JP2007228639A - Voltage boosting chopper apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a voltage boosting chopper apparatus for reducing wiring inductances in conductive plates and an imbalance between currents flowing in parallel semiconductor switching circuits. <P>SOLUTION: In paths, the first and second conductive plates 5, 6 are linearly disposed at an interval, the third conductive plate 7 is attached to them in parallel, IGBTs 11-14 are disposed between the second and third conductive plates 6, 7, diodes 8, 9 are disposed between the first and second conductive plates so as to place both terminals in the longitudinal direction of the conductive plates, one connection terminal 15 of a DC capacitor 10 is connected to the first conductive plate 5, the other connection terminal 16 of the DC capacitor 10 is connected to the third conductive plate 7 opposite to the first conductive plate 5, distances of all paths for flowing the currents in the conductive plates are substantially equal when a switching operation is not implemented, and the currents are interrupted when the switching operation is implemented. A both-way conductor structure has orientations of the currents on the conductive plates so as to cancel a change in a magnetic flux. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a step-up chopper device using a semiconductor switching element, and relates to an improvement in a wiring structure of a semiconductor switching element constituting the step-up chopper apparatus.

In a power converter such as a step-up chopper device configured using a semiconductor switching element, when the semiconductor switching element cuts off the current, a spike-like voltage higher than the circuit voltage is generated at both ends of the semiconductor switching element due to the influence of the inductance of the wiring conductor. A surge voltage may occur. The surge voltage may generate a higher voltage as the current blocking speed is higher, and may induce overvoltage breakdown of the semiconductor switching element. If the current change rate of the wiring inductance L generated when the switching element cuts off the current is di / dt, a voltage of ΔVs = L · di / dt is generated at both ends of the wiring inductance L. As a result, the voltage Vsw across the semiconductor switching element is the sum of the circuit voltage and ΔVs applied as a surge voltage.

As this semiconductor switching element, there is no problem as long as it can withstand the surge voltage Vsw at the time of current interruption. However, when Vsw is higher than the withstand voltage of the semiconductor switching element, there are the following prevention methods.
(1) Decrease di / dt.
(2) A snubber circuit is added in parallel with the semiconductor switching element.
(3) Reduce wiring inductance (Patent Document 1).

The method (1) is a method in which di / dt is reduced by increasing the gate resistance when an IGBT is used as a semiconductor switching element. However, there is a problem in that switching loss increases. Further, the method (2) has a problem that the apparatus becomes large and the cost is high. Then, the method (3) is a so-called parallel plate reciprocating conductor in which the wiring conductor plate (bus bar), which is a path for interrupting current, is made as flat as possible and the forward and return conductor plates are arranged as close as possible. It is known to be good.

In a power converter having a voltage source inverter circuit, a smoothing DC capacitor is generally provided. For example, in the case where a DC voltage is supplied to the inverter by a boost chopper circuit as shown in FIG. In the step-up chopper circuit, when the IGBTs 11 to 14 are used as semiconductor switching elements, the magnitude of the surge voltage in the path of the loop 100 generated at the time of switching is the wiring inductance between the DC capacitor 10 and the IGBTs 11 to 14. Determined by the size of

When a high-speed switching element such as an IGBT is used as the semiconductor switching element, the rate of change in current also increases, so that it is required to reduce the wiring inductance as much as possible. Further, when the semiconductor switching elements are in a parallel configuration and are always on, the current must be balanced between the elements in the loop 200 path.
JP2002-44960

In order to solve the above-described problems, the present invention provides a step-up chopper device that suppresses the wiring inductance of a conductor plate with a simple circuit configuration and reduces the current imbalance of a semiconductor switching circuit having a parallel configuration. .

