JPH1169774A - Power conversion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power conversion device which can suppress temperature rise in electronic components formed at a heavy-current substrate and a control circuit formed at a control substrate, and block radiation noise from the control circuit. SOLUTION: A control circuit substrate 8 formed with a control circuit is supported on a shield plate 6, and a plurality of vent holes (e) are formed so that the plurality of vent holes (e) are divided by the shield plate 6 and a heavy-current substrate 4, at the top surface of a heavy-current substrate 4 formed with a main circuit conductor 4a and toward the plurality of vent holes (e) side of a shield cover 12. As a result, cooling wind taken from the plurality of the vent holes is introduced by the heavy-current substrate 4 and the control circuit substrate 8, and circuit components formed on the substrates 4, 8 are cooled, so that temperature rise can be maintained within a fixed value. The control circuit substrate 8 which is easily affected by radiation noise is blocked and protected by the shield plate 6, thus enabling suppression of outflow radiation noise to the outside of the device by the shield cover 12, and suppress infiltrating radiation noise to the inside of the device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power converter, and more particularly, to a power converter including a power converter using a forward converter, an inverse converter, or both, and the power converter is formed of a semiconductor. To a power converter to be used.

[0002]

2. Description of the Related Art Forward converters (full-wave rectifier diodes or regeneratively controllable converters) and inverters (inverters for converting a DC voltage into a variable frequency / variable voltage AC) which are power converters, and these converters As a conventional technique relating to a power conversion device provided with a control circuit for controlling the power, a technique described in, for example, Japanese Patent Application Laid-Open No. 8-13088 is known. The power conversion device according to the related art includes a main circuit made of a semiconductor constituting a forward converter and an inverse converter provided on a heat sink, a control circuit for controlling the semiconductor, and a device for forcibly cooling the main circuit. A cooling fan, and a structure in which the main circuit, the control circuit, and the cooling fan made of these semiconductors are all covered with a cover from above, and the control circuit is cooled by a cooling air generated by the cooling fan above the semiconductor constituting the main circuit. Is provided at a position higher than the flow of the air.

[0003] Another prior art is disclosed in Japanese Patent Laid-Open No. 2-1.
A technique described in Japanese Patent No. 3266 is known. This power conversion device according to the prior art is configured such that a fin of a cooling heat sink is provided upward, a control board is provided above a fin end at a predetermined interval, and the control board is covered by an upper case. And this power converter,
In addition, the main circuit electrical components (forward converter,
Smoothing capacitors, inverters, etc.) are arranged, the entire main circuit electrical component part is hermetically sealed with a lower case, and an air passage is provided only in the cooling fin part.

Further, as a prior art relating to a power converter, there is, for example, a technique proposed in Japanese Patent Application No. 8-250532. This prior art power converter is:
Main circuit for connecting main components such as forward converter, electromagnetic contactor, initial charging current suppression resistor connected in parallel with the electromagnetic contactor, smoothing capacitor, discharge resistor for discharging the charge of the smoothing capacitor, inverter, etc. Supplying power to a conductor, a gate drive circuit for driving a forward converter and an inverter, a power supply circuit thereof, a voltage detection circuit for detecting a voltage (smoothing capacitor voltage) on an input side of the inverter, and a control circuit. A power supply circuit is provided with a large current board made of one insulating board, and an insulating member is interposed between the plus main circuit conductor and the minus main circuit conductor of the main circuit conductor to reduce radiation noise. This makes it possible to achieve a reduction.

[0005]

In recent years, a control circuit provided on a control board of a power conversion device has a large capacity memory such as a one-chip microcomputer, a ROM and a RAM for miniaturization and weight reduction, and peripheral circuit components thereof. , Which are arranged very densely to increase the mounting density. Therefore, the distance between the electronic components used in the control circuit is very short, and heat generation is a problem.

On the other hand, Japanese Unexamined Patent Application Publication No.
The power converter described in Japanese Patent Publication No. 84 has a problem that the control circuit may malfunction due to a rise in temperature because the main circuit is cooled but the control circuit board is not cooled. I have. That is, this prior art is
A cooling fan and ventilation holes for taking in cooling air are provided at both ends of the case so as to face each other in a substantially straight line.The control circuit board is fixed at a position higher than the flow of air from the cooling fan to control the flow of cooling air. Since there is no guide plate leading to the circuit board side, the control circuit board is hardly cooled, and the electronic components used in the control circuit generate heat, and the temperature rise due to this heat tends to cause a malfunction. Have.

