JP2011135725A - Power converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power converter including a break-proof current sensor which has an accurate measurement value. <P>SOLUTION: The power converter includes a laminate 4 in which a plurality of semiconductor modules 2 and a plurality of cooling tubes 3 for cooling the semiconductor modules 2 are stacked. Each of the semiconductor modules 2 includes a body part 20 incorporating a switching element 23 constituting a power conversion circuit. A control terminal 22 and a power terminal 21 being conductive to the switching element 23 protrude from the body part 20 in the directions opposite to each other. The power converter 1 includes a current sensor 5 which measures a current flowing in the power terminal 21. At least a part of the current sensor 5 is interposed between adjoining two cooling tubes 3. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a power converter having a current sensor.

  Conventionally, a power converter that performs power conversion between DC power and AC power is known (see Patent Document 1 below). As shown in FIGS. 10 and 11, the conventional power converter is configured by stacking a semiconductor module 92 having a built-in switching element and a cooling tube 93 for cooling the semiconductor module 92. Each semiconductor module 92 has a power terminal 94 and a control terminal 96 which are electrically connected to the switching element.

  As shown in FIG. 10, the power terminal 94 includes a positive terminal 94a connected to the positive terminal of the DC power source, a negative terminal 94b connected to the negative terminal of the DC power source, and an AC terminal 94c connected to the AC load. There is. A bus bar 97 is connected to the AC terminal 94c. A DC bus bar (not shown) is also connected to the positive terminal 94a and the negative terminal 94b.

  As shown in FIG. 11, a control circuit board 98 is connected to the control terminal 96 of the semiconductor module 92. The control circuit board 98 controls the operation of the switching elements in the semiconductor module 92. As a result, the DC voltage applied between the positive terminal 94a and the negative terminal 94b is converted into a three-phase AC voltage and output from the AC terminal 94c.

  Of the three bus bars 97U, 97V, and 97W through which the three-phase alternating current flows, current sensors 95 are attached to the two bus bars 97U and 97V. As shown in FIG. 11, the current sensor 95 is connected to the control circuit board 98 through the connection wiring 99, and transmits a sensor output signal to the control circuit board 98 through the connection wiring 99. The control circuit board 98 uses the sensor output signal of the current sensor 95 for controlling the operation of the switching element.

JP 2005-332863 A

  However, the conventional power converter 91 has a problem that the temperature of the current sensor 95 rises due to resistance heat generated by the current flowing through the bus bar 97 and heat generated from the semiconductor module 92. When the temperature rises, the current sensor 95 tends to be broken or the measured value tends to be inaccurate.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a power conversion device having a current sensor that is hard to break and has an accurate measurement value.

The present invention includes a main body having a built-in switching element constituting a power conversion circuit, and a plurality of semiconductor modules in which a power terminal and a control terminal conducted to the switching element protrude in opposite directions from the main body. A laminated body in which a plurality of cooling tubes for cooling the semiconductor module are laminated;
A current sensor for measuring the current flowing through the power terminal,
The current sensor is in a power converter characterized in that at least a part of the current sensor is interposed between two adjacent cooling tubes.

  The function and effect of the present invention will be described. In the present invention, at least a part of the current sensor is interposed between two adjacent cooling tubes. Thereby, it becomes possible to cool a current sensor from the both surfaces with a cooling tube. Therefore, it is possible to prevent a problem that the current sensor is easily broken as the temperature rises. In addition, since the temperature of the current sensor is easily kept constant, it is possible to accurately measure the current flowing through the power terminal.

  As described above, according to the present invention, it is possible to provide a power conversion device that includes a current sensor that is not easily broken and has an accurate measurement value.

It is sectional drawing of the power converter device in Example 1, Comprising: It is BB sectional drawing of FIG. AA sectional drawing of FIG. The circuit diagram of the power converter device in Example 1. FIG. It is sectional drawing of the power converter device in Example 2, Comprising: DD sectional drawing of FIG. CC sectional drawing of FIG. It is sectional drawing of the power converter device in Example 3, Comprising: It is FF sectional drawing of FIG. EE sectional drawing of FIG. It is a top view of the power converter device in Example 4, Comprising: The H arrow line view of FIG. GG sectional drawing of FIG. It is a top view of the power converter device in a prior art example, Comprising: The arrow J figure of FIG. FIG. 11 is a view as viewed from the direction of the arrow H in FIG. 10, omitting the connecting pipe of the cooling tube.

