JPH06245525A - Power converter - Google Patents

Abstract

PURPOSE:To arrange an automatic type converter and an inverter optimally, and to attain miniaturization and the saving of space by housing the converter and the inverter in the same box body and cooling the converter and the inverter by a common cooling fan. CONSTITUTION:A converter and an inverter are housed in the same box body, a semiconductor stack 6 for the inverter is disposed to the lower section of a semiconductor stack 3 for the converter, cooling air 10 is taken in from a suction hole 11 formed to the lower section of a device by a cooling fan 9, and air is flowed through a heat sink 8 cooling semiconductor elements 7 for the inverter, thus cooling the semiconductor stack 6 for the inverter. Cooling air 10 passed through the heat sink 8 is flowed through a heat sink 5 for the converter in semiconductor elements 4 for the converter, thus cooling the semiconductor stack 3 for the converter. Accordingly, the power converter can be miniaturized, space saved and cost reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power conversion device which is housed in the same box body and is composed of a converter and an inverter, and is particularly aimed at downsizing, space saving, and cost reduction. Power converter.

[0002]

2. Description of the Related Art A power converter using a semiconductor element is
With the development of high-performance semiconductor devices and the development of PWM control technology, they are being used more and more.

The power converter is represented by an uninterruptible power supply, as shown in FIG. 5, a converter 22 for converting AC of the commercial power supply 1 into DC and an inverter 2 for converting DC into AC.
A device having a combination of 3 is generally used. Due to the recent technological progress, in addition to the PWM conversion of the inverter part,
It is becoming more and more common for the data section to also consist of a PWM type self-exciting converter.

Here, the advantage of using the self-exciting converter will be briefly described. Unlike a general thyristor rectifier, active power and reactive power can be independently controlled, and the input power factor is controlled to 1. By doing so, it is possible to minimize the required input capacity as a power conversion device. Also, if the semiconductor elements that compose the self-exciting converter have a pulse train with a predetermined pulse width, they can be connected to the AC input side. This is the point that it is possible to suppress the harmonic current that is generated.

As a drawback, since it is necessary to switch the semiconductor element used for the converter with higher harmonics, the loss generated from the semiconductor element is relatively large, and it is necessary to discharge and cool the heat generated by the loss. There is a point. Next, referring to FIG. 4, description will be given of an in-panel configuration of a conventional power conversion device including a converter and an inverter.

In the figure, 1A is a semiconductor element, a first housing box for accommodating a self-exciting converter for converting AC power into DC, and 1B is a semiconductor element for converting DC power into AC. A second storage box for accommodating the self-excited inverter to be converted, 2 is a self-excited converter and a self-excited inverter
It is a power conversion device that also has a power supply. Further, 3 is a semiconductor stack for converters, and 6 is a semiconductor stack for inverters. The cooling of the semiconductor stack 6 for inverter will be described as an example.

The semiconductor stack 6 for inverter is composed of an air-cooled heat sink 8 for cooling the heat loss generated by the semiconductor element 7 for reverse conversion, and a cooling fan 9B is provided on the upper part of the device.
The cooling air 10 is taken in through the intake hole 11 and is exhausted from the power converter exhaust hole 12B via the heat sink 8 and the cooling fan 9B.

Similarly, the converter semiconductor stack 3 is also housed in the first housing box 1A and is cooled in the same manner as the inverter semiconductor stack 6 except that it is cooled by using another cooling fan 9A. .

The circuit configuration of the PWM converter and the inverter will be described with reference to FIG. The converters and inverters are formed by bridge-connecting a circuit composed of switchable semiconductor elements 101 to 104 such as transistors and diodes 105 to 108 which are respectively connected to these semiconductor elements 101 to 104 in antiparallel. The AC side is a voltage-type self-exciting converter or inverter, which is connected to an AC power source (not shown) via an AC reactor 109 and a large-capacity electrolytic capacitor 110 is connected to the DC side.

That is, since the converter and the inverter have almost the same circuit configuration, if the capacity is the same, the converter and the inverter are often composed of the same parts, and the semiconductor stack It is advantageous from the viewpoint of standardization that the configurations are the same or that the number of types of stack configurations is not increased.

Therefore, if the semiconductor stacks 3 and 6 of the converter and the inverter have the same structure, the first and second storage boxes 1A and 1B for storing them and the cooling fans 9A and 9 are stored.
It is advantageous that the first storage box body 1A and the second storage box body 1B have the same structure, with B being the same. Now, in order to consider the loss generated in the converter and inverter circuits having the same capacity, the current flowing through the semiconductor will be described.

Considering FIG. 2 as a converter circuit, and letting the current flowing through one arm be ICON, the energizing current per cycle is expressed as shown in FIG. (However, in order to make it easier to understand, the PWM frequency is shown as an extremely low frequency here.)