In general, a forward converter and an inverse converter, which are power converters, are constituted by high-speed switching elements, and a method of controlling the high-speed switching elements by high-frequency pulse width modulation (PWM) is widely used. And the capacity is increasing. The high-speed switching elements and the main circuit conductors connecting them emit radiation noise (a kind of electromagnetic wave) due to high dv / dt and high di / dt during high-speed switching. Since the radiation noise adversely affects a control circuit in the power conversion device and other peripheral devices other than the power conversion device, it is necessary to minimize the radiation noise.

On the other hand, in the power converter described in Japanese Patent Application Laid-Open No. Hei 8-130884, since the control circuit board is disposed directly above the inverter and the main circuit conductor, the influence of radiation noise is directly reduced. The problem is that electronic components such as one-chip microcomputers are liable to malfunction, and there is also a problem that suppression of radiation noise emitted outside the device is not considered. I have.

On the other hand, a power conversion device proposed in Japanese Patent Application No. 8-250532 is composed of a forward converter, a smoothing capacitor,
A large-current board on which a main circuit conductor for connecting an inverter and a gate drive circuit, its power supply, a voltage detection circuit, a power supply circuit for a control circuit, and the like are provided on the same board, and a control circuit board on which a control circuit is provided. Cooling is not considered. That is, in this prior art, in particular, while the heat generated by the main circuit conductors provided on the large-current board, the power supply circuit for the control circuit, and the discharge resistance of the smoothing capacitor is relatively large, cooling for these is hardly considered. Therefore, there is a problem in that the main circuit conductor generates heat due to a current that increases with an increase in load, and warps the large current substrate due to thermal deformation. Further, in this conventional technology, no electromagnetic wave shielding is performed between the forward converter, the inverse converter, and the control circuit board, and measures are taken to suppress radiation noise emitted to the outside of the device, and from the outside of the device to the inside of the device. There is a problem that the control circuit is liable to malfunction because no measures are taken to suppress intrusion of radiation noise.

Further, a power converter described in Japanese Patent Application Laid-Open No. Hei 2-13266 has a lower case in which a forward converter, a smoothing capacitor, an inverse converter and the like, which are main circuit electrical components, are arranged on a cooling fin base. Since there is no ventilation hole for cooling the main circuit electrical components themselves, each main circuit electrical component is not directly exposed to the cooling air, and the cooling of each main circuit electrical component is performed by fins. There is a problem that the cooling must be performed only from the part and the cooling effect is small.

Further, in this prior art, a cooling fan for cooling the cooling fins and a ventilation hole for taking in the cooling air are arranged substantially in a straight line, similarly to the above-mentioned Japanese Patent Application Laid-Open No. Hei 8-130884. However, since the control circuit board is fixed at a position higher than the flow of the wind by the cooling fan, the cooling of the control circuit board must be performed in anticipation of cooling by natural convection. ing. Further, in this conventional technique, even in the case of a structure in which a guide is provided in a cooling fin cooling air passage, a part of the air flow in the air passage is branched along the guide and flows to the control board, the heat is generated by a main heat source in the power converter. As the temperature of the cooling fins that cool a certain forward converter or inverse converter rises, the temperature of the cooling air in the wind path also rises, and a part of the increased airflow in the wind path is sent to the control circuit board side by a guide. Even if branched, the cooling effect of the control circuit board cannot be improved,
In some cases, the cooling performance of the control circuit board is deteriorated more than the cooling by natural convection, and there is a problem that the wind having a higher temperature than the temperature rise by the control circuit board itself may be sent.

An object of the present invention is to solve the above-mentioned problems of the prior art, to enhance the cooling effect of the power converter,
Provided is a highly reliable power conversion device capable of shielding radiation noise from a control circuit, suppressing radiation noise emitted outside the device, suppressing radiation noise from entering the device, and absorbing radiation noise. It is in.

