JP6422638B2 - Power converter - Google Patents

Description

  The present invention relates to a power converter having a main circuit unit and a control circuit unit.

A power conversion device such as an inverter includes a main circuit unit including a semiconductor module and a control circuit unit that controls the semiconductor module in a case.
The case protects the main circuit section and control circuit section from water and other foreign substances and prevents water from entering the case. However, even if water enters, it can be detected early. Therefore, an electrical leakage prevention device for an electrical device provided with a flood detection unit has been proposed (Patent Document 1).
In the electric leakage prevention apparatus for an electric device, the inundation detection unit is disposed below the lowermost energization unit, so that it is possible to detect inundation into the case before the water level reaches the energization unit.

JP 2010-25624 A

However, in the above-described leakage prevention device for an electric device, a flood detection unit must be newly provided. Therefore, the number of parts in the case increases.
In addition, since the high-voltage energization part is arranged near the lower end part in the case, if there is no above-described flooding detection part, when water accumulates in the case, a high-voltage leakage may be caused.

  The present invention has been made in view of such a background, and an object of the present invention is to provide a power conversion device capable of early detection of water intrusion into a case without increasing the number of parts.

One aspect of the present invention is a main circuit portion including a semiconductor module incorporating a switching element;
A control circuit unit for controlling the semiconductor module,
A cooler for cooling the semiconductor module;
A power conversion device having a case in which the main circuit unit , the control circuit unit , and the cooler are housed,
The case includes a high-voltage energization unit through which a main power current converted by the main circuit unit flows, and a portion in the control circuit unit or electrically connected to the control circuit unit, the high-voltage energization unit There is a low-voltage energized part that flows a lower voltage current than the part,
At least a part of the low-voltage energization part is disposed below the lower end of the high-voltage energization part in the vertical direction ,
The cooler has a refrigerant flow path for circulating a cooling medium therein,
A lower end of the high-voltage energization unit is located in a vertical direction higher than a lower end of the cooler .

  In the power conversion device, at least a part of the low-voltage energization unit is disposed below the lower end of the high-voltage energization unit in the vertical direction. Therefore, even if water accumulates in the case, a part of the low-voltage energizing portion is first submerged. Thereby, when the low voltage energizing part is short-circuited, an abnormality can be detected without causing a high-voltage leakage. That is, the control system that controls the power converter normally has a self-diagnosis function that detects an abnormality such as a short circuit or disconnection in the low-voltage energization unit and outputs a detection signal. Therefore, the power conversion device detects at least one part of the low-voltage energization part below the lower end of the high-voltage energization part in the vertical direction, and detects flooding of the low-voltage energization part using the self-diagnosis function. Can do. Thereby, it is possible to detect water in the case without using new parts. Moreover, since the inundation in the case can be detected at an early stage due to a short circuit of the low-voltage energization unit, high-voltage leakage can be surely prevented.

  As described above, according to the present invention, it is possible to provide a power conversion device that can quickly detect water intrusion into a case without increasing the number of components.

Sectional drawing of the power converter device in Example 1. FIG. FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1.

  The power conversion device may be an inverter or the like that is mounted on, for example, an electric vehicle, a hybrid vehicle, or the like and used to generate AC power to a rotating electric machine for driving.

Example 1
An embodiment of the power conversion device will be described with reference to FIGS.
As shown in FIGS. 1 and 2, the power conversion device 1 of this example includes a main circuit unit 2 including a semiconductor module 21 with a built-in switching element, a control circuit unit 3 that controls the semiconductor module 21, and a main circuit unit. 2 and a case 4 in which the control circuit unit 3 is housed. The case 4 includes a high-voltage energization unit through which a main power current converted by the main circuit unit 2 flows, and a part in the control circuit unit 3 or electrically connected to the control circuit unit 3. There is a low-voltage energizing section through which a current having a voltage lower than that of the section flows. At least a part of the low-voltage energization unit is disposed below the lower end B of the high-voltage energization unit in the vertical direction Z.

