JPH07303380A - Semiconductor power converter - Google Patents

Abstract

PURPOSE:To reduce the snubber loss of a semiconductor power converter by reducing the inductances of conductors connecting a semiconductor device to smoothing capacitors by reducing the lengths of the conductors. CONSTITUTION:A plurality of P-side modules 4 and N-side modules 5 are fitted to both surfaces of a cool 15, with their directions in polarity being the same. A plurality of smoothing capacitors 3 are arranged in a row adjacently to the cooler 15. The terminals of the capacitors 3 are set at the same height as that of the terminals of the modules 4 and 5. The emitter terminals of the modules 4 and the collector terminals of the module 5 facing to the emitter terminals are connected in series-parallel through output terminal connecting conductors 13. The collector terminals of the modules 4 are positive-side collector connecting conductors 11 formed to have a zigzag cross section and the emitter terminals of the modules 5 are connected in parallel through negative- side emitter connecting conductors 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor power converter in which a power semiconductor element and a smoothing capacitor are connected in series and parallel, and in particular, the inductance of a conductor of a main circuit is reduced,
The present invention relates to a semiconductor power conversion device having a compact outer shape.

[0002]

2. Description of the Related Art As is well known, a high-performance IGBT capable of converting electric power with high efficiency because it can perform high-speed switching.
When configuring a semiconductor power conversion device that is switched at a high frequency using such semiconductor modules, it is required to reduce the inductance of the conductors that connect the semiconductor modules that configure this semiconductor power conversion device. Further, due to restrictions on the installation space of the semiconductor power conversion device and the like, it is also required to reduce the outer shape of the semiconductor power conversion device.

In FIG. 7, six semiconductor modules are connected in parallel on both the positive and negative sides, and two smoothing capacitors are connected in series and four in parallel to form a main circuit of a large-capacity inverter. Connection diagram showing a conventional inverter stack,
8 is a front view showing an assembled state of the inverter stack shown in FIG. 7, and FIG. 9 is a front view of FIG.

In FIGS. 7, 8 and 9, the input terminals 1A and 1B on the DC side are connected to the left ends of the strip-shaped connecting conductors 6C and 7C arranged in parallel via an input line indicated by a broken line. Has been done. Eight smoothing capacitors mounted on the mounting plate 16 by the connecting conductors 6C and 7C and the strip-shaped connecting conductors 8A having a wide width and a thin thickness arranged between the connecting conductors 6C and 7C. Two 3 are connected in series and four are connected in parallel.

Of these, the right end of the connecting conductor 6C is shown in FIG.
The left end of the positive-electrode-side input conductor 9 bent in the Z shape is connected, and the input conductor 9 is also connected to the right end of the connection conductor 7C.
The left end of the negative-side input conductor 10 having the same shape as that of is connected symmetrically to the input conductor 9.

On the other hand, as shown in FIG. 9, the IGBT module 4 on the positive electrode side is provided on one side of both sides of the rectangular cooler 15.
Three pieces (hereinafter referred to as P-side modules) are attached adjacent to each other with the polarities of the terminals aligned so that the terminal surfaces face outward. Similarly, three negative-side IGBT modules (hereinafter, referred to as N-side modules) 5 are arranged so that the polarities of the terminals are aligned so that the terminal faces face outward.
Are mounted symmetrically adjacent to.

Of these, the collector terminals of the P-side module 4 are connected in parallel with each other by a strip-shaped positive electrode side collector connecting conductor 11A, and the emitter terminal of the N side module 5 is also the same as the positive electrode side collector connecting conductor 11A. They are connected in parallel with each other by the negative electrode side emitter connecting conductor 12A. The emitter terminal of the P-side module 4 and the collector terminal of the N-side module 5 are connected by a common strip-shaped common output terminal connecting conductor 13 similar to the connecting conductor 8A described above.

