the cooling fin 1 is cooled by the cooling fan 6. The cooling fan 6 can protect the composite module 11 from being overheated due to a temperature rise. A control terminal block TM1 is attached to the cover 3 with two screws as shown by attachment lines C1 to C2. Further, the main circuit board 7 is attached to the casing 2 with three screws as indicated by the attachment lines C4 to C6.

  Further, the casing 2 is provided with ten holes A1 through which the electrolytic capacitor CB passes so that the electrolytic capacitor substrate 8 is attached by two screws with attachment lines C7 to C8. Since the cooling fan 6 is a life component, it is designed to be housed in the cooling fan mounting plate 5 so that the cooling fan mounting plate 5 can be fitted to the casing 2 without using screws, in order to facilitate attachment and detachment. . As described above, the power conversion device according to the present embodiment includes the composite module in the casing, the main circuit board is disposed on the front surface of the casing, and the cover (main body cover 3) is further provided so as to cover the main circuit board. It is constituted by. And it integrates by connecting a housing | casing and a cover, and forms a power converter device.

  Electrolytic capacitors CB (10) that are most vulnerable to temperature rise are arranged side by side at the bottom of the power converter. The lower part of a power converter here is the lower part in the state which attached the wall-mounted power converter to the wall. That is, the figure shown in FIG. 1 shows the attached state. FIG. 5 also shows the assembled state, but when actually installed, the apparatus is raised from this state and installed. At this time, the electrolytic capacitor CB is installed on the uppermost stream side in the direction of flow of the cooling air by the cooling fan 6, that is, on the lower part of the apparatus.

  An inverter, which is a power conversion device, generally has a wall-hanging structure and is vertically attached to an iron plate such as a panel, and requires a device that is as small and compact as possible. Then, using a die-cast case or the like in which a cooling fin is formed on the inner surface of a box-shaped member having a side wall, a power semiconductor, and a circuit device such as a control circuit unit are mounted on the die-cast case. The case is forcibly air-cooled to reduce the size so as to suppress the temperature rise inside the power converter.

  A vent hole slit A4 for sucking air from the outside is provided in the lower part of the casing. As shown in FIG. 2, the air vent slit A <b> 4 that is the air inlet has a structure that is provided not only on the lower surface of the casing but also on the lower portion of the side surface. And the electrolytic capacitor can fully be cooled by the external air suck | inhaled from this vent-hole slit A4 being sent first.

  As is well known, the electrolytic capacitor is strongly affected by the temperature rise, and as known as Arrhenius' law (10 ° C. half law), the life of the electrolytic capacitor is extremely reduced with respect to the temperature rise. However, according to the present embodiment, the electrolytic capacitor CB is disposed on the lower side of the composite module 11 that is the main heat generation source and on the cooling air inflow side (upstream side). It is possible to sufficiently suppress deterioration due to temperature rise. In addition, since the life of consumables such as electrolytic capacitors can be extended, the reliability of the power conversion device can be improved while reducing costs.

  In this embodiment, the reason why ten electrolytic capacitors are used instead of one is as follows. That is, the present embodiment is characterized in that even if the capacity and input voltage of the power conversion device are different, the same electrolytic capacitor substrate 8 and casing 2 can be used up to a certain extent so as to be shared.

  FIG. 4 is an explanatory view showing a state in which circuit components are attached to the cooling fins 1 (fins). The cooling fin dissipates the heat of the composite module by heat exchange as described above. The cooling fin 1 is attached to the casing 2 with eight screws as indicated by attachment lines C13 to C20. Further, the composite module 11 is attached to the cooling fin 1 with four screws as indicated by attachment lines C9 to C12.

  Here, in the lower part of the front of the casing 2, that is, on the upstream side of the cooling air from the vent slit A4, a direction substantially perpendicular to the flow direction of the cooling air (horizontal direction when the power converter is installed) The notch ventilation hole A3 provided in is provided. In this embodiment, the heat of the power semiconductor module is not shielded so as not to go to the main circuit board having the driver circuit, and the heat generated in the main circuit board is circulated by providing this notch air hole A3. To. That is, by the operation of the fan that sucks out the air inside the casing, the air from the main circuit board can be cut out and allowed to flow to the cooling fins through the ventilation holes. In this embodiment, the cutout ventilation holes A3 are provided at two locations, but the number of the cutout ventilation holes A3 and the area of the ventilation holes are not limited. Further, in this embodiment, the position of the cutout vent hole A3 is provided below the cooling fin, the fan is provided at the upper portion of the casing, and the air inside the casing is sucked out, so that the cutout vent hole A3 is formed. The air from the main circuit board is passed through the fins.