A preferred embodiment of the present invention described above will be described.
In the present invention, it is preferable that the cooling tube is made of a conductive material.
If it does in this way, the electromagnetic noise radiated | emitted from the adjacent semiconductor module can be shielded with a cooling tube. For this reason, the current sensor is not easily affected by electromagnetic noise, and is unlikely to malfunction.

In addition, the current sensor includes a signal terminal protruding in the same direction as the control terminal, and receives a signal output from the current sensor and controls the operation of the switching element at the signal terminal and the control terminal. It is preferable that the substrate is connected (claim 3).
If it does in this way, a current sensor and a control circuit board can be connected by the shortest distance. Therefore, it is not necessary to secure a space for arranging the connection wiring around the laminated body, as compared with the case where the wiring connecting the current sensor and the control circuit board is routed around the laminated body (see FIG. 11). Therefore, the power conversion device can be reduced in size.
Moreover, since the control terminal of the semiconductor module and the signal terminal of the current sensor protrude in the same direction, the control terminal and the signal terminal can be connected to the control circuit board at the same time. Since these connection steps can be automatically performed by soldering or the like, the manufacturing cost of the power conversion device can be reduced.

The current sensor includes a detection element that detects a current flowing through the power terminal and a circuit unit that is electrically connected to the detection element. At least the circuit unit is interposed between two adjacent cooling tubes. (Claim 4).
The circuit part of the current sensor is a part that is particularly susceptible to an increase in temperature, and is a part that is likely to break due to a rise in temperature or to make the sensor output unstable. Therefore, by cooling at least the circuit portion with the cooling tube, the effect of the present invention, that is, the effect that the current sensor is hardly broken and the measured value can be accurately obtained can be sufficiently exhibited.
The circuit unit is a part including an electric circuit that processes the output signal of the detection element, and includes, for example, an amplifier circuit that amplifies the output signal.

The current sensor is preferably formed integrally with the semiconductor module.
Thus, when the current sensor and the semiconductor module are integrated, the size can be reduced as compared with the case where they are formed separately. Moreover, according to the said structure, when manufacturing a laminated body, it becomes unnecessary to laminate | stack a current sensor and a semiconductor module separately, Therefore Workability | operativity can be improved.

The cooling tubes are stacked and arranged at a predetermined interval, and either one of the semiconductor module or the current sensor is interposed between two adjacent cooling tubes, and the current sensor is It is preferable that the current flowing in the power terminal of the semiconductor module arranged adjacent to the cooling tube through the cooling tube is measured.
If it does in this way, the cooling efficiency of a semiconductor module can be raised. That is, when there is a semiconductor module that generates a particularly large amount of heat, the temperature of the cooling tube that sandwiches the semiconductor module tends to increase. When another semiconductor module is brought into contact with this cooling tube, the temperature further rises and the cooling efficiency tends to decrease. For this reason, the temperature of the cooling tube can be prevented from rising and the cooling efficiency of the semiconductor module can be prevented from lowering by contacting a current sensor with a small amount of heat without contacting another semiconductor module with the cooling tube where the temperature tends to rise. Can do.

Example 1
A power converter according to an embodiment of the present invention will be described with reference to FIGS.
As shown in FIGS. 1 and 2, the power conversion device 1 of this example includes a stacked body 4 in which a plurality of semiconductor modules 2 and a plurality of cooling tubes 3 that cool the semiconductor modules 2 are stacked. Each semiconductor module 2 has a main body portion 20 including a switching element 23 that constitutes a power conversion circuit, and a power terminal 21 and a control terminal 22 that are conducted to the switching element 23 are opposite to each other from the main body portion 20. It protrudes.
The power conversion device 1 also includes a current sensor 5 that measures the current flowing through the power terminal 21.
At least a part of the current sensor 5 is interposed between two adjacent cooling tubes 3.
The details will be described below.

  The power conversion device 1 of this example is mounted on an electric vehicle, a hybrid car, or the like, and performs power conversion between DC power and AC power. The power terminal 21 of the semiconductor module 2 includes a positive terminal 21a connected to the positive electrode of the DC power supply 11 (see FIG. 3), a negative terminal 21b connected to the negative electrode of the DC power supply 11, and an AC terminal 21c. is there. A bus bar (not shown) is connected to these power terminals 21a to 21c.

