JP2001268942A - Power converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance power converting efficiency in a power converter to control a temperature rise within the parts and achieve reliability. SOLUTION: In a power converter including a plurality of storage batteries 1 and conductors 2, 3 connecting in parallel such storage batteries 1, the storage batteries are placed so that when reference is made to the positive terminal of one storage battery of the two adjacent storage batteries 1, the negative terminal of the other storage terminal is placed more adjacently in comparison with the positive terminal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power converter for converting and controlling DC power obtained from a DC power supply into AC power, and more particularly to a power converter using a plurality of storage batteries used for smoothing power fluctuations. It is suitable for the device.

[0002]

2. Description of the Related Art As a conventional power converter, for example, as described in Japanese Patent Application Laid-Open No. H11-55938, a plurality of capacitors are arranged in parallel so that they have the same polarity.
Some flat conductors are connected with both ends open.

[0003]

In such a conventional power converter, since the flat conductors connecting a plurality of capacitors are arranged close to each other, the magnetic energy generated from the positive and negative conductors is offset. This is effective for reducing inductance. However, in order to further reduce the inductance, it is desirable to arrange the current flow lines flowing through the positive conductor and the negative current conductor so as to cross each other.

Since heat generated by a storage battery, for example, a capacitor, is radiated to a conductor to which the storage battery is connected, it is desired to effectively use the conductor as a cooling device.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a compact and highly reliable power converter by reducing the inductance and increasing the cooling efficiency of the storage battery by considering the electrode position of the storage battery constituting the power converter. And

[0006]

A first feature of the present invention to achieve the above object is a power conversion device including a semiconductor element and a plurality of storage batteries connected to the semiconductor element, wherein the storage battery is an electric power converter. Are connected in parallel in such a manner that, between the adjacent storage batteries, when the positive electrode of one storage battery is used as a reference, the negative electrode of the other storage battery is closer than the positive electrode.

A second feature of the present invention is that in a power conversion device including a semiconductor element and a plurality of storage batteries connected to the semiconductor element, the storage batteries are electrically connected in parallel, and a capacitor is used as the storage battery. Is used, and between adjacent capacitors, when the positive electrode of one capacitor is used as a reference, the capacitors are arranged such that the negative electrode of the other capacitor is closer to the positive electrode. A third feature of the present invention is that in a power conversion device including a semiconductor element and a plurality of storage batteries connected to the semiconductor element, the storage batteries are electrically connected in parallel, and a capacitor is used as the storage battery. A flat conductor is used to connect the semiconductor element and the capacitor, and between adjacent capacitors, when the positive electrode of one capacitor is used as a reference, the negative electrode of the other capacitor is closer to the positive electrode. The configuration is such that a capacitor is disposed at

According to a fourth feature of the present invention, in a power converter including a semiconductor element and a plurality of storage batteries connected to the semiconductor element, the storage batteries are electrically connected in parallel, and a capacitor is used as the storage battery. Is used, a flat conductor is used to connect the semiconductor element and the capacitor, and a positive conductor and a negative conductor of the flat conductor are arranged close to each other with an insulator interposed therebetween, and between the adjacent capacitors. , Based on the positive electrode of one capacitor,
The capacitor is arranged so that the negative electrode of the other capacitor is closer to the positive electrode than the positive electrode.

A fifth feature of the present invention is that in a power conversion device including a semiconductor element and a plurality of storage batteries connected to the semiconductor element, the storage batteries are electrically connected in parallel, and Capacitors are used,
The cathode foil in the electrolytic capacitor is thermally connected to the case of the electrolytic capacitor, and between adjacent electrolytic capacitors, when the positive electrode of one electrolytic capacitor is used as a reference, the negative electrode of the other electrolytic capacitor is An electrolytic capacitor is arranged so as to be close to the positive electrode.

A sixth feature of the present invention is that in a power conversion device including a semiconductor element and a plurality of storage batteries connected to the semiconductor element, the storage batteries are electrically connected in parallel, and the storage battery is an electrolytic battery. Capacitors are used,
A flat conductor is used to connect the semiconductor element and the capacitor, and a positive conductor and a negative conductor of the flat conductor are arranged close to each other with an insulator interposed therebetween. It is thermally connected to the case of the capacitor, and between adjacent electrolytic capacitors, when the positive electrode of one electrolytic capacitor is used as a reference, the negative electrode of the other electrolytic capacitor is closer than the positive electrode. It is configured to arrange a capacitor.