  FIG. 5 is a diagram illustrating an appearance of the power conversion device according to the present embodiment. A front cover 14 and a terminal block cover 15 are each attached to the cover 3 by two screws as shown by attachment lines C21 to C22 and C23 to C24. The front cover 14 has a structure in which a digital operation panel 17 is attached after the blind cover 16 is attached.

  FIG. 6 is a diagram showing an arrangement of main components of the main circuit board 7 in this embodiment. The cable 18 is for interface with the control board 9. The switching transformer 19 and the switching element 21 are MOS-FETs and are basic components of a DC / DC converter. The cable 20 is a power cable for the cooling fan 6.

  FIG. 7 is a schematic diagram of a main circuit board of the power conversion device according to the present embodiment. Here, in the present embodiment, a plurality of notched through holes 22 are provided on the main circuit board. By providing the cutout through hole 22 in the main circuit board 7, air between the main circuit board 7 and the cover 3 covering the main circuit board 7 flows through the cutout through hole 22 to the front of the casing. . This air flow is also due to the operation of the fan 6 shown in FIGS. That is, in this embodiment, the main circuit board 7 and the composite module are not thermally shielded, but the main circuit board 7 is provided with the notched through hole 22 and the casing is provided with the notched air hole A3. The air from the main circuit board can also be circulated by the suction operation of the fan 6 for flowing the air inside the casing to the fins 1.

  Furthermore, in the present embodiment, as shown in FIGS. 1 and 3, ventilation hole slits A <b> 2 are provided on both side surfaces of the cover 3. In the exploded perspective view shown in FIG. 3, the main circuit board 7 is properly mounted and mounted on the casing 2, and the cooling fan mounting plate 5 is mounted on the casing 2, and the ventilation hole slits A <b> 2 opened on both side surfaces of the cover 3. The positional relationship of the notch through hole 22 will be described.

  D1-D2 in FIG. 3 is the uppermost line of the vent hole slit A2. That is, in the flow direction of the cooling air, which is the longitudinal direction of the casing 2, D1-D2 is a line indicating the most downstream side of the vent hole slit A2. The notch through hole 22 is provided on the main circuit board in a region between the D1-D2 and the cooling fan mounting plate 5. That is, the uppermost line D3-D4 in the orthogonal direction of the vent hole slit A2 opened on both side surfaces of the cover 3 in FIG. 3 corresponds to the projection line D3-D4 of the main circuit board 7 in FIG.

  The region between the uppermost line D1-D2 of the ventilation hole slit A2 and the cooling fan mounting plate 5 indicates the region of the arrow line E of the main circuit board 7 in FIG. As described above, the plurality of cutout through-holes 22 are designed to be arranged on the main circuit board in the region between D1-D2 and the cooling fan mounting plate 5 (the region of the arrow line E). The reason is as follows.

  As described above, the second notch through-hole portion 22 is arranged on the main circuit board corresponding to the region indicated by the arrow E in FIG. 6, and this region is used for cooling from the vent hole slit A4 in the casing. It is the downstream side of air and corresponds to the upper part in the power conversion device. The power conversion device in the present embodiment has a wall-mounted structure, and the cooling fan 5 is installed at the top of the power conversion device when the device is installed.

  And since heat is normally conducted from the lower side to the upper side of the inside of the apparatus, the higher the temperature is on the downstream side of the cooling air of the apparatus (the upper side of the apparatus), the higher the temperature becomes. The lower it is, the lower it is. Also in this sense, the area around the notch through-hole portion 22 arranged in the upper part of the apparatus becomes a heat accumulation place, and the temperature is highest in the apparatus. For this reason, the notched through-hole portion 22 is provided in the vicinity of a component in which the generated loss of the component itself mounted on the main circuit board is relatively large. Components with relatively large loss generated by the components mounted on the main circuit board include the DC / DC converter MOS-FETs of the switching transformers 19 and 21 and resistors not shown.