A step-up chopper device according to claim 1 includes a plurality of semiconductor switching elements connected in parallel, a DC capacitor connected in parallel to the semiconductor switching element via a diode connected in series therewith, and electrically connecting them. In a step-up chopper device composed of a conductor plate to be connected, the conductor plate is composed of three sheets, and the first conductor plate and the second conductor plate are arranged on a straight line with an interval therebetween, in parallel with these. A third conductor plate is attached via an insulating layer, one connection terminal connected to the power supply device via a DC reactor is connected to one end of the second conductor plate, and the second conductor plate and The semiconductor switching element is arranged between a third conductor plate arranged in parallel so that both terminals thereof are along the longitudinal direction of the conductor plate, and one terminal side thereof is aligned to form a second conductor plate. , The other terminal side is the third A distance from one connection terminal of the power supply device connected to the conductor plate and attached to the second conductor plate to one terminal of the semiconductor switching element disposed on the first conductor plate side; and a third conductor plate The other connection terminal of the power supply device is connected to a position where the distance from the other terminal of the semiconductor switching element connected to the same is approximately the same, a diode is connected between the first conductor plate and the second conductor plate, Arranged along the longitudinal direction of the conductor plate, one terminal is connected to the end of the second conductor plate, and the other terminal is connected to the end of the first conductor plate facing it at an interval And connecting one connection terminal of the DC capacitor to the first conductor plate and connecting the other connection terminal of the DC capacitor to the third conductor plate at a position opposite to the connection terminal, and switching operation. When the conductor plate is not used A reciprocating conductor structure is formed so that the distances of all the current paths flowing in the path are substantially equal, and the direction of the current on the conductor plate cancels the magnetic flux change in the path that cuts off the current when switching operation is performed. It is characterized by this.

The step-up chopper device according to a second aspect is characterized in that, in the first aspect, the arrangement of the two semiconductor switching elements is uniformly distributed on both sides of the second conductor plate side and the third conductor plate side. Is.

A step-up chopper device according to a third aspect is characterized in that, in the first aspect, the semiconductor switching elements are arranged in a horizontal row along the longitudinal direction of the conductor plate.

According to the step-up chopper device of the first aspect of the present invention, with a simple circuit configuration, the distances of all the current paths flowing on the conductor plate when the switching operation is not performed are formed to be substantially equal, and the switching operation is performed. Suppresses surge voltage due to wiring inductance of the conductor plate in the semiconductor switching circuit by adopting a reciprocating conductor structure so that the direction of the current on the conductor plate cancels the change of magnetic flux in the path that cuts off the current when done In addition, current imbalance between the semiconductor switching elements connected in parallel can be reduced.

According to the step-up chopper device of the second aspect, by arranging the semiconductor switching elements on both sides of the conductor plate, the temperature distribution of the semiconductor switching elements can be made uniform, and the current balance can be further improved. .

According to the step-up chopper device of the third aspect, since the semiconductor switching elements are arranged in a horizontal line along the longitudinal direction of the conductor plate, the thermal effect is less than in the case where the semiconductor switching elements are arranged vertically, and the temperature of the semiconductor switching element is reduced. Distribution can be made uniform.

Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. In FIG. 1, 1 is a DC power source, 3 is a step-up chopper circuit, 4 is a series reactor, 5 is a first conductor plate (busbar), 6 is a second conductor plate, 7 is a third conductor plate, and 8 and 9 are Diode, 10 is a DC capacitor, 11-14 is an IGBT which is a semiconductor switching element, and these IGBTs 11-14 are connected in parallel to DC capacitor 10 and operate as a closed switch in a mode in which DC current energy is stored in series reactor 4. In the mode in which the energy of the direct current accumulated in the series reactor 4 is output, it operates as a step-up chopper.

Reference numeral 15 denotes a positive electrode side connection terminal of the DC capacitor 10, 16 denotes a negative electrode side connection terminal of the DC capacitor 10, 17 denotes one connection terminal on the power source side attached to the second conductor plate 6, and 18 denotes a third conductor plate 7. It is the other connection terminal of the attached power supply side. 21 and 22 are anode terminals of the diodes 8 and 9, 23 and 24 are cathode terminals, 31 to 34 are collector terminals of the IGBTs 11 to 14, and 41 to 44 are emitter terminals.