At the left end of the positive electrode side collector connecting conductor 11A,
The right end of the input conductor 9 is connected, and the right end of the input conductor 10 is also connected to the left end of the negative electrode side emitter connecting conductor 12A. The left end of the output terminal connection conductor 13 is connected to the right end of the output line 14 indicated by a broken line, and the left end of the output line 14 is connected to the output terminal 2.

As is well known, the influence of the inductance of the conductor of the main circuit accompanying the faster switching of the semiconductor power converter becomes more significant as the capacity of the semiconductor power converter increases. When the modules are switched at a high switching frequency, in FIG. 7, the input conductors 9 and 10 that connect the smoothing capacitor 3 to the P-side module 4 and the N-side module 5 and the connection conductor 11 that connects the modules in parallel.
The inductance due to A and 12A is a particular problem.

In the inverter stack thus constructed, when the DC voltage V shown in FIG. 7 is applied to the smoothing capacitor 3 and the P-side module 4 is turned off and the N-side module 5 is turned on, the rate of change of current is reduced. Assuming di / dt, the surge voltage applied between the collector and the emitter of the P-side module 4 which has been turned off is Vs = L · di / dt + V
Becomes

Here, the current i is the current for one module, the inductance L is different for each module, and the inductance of the module distant from the smoothing capacitor 3 depends on the inductance of the parallel connection conductor between the modules. , It becomes larger than the inductance of the module located near the smoothing capacitor.

A high-speed switching module has a large current change rate di / dt, and reducing the current rate diverts the original purpose of the module. Therefore, in a semiconductor power conversion device that switches at a high switching frequency, a main circuit is used. It is required to reduce the inductance.

Generally, when the capacity of the inverter is relatively small, the electromagnetic energy generated by the inductance of the main circuit is consumed by the snubber unit. This consumed energy becomes a snubber loss and reduces the efficiency of the inverter circuit. Further, it is difficult to raise the switching frequency to about 20 kHz which is the limit of the audible frequency to eliminate noise. Therefore, as the capacity of the semiconductor power conversion device increases, lower inductance is required accordingly.

On the other hand, there is a limit to the ratings of the components that make up the main circuit, and as the capacity of the inverter increases, a large number of main circuit components such as semiconductor modules and smoothing capacitors are connected in series and parallel to increase the voltage / current capacity. It is necessary to raise it.

[0015]

When connecting a plurality of main circuit components in series and parallel, there are restrictions such as cooling of the semiconductor module and equalization of the inductance due to the wiring conductors, so that the main circuit is constructed. The external size of the inverter stack required for this is large, and as a result, the external size of the semiconductor power changing device is large.

However, there are many cases where the installation space cannot be sufficiently secured due to the restriction of the place where the semiconductor power conversion device is installed, and it is necessary to reduce the outer shape of the main circuit of the semiconductor power conversion device as much as possible.

As described above, in the semiconductor power conversion device which switches at a high switching frequency, it is necessary to reduce the inductance of the conductor forming the main circuit in order to reduce the surge overvoltage and prevent the efficiency from lowering and the noise from increasing. Become. At the same time, in order to miniaturize the outer shape of the semiconductor power converter, it is necessary to reduce the volume occupied by the components of the main circuit. However, when a plurality of semiconductor elements having a relatively large capacity are connected in series and in parallel,
It was difficult to reduce the inductance of the main circuit due to structural restrictions such as mounting on a cooler.

Therefore, an object of the present invention is to reduce the inductance of the conductor of the main circuit and suppress the surge voltage in a semiconductor power conversion device that switches at a high switching frequency, and further reduce the efficiency due to snubber loss due to the inductance. It is an object of the present invention to provide a semiconductor power conversion device that can prevent the above problems and can reduce the installation area.

[0019]

According to a first aspect of the present invention, a plurality of semiconductor elements are arranged on both sides of a cooler, and a plurality of smoothing capacitors are arranged adjacent to the cooler. In a semiconductor power conversion device provided with a conductor for connecting smoothing capacitors in parallel, the terminals of adjacent smoothing capacitors arranged in a row are oriented in the opposite direction, and are arranged at the same height as the terminals of the semiconductor element.