[0013]

According to the present invention, there is provided a power converter comprising at least one of a forward converter for converting AC to DC and an inverse converter for converting DC to AC.
In the power converter, the power converter includes a cooling fin attached to a cooling fin base, a control circuit that controls the power converter, and a cover that covers the power converter and the control circuit. This is achieved by providing an independent ventilation hole for sucking cooling air for the control circuit in the cover, and simultaneously cooling the cooling fins and the control circuit with a predetermined air volume by a cooling fan that is the same cooling source. You.

[0014] Further, the object is that the power converter and other electrical components are connected on a cooling fin base, and a cooling fin base on which these main circuit electrical components are arranged and the control circuit are configured. The cover position corresponding to the space between the control circuit board and the cover position corresponding to the cover between the control circuit board and the upper surface of the cover is provided with independent ventilation holes for cooling air suction. This is achieved by simultaneously cooling the cooling fins, the main circuit electrical components, and the control circuit with a predetermined air flow rate by using a cooling fan as a cooling source.

Further, the object is to provide a main circuit conductor for connecting the power converter to another electrical component, a gate drive circuit for driving the power converter, a DC voltage detection circuit, and a power supply circuit for a control circuit. A large current board, and a control circuit board constituting the control circuit, wherein a position of a cover corresponding to between the cooling fin base and the large current board; Independent cooling air suction holes are provided at the position of the cover corresponding thereto, and at the position of the cover corresponding between the control circuit board and the upper surface of the cover, and the same cooling source is provided. This is achieved by simultaneously cooling the cooling fins, the main circuit electrical components on the high-current board, and the control circuit with a predetermined air flow, respectively, with the fan.

As described above, according to the present invention, the circuit components to be cooled are provided with the independent ventilation holes, respectively, so that the cooling air is distributed to respective predetermined air volumes by the cooling fans which are the same cooling source. This makes it possible to keep the temperature rise of the electronic components of the forward converter, the inverse converter, the control circuit, and the circuit provided on the large current board within a certain value.

Another object of the present invention is to support a control circuit board provided with a control circuit on a shield plate having a plate-shaped metal or a plate-shaped synthetic resin plated with metal on the entire surface or one surface thereof. Move the board, the main circuit conductor, the power circuit for the control circuit, the gate drive circuit and its power circuit, and the large current board on which the DC voltage detection circuit is provided on the same board to the side opposite to the cooling fan. This is achieved by providing a predetermined space between the shield plates and a predetermined space between the shield plate and the large current substrate, and providing these spaces on the upper surface of the cooling fins serving as heat sinks.

With this configuration, since a shield plate is provided between the control circuit and the main circuit, radiation noise emitted from the main circuit is shielded by the shield plate, and the control circuit stably malfunctions. It can work without happening.

Further, the object is to provide a plurality of ventilation holes on the side opposite to the cooling source (opposite to the cooling fan) of a cover in which metal or synthetic resin is metal-plated on the entire surface or on the inner surface, so that the cover and the shield plate are large. A plurality of ventilation holes that cover the current board and are separated by the shield plate and the large current board are used to cool the control circuit, cool the electronic components mounted on the large current board and the main circuit conductors, forward converters, and inverters. This is achieved by providing for distribution for cooling.

According to the present invention, by providing the shield cover as described above, it is possible to prevent radiation noise from randomly leaking out of the device and adversely affecting peripheral devices. Intrusion radiation noise can also be suppressed.

It is preferable to provide a shield plate for supporting a control circuit board provided with a control circuit, and a hole or notch at an end of the large current board on the cooling source side.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the power converter according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is an exploded perspective view showing the structure of a power converter according to one embodiment of the present invention, FIG. 2 is a cross-sectional view of the power converter according to one embodiment of the present invention, and FIG. FIG. 4 is a cross-sectional view of the power converter according to one embodiment as viewed from a cooling air intake port side. 1 to 3, 1 is a forward converter, 2 is a smoothing capacitor, 3 is an inverter, 4 is a large current board, 4a is a main circuit conductor, 4b is a discharge resistor, 5 is a cooling fin base, and 6 is a shield. 7, 7a are shield plate support members, 8 is a control circuit board, 11 is a cooling fan, 12
Is a shield cover.