2 and 3 are horizontal sectional views showing the step-up chopper device 3. As shown in FIG. 2, the conductor plate of the step-up chopper device 3 is linearly spaced from the first conductor plate 5. A third conductive plate 7 is provided in parallel with an insulating plate 81 in front of the arranged second conductive plate 6 and these so as to form a laminated contact structure. In this case, the first conductor plate 5 and the second conductor plate 6 and the third conductor plate 7 are in close contact with each other through an insulating plate 81 for insulation. However, if an insulation distance is ensured, air is introduced. May be arranged.

FIG. 4 is a front view of the conductor plates 5 to 7 constituting the boost chopper device 3. In FIG. 4, a third conductor plate 7 is arranged in parallel on the front side of the first conductor plate 5 and the second conductor plate 6. FIGS. 5 and 6 show the conductor plates 5 to 7 as a single body, (a) shows the first conductor plate 5 and the second conductor plate 6, and (b) shows the third conductor. A plate 7 is shown.

As shown in FIGS. 1 and 2, one connection terminal 17 connected to the DC power source 1 through the DC reactor 4 is connected to one end of the second conductor plate 6. As shown in FIGS. 2 and 4, four IGBT elements 11 to 14 are connected between the second conductor plate 6 and the third conductor plate 7 arranged in parallel with the collector terminals 31 to 34 and the emitter. The terminals 41 to 44 are arranged along the longitudinal direction of the second conductor plate 6 and the third conductor plate 7, and the collector terminals 31 to 34 are aligned with the second conductor plate 6 to the emitter terminals 41 to 41. The 44 side is connected to the third conductor plate 7 respectively.

The anode terminals 21 and 22 and the cathode terminals 23 and 24 of the diodes 8 and 9 are arranged along the longitudinal direction of the second conductor plate 6 and the third conductor plate 7 as shown in FIG. The anode terminals 21 and 22 are connected to the end portion of the second conductor plate 6, and the cathode terminals 23 and 24 are connected to the end portion of the first conductor plate 5 that is opposed to the anode terminals 23 and 24.

The terminals of the IGBTs 11 to 14 and the diodes 8 and 9 are fixedly connected to each conductor with bolts or the like using pipes that are cylindrical conductors. Illustrations of pipes and bolts are omitted.

As shown in FIG. 1, the third conductor plate 7 is connected to the negative electrode side connection terminal 18 of the DC power source 1 and the negative electrode side connection terminal 16 of the DC capacitor 10. Further, the first conductor plate 5 is connected to the positive electrode side connection terminal 15 of the DC capacitor 10. Further, as shown in FIG. 2, heat sinks 71 and 72 for preventing overheating are attached to the diodes 8 and 9 and the IGBTs 11 to 14, respectively.

As shown in FIG. 5 (a), the second conductor plate 6 has opening holes 61 to 64, and emitter terminals 41 to 44 of the IGBTs 11 to 14, and pipes and bolts connecting the terminals and the third conductor plate 7. It is provided to ensure an insulation distance from a conductor such as. Similarly, as shown in FIG. 5B, the third conductor plate 7 is also provided with opening holes 51, 52, 65, 66, and the anode terminals 21, 22 of the diodes 8, 9, and the cathode terminals 23, 24. And the insulation distance with the collector terminals 31 and 32 of IGBT11-14 is ensured.

When the distance from one connection terminal 17 of the DC power source 1 attached to the end of the second conductor plate 6 to the collector terminals 31 and 32 of the IGBTs 11 and 12 arranged on the first conductor plate 5 side is A, The distances A ′ from the emitter terminals 43 and 44 of the IGBTs 13 and 14 of the third conductor plate 7 to the other connection terminal 18 of the DC power supply 1 are formed to be substantially equal.