According to a second aspect of the invention, a plurality of semiconductor elements are arranged on both sides of the cooler, a plurality of smoothing capacitors are arranged adjacent to the cooler, and the semiconductor elements and the smoothing capacitors are arranged in parallel. In a semiconductor power conversion device provided with a conductor to be connected to, the height of the smoothing capacitor is set to ½ between the terminals on the outside of the semiconductor element attached to the cooler, and the terminals are arranged in a line with the terminals facing outward. It is characterized by

According to a third aspect of the present invention, a plurality of semiconductor elements are arranged on both sides of the cooler, a plurality of smoothing capacitors are arranged adjacent to the cooler, and the semiconductor elements and the smoothing capacitors are arranged in parallel. In the semiconductor power conversion device provided with a conductor to be connected to, terminals are provided on both end surfaces of the smoothing capacitor, and the height between the terminals on both end surfaces is equal to the height between the terminals on the outside of the semiconductor element attached to the cooler. The feature is that they are the same.

Further, according to the invention of claim 4, a plurality of semiconductor elements are arranged on both sides of the cooler, a plurality of smoothing capacitors are arranged adjacent to the cooler, and the semiconductor elements and the smoothing capacitors are arranged in parallel. In a semiconductor power conversion device provided with a conductor to be connected to a terminal plate, the height of the terminals of the smoothing capacitor is the same as the height of the terminals of the semiconductor element, and the terminals of the semiconductor element and the smoothing capacitor are stacked via an insulating plate It is characterized by connecting with.

[0023]

In the inventions described in claims 1, 2 and 3, the length of the conductor connecting the semiconductor element and the smoothing capacitor is greatly shortened as compared with the conventional conductor, and the main circuit is constructed. The space required to do this is significantly reduced and the inductance is reduced.

Further, in the invention according to claim 4, the length of the conductor connecting the smoothing capacitor and the semiconductor element is significantly shortened as compared with the conventional conductor, and the space required for constructing the main circuit is formed. Is also significantly reduced, and the direction of the current flowing through the adjacent conductor is reversed, so that the inductance is greatly reduced.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the semiconductor power converter of the present invention will be described below with reference to the drawings. FIG. 1 is a front view showing a semiconductor power conversion device according to a first aspect of the present invention, which is a view corresponding to FIG. 8 shown in the prior art, and FIG. 2 is a front view of FIG. 1 corresponding to FIG. FIG. The same parts as those in FIGS. 1 and 2 are designated by the same reference numerals and the description thereof will be omitted.

1 and 2, the P-side module 4
The three N-side modules 5 are attached to both sides of the cooler 15 with three terminal faces facing outward and the polarities aligned.
The emitter terminal of the P-side module 4 and the collector terminal of the N-side module 5 are wide strip-shaped output terminal connecting conductors 13.
Connected by.

The collector terminal of the P-side module 4 is Z-shaped so as to cover a part of the output terminal connecting conductor 13 as shown in FIG. 6 (a) showing an enlarged sectional view taken along the line AA of FIG. They are connected in parallel by the positive electrode side collector connection conductor 11 formed by bending. The emitter terminal of the N-side module 5 is also connected in parallel with the negative electrode side emitter connecting conductor 12 having the same shape as the positive electrode side collector connecting conductor 11 so as to cover a part of the output terminal connecting conductor 13. Output terminal connection conductor 13 is flat head screw
By tightening on the side module 4, it is considered that the gap between the positive side collector connecting conductor 11 is minimized and the withstand voltage is maintained.

The smoothing capacitor 3 is composed of the P-side module 4,
With respect to the height of the terminals of the N-side module 5, they are attached to the mounting plate 16 one by one in opposite directions so that their terminal surfaces are flush with each other. Two sets of connection conductors 6 and 7 are connected to the DC side input terminals 1A and 1B, respectively, and these connection conductors 6 and 7 are, like the positive electrode side collector connection conductor 11, respectively, wide strip-shaped members. Is formed in a Z shape so as to cover a part of the connection conductor 8. By these connecting conductors 6, 7 and 8, eight smoothing capacitors 3 are connected in series and four in parallel.