  These positional relationships and air flows will be described with reference to FIG. The cutout through hole 22 of the main circuit board 7 is provided above the ventilation hole slit A2, and the cutout ventilation hole A3 of the casing is provided below the cutout through hole 22 and below the cooling fin. It has been. As a result, the air from the intake port flows to the upper portion of the main circuit board, and then flows to the cutout ventilation hole A3 in the lower portion of the casing through the cutout through hole 22. After passing through the cooling fins 1 through the notch ventilation holes A3, the air is sucked out by the fan 5. As described above, the circulation efficiency of the air inside the apparatus can be further increased by the positional relationship between the vent and the intake.

  The operation when air flows in this way will be described. As the cooling fan 5 rotates in a suction manner, the air sucked from the intake hole slit A4 cools the electrolytic capacitor CB as described above, and then flows to the cooling fins to perform heat exchange. Here, although heat conduction is performed in the cooling fin 1 from the power semiconductor that is a heating element, since the loss of the power semiconductor is large, even the air after cooling the electrolytic capacitor CB takes heat of the cooling fin. It is possible to exchange heat.

  On the other hand, the air sucked from the vent hole slit A2 provided on both side surfaces of the cover 3 is circulated in the power conversion device by the cooling fan 5 performing the sucking operation. First, after passing through the notch through hole 22 (first vent) provided on the main circuit board, it flows through the space between the main circuit board and the casing, and the notch vent hole A3 (second Head to the vent. At this time, warm air stagnated in the vicinity of the notch through hole 22 (first vent) can be circulated inside the apparatus. That is, it is possible to allow warm air inside the power conversion device to flow and eliminate heat stagnation that becomes a heat accumulation place.

  Thus, in the present embodiment, air from the vent hole slit A2 (intake port) flows into the first space between the main circuit board and the cover, and the main circuit board and the front surface from the first space. Flows into the second space between. Then, after flowing from the second space into the casing, the fan 6 sucks it out of the power converter. At this time, as described above, the notch through-hole 22 (first vent) that communicates the first space and the second space is disposed above the vent hole slit A2 (intake port). . In addition, the second ventilation port that communicates the second space and the inside of the casing is disposed below the first ventilation port and below the cooling fin that the casing covers.

  Furthermore, the air inside the casing is sucked out by a fan provided in the upper part of the casing, so that the air from the second vent is heat-exchanged by the cooling fins and then released to the outside of the power converter. As described above, the fan operates so as to flow the air from the second ventilation port to the cooling fin, and the arrangement thereof is not limited to the upper part of the casing.

FIG. 8 is an explanatory diagram showing a simulation example of the flow velocity distribution inside the housing in one embodiment of the power conversion device according to the present invention.
(A) is a case where the cutout ventilation hole A3 of the casing 2 is provided in the direction substantially perpendicular to the flow direction on the downstream side of the cooling air, and the cutout through hole portion 22 is not provided on the main circuit board. It is an example of the flow velocity distribution simulation inside an inverter apparatus.
(B) is an embodiment according to the present invention, in which a cutout ventilation hole A3 (second vent) of the casing 2 is provided on the upstream side (lower part of the apparatus) of the cooling air, and the orientation of the cutout ventilation hole A3 is shown. The direction is almost perpendicular to the flow direction. Further, it is a flow velocity distribution simulation example inside the inverter device when the cutout through hole 22 (first vent) is provided on the main circuit board. In this case, it can be seen that the flow velocity distribution inside the inverter device flows evenly and heat stagnation does not occur.

  In order to reduce the size of the device, it is necessary to increase the mounting density of elements on the main circuit board. However, the temperature inside the device tends to increase. Therefore, in the present embodiment, as described above, the parts having a relatively large generated loss are arranged in the region E of FIG. 5, and a notch through hole (first vent) is provided in the periphery thereof, and these parts are provided. The air around the parts is circulated inside the device. Thereby, as shown in the simulation (b) of FIG. 8, generation of heat stagnation can be suppressed, so that it is possible to improve the cooling capacity while reducing the size of the power converter.

  As described above, according to the present embodiment, in an apparatus that can supply AC power of variable voltage and variable frequency to an AC motor, a cooling action by a cooling fan (fan) can be sufficiently obtained even when the mounting density is increased. Thus, it is possible to provide a power conversion device that can be sufficiently miniaturized without causing a temperature increase.