A power converter according to an embodiment of the present invention shown in FIGS. 1 to 3 includes a rectifier circuit using a rectifier diode for converting an alternating current such as a commercial AC power supply to a direct current or a regeneratively controllable converter including a semiconductor element. Forward converter 1
And a smoothing capacitor 2 for smoothing the DC voltage of the forward converter 1.
And an inverter 3 of a voltage type inverter constituted by a high-frequency switching element for converting a direct current into an alternating current of a desired frequency are arranged on a cooling fin base 5 having a cooling fin 5a. The main body of the smoothing capacitor 2 is attached to the cooling fin base 5 so that its terminal is on the cooling fin base 5 so as to project toward the cooling fin 5a.

The large current substrate 4 includes a main circuit conductor 4a for connecting terminals of main circuit electrical components such as a forward converter 1, a smoothing capacitor 2, and an inverter 3, and a discharge resistor 4b for the smoothing capacitor 2. And electrical components such as a gate drive circuit (or base drive circuit), a control power supply circuit, and a voltage detection circuit (not shown). The main circuit electrical components such as the forward converter 1, the smoothing capacitor 2, and the inverse converter 3 are connected to the cooling fin base 5 so that the connection terminals of the main circuit conductors coincide with the respective connection portions of the main circuit conductor 4a. Are located. The connection portion is electrically connected by being tightened with a screw, whereby the large current board 4 is fixed on the main circuit electrical component.

The shield plate 6 is made of a metal such as copper, aluminum, iron or the like, or a member obtained by plating a synthetic resin with a metal such as copper, aluminum or the like. Support members 7, 7 erected through holes 4 a through which support members 7 opened at both ends are passed
Due to “a”, the large current substrate 4 is supported at a predetermined interval. A control circuit such as a microcomputer for controlling the forward converter 1 and the inverse converter 3 is disposed on the control circuit board 8. The control circuit board 8 comes into contact with the shield plate 6 via the support member 9. The shield plate 6 is fixedly supported on the shield plate 6 at such an interval as not to be provided.

As described above, according to the embodiment of the present invention, the shield plate 6 is used as a part of the support member of the control circuit board 8, and the shield plate 6 is used as the forward converter 1 which is a source of radiation noise. , The inverter 3, and the main circuit conductor 4a, and the control circuit on the control circuit board 8 which is most susceptible to the noise. Can be performed.

The signal line 10 transmits a control signal of a control circuit provided on the control circuit board 8 to the inverter 3 and the forward converter 1 via the gate drive circuit of the large current board 4.
Further, the cooling fan 11 is fixed to the front side of the cooling fin base 5 and the cooling fin 5a via a cooling fan fixing seat 11a so as to protrude partially above the cooling fin base 5.

The above-mentioned large current board 4, shield plate 6, control circuit board 8 and cooling fin base 5 are made of metal such as copper, iron or aluminum, or metal plating such as copper or aluminum on the whole or inner surface of a synthetic resin. It is covered by the applied shield cover 12. This shield cover 12
Is provided with a plurality of ventilation holes e on the surface opposite to the cooling fan 11, and is fixed by screws 13 to the front, rear, left and right side surfaces of the upper portion of the cooling fin base 5. The inner surface of the fixed portion of the shield cover 12 is formed into an inverted L-shape as shown in the portion A of FIGS. 2 and 3, and the fixed portion with the cooling fin base 5 so that radiation noise does not leak outside. Is provided with a structure for increasing the contact area and fixing the contact area.

As can be seen from FIG. 2, the embodiment of the present invention includes the space between the cooling fin base 5 and the large current board 8, the space between the large current board 8 and the shield plate 6, and the control circuit board 8 and the shield. An airway-shaped space F between the upper surface of the cover 12 and
G and H are formed, and ventilation holes e provided in the shield cover 12 are provided corresponding to the positions of this space.
FIG. 2 shows the states of the cooling air flowing in the above-described airway-shaped spaces F, G, and H as N1 to N5.