Further, as shown in FIG. 6, the other connection terminal 16 of the DC capacitor 10 is connected to the third conductor plate 7 at a position facing one connection terminal 15 of the DC capacitor 10 attached to the first conductor plate 5. ing. The distance B from the collector terminals 33 and 34 of the IGBTs 13 and 14 of the second conductor plate 6 to the one connection terminal 15 of the DC capacitor 10 of the first conductor plate 5 and the IGBTs 13 of the third conductor plate 7 The distances B ′ from the 14 emitter terminals 43 and 44 to the other connection terminal 16 of the DC capacitor 10 are formed to be substantially equal.

Next, the operation of the boost chopper device will be described. A loop 200 in FIG. 1 shows a current path in a mode in which the energy of the direct current accumulated in the series reactor 4 is held, and the arrows in FIGS. 2 and 5 show this concretely. In the current path of the loop 200, the switching operation of the IGBTs 11 to 14 is not performed, and the continuous energization state is maintained.

First, the arrow indicating the current path in the front view of FIG. 5 passes through the collector terminals 31 to 34 of the IGBTs 11 to 14 from the positive electrode side connection terminal 17 of the series reactor 4 provided at the end of the second conductor plate 6. Then, it passes through the inside of the IGBTs 11 to 14, passes through the emitter terminals 41 to 44, and goes to the negative electrode side connection terminal 18 of the DC power source 1 connected to the third conductor plate 7.

At this time, when the distance from the connection terminal 17 of the second conductor plate 6 to the collector terminals 31 and 32 of the IGBTs 11 and 12 is A, from the emitter terminals 43 and 44 of the IGBTs 13 and 14 of the third conductor plate 7, The distance A ′ to the other connection terminal 18 of the DC power supply 1 is formed to be substantially equal to the distance A. At the same time, since it has a vertically symmetrical structure with the positive electrode side connection terminal 17 and the negative electrode side connection terminal 18 as axes, the distance of the current path flowing through the IGBTs 11 and 13 and the distance of the current path flowing through the IGBTs 12 and 14 are as follows. Equally, the current between the upper and lower elements is evenly balanced.

Similarly, in the horizontal sectional view of FIG. 2, the arrow indicating the current path extends from the positive electrode side connection terminal 17 to the negative electrode side connection terminal 18 via each terminal of the IGBTs 11 to 14. At this time, the distance between the current paths flowing through the IGBTs 11 and 12 and the distance between the current paths flowing through the IGBTs 13 and 14 are equal, and the current between the left and right elements is evenly balanced.

Therefore, in the current path of the loop 200, there is no variation in current between the IGBTs 11 to 14 arranged in parallel, and it is possible to avoid element destruction caused by excessive current flowing through a specific element.

Next, the loop 100 in FIG. 1 cuts off the current when the IGBT elements 11 to 14 operating as the step-up chopper perform the switching operation in the mode of outputting the energy of the direct current accumulated in the series reactor 4. The route is shown, and the arrows in FIG. 3 and FIG. 6 show this concretely.

In the front view of FIG. 6, the distance B from the collector terminals 33 and 34 of the IGBTs 13 and 14 of the second conductor plate 6 to the one connection terminal 15 of the DC capacitor 10 of the first conductor plate 5, and the third The distances B ′ from the emitter terminals 43 and 44 of the IGBTs 13 and 14 of the conductor plate 7 to the other connection terminal 16 of the DC capacitor 10 are formed to be substantially equal. At the same time, since it has a vertically symmetrical structure with the connection terminals 17 and 18 of the DC power supply 1 and the connection terminals 15 and 16 of the DC capacitor 10 as axes, the distance of the path across the IGBTs 11 and 13 and the IGBTs 12 and 14 The path distances across are equal.