According to a seventh feature of the present invention, in a power conversion device including a semiconductor element and a plurality of storage batteries connected to the semiconductor element, the storage batteries are electrically connected in parallel, and the storage battery is an electrolytic battery. Capacitors are used,
A flat conductor is used to connect the semiconductor element and the capacitor, and a positive conductor and a negative conductor of the flat conductor are arranged close to each other with an insulator interposed therebetween. It is thermally connected to the case of the capacitor, and the positive conductor of the flat conductor is used on the upper side as compared with the negative conductor, and between the adjacent electrolytic capacitors, based on the positive electrode of one electrolytic capacitor. In this case, the electrolytic capacitor is arranged such that the negative electrode of the other electrolytic capacitor is closer to the positive electrode than the positive electrode.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. Note that common parts of the embodiments are omitted, and the same reference numerals in the drawings of the embodiments indicate the same or corresponding components.

First, a first embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to FIG. FIG. 1 is a perspective view of a flat conductor and a storage battery in a power converter according to a first embodiment of the present invention.
FIG. 3 is a circuit diagram of a power converter to which the present invention is applied, and FIG. 3 is a schematic diagram of a current flow line flowing through a conductor in the first embodiment of the present invention.

The flow of power in the power converter will be described with reference to FIG. 101 is a DC power supply, 102 is a storage battery, a plurality of which are connected in parallel. 103 ~
108 is a semiconductor element, and 109 is a load. DC power supply 10
The DC power supplied by 1 is converted into three-phase AC using the semiconductor elements 103 to 108, and is passed to the load 109. At this time, the inductance generated in the conductor between the DC power supply 101 and the semiconductor elements 103 to 108 is reduced, and the DC power supply 1
The frequency that occurs when 01 supplies power is several tens of kHz.
In order to smooth the fluctuation component of the DC current, it is essential to connect the storage battery 102 in parallel with the DC power supply. The storage battery 102 and the semiconductor elements 103 to 10
In order to reduce the inductance between the two, it is desirable that the distance between them is as close as possible.

FIG. 2 shows an IGBT element as an example of the semiconductor elements 103 to 108.
It is not limited to this.

Referring to FIG. 1, the arrangement of the storage battery and the conductor in the power converter will be described. 1 is a storage battery, 2 is a positive conductor, 3 is a negative conductor, and 4 is an insulating plate. FIG. 1 shows a case where two storage batteries are used.

The conductors 2 and 3 connect the two storage batteries 1 in parallel to reduce the inductance between the storage batteries and the semiconductor elements. Furthermore, in order to reduce the inductance in this section, it is desirable to shorten the distance between the semiconductor element and the positive electrode and the negative electrode of the storage battery. More specifically, as shown in FIG. It is preferable that the positive electrode, which is close to the semiconductor element, is close to a terminal of the conductor connected to the positive electrode of the semiconductor element.

As the storage battery 1, a capacitor can be used. Further, when the DC voltage is low, a large capacity can be obtained by using the electrolytic capacitor, and it becomes possible to temporarily store excess electric energy generated from the load in the electrolytic capacitor depending on the operating condition.

The conductors 2 and 3 are desirably made of a material having a small volume resistivity, specifically copper, in order to reduce the electric resistance. In order to reduce the inductance of the conductor, it is desirable to use a flat conductor as shown in FIG. 1 and arrange the current flow lines flowing through the positive conductor 2 and the negative conductor 3 so as to overlap each other.

The positive electrode-side conductor 2 and the negative electrode-side conductor 3 are arranged with an insulating plate 4 interposed therebetween to ensure insulation. To reduce inductance, the positive conductor 2 and the negative conductor 3
Is preferably as close as possible, and therefore the insulating plate 4 is desirably thin. Therefore, the insulating plate 4 is generally made of a ceramic having a high withstand voltage,
Alternatively, plastics is used for ease of processing.

The current flowing from the storage batteries 1a, 1b to the semiconductor element will be described with reference to FIG. As described above, in order to reduce the inductance between the storage batteries 1a and 1b and the semiconductor element, it is preferable to reduce the distance between each positive electrode and each cathode. Therefore, as shown in FIG. 3, when the power conversion element connection terminal on the positive electrode side is disposed in the upper right part, it is desirable that the storage battery 1 a has the positive terminal on the upper side and the negative terminal on the lower side.

On the other hand, the storage battery 1b is arranged so as to have a positive terminal on the lower side and a negative terminal on the upper side, opposite to the storage battery 1a. By arranging the terminals in a staggered manner as in the present structure, a portion where the current flow lines on the positive electrode side and the current flow line on the negative electrode side flowing through the conductors 2 and 3 overlap with each other is effective in reducing inductance. Hereinafter, this structure in which the terminals of adjacent storage batteries are arranged so that their polarities are alternated is referred to as a staggered structure.