The right end of the connecting conductor 6 and the left end of the positive collector connecting conductor 11 are connected by two sets of the positive input conductors 9. Similarly, the right end of the connecting conductor 7 and the left end of the negative emitter connecting conductor 12 are also connected to each other. It is connected by two sets of negative electrode side input conductors 10. Similarly to the P-side module 4 and the N-side module 5, the positive-side input conductor 9 and the negative-side input conductor 10 also have a Z-shape in a longitudinal sectional view (not shown) so as to cover a part of the output-terminal connecting conductor 13. It is bent.

In the semiconductor power converter configured as described above, the distance between the P-side module 4, N-side module 5 and the smoothing capacitor 3 is reduced, and the positive electrode side collector connecting conductor 11, the negative electrode side emitter connecting conductor 12, Connection conductor 6,
7 has a wide width and is Z-shaped so as to cover a part of the output terminal connecting conductor 13 or the connecting conductor 8, so that the currents flowing between the conductors vertically adjacent to each other have the same value. Thus, the direction becomes opposite, and the self-inductance caused by these conductors and the mutual inductance between the conductors can be reduced.

Further, P, which is necessary for constructing the main circuit,
The overall outer shape occupied by the side module 4, the N side module 5, the cooler 15, and the smoothing capacitor 3 can be made smaller than the conventional inverter stack configuration.

FIG. 3 is a front view showing a semiconductor power conversion device according to a second aspect of the present invention and is a view corresponding to FIG.
In FIG. 3, the height of the smoothing capacitor 3 is about one half of that shown in FIG. 1, and the sad terminal side mounting surfaces face each other and the terminal surfaces are the same as those of the P side module 4 and the N side module 5. It is attached to the mounting plate 16A so as to be divided into two so as to be flush with each other. Similarly, two smoothing capacitors 3 are connected in series and four in parallel by connecting conductors 6A and 7A and connecting conductor 8A.

In the semiconductor power converter configured as described above, the lengths of the two sets of positive electrode side input conductors 9 and the two sets of negative electrode side input conductors 10 can be shortened, and the positive electrode side and the negative electrode side each have two sets. Since the input conductors can have the same length, the inductance can be further reduced as compared with the semiconductor power conversion device shown in FIG.

Next, FIG. 4 is a front view showing a semiconductor power conversion device according to a third aspect of the present invention, which is also a view corresponding to FIG. In FIG. 4, the smoothing capacitor 3 has two positive and negative terminals, two on each end, protruding from both sides. The terminal surfaces on both sides of the smoothing capacitor 3 are flush with the terminal surfaces of the P-side module 4 and the N-side module 5, respectively. Similar to FIG. 1, two smoothing capacitors 3 are connected in series and four in parallel by the connecting conductors 6A, 7A and the connecting conductor 8A.

In the semiconductor power converter configured as described above, as compared with the embodiment of the invention described in claim 1, two sets of the positive electrode side input conductors 9 are provided without reducing the number of smoothing capacitors 3 connected. Since the lengths of the two sets of negative electrode side input conductors 10 can be shortened and the lengths of the two positive electrode side and negative electrode side input conductors can be made equal to each other, similar to the embodiment shown in FIG. The inductance can be further reduced as compared with the semiconductor power changing device shown in FIG.

Next, FIG. 5 is a front view showing a semiconductor power conversion device according to a fourth aspect of the invention and is a view corresponding to FIG. In FIG. 5, a connecting conductor 6B connecting the collector terminal of the P-side module 4 and the positive electrode side terminal of the smoothing capacitor in parallel, a connecting conductor 7B connecting the emitter terminal of the N-side module 5 and the negative electrode side terminal of the smoothing capacitor in parallel, The connection conductor 13A for connecting the emitter terminal of the module and the collector terminal of the N-side module in parallel and the connection conductor 8B for connecting the series connection portion of the smoothing capacitor in parallel are each in the form of a flat plate having a large surface area.