  The semiconductor module 21 includes a switching element such as an IGBT (Insulated Gate Bipolar Transistor) or a MOSFET (MOS field effect transistor). The semiconductor module 21 includes a main body 211 formed by resin-molding a switching element, and a main electrode terminal 212 and a control terminal 213 protruding from the main body 211 in opposite directions. A controlled current controlled by the power conversion device 1 flows through the main electrode terminal 212, and a control current for controlling the switching element flows through a part of the plurality of control terminals 213. The control terminal 213 includes a terminal that is built in the semiconductor module 21 and through which a signal current of a temperature sensor that detects the temperature of the semiconductor module 21 flows. Furthermore, as the control terminal 213, there is also a terminal connected to a current detection unit that detects a controlled current. A part of the main current flows through the control terminal 213.

  As shown in FIG. 2, the power conversion device 1 of this example includes a plurality of semiconductor modules 21, and the plurality of semiconductor modules 21 are alternately stacked with a plurality of cooling pipes 22 for cooling them to form a stacked body. Yes. The semiconductor module 21 is sandwiched by cooling pipes 22 from both main surfaces.

  The plurality of cooling pipes 22 have a refrigerant flow path through which a cooling medium flows, and the flow path direction of the refrigerant flow path is a direction orthogonal to the stacking direction of the stacked body. Adjacent cooling pipes 22 are connected to each other at both ends in the flow path direction. Examples of the cooling medium include natural refrigerants such as water and ammonia, water mixed with ethylene glycol antifreeze, fluorocarbon refrigerants such as Fluorinert (registered trademark), Freon refrigerants such as HCFC123 and HFC134a, and methanol. A refrigerant such as an alcohol refrigerant such as alcohol or a ketone refrigerant such as acetone can be used.

  As shown in FIG. 1, the bus bar 6 is connected to each of the main electrode terminals 212. Each bus bar 6 is connected to a capacitor, a reactor, an output terminal and the like (not shown). On the other hand, the control terminal 213 is connected to the control circuit board 31 on which the control circuit unit 3 is formed. The control circuit board 31 (control circuit unit 3) includes a substrate high-voltage unit through which a high-voltage current of main power flows and a substrate low-voltage unit through which a low-voltage control current flows.

  For example, the above-described part of the control terminals 213 (control terminal through which a part of the main current flows) is connected to the substrate high-voltage part. In addition, a voltage sensor that detects a voltage applied to the main circuit unit 2 is provided in the substrate high voltage unit (not shown). The control circuit unit 3 adjusts the on / off control of the semiconductor module 21 based on the detection signal of the voltage sensor. Since the voltage sensor detects the voltage applied to the main circuit unit 2 as described above, the voltage of the main power is applied and the current of the main power flows. Therefore, the voltage sensor is also a part of the high-voltage energization unit.

  The high-voltage energization unit is mainly a main electrode terminal 212 in the semiconductor module 21, a part through which a main current flows in the main body unit 211, and a high-voltage unit (substrate high-voltage unit) in the control circuit board 31. In addition, the bus bar 6 connected to the main electrode terminal 212 and the portion connected to the bus bar 6 also serve as a high-voltage energization unit. That is, the part electrically connected to the main electrode terminal 212 becomes a high-voltage energization part.

  On the other hand, the substrate low-voltage unit, which is a part of the control circuit unit 3, and the part electrically connected to this are the main low-voltage energization units. For example, some control terminals 213 in the semiconductor module 21 and signal lines of various sensors (temperature sensors) also serve as the low-voltage energization unit. In addition, for example, the signal current of the torque sensor of the rotating electrical machine driven by the power conversion device 1, the signal current of the current sensor that detects the output current output from the power conversion device 1, and the like are also low in the substrate voltage of the control circuit board 31. Flowing to the part.