  FIG. 9 is a main circuit configuration diagram of the power converter. The inverter device of this embodiment includes, as a power conversion circuit, a forward converter CON that converts AC power into DC power, a smoothing capacitor CB, and an inverse converter INV that converts DC power into AC power having an arbitrary frequency. The AC motor IM can be operated at a desired frequency. And the cooling fan 6 is attached to the position which can cool the power module in the forward converter CON and the reverse converter INV.

  Various control data of the power conversion device can be set and changed from the operation panel 17. The operation panel 17 is provided with a display unit capable of displaying an abnormality. When an abnormality of the power conversion device is detected, the display is displayed on the display unit. The type of the operation panel 17 of the present embodiment is not particularly limited, but it is configured as a digital operation panel so that the operation can be performed while viewing the display on the display unit in consideration of the operability of the apparatus user. . The display unit is not necessarily configured integrally with the operation panel 17, but it is desirable that the display unit be configured integrally so that an operator of the operation panel 17 can operate while viewing the display. Various control data of the power converter input from the operation panel 17 is stored in a storage unit (not shown).

  The temperature detector THM detects the temperature of the power module in the forward converter CON and the inverse converter INV. The temperature detector THM may be a temperature relay whose output contact is turned on or off at a preset temperature, or a thermistor whose resistance value changes depending on the temperature. Note that the thermistor may have a characteristic that the resistance value increases or decreases as the temperature rises.

  In this embodiment, the control circuit 9 controls the entire inverter device. The control circuit 9 controls the switching elements of the inverse converter INV based on various control data input from the operation panel 17 and performs control processing necessary for the entire apparatus. Although an internal configuration is omitted, a microcomputer (control arithmetic unit) that performs an operation based on information from storage data of a storage unit in which various control data is stored is mounted.

  The driver circuit 7 drives the switching element of the inverse converter INV based on a command from the control circuit 9. As will be described later, a switching regulator circuit (DC / DC converter) is mounted in the driver circuit 7 to generate each DC voltage necessary for the operation of the power conversion device, Supply.

CON ... forward converter, CB ... smoothing electrolytic capacitor, INV ... reverse converter, IM ... AC motor, 1 ... cooling fin (fin), 2 ... body case (casing), 3 ... body cover (cover), 4 ... Wire drawing plate, 5 ... Cooling fan mounting plate, 6 ... Cooling fan (fan), THM ... Temperature detector (temperature sensor), 7 ... Main circuit board, 8 ... Electrolytic capacitor board, 9 ... Control board, 10 ... Conductor copper Bar 11, composite module (aggregate of power semiconductors) 12 control power holding substrate 13 base plate 14 surface cover 15 terminal block cover 16 blind cover 17 digital operation panel 18 flat Cable, 19 ... switching transformer, 20 ... cooling fan power cable, 21 ... DC-DC converter MOS-FET, 2
2 ... Notched through hole (first vent) provided on the main circuit board, TM1 ... Control circuit terminal block, TM2 ... Main circuit terminal block, R ... Resistor, A1 ... Hole through which the electrolytic capacitor CB passes, A2: Ventilation hole slits opened on both sides of the cover 3, A3: Notched ventilation holes (second ventilation holes) provided in the casing 2, A4: Ventilation hole slits provided in the lower part of the casing.

Claims (5)

Power semiconductors,
Cooling fins for cooling the power semiconductor;
A casing provided with the cooling fins,
A main circuit board including a driver circuit,
A cover covering the main circuit board;
A power conversion device comprising:
A vent hole that is provided below the cooling fin in the use state of the power converter, and allows air from the main circuit board to flow into the casing;
A power conversion device comprising: a cooling fan for flowing air from the vent to the cooling fins. The power conversion device according to claim 1,
A smoothing capacitor provided below the vent in the usage state of the power converter; and a first intake port provided below the smoothing capacitor;
The power converter according to claim 1, wherein the cooling fan causes air flowing from the first air inlet to the smoothing condenser to flow through the cooling fin. The power converter according to claim 1 or 2 ,
One or more said vent holes are provided, The power converter device characterized by the above-mentioned. The power conversion device according to any one of claims 1 to 3 ,
The circuit board is provided with a vent on the upper side of the cooling fin when the power converter is in use. The power conversion device according to any one of claims 1 to 4 ,
The power converter according to claim 1, wherein the cooling fan is provided above the cooling fin in a use state of the power converter.

Images