In the waveform of FIG. 3, the current on the positive side is diode 1
05, the current on the negative side is the transistor 1
Although it is a current flowing through the transistor 01, which differs depending on the control amount, according to the usual selection of the converter, the current flowing to the diode side is generally about twice as large as the current flowing to the transistor.

The loss of the semiconductor is represented by the product of the current flowing and the voltage drop of the semiconductor. The voltage drop of the diode is lower than that of a switching element such as a transistor. For example, the switching element has a rated current of about 3v. The voltage drop is about 1.5 V, which is about 1/2 of the voltage drop.

Next, considering FIG. 2 as an inverter circuit,
Letting IINV be the current flowing through the arm, the conduction current per cycle is as shown in FIG. 3 like the converter, but this time, the positive side current is the current flowing through the transistor 101, and the negative side current. Becomes the current flowing in the diode 105, which is the opposite of the converter, and differs depending on the control amount and the load power factor. However, according to the usual inverter selection, the current flowing to the transistor side is now the diode. It is generally about twice as large as the current flowing to the gate side.

Therefore, regardless of the fact that the same amount of energizing current is applied to the converter and the inverter, the respective generated losses are different. In other words, the converter has a large amount of current flowing to the diode side, and the inverter has a large amount of current flowing to the transistor side. Therefore, the generated loss is 20 to 40% more on the inverter side than on the converter side. Become.

[0017]

Now, in the power converter having such a structure, a converter and an inverter are provided.
Summarizing the configuration of the inverter and the cooling method, the components of the converter or the inverter are almost the same as the structure of the power converter having both the converter and the inverter with the same current rating. Therefore, the hard structure is the same, but the cooling design is typified by an inverter with a large loss generated. In other words, when the converter and the inverter have the same configuration and are stored in the same box for cooling, the cooling on the converter side has less loss than the inverter, so there is a margin. The power converter is disadvantageous in terms of downsizing, footprint, and price.

The object of the present invention has been made in view of the above-mentioned points, and in a power conversion device composed of a converter and an inverter, the components of the converter and the inverter are the same or not. If the configuration is close to the above, considering the difference in the loss generated by the converter and the inverter, the layout of the converter and the inverter in the storage box is optimized to reduce the size and save the space. Another object is to provide a power converter.

[0019]

In order to achieve the above object, a power converter according to a first aspect of the present invention comprises a self-exciting inverter for converting direct current of a self-exciting converter into alternating current. In the conversion device, the self-exciting converter and the self-exciting inverter are housed in the same box, and the self-exciting converter is cooled by cooling air sucked from the outside of the housing box. -A common cooling fan is used to cool the printer and discharge it to the outside of the storage box.

Further, the power converter of claim 2 of the present invention comprises:
In a power converter comprising a self-excited inverter for converting direct current of a self-excited converter into alternating current, a semiconductor stack for a converter that constitutes the self-excited converter and an inverter that constitutes the self-excited inverter. -A heat sink is attached to each of the semiconductor stacks for data, the heat sinks are housed in the same box, and the cooling air sucked from the outside of the storage box cools the heat sink for the inverter. Convert
It is characterized in that a common cooling fan is used so as to cool the heat sink for data and discharge it to the outside of the storage box.

The power converter according to claim 3 of the present invention is
In a power converter comprising a self-exciting inverter that converts direct current of a self-exciting converter into alternating current, the self-exciting converter and the self-exciting inverter have the same hard configuration,
The self-exciting converter is arranged in the upper part of the box body, the self-exciting inverter is arranged in the lower part of the box body, and cooling air is taken in from the lower part of the side surface of the box body, the self-exciting inverter and the self-exciting converter. It is characterized in that the air is cooled in the order of the air conditioners and exhausted through a common cooling fan attached to the upper part of the box.

[0022]

In the inventions according to claims 1, 2 and 3, the self-exciting converter and the self-exciting inverter having the same current rating are housed in the same box, and the self-exciting inverter is first. Even if the self-exciting converter is cooled after cooling to the above, the heat loss of the self-exciting converter is smaller than that of the self-exciting inverter, so that the cooling capacity is self-excited by the common cooling fan. It is possible to configure the converter and the self-excited inverter with the required and minimum capacity in accordance with the total loss generated, and it is possible to reduce the size and cost of the power conversion device.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. 1 is different from FIG. 4 which is an embodiment of the prior art in that the converter and the inverter are housed in the same box,
The semiconductor stack 6 for inverter is arranged under the semiconductor stack 3 for converter, and the cooling air 10 is taken in from the intake hole 11 attached to the lower part of the device by the cooling fan 9 to attach the semiconductor element 7 for inverter. The semiconductor stack 6 for inverter is cooled by flowing it through the cooling heat sink 8. Further, the converter semiconductor element 4 is configured to cool the converter semiconductor stack 3 by allowing the cooling air 10 passing through the heat sink 8 to flow through the converter heat sink 5. That is the point.