According to the first embodiment of the present invention, the connection method of the plurality of storage batteries 1 connected to the conductors 2 and 3 constituting the power converter is arranged in a staggered arrangement, whereby the storage batteries 1
Since the inductance between the semiconductor element and the semiconductor element can be reduced and the jump voltage generated at the time of switching in the semiconductor element can be suppressed, the snubber circuit can be eliminated and high conversion efficiency can be secured.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 4 is a diagram showing a positional relationship between a storage battery and a flat conductor in a power converter according to a second embodiment of the present invention.

The second embodiment is different from the first embodiment in that the storage battery 1
Is different from using two, in that three are used. In this embodiment, adjacent storage batteries 1
a and 1b, 1b and 1c are connected to conductors 2 and 3 in a staggered arrangement.

Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 5 is a diagram showing a positional relationship between a storage battery and a flat conductor of a power converter according to a third embodiment of the present invention.

The third embodiment differs from the first and second embodiments in that four storage batteries 1 are used. In this embodiment, the adjacent storage batteries 1a and 1b, 1b and 1
c, 1c and 1d have a staggered arrangement, and conductors 2, 3
Connected to

According to the second and third embodiments of the present invention,
As in the first embodiment, the inductance between the storage battery 1 and the power conversion element can be reduced by using a staggered connection method for connecting the plurality of storage batteries 1 constituting the power conversion device to the conductors 2 and 3. . By using many batteries at the same time,
Since the inductance can be further reduced and the jump voltage generated at the time of switching in the semiconductor element can be suppressed, high conversion efficiency can be secured.

Next, a fourth embodiment of the present invention will be described with reference to FIGS. FIG. 6 is a cross-sectional view of the storage battery, the conductor, and the insulating plate of the power converter according to the fourth embodiment of the present invention, taken along the line AA 'shown in FIG.

The fourth embodiment differs from the first, second and third embodiments in that a capacitor is used as the storage battery 1 and the cathode foil 53 constituting the capacitor is thermally connected to the capacitor case 51. Are different. When electricity is supplied, the capacitor generates heat in the anode foil 54 and the cathode foil 53 due to Joule loss. Since the cathode foil 53 is thermally connected to the capacitor case 51, the heat generated in the cathode foil 53 is radiated to the capacitor case 51 and
The heat is radiated from the surface of the power conversion device 1 to the air in the power converter. On the other hand, the heat generated by the anode foil 54 is such that the thermal conductivity of the insulating paper 52 sandwiched between the anode foil 54 and the cathode foil 53 is 0.
Since it is as small as 1 W / (m · K) or less and works as a heat insulating material, most of the heat is radiated to the anode terminal 56.

According to the fourth embodiment of the present invention, the connection method of the plurality of capacitors connected to the conductors 2 and 3 constituting the power conversion device is arranged in a staggered structure, and the connection between the positive terminals as the heat radiation source is performed. By increasing the distance, the heat radiation efficiency from the anode foil 54 to the positive electrode-side conductor 2 is improved, and it is possible to suppress an increase in the internal temperature of the capacitor. As a result, the life of the capacitor is improved, and a highly reliable power converter can be secured. In addition, the size of the capacitor can be reduced, and the size of the entire power converter can be reduced.

[0032]

According to the present invention, by staggering the pole arrangement of the storage battery connected to the conductor, the inductance between the storage battery and the power conversion element can be reduced, and the rise in the internal temperature of the storage battery is suppressed. It is possible to obtain a small and highly reliable power conversion device with high conversion efficiency.

[Brief description of the drawings]

FIG. 1 shows a power converter according to a first embodiment of the present invention.
It is a perspective view which shows a storage battery and a flat conductor.

FIG. 2 is a circuit diagram of the power converter according to the first embodiment of the present invention.

FIG. 3 is a schematic diagram showing current flow lines from a storage battery to a power conversion element in the flat conductor of the power conversion device according to the first embodiment of the present invention.

FIG. 4 shows a power conversion device according to a second embodiment of the present invention.
It is a figure which shows the positional relationship of a storage battery and a flat conductor.

FIG. 5 is a diagram showing a power converter according to a third embodiment of the present invention;
It is a figure which shows the positional relationship of a storage battery and a flat conductor.