In the embodiment of the present invention constructed as described above, the dimension of the inner surface of the shield cover 12 in the longitudinal direction (the direction in which the cooling air flows) is L1, and the dimension of the shield plate 6 in the same direction is L1. Is defined as L2 and the dimension of the large current substrate 4 in the same direction is defined as L3, in one embodiment of the present invention, it is defined that the relationship of L1> L2 ≧ L3 is satisfied. The large current board 4 and the shield plate 6 are both arranged on the side of the ventilation hole of the shield cover 12, and as shown in FIG. 2, the distance d between the inner surface of the shield cover 12 on the cooling fan side and the shield plate 6. Are spaced a few centimeters apart.

By providing the structure as described above,
Cooling air flows N1 to N3 flowing in the air passage-shaped space H between the control circuit board 8 and the upper surface of the shield cover 12 are introduced from the ventilation holes e of the shield cover 12 and guided by the shield plate 6, and N1 to N2 To N3, and the cooling fan 1 while cooling the control circuit components provided on the control circuit board 8.
1 will be discharged. Further, the cooling air N5 also flows through the airflow path-shaped space F formed by the cooling fin base 5, the high-current board 4, and both sides of the inner surface of the shield cover 12. This space serves as an air path for guiding cooling air N5 for cooling main circuit electrical components such as a forward converter, an inverse converter, and a smoothing capacitor. Similarly, the cooling air N4 also flows through the airflow path-shaped space G formed by the large current board 4, the shield plate 6, and both inner side surfaces of the shield cover 12, and cools the circuit components on the large current board 4.

As described above, according to the embodiment of the present invention, the air passage-shaped spaces H, G, and F are formed, and the plurality of ventilation holes e provided in the shield cover 12 are arranged at the positions of these spaces. Then, the air is distributed by the large current substrate 4 and the shield plate 6, and as a result, a plurality of dedicated ventilation holes e are formed in each of the air passage-shaped spaces H, G, and F. As shown by the cooling winds N1 to N5, a smooth flow of the cooling wind can be obtained.

In the above-described embodiment of the present invention, the air passage-shaped spaces H, G, and F can obtain the required fresh cooling air volume by changing the number or the size and shape of the ventilation holes. In addition, the temperature rise of the electronic components and the like in each airway-shaped space can be maintained within a certain value. In the above-described embodiment of the present invention, the shield plate 6 and the shield cover 1 are used.
By using a synthetic resin for 2 and plating the entire surface or the inner surface with copper, aluminum, or the like, it is possible to reduce the weight of the entire device and obtain an advantage that it is advantageous for supporting the shield plate 6. be able to.

It should be noted that the amount of heat generated by the electronic components on the substrate is smaller than the amount of heat generated by the main body caused by the forward converter 1 and the inverse converter 3, so that the amount of air flowing through the air space H, G, F is smaller. ,
This is a part of the air volume that can be obtained by the cooling fan 11, and most of the cooling air flows to the cooling fin 5a side.

FIG. 4 is a diagram showing a structure of a power converter according to another embodiment of the present invention. The example shown in FIG. 4 shows the shapes of the large current board 4 and the shield plate 6 and the flow of the cooling air, and the cooling fan, the shield cover, and the like are the same as those shown in FIGS. Not. In FIG. 4, 14 is a hole, 15 is a notch, and other reference numerals are FIGS.
This is the same as in FIG.

In the embodiment of the present invention shown in FIG. 4, the large current substrate 4 and the radiation noise shielding shield plate 6 are not shown. Dimensions), and a large-current board 4 and a shield plate 6 are provided with a cooling air passage hole 14 and a cutout 15 at one end on the cooling fan 5 side.

Thus, the cooling air N3 for cooling the control circuit provided on the control circuit board 8, the gate drive circuit provided on the large current board 4 and its power supply circuit, voltage detection circuit, and power supply for the control circuit , The cooling air N4 for cooling the discharge resistor 4b, the cooling air N5 for cooling the k main circuit electrical components such as the forward converter 1, the smoothing capacitor 2, and the inverse converter 3 arranged on the cooling fin base 5. As shown in FIG. 4, the electronic components flow smoothly and can be sufficiently cooled.

In the example shown in FIG. 4, the large current board 4 is provided with the hole 14 and the shield plate 6 is provided with the cutout 15, but both the large current board 4 and the shield plate 6 are provided with the hole 14 or the cutout 15. May be provided. As in the case of the embodiment described with reference to FIGS. 1 to 3, it is possible to shield radiation noise and obtain a good cooling effect.