With the above-described structure, the cooling air 10 from the cooling fan 9 is taken in through the intake hole 11, cools the heat sink 8 for the inverter, and further passes through the heat sink 5 for the converter. And passes through the cooling fan 9 and the exhaust hole 12 to be discharged to the outside of the panel. In this way, the cooling air that has cooled the heat sink 8 for the inverter becomes warm, but as explained in the prior art, even if the converter and the inverter operate at the same rating, the generated loss is , It depends on whether the energizing current is flowing mainly on the transistor side or the diode side, that is, since the converter produces less loss with respect to the inverter, the cooling air that has been warmed by the cooling of the inverter Even if cooled, the converter can be cooled sufficiently.

In the above embodiment, the converter is arranged in the upper part and the inverter is arranged in the lower part, and the cooling air is discharged from the entire lower part to the upper part of the apparatus. However, the intention of the present invention is not limited to this. The purpose is to cool the converter by using the cooling air that has cooled the inverter. For example, the converter at the bottom,
The same effect can be obtained even if the cooling air is blown from the upper part to the lower part with the invertor as the upper part, which is not intended by the present invention.

Further, in the above description, in order to cool the converter and the inverter, the converter semiconductor stack 3 and the inverter semiconductor stack 6 are respectively provided with the converter heat sink 5 and the inverter. The heat sink 8 for the motor is attached, but the cooling structure is not particularly limited.

Further, in the above-mentioned embodiment, the case where the transistor is used for the circuit configuration of the converter and the inverter is explained, but the same effect can be obtained by the self-excited converter.
The type of semiconductor element is not particularly limited.

[0028]

As described above, claim 1 and claim 2
According to the invention of claim 3 and the converter of the same current rating.
When cooling the converter and the inverter, the converter and the inverter
Due to the difference in the generation loss of the inverter, the cooling air cooled by the inverter can be used for cooling the converter, so that the converter and the inverter are stored in the same box, and The cooling fan of the inverter can be the same, and the power converter can be downsized, the space can be saved, and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a power conversion device of the present invention, in which (a) is a front view and (b) is a side view.

FIG. 2 is a circuit configuration diagram of a converter and an inverter.

FIG. 3 is a waveform diagram of a current flowing through each arm of the converter and the inverter.

FIG. 4 is a configuration diagram of a conventional power conversion device, in which (a) is a front view and (b) is a side view.

FIG. 5 is a block diagram showing a connection relationship of power conversion devices.

[Explanation of symbols]

 1A, 1B ... Storage box 2 ... Power converter 3 ... Converter semiconductor stack 4 ... Converter semiconductor element 5 ... Converter heat sink 6 ... Inverter semiconductor stack 7 ... Inverter Semiconductor element 8 ... Inverter heat sink 9, 9A, 9B ... Cooling fan 10 ... Cooling air 11 ... Intake holes 12, 12A, 12B ... Exhaust hole 109 ... AC reactors 101-104 ... Transistors 105-108 ... Dio -Do 110 ... Electrolytic capacitor

Claims (3)

[Claims] 1. A power conversion device comprising a self-excited inverter for converting direct current of a self-excited converter into alternating current,
The self-exciting converter and the self-exciting inverter are housed in the same box body, and the self-exciting converter is cooled after the cooling air sucked from outside the housing box cools the self-exciting inverter.
An electric power conversion device characterized in that a common cooling fan cools the battery and discharges it outside the storage box. 2. A power converter comprising a self-excited inverter for converting direct current of a self-excited converter into alternating current,
A heat sink is attached to each of the semiconductor stack for converters forming the self-exciting converter and the semiconductor stack for inverters forming the self-exciting inverter, and the heat sinks are housed in the same box. In addition, common cooling is performed so that the cooling air sucked from the outside of the storage box cools the heat sink for the inverter and then cools the heat sink for the converter and discharges it to the outside of the storage box. A power conversion device characterized by being cooled by a fan. 3. A power converter comprising a self-exciting inverter for converting direct current of a self-exciting converter into alternating current,
The hard configuration of the self-exciting converter and the self-exciting inverter are the same, and the self-exciting converter is on the top of the box.
The self-exciting inverter is arranged in the lower part of the box body, and cooling air is taken in from the lower part of the side surface of the box body.
A power conversion device characterized in that a cooling fan and a self-exciting converter are cooled in this order and exhausted through a common cooling fan mounted on the upper part of the box body.