FIG. 6 shows a power conversion device according to a fourth embodiment of the present invention.
FIG. 4 is a cross-sectional view of a storage battery and a flat conductor taken along the line AA ′ of the power converter in FIG. 3.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Storage battery, 2 ... Positive side conductor, 3 ... Negative side conductor, 4 ... Insulating plate, 51 ... Capacitor case, 52 ... Insulating paper, 53 ...
Cathode foil, 54 ... Anode foil, 55 ... Capacitor cap, 5
6 ... Positive terminal, 57 ... Negative terminal, 58 ... Mounting screw, 1
01 ... DC power supply, 102 ... storage battery, 103 ... inverter, 109 ... load.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Eiji Fukumoto 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture F-term in Hitachi Research Laboratory, Hitachi Ltd. 5H007 AA01 AA06 AA07 BB06 CA01 CC01 CC23 HA03 HA04 5H740 BA11 BB05 BB09 BB10 MM10 NN17 PP04

Claims (7)

[Claims] In a power converter including a semiconductor element and a plurality of storage batteries connected to the semiconductor element, the storage batteries are electrically connected in parallel, and one of the storage batteries is connected between the adjacent storage batteries. A power converter, wherein a plurality of storage batteries are arranged on a positive electrode such that a negative electrode of the other storage battery is close to the positive electrode. 2. A power converter comprising a semiconductor element and a plurality of storage batteries connected to the semiconductor element, wherein the storage batteries are electrically connected in parallel, a capacitor is used as the storage battery, Between the capacitors, based on the positive electrode of one capacitor,
A power converter wherein a capacitor is arranged such that a negative electrode of the other capacitor is closer to a positive electrode than a positive electrode. 3. A power converter comprising a semiconductor element and a plurality of storage batteries connected to the semiconductor element, wherein the storage batteries are electrically connected in parallel, and a capacitor is used as the storage battery. A flat conductor is used to connect the capacitor and the capacitor, and the capacitors are arranged so that when the positive electrode of one capacitor is used as a reference between the adjacent capacitors, the negative electrode of the other capacitor is closer to the positive electrode. A power conversion device characterized in that: 4. A power converter comprising a semiconductor element and a plurality of storage batteries connected to the semiconductor element, wherein the storage batteries are electrically connected in parallel, and a capacitor is used as the storage battery. A flat conductor is used for connection of the capacitor and the positive conductor and the negative conductor of the flat conductor are arranged close to each other with an insulator interposed therebetween. A power converter, wherein a capacitor is arranged such that a negative electrode of the other capacitor is closer to a positive electrode than a positive electrode when the reference is used. 5. A power converter comprising a semiconductor element and a plurality of storage batteries connected to the semiconductor element, wherein the storage batteries are electrically connected in parallel, and an electrolytic capacitor is used as the storage battery, The cathode foil in the capacitor is thermally connected to the case of the electrolytic capacitor, and between the adjacent electrolytic capacitors, when the positive electrode of one electrolytic capacitor is used as a reference, the negative electrode of the other electrolytic capacitor is connected to the positive electrode. An electric power converter, wherein an electrolytic capacitor is arranged so as to be relatively close to each other. 6. A power converter comprising a semiconductor element and a plurality of storage batteries connected to the semiconductor element, wherein the storage batteries are electrically connected in parallel, and an electrolytic capacitor is used as the storage battery. A flat conductor is used to connect the element and the capacitor, the positive conductor and the negative conductor of the flat conductor are arranged close to each other with an insulator interposed therebetween, and the cathode foil in the electrolytic capacitor is a negative electrode of the electrolytic capacitor. The electrolytic capacitor is thermally connected to the case, and between the adjacent electrolytic capacitors, when the positive electrode of one electrolytic capacitor is used as a reference, the electrolytic capacitor is so positioned that the negative electrode of the other electrolytic capacitor is closer than the positive electrode. A power converter, which is arranged. 7. A power converter comprising a semiconductor element and a plurality of storage batteries connected to the semiconductor element, wherein the storage batteries are electrically connected in parallel, an electrolytic capacitor is used as the storage battery, A flat conductor is used to connect the element and the capacitor, the positive conductor and the negative conductor of the flat conductor are arranged close to each other with an insulator interposed therebetween, and the cathode foil in the electrolytic capacitor is a negative electrode of the electrolytic capacitor. When the positive conductor of the plate-shaped conductor is thermally connected to a case, and is used at an upper portion as compared with the negative conductor, and between the adjacent electrolytic capacitors, based on the positive electrode of one electrolytic capacitor. A power conversion device, wherein the electrolytic capacitor is arranged so that the negative electrode of the other electrolytic capacitor is closer to the positive electrode than the positive electrode.