Next, in the above-described embodiment, the reason why the size of the large current substrate 4 and the shield plate 6 is set to be substantially the same as the size of the surface of the cooling fin base 5 (also substantially equal to the size of the inner surface of the shield cover 12). Will be described.

With the downsizing of the power converter, a large current substrate 4
However, there is a case where it is difficult to mount electronic components to be mounted on the large current board 4 due to the miniaturization. Embodiments of the present invention solve the above points,
In order to make the large-current board 4 as large as possible, its size is made substantially the same as the size of the surface of the cooling fin base 5, and the cutout 15 is made to have a size that allows the minimum necessary amount of cooling air to pass through.
Electronic components can be mounted on the vacant portions remaining on both sides of the cutout.

The shield plate 6 has the same size as that of the inner surface of the shield cover 12 in order to shield radiation noise.
It is good that there is no gap between
It is better not to have the hole 14. Therefore, in the above-described embodiment of the present invention, the holes 14 having a necessary minimum size for the passage of the cooling air are provided, and the intrusion of radiation noise from the corners at both ends of the holes 14 is shielded.

FIG. 5 is a diagram showing a structure of a power converter according to still another embodiment of the present invention. The example shown in FIG.
The large current substrate used in the above-described embodiment is unnecessary,
This is an example in which main circuit electrical components are connected by bus bars (copper bars) instead of the main circuit conductor provided on the large current board. In FIG. 5, reference numeral 4d denotes a bus bar, and other reference numerals are the same as those in FIGS.

In the embodiment of the present invention shown in FIG. 5, connection terminals of main circuit electrical components such as a forward converter 1, a smoothing capacitor 2, an inverse converter 3, and a discharge resistor 4b are connected by bus bars 4d as main circuit conductors. The shield plate 6 is directly connected, and a shield plate 6 is provided above the support member 7 in the same manner as in the embodiment described above.
7a. This shield plate 6 has a control circuit board 8 provided with a control circuit on the surface opposite to the surface on which the main circuit electrical components are arranged, as in the above-described embodiment.
Are fixedly supported, and are covered with a shield cover 12 so as to include the entirety. The shield cover 12 is fixed to the upper side surface of the cooling fin base 5.

The shield plate 6 and the shield cover 12
Is made of a metal such as copper, iron, or aluminum, or a member formed by plating a metal such as copper or aluminum on the entire surface or one surface of the synthetic resin (the inner surface of the shield cover 12). The shield cover 12 is provided with a plurality of ventilation holes e on the opposite surface (opposing surface) of the cooling fan 11. These ventilation holes e correspond to positions of a space formed between the shield plate 6 and the upper surface of the shield cover 12 and between the fin base 5 and the shield plate 6 and serving as an air path. Provided. Furthermore, the size L2 of the shield plate 6 is larger than the inner size L1 of the shield cover 12.
And the shield plate 6 is moved toward the ventilation hole e side,
A space d (d ≒ L1−L2) between the inner surface of the shield cover 12 on the side of the cooling fan 11 and the end of the shield plate 6 is provided.

The embodiment of the present invention described with reference to FIG.
With the above-described configuration, the space between the cooling fin base 5 and the shield plate 6 serves as an air path, and cooling air entering through the ventilation holes e cools while cooling the main circuit electrical components. It is discharged outside by the fan 11. Also,
The space between the shield plate 6 and the shield cover 12 serves as an air path, and the cooling air flowing through the ventilation holes e cools the control circuit board 8 while cooling through the space having the above-described distance d. It is discharged outside by the fan 11.

As described above, the plurality of ventilation holes e provided in the shield cover 12 are vertically divided into two by the shield plate 6, and the ventilation holes divided upward are formed by the control circuit board 8.
The cooling fins, the main circuit electrical components, and the control circuit board are each fresh, because the ventilation holes are dedicated to cooling the main circuit components and the multiple ventilation holes divided below are dedicated to cooling the main circuit components. The cooling effect is enhanced by the cooling air.