That is, as shown in FIG. 3, from the connection terminal 16 of the DC capacitor 10, via the connection terminal 18 of the third conductor plate 7, via the emitter terminals 41, 42 of the IGBTs 11, 12, and inside the IGBTs 11, 12. And the path to the collector terminals 31 and 32 is defined as the forward path 1. Further, a path extending from the connection terminal 16 through the third conductor plate 7, through the emitter terminals 43 and 44 of the IGBTs 13 and 14, to the inside of the IGBT, and to the collector terminals 33 and 34 of the IGBT is forward path 2. And

Also, the collector terminals 31 and 32 of the IGBTs 11 and 12 pass through the second conductor plate 6, pass through the anode terminals 21 and 22 of the diodes 8 and 9, cross the inside of the diode, and pass through the cathode terminals 23 and 24. Then, the path extending to the connection terminal 15 through the first conductor plate 5 is defined as a return path 1. Further, from the collector terminals 33 and 34 of the IGBTs 13 and 14, via the second conductor plate 6, via the anode terminals 21 and 22 of the diodes 8 and 9, and across the inside of the diodes 8 and 9, this cathode terminal 23, A path extending to the connection terminal 15 via the first conductor plate 5 via 24 is defined as a return path 2.

Here, as can be seen from the illustrated arrows, the sum of the distances of the forward path 1 and the forward path 2 and the sum of the distances of the backward path 1 and the backward path 2 are substantially equal in magnitude and opposite in direction, so that the forward path and the backward path Changes in the magnetic flux created by each other are canceled out, and apparently there is almost no change in the magnetic flux. Therefore, it is possible to reduce the wiring inductance in the loop 100 that operates as a boost chopper. Further, since the reciprocating conductor plate occupying most of the forward paths 1 and 2 and the return paths 1 and 2 has a parallel contact conductor structure, the wiring inductance is reduced and the surge voltage is suppressed. In this case, by reducing the distance between the forward path and the return path as much as possible, that is, by shortening the distance between B and B ′ in FIG. 6 as much as possible, the wiring inductance is further reduced and the surge voltage can be suppressed.

Further, in the above embodiment, the number of IGBT elements is four in parallel. However, in the case of two parallel, IGBTs 13 and 14 are excluded, and in the case of three parallels, IGBT 14 is excluded. And wiring inductance is suppressed. Furthermore, when the number of parallel increases by 2n times (n: natural number), like the method of increasing from 2 to 4 parallel, by adding the increasing IGBT in the horizontal direction in the same direction as the already-existing IGBT, The same effect as described above can be obtained.

FIG. 7 is a front view of a conductor plate according to the second embodiment of the present invention. Compared with the embodiment shown in FIG. 4, the IGBTs 11 to 14 are arranged in a horizontal row. Here, with respect to the current balance of the path in the loop 200 of FIG. 1, it is not necessary to consider the balance between the upper and lower elements, and the balance between the left and right elements is considered to be the same as described with reference to FIG. Evenly balanced. Accordingly, there is no variation in current between the IGBTs 11 to 14 arranged in parallel.

As for the wiring inductance of the path in the loop 100 of FIG. 1, the forward path and the return path cancel each other's change in magnetic flux as in FIG. 3, and the wiring inductance can be reduced.

Moreover, in this 2nd Embodiment, IGBT is 4 parallel, but in the case of 2 parallel, if IGBT13 and 14 are excluded and IGBT14 is excluded in the case of 3 parallel, current imbalance is demonstrated by the same description. Reduction and suppression of wiring inductance can be achieved. Further, when the parallel number increases by n times (n: natural number), the same effect as described above can be obtained by adding the increasing IGBT in the horizontal direction in the same direction as the already-arranged IGBT element.

FIG. 8 shows a conductor plate according to a third embodiment of the present invention, in which (a) is a front view and (b) is a cross-sectional view. 72A and 72B are heat sinks provided to prevent overheating of the IGBTs 11 to 14, respectively. The mounting positions of the collector terminals 31 to 34 and the emitter terminals 41 to 44 of the IGBTs 11 to 14 are the same as those in FIG. 4, but the mounting directions of the IGBTs 11 and 12 and the IGBTs 13 and 14 are reversed by 180 degrees.

One factor causing current imbalance between the IGBTs is the temperature dependence of the element characteristics, but the IGBTs 11 to 14 are moved to both sides of the second conductor plate 6 and the third conductor plate 7 as shown in FIG. Distributing and arranging the heat sinks 72A and 72B to both sides makes the cooling conditions of the IGBTs 11 to 14 the same and makes the temperature distribution uniform, thereby suppressing current imbalance.