  Further, as shown in FIG. 2, the control circuit board 6 is connected to the control terminal 22 of the semiconductor module. The control circuit board 6 controls the operation of the switching element 23 (IGBT element). Thereby, the direct-current voltage applied between the positive electrode terminal 21a and the negative electrode terminal 21b is converted into alternating current, and an alternating voltage is output from the power terminal 21c.

The current sensor 5 includes an iron core 52 that surrounds the power terminal 21c, a detection element 50 that detects a current flowing through the power terminal 21c, and a circuit unit 51 that is electrically connected to the detection element 50.
The detection element 50 is a Hall element, and detects the magnitude of the current flowing through the power terminal 21c by detecting the magnetic field generated around the power terminal 21c. The circuit unit 51 is a part including an electric circuit that processes the output signal of the detection element 50, and includes, for example, an amplifier circuit that amplifies the output signal of the detection element 50.

The core 52 has a slit 500 (see FIG. 1), and the detection element 50 is provided in the slit 500. Further, the detection element 50 and the circuit unit 51 are connected by a connection wiring 501.
As shown in FIG. 2, the core 52, the detection element 50, and the circuit unit 51 are sealed with a synthetic resin sealing part 502. In the sensor 5, the core 52 and the circuit unit 51 are orthogonal to each other, and the whole is formed in an L shape.
Components constituting the sensor 5, that is, the core 52, the detection element 50, and the circuit unit 51 are all sandwiched between the cooling tubes 3.

On the other hand, as shown in FIG. 2, the main body 20 of the semiconductor module 2 seals three electrode plates 201 a to 201 c connected to a switching element 23 and a flywheel diode (not shown). These electrode plates 201a to 201c are drawn in an overlapping manner in FIG. The power terminals 21a to 21c are connected to different electrode plates 201a to 201c, respectively.
The main body 20 is sealed up to the central portion of the power terminals 21a and 21b, whereas the power terminal 21c is not sealed up to the central portion, and the concave portion 200 is formed around the power terminal 21c. Is formed. A core 52 is disposed in the concave portion 200.

  As shown in FIG. 1, in this example, the three power terminals 21c (21U, 21V, 21W) are set as one set so that a three-phase alternating current flows. In this case, when the currents of the two power terminals 21c are measured, the remaining one current can be calculated without measurement. Therefore, the current sensor 5 is attached to only the two power terminals 21U, 21V among the three power terminals 21U, 21V, 21W.

  On the other hand, as shown in FIG. 1, the plurality of cooling tubes 3 are connected by a connecting pipe 15. When the refrigerant is introduced into the introduction pipe 16, the refrigerant flows through all the cooling tubes 3 through the connection pipe 15 and is led out from the outlet pipe 17. Thereby, the semiconductor module 2 and the current sensor 5 can be cooled. The cooling tube 3 is made of a conductive material. In this example, the cooling tube 3 is made of aluminum. The connecting pipe 15, the introducing pipe 16, and the outlet pipe 17 are also made of aluminum.

  As shown in FIG. 2, the current sensor 5 includes a signal terminal 53 that protrudes in the same direction as the control terminal 22, receives an output signal of the current sensor 5 at the signal terminal 53 and the control terminal 22, and operates the switching element 23. A control circuit board 6 for controlling the control is connected.

  Next, the circuit of the power conversion device 1 of this example will be described. As shown in FIG. 3, the power conversion device 1 includes an inverter unit 10 a and a converter unit 10 b. The voltage of the DC power supply 11 is boosted by the converter unit 10b, and is converted to AC by the inverter unit 10a. The AC power obtained by the inverter unit 10a is used to drive the three-phase AC motor 12 to drive the vehicle. As shown in FIG. 3, the inverter unit 10 a includes a plurality of semiconductor modules 2. Each semiconductor module 2 has two switching elements 23 (IGBT elements) and two free wheel diodes 24. Of the three AC terminals 21U, 21V, and 21W connected to the three-phase AC motor 12, the current sensor 5 is attached to the two AC terminals 21U and 21V.

Next, the effect of the power converter device 1 of this example is demonstrated.
As shown in FIGS. 1 and 2, the power conversion device 1 of this example has a current sensor 5 interposed between two adjacent cooling tubes 3. Thereby, the current sensor 5 can be cooled by the cooling tube 3 from both sides. Therefore, it is possible to prevent a problem that the current sensor 5 is easily broken as the temperature rises. Moreover, since it becomes easy to keep the temperature of the current sensor 5 constant, the current flowing through the power terminal 21 can be accurately measured.