In each of the above-described embodiments, the forward converter 1 can also be formed by attaching a radio wave absorbing material to the entire surface or one surface of the shield plate 6 and the shield cover 12 or applying a radio wave absorbing paint. And the radiation noise generated from the inverter 3 can be absorbed by the shield plate 6 so as not to reach the control circuit on the control circuit board 8, and the radiation noise can be absorbed by the shield cover 12. In addition, it is possible to suppress outflow of radiation noise from the power conversion device to the outside, and also to suppress radiation noise that enters the device from outside the power conversion device.

In the embodiment of the present invention described above, two cooling fans are provided. However, one cooling fan may be provided depending on the required air volume, or more fans may be provided. When a plurality of cooling fans are provided, the plurality of cooling fans may be considered as one unit.

As described above, in the embodiment of the present invention, a part of the cooling air obtained by the cooling fan is transferred to the side of the cooling fin base on which the main circuit electrical components such as the forward converter, the smoothing capacitor, and the inverter are arranged. A ventilation hole is arranged in the shield cover so that the flow also flows, and the control circuit board is supported by the shield plate, and the shield plate, the large current board provided with the main circuit conductor, and the cooling fin base are separated by a predetermined distance. Are arranged.

Further, in the above-described embodiment of the present invention, the large current board and the shield plate are stacked in two steps on the upper surface of the main circuit electrical component arrangement surface, approaching the plurality of ventilation holes provided in the shield cover. Due to the arrangement, the control circuit board is divided into three layers of space, and a control circuit requiring cooling is provided in each space, the main circuit conductor and the mounting circuit provided on the large current board, and the main circuit electrical equipment. Products are arranged, and a plurality of dedicated ventilation holes are formed respectively corresponding to the three wind path-shaped spaces, so that cooling air entering through the ventilation holes is guided to the shield plate and the large current board. .

In the embodiment of the present invention, the cooling air from the ventilation holes cools the control circuit on the control circuit board, the electronic components on the large current board, and the main circuit electrical components by providing the above-described configuration. After that, it is discharged to the outside by the cooling fan, so that the temperature rise of the main circuit conductors and circuit parts on the large current board, the control circuit parts on the control circuit board, and the main circuit electrical components are kept within a certain value. Temperature problems can be avoided.

In the above-described embodiment of the present invention, the control circuit which is weakest against radiation noise emitted from the forward converter and the inverse converter, that is, the one-chip microcomputer, the RO
M, a control circuit constituted by a memory such as a RAM,
Since the radiation noise is shielded and protected by the shield plate supporting the control circuit board, stable control can be performed. Also, in the above-described embodiment of the present invention, the shield cover can suppress the radiation noise flowing out of the power conversion device and also suppress the radiation noise intruding from the outside of the power conversion device. Can be. Furthermore, the above-described embodiment of the present invention provides a highly reliable power conversion device that is reduced in weight by using a shield plate and a shield cover in which a synthetic resin is plated with metal such as copper or aluminum. be able to.

Although the above-described embodiment of the present invention has been described as being a power converter including a forward converter, a smoothing capacitor, and an inverter, the present invention is directed to any one of a forward converter and an inverter. The present invention can also be applied to a power converter configured with a power converter by only one side, and further includes an inverter that includes a smoothing inductance and forms a current-type inverter instead of a smoothing capacitor. The same applies to the case of using. However, when the device is provided with a smoothing inductance and the inductance becomes large and cannot be accommodated in the device, the inductance may be externally provided.

[0055]

As described above, according to the present invention, the cooling effect of the power converter is improved, the radiation noise is shielded from the control circuit, the radiation noise emitted to the outside of the device is suppressed, and the radiation noise into the device is reduced. It is possible to provide a highly reliable power conversion device capable of suppressing intrusion of radiated noise and absorbing radiation noise.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a structure of a power converter according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the power converter according to the embodiment of the present invention, as viewed from a side.

FIG. 3 is a cross-sectional view of the power converter according to the embodiment of the present invention as viewed from a cooling air intake port side.

FIG. 4 is a diagram illustrating a structure of a power conversion device according to another embodiment of the present invention.