Between the conductors, as shown in FIG. 6B of the enlarged detailed view of B part of FIG. 5, there are provided two sets of connection units 17 into which the insulating plates 19 are inserted. To do. The smoothing capacitor 3 may be arranged in the same manner as the embodiment of claim 1 shown in FIG. 1 or the embodiment of claim 2 shown in FIG.

In the semiconductor power converter having the above structure, the lengths of the two sets of positive electrode side input conductors 6B and the two sets of negative electrode side input conductors 7B are longer than those of the embodiment of the invention described in claim 1. In addition to reducing the length, the self-inductance of the conductor itself is reduced by increasing the surface area of the conductor, and the mutual inductance between the conductors is reduced by stacking the conductors via the insulating plate 19 and bringing them closer to each other. The effective inductance can be further reduced.
Further, since each conductor can be formed into a connection unit to reduce the number of parts, a semiconductor power conversion device having a simple structure can be obtained.

[0039]

As described above, according to the invention of claim 1,
A plurality of semiconductor elements are arranged on both sides of the cooler, a plurality of smoothing capacitors are arranged adjacent to the cooler, in a semiconductor power conversion device provided with a conductor for connecting the semiconductor element and the smoothing capacitor in parallel, By making the terminals of adjacent smoothing capacitors arranged in a row the opposite direction and making them the same height as the terminals of the semiconductor element, the length of the conductor connecting the semiconductor element and the smoothing capacitor can be significantly increased compared to the conventional conductor. Since it has been shortened, the space required to configure the main circuit has been greatly reduced, and the inductance has also been reduced.Therefore, the inductance of the main circuit conductor has been reduced, surge voltage has been suppressed, and the efficiency due to snubber loss due to the inductance has been reduced. It is possible to provide a semiconductor power conversion device that can prevent a decrease in power consumption and can reduce the installation area.

According to the second aspect of the invention, a plurality of semiconductor elements are arranged on both sides of the cooler, and a plurality of smoothing capacitors are arranged adjacent to the cooler. In a semiconductor power conversion device provided with a conductor for connecting in parallel with each other, the height of the smoothing capacitor is set to ½ between the terminals on the outside of the semiconductor element attached to the cooler, and the terminal side is directed outward. By installing it, the length of the conductor that connects the semiconductor element and the smoothing capacitor was greatly shortened compared to the conventional conductor, the space required to configure the main circuit was greatly reduced, and the inductance was also reduced. , Reduce the inductance of the conductor of the main circuit, suppress the surge voltage, and prevent the efficiency from decreasing due to snubber loss due to the inductance, and also reduce the installation area. It is possible to provide a semiconductor power conversion device that.

According to the third aspect of the invention, a plurality of semiconductor elements are arranged on both sides of the cooler, and a plurality of smoothing capacitors are arranged adjacent to the cooler. In a semiconductor power conversion device provided with a conductor for connecting in parallel with each other, terminals are provided on both end faces of the smoothing capacitor, and the height between the terminals on the both end faces is between the outer terminals of the semiconductor element attached to the cooler. By making it equal to the height, the length of the conductor that connects the semiconductor element and the smoothing capacitor is greatly shortened compared to the conventional conductor, the space required to configure the main circuit is greatly reduced, and the inductance is also reduced. As a result, it is possible to reduce the inductance of the conductor of the main circuit, suppress the surge voltage, and prevent the efficiency from decreasing due to snubber loss due to the inductance.
Further, it is possible to provide a semiconductor power conversion device that can reduce the installation area.