Moreover, in this example, the cooling tube 3 is comprised from the electroconductive material.
In this way, the electromagnetic noise radiated from the adjacent semiconductor module 2 can be shielded by the cooling tube 3. For this reason, the current sensor 5 is not easily affected by electromagnetic noise, and is unlikely to malfunction.

As shown in FIG. 2, the current sensor 5 includes a signal terminal 53 protruding in the same direction as the control terminal 22, and the control circuit board 6 is connected to the signal terminal 53 and the control terminal 22.
In this way, the current sensor 5 and the control circuit board 6 can be connected with the shortest distance. Therefore, unlike the conventional case, the wiring 99 that connects the current sensor 95 (see FIG. 11) and the control circuit board 98 is arranged around the multilayer body as compared with the case where the wiring 99 is routed around the multilayer body. Since it is not necessary to secure the space 990 (see FIG. 10) to be performed, the power conversion device can be reduced in size.
In this example, since the control terminal 22 of the semiconductor module 2 and the signal terminal 53 of the current sensor 5 protrude in the same direction, the control terminal 22 and the signal terminal 53 are simultaneously connected to the control circuit board 6. can do. Since these connection processes can be automatically performed by soldering or the like, the manufacturing cost of the power conversion device 1 can be reduced.

  In this example, the circuit unit 51 of the current sensor 5 is cooled by the cooling tube 3. The circuit unit 51 is a part that is particularly susceptible to the effect of temperature rise, and is a part that is likely to break due to temperature rise or to make sensor output unstable. Therefore, by cooling at least the circuit unit 51 with the cooling tube 3, the effect of this example, that is, the effect that the current sensor 5 is hardly broken and the measured value can be accurately obtained can be sufficiently exhibited. .

  As described above, according to this example, it is possible to provide the power conversion device 1 having the current sensor 5 that is not easily broken and has an accurate measurement value.

(Example 2)
In this example, the configuration of the current sensor 5 is changed. As shown in FIGS. 4 and 5, the current sensor 5 in this example includes an iron core 52 surrounding the power terminal 21c, and a detection element 50 (Hall element) that is sandwiched between the cores 52 and measures the current flowing through the power terminal 21c. ) And a circuit part 51 conducted to the detection element 50, and the circuit part 51 is interposed between two adjacent cooling tubes 3. In this example, the core 52 and the detection element 50 are not sandwiched between the cooling tubes 3 and are provided at positions protruding from the stacked body 4 to the protruding side of the power terminal 21.
In addition, the configuration is the same as that of the first embodiment.

The effect of this example will be described.
In this example, since the core 52 and the detection element 50 are not disposed between the cooling tubes 3, as shown in FIG. 4, the core 52 having a longer dimension in the stacking direction than the semiconductor module 2 can be used.
In the present example, the cooling tube 3 cools the circuit portion 51. As described above, the circuit unit 51 is a part that is particularly susceptible to an increase in temperature. Therefore, by cooling the circuit unit 51, the circuit unit 51 is hardly broken and the measured value of the current sensor 5 is made accurate. be able to.
In addition, compared with the circuit unit 51, the core 52 and the detection element 50 have relatively high heat resistance. Therefore, the core 52 and the detection element 50 may not be sandwiched between the cooling tubes 3. If it does in this way, the laminated body 4 can be reduced in size, without producing a malfunction in the current sensor 5. FIG.
In addition, the same effects as those of the first embodiment are obtained.

(Example 3)
In this example, the configuration of the current sensor 5 is changed. As shown in FIGS. 6 and 7, the present example includes an integrated module 2 a in which the current sensor 5 and the semiconductor module 2 are integrated. The integrated module 2 a has a main body portion 20 made of synthetic resin, and the switching element 23, the core 52, the detection element 50, and the circuit portion 51 are sealed in the main body portion 20. Further, the power terminal 21 and the control terminal 22 that are conducted to the switching element 23 and the signal terminal 53 that is conducted to the circuit unit 51 protrude from the main body unit 20.

Moreover, the power converter device 1 of this example includes the semiconductor module 2 that is not integrated with the current sensor 5 in addition to the integrated module 2a. As shown in FIG. 6, in this example, two integrated modules 2a and one semiconductor module 2 are combined to output a three-phase alternating current.
In addition, the same configuration as that of the first embodiment is provided.