Moreover, in this 3rd Embodiment, IGBT11-14 is 4 parallel, but in the case of 2 parallel, IGBT13,14 is excluded or either one of IGBT11,13 and IGBT12,14 In the same way, it is possible to reduce current imbalance and suppress wiring inductance. Further, when the parallel number increases by 2n times (n: natural number), the same effect as described above can be obtained by dispersing n IGBTs on both sides of the conductor plate.

1 is a circuit diagram showing a boost chopper device according to an embodiment of the present invention. It is a horizontal sectional view which shows the pressure | voltage rise chopper apparatus of FIG. It is a horizontal sectional view which shows the pressure | voltage rise chopper apparatus of FIG. It is a front view of the conductor board which comprises the pressure | voltage rise chopper apparatus of FIG. (A) is a front view which shows a 1st conductor board and a 2nd conductor board, (b) is a front view which shows a 3rd conductor board. (A) is a front view which shows a 1st conductor board and a 2nd conductor board, (b) is a front view which shows a 3rd conductor board. It is a front view of the conductor board which comprises the pressure | voltage rise chopper apparatus by the 2nd Embodiment of this invention. (A) is a front view of the conductor board which comprises the pressure | voltage rise chopper apparatus by the 3rd Embodiment of this invention, (b) is the sectional drawing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 DC power supply 3 Boost chopper circuit 4 Series reactor 5 1st conductor board 6 2nd conductor board 7 3rd conductor board 8, 9 Diode 10 DC capacitor 11-14 IGBT
15 connection terminal 16 connection terminal 17 connection terminal 18 connection terminal 21, 22 anode terminal 23, 24 cathode terminal 31-34 collector terminal 41-44 emitter terminal 71, 72, 71A, 72B heat sink 81 insulating plate 100, 200 showing current path loop

Claims (3)

  A plurality of semiconductor switching elements connected in parallel, a DC capacitor connected in parallel with the semiconductor switching element via a diode connected in series with the semiconductor switching element, and a conductor plate electrically connecting them In the step-up chopper device, the conductor plate is composed of three sheets, the first conductor plate and the second conductor plate are arranged on a straight line with an interval therebetween, and the third conductor is interposed in parallel with these via an insulating layer. A third conductor plate that is mounted in parallel with one of the connection terminals connected to the power supply device via a DC reactor at one end of the second conductor plate; The semiconductor switching element is disposed so that both terminals thereof are along the longitudinal direction of the conductor plate, and one terminal side thereof is aligned with the second conductor plate, and the other terminal side is disposed with the third terminal. Connected to the conductor plate, the second conductor plate The distance from one connection terminal of the attached power supply device to one terminal of the semiconductor switching element arranged on the first conductor plate side, and the other terminal of the semiconductor switching element connected to the third conductor plate Connecting the other connection terminal of the power supply device at a position where the distance is substantially the same, arranging a diode between the first conductor plate and the second conductor plate so that both terminals are along the longitudinal direction of the conductor plate; One terminal is connected to the end of the second conductor plate, and the other terminal is connected to the end of the first conductor plate facing the first conductor plate with a space therebetween, and one of the DC capacitors is connected to the first conductor plate. And connecting the other connection terminal of the DC capacitor to the third conductor plate at a position opposite to the connection terminal, and all of the current flowing on the conductor plate when no switching operation is performed. Current path distance Substantially equal form, in the path to cut off the current when the performing switching operation, step-up chopper and wherein the orientation of the current on the conductor plate has a reciprocal conductor structure in such a manner as to cancel the change in magnetic flux.   2. The step-up chopper device according to claim 1, wherein the semiconductor switching elements are uniformly distributed on both sides of the second conductor plate side and the third conductor plate side. 2. The step-up chopper device according to claim 1, wherein the semiconductor switching elements are arranged in a horizontal row along the longitudinal direction of the conductor plate.