Further, according to the invention of claim 4,
A plurality of semiconductor elements are arranged on both sides of the cooler, a plurality of smoothing capacitors are arranged adjacent to the cooler, in a semiconductor power conversion device provided with a conductor for connecting the semiconductor element and the smoothing capacitor in parallel, The height of the terminals of the smoothing capacitor is the same as the height of the terminals of the semiconductor element, and the terminals of the semiconductor element and the smoothing capacitor are connected by the terminal plates that are stacked via the insulating plate to connect the smoothing capacitor and the semiconductor element. Since the length of the conductor is greatly shortened compared to the conventional conductor, the space required to configure the main circuit is also greatly reduced, and the direction of the current flowing through the adjacent conductor is reversed,
To provide a semiconductor power conversion device capable of reducing the inductance of a conductor of a main circuit, suppressing a surge voltage, preventing a decrease in efficiency due to a snubber loss caused by the inductance, and reducing an installation area. You can

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a semiconductor power conversion device according to the invention of claim 1.

FIG. 2 is a front view of FIG.

FIG. 3 is a front view showing an embodiment of the semiconductor power conversion device according to the invention described in claim 2.

FIG. 4 is a front view showing an embodiment of the semiconductor power converter of the invention described in claim 3;

FIG. 5 is a front view showing an embodiment of the semiconductor power conversion device according to the invention of claim 4.

6A is an enlarged cross-sectional view taken along the line AA of FIG. 1, FIG.
Is an enlarged detailed view of a B part of FIG. 5.

FIG. 7 is a connection diagram showing an example of a conventional semiconductor power conversion device.

FIG. 8 is a front view showing an example of a conventional semiconductor power conversion device.

9 is a front view of FIG.

[Explanation of symbols]

1A, 1B ... Input terminal, 2 ... Output terminal, 3 ... Smoothing capacitor, 4 ... P-side module, 5 ... N-side module, 6,
6A, 6B, 6C; 7, 7A, 7B, 7C; 8, 8A,
8B ... connecting conductor, 9, 9A; 10, 10A ... input conductor, 11,
11A ... Positive side collector connecting conductor, 12, 12A ... Negative side emitter connecting conductor, 13, 13A ... Output terminal connecting conductor, 14 ... Output line, 15 ... Cooler, 16, 16A ... Mounting plate, 17 ... Connection unit, 19 … Insulation board.

Claims (4)

[Claims] 1. A plurality of semiconductor elements are arranged in a row on both sides of a cooler, a plurality of smoothing capacitors are arranged in a row adjacent to the cooler, and a conductor for connecting the semiconductor element and the smoothing capacitor in parallel is provided. In the semiconductor power conversion device described above, the terminals of the adjacent smoothing capacitors arranged in a row are oriented in the opposite direction, and the height is the same as that of the terminals of the semiconductor element. 2. A plurality of semiconductor elements are arranged in a row on both sides of a cooler, a plurality of smoothing capacitors are arranged in a row adjacent to the cooler, and a conductor for connecting the semiconductor element and the smoothing capacitor in parallel is provided. In the semiconductor power conversion device described above, the height of the smoothing capacitor is set to one half between the terminals outside the semiconductor element attached to the cooler,
A semiconductor power conversion device, which is arranged in a row with the terminal side facing outward. 3. A plurality of semiconductor elements are arranged in a line on both sides of a cooler, a plurality of smoothing capacitors are arranged in a row adjacent to the cooler, and a conductor for connecting the semiconductor element and the smoothing capacitor in parallel is provided. In the semiconductor power conversion device described above, terminals are provided on both end surfaces of the smoothing capacitor, and the height between the terminals on the both end surfaces is made equal to the height between the outer terminals of the semiconductor element mounted on the cooler. A semiconductor power conversion device characterized by the above. 4. A plurality of semiconductor elements are arranged on both sides of a cooler, a plurality of smoothing capacitors are arranged adjacent to the cooler, and a conductor for connecting the semiconductor element and the smoothing capacitor in parallel is provided. In the semiconductor power conversion device described above, the height of the terminals of the smoothing capacitor is the same as the height of the terminals of the semiconductor element, and the terminals of the semiconductor element and the smoothing capacitor are connected by a terminal plate stacked via an insulating plate. A semiconductor power conversion device characterized by the above.