The effect of this example will be described.
Thus, when the current sensor 5 and the semiconductor module 2 are integrated, the size can be reduced as compared with the case where they are formed separately. Moreover, according to the said structure, when manufacturing the laminated body 4, since it becomes unnecessary to laminate | stack the current sensor 5 and the semiconductor module 2 separately, workability | operativity can be improved.
In addition, the same functions and effects as those of the first embodiment are provided.

Example 4
In this example, the configuration of the current sensor 5 is changed. As shown in FIGS. 8 and 9, in this example, the cooling tubes 3 are laminated and arranged at a predetermined interval, and the semiconductor module 2 and the current sensor 5 are disposed between two adjacent cooling tubes 3. Either one of them is interposed, and the current sensor 5 is configured to measure a current flowing through the power terminal 21c of the semiconductor module 2 disposed adjacently via the cooling tube 3.

  The current sensor 5 of this example includes a resin portion 55 made of synthetic resin. The resin portion 55 has substantially the same size as the main body portion 20 of the semiconductor module 2. The circuit portion 51 is sealed in the resin portion 55. The core 52 and the detection element 50 (Hall element) are not sealed by the resin portion 55 and are disposed at a position protruding from the stacked body 4 to the protruding side of the power terminal 21. The core 52 surrounds the power terminal 21 c of the semiconductor module 2 disposed adjacent to the core 52 via the cooling tube 3. The detection element 50 is sandwiched between the slits 500 in the core 52. When a current flows through the power terminal 21c and a magnetic field is generated around it, the detection element 50 detects the magnetic field. Thus, the amount of current flowing through the power terminal 21c is measured.

As shown in FIG. 8, in this example, three semiconductor modules 2 are made into one set and a three-phase alternating current is output. Of the three semiconductor modules 2, the current flowing through the power terminals 21 U and 21 V of the two semiconductor modules 2 is measured by the current sensor 5. A dummy module 8 that does not seal the circuit portion 51, the switching element 23, or the like is disposed adjacent to the semiconductor module 2b that does not measure current.
In addition, the same configuration as that of the first embodiment is provided.

The effect of this example will be described.
With the above configuration, the cooling efficiency of the semiconductor module 2 can be increased. That is, as shown in FIG. 8, when there is a semiconductor module 2c that generates a particularly large amount of heat, the temperature of the cooling tube 3a that sandwiches the semiconductor module 2c tends to increase. When another semiconductor module 2 is brought into contact with the cooling tube 3a, the temperature further rises and the cooling efficiency tends to decrease. Therefore, the temperature rise of the cooling tube 3a can be prevented by bringing the current sensor 5 or the dummy module 8 having a small amount of heat into contact with the cooling tube 3a whose temperature is likely to rise without contacting another semiconductor module 2. A decrease in cooling efficiency of the module 2c can be prevented.
In addition, the same effects as those of the first embodiment are obtained.

DESCRIPTION OF SYMBOLS 1 Power converter 2 Semiconductor module 20 Main-body part 21 Power terminal 22 Control terminal 3 Cooling tube 4 Laminated body 5 Current sensor 6 Control circuit board

Claims (6)

A plurality of semiconductor modules each having a main body including a switching element constituting a power conversion circuit, wherein a power terminal and a control terminal electrically connected to the switching element protrude in opposite directions from the main body; and the semiconductor module A laminated body in which a plurality of cooling tubes for cooling is laminated;
A current sensor for measuring the current flowing through the power terminal,
The power conversion device according to claim 1, wherein at least a part of the current sensor is interposed between two adjacent cooling tubes.   2. The power conversion device according to claim 1, wherein the cooling tube is made of a conductive material.   3. The current sensor according to claim 1 or 2, wherein the current sensor includes a signal terminal protruding in the same direction as the control terminal, and receives the output signal of the current sensor at the signal terminal and the control terminal, and the switching element. A control circuit board for controlling the operation of the power converter is connected.   In any one of Claims 1-3, the said current sensor consists of the detection element which detects the electric current which flows into the said power terminal, and the circuit part electrically connected to this detection element, At least this circuit part is A power conversion device, wherein the power conversion device is interposed between two adjacent cooling tubes.   5. The power conversion device according to claim 1, wherein the current sensor is formed integrally with the semiconductor module. 6.   5. The cooling tube according to claim 1, wherein the cooling tubes are stacked and arranged at a predetermined interval, and the semiconductor module and the current sensor are disposed between two adjacent cooling tubes. Any one of these is interposed, The said current sensor is comprised so that the electric current which flows into the said power terminal of the said semiconductor module arrange | positioned adjacently via the said cooling tube may be measured.

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