FIG. 5 is a diagram illustrating a structure of a power conversion device according to still another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Forward converter 2 Smoothing capacitor 3 Inverter 4 Large current board 4a Main circuit conductor 4b Discharge resistance 4d Bus bar 5 Cooling fin base 6 Shield board 7, 7a Shield board support material 8 Control circuit board 11 Cooling fan 12 Shield cover 13 Screw 14 hole 15 notch

Claims (10)

[Claims] A power converter comprising at least one of a forward converter for converting alternating current to direct current and a reverse converter for converting direct current to alternating current; a cooling fin having the power converter mounted on a cooling fin base; In a power converter configured to include a control circuit that controls the power converter and a cover that covers the power converter and the control circuit, an independent ventilation hole for cooling air suction is provided for the control circuit. Provided on the cover, by a cooling fan that is the same cooling source,
An electric power conversion device, wherein a cooling fin and a control circuit are simultaneously cooled at a predetermined air volume, respectively. 2. A power converter comprising at least one of a forward converter for converting alternating current to direct current and an inverse converter for converting direct current to alternating current, a cooling fin having the power converter mounted on a cooling fin base, In a power converter including a control circuit for controlling the power converter and a cover for covering the power converter and the control circuit, the power converter and other electrical components are mounted on a cooling fin base. And the position of the cover corresponding between the cooling fin base on which the main circuit electrical components are arranged and the control circuit board constituting the control circuit, and the upper surface of the control circuit board and the cover Independent ventilation holes for sucking cooling air are provided at the corresponding positions of the cover, and the cooling fins, the main circuit electrical components, and the control circuit are simultaneously operated by a cooling fan as the same cooling source. A power converter that cools each of them at a predetermined air volume. 3. A control circuit board provided with the control circuit is supported on a plate-shaped metal or a shield plate having a plate-shaped synthetic resin coated with metal on the entire surface or on one surface. 3. The power converter according to 1 or 2. 4. The cover is formed by applying metal plating on the entire surface or the inner surface of a metal or a synthetic resin, and is provided with a plurality of ventilation holes on a side opposite to a cooling fan serving as a cooling source. The power converter according to claim 1, 2, or 3. 5. A power converter comprising at least one of a forward converter for converting an alternating current to a direct current and a reverse converter for converting a direct current to an alternating current; a cooling fin having the power converter mounted on a cooling fin base; In a power converter configured to include a control circuit for controlling the power converter and a cover that covers the power converter and the control circuit, a main circuit conductor that connects the power converter to another electrical component , A gate drive circuit that drives a power converter, a DC voltage detection circuit,
A large-current board provided with a power supply circuit for a control circuit; and a control circuit board constituting the control circuit, wherein a position of a cover corresponding to between the cooling fin base and the large-current board, The position of the cover corresponding to between the current board and the control circuit board, and the ventilation hole for cooling air suction independent at the position of the cover corresponding to between the control circuit board and the upper surface of the cover. A power converter, wherein a cooling fan provided as the same cooling source simultaneously cools a cooling fin, a main circuit electrical component on a large-current board, and a control circuit with a predetermined airflow. 6. The control circuit board provided with the control circuit is supported on a plate-shaped metal or a shield plate having a metal-plated metal plate on the entire surface or one surface of a plate-shaped synthetic resin. 7. The power converter according to 6. 7. The shield plate and the high-current board are arranged such that the shield plate and the high-current board are moved to the opposite side of a cooling fan serving as a cooling source and a predetermined space is provided between the shield plate and the cooling fan. 7. A power converter according to claim 6, wherein a predetermined space is provided between the fin base and the fin base. 8. The cover is formed by applying metal plating on the entire surface or the inner surface of a metal or a synthetic resin, and is provided with a plurality of ventilation holes on a side opposite to a cooling fan as a cooling source. The power converter according to claim 5, 6, or 7. 9. A plurality of ventilation holes provided in the cover are provided for cooling a control circuit by the shield plate and the large current board, cooling electronic components mounted on the large current board and a main circuit conductor.
For cooling of at least one of the forward converter and the inverse converter,
9. The power converter according to claim 8, wherein the power converter is provided so as to be distributed to a predetermined air volume. 10. A shield plate for supporting a control circuit board on which said control circuit is provided, and a hole or notch provided at an end of a cooling fan which is a cooling source for a large current board. The power converter according to claim 7, 8 or 9.