  The low-voltage energization unit has a signal connector unit 5 for electrically connecting the control circuit unit 3 to the outside. The signal connector unit 5 is disposed below the lower end B of the high-voltage energization unit in the vertical direction Z. That is, the power conversion device 1 is mounted on a vehicle or the like so that the vertical direction of the paper surface in FIGS. 1 and 2, the upper side of the paper surface is the upper side in the vertical direction Z, and the lower side of the paper surface is the lower side in the vertical direction Z.

  The signal connector portion 5 is disposed so as to be exposed to the outside from the lowermost portion on the side surface of the case 4. The signal connector unit 5 is connected to the control circuit unit 3 in the control circuit board 31 via a signal cable 51. Further, the signal connector portion 5 is disposed below the control circuit portion 3 in the vertical direction Z.

  The main circuit unit 2 and the control circuit unit 3 are accommodated in a case 4 made of metal. However, the case 4 does not necessarily have to be made of metal, and can be made of, for example, resin.

  Note that, for example, the lower end of the high-voltage energization part may be the lower end B of the high-voltage energization part, but another part such as the lower end of the bus bar 6 may be the lower end B of the high-voltage energization part.

Next, the function and effect of this example will be described.
In the power conversion device 1, at least a part of the low-voltage energization unit is disposed below the lower end of the high-voltage energization unit in the vertical direction Z. Therefore, even if water accumulates in the case 4, a part of the low-voltage energizing portion is first submerged. Thereby, when the low voltage energization part is short-circuited, an abnormality can be detected without causing a high-voltage leakage. That is, the control system that controls the power conversion device 1 includes a self-diagnosis function that detects an abnormality such as a short circuit or disconnection in the low-voltage energization unit and outputs a detection signal. Therefore, the power conversion device 1 detects at least a part of the low-voltage energization unit below the lower end B of the high-voltage energization unit in the vertical direction, and detects flooding of the low-voltage energization unit using the self-diagnosis function. can do. Thereby, it is possible to detect water in the case 4 without using new parts. Moreover, since the inundation in the case 4 can be detected at an early stage due to the short circuit of the low-voltage energization section, it is possible to reliably prevent high-voltage leakage.

Moreover, the signal connector part 5 is arrange | positioned below the perpendicular direction Z rather than the lower end B of a high voltage | pressure electricity supply part. According to this configuration, a configuration in which a part of the low-voltage energization part is disposed below the lower end B of the high-voltage energization part can be easily realized. That is, since the signal connector portion 5 has a relatively high degree of freedom in arrangement, the design of the power conversion device 1 that realizes the above configuration can be facilitated. Moreover, since the signal connector unit 5 is submerged, the self-diagnosis function can detect the submergence more reliably.
Needless to say, leakage of the cooling medium from the cooling pipe 22 into the case 4 can be detected in the same manner.

  As described above, according to this example, it is possible to provide a power conversion device that can quickly detect the intrusion of water into the case without increasing the number of components.

  In the above-described embodiment, the example in which the signal connector unit 5 is disposed below the lower end B of the high-voltage energization unit in the vertical direction Z is shown. For example, a part of the substrate low-voltage unit in the control circuit unit is It is good also as a structure arrange | positioned below the lower end of an electricity supply part.

DESCRIPTION OF SYMBOLS 1 Power converter 2 Main circuit part 21 Semiconductor module 3 Control circuit part 4 Case

Claims (3)

A main circuit section (2) including a semiconductor module (21) incorporating a switching element;
Control circuit for controlling the semiconductor module (21) and (3),
A cooler (22) for cooling the semiconductor module (21);
The main circuit section (2), the control circuit section (3), and the cooler (22) case housing therein (4), a power conversion device having (1),
In the case (4), there is a high-voltage energizing section through which the main power current converted by the main circuit section (2) flows, and the control circuit section (3) or the control circuit section (3) and the electric circuit. There is a low-voltage energization part that is a part connected to each other and in which a current having a lower voltage flows than the high-voltage energization part,
At least a part of the low-voltage energization part is disposed below the lower end (B) of the high-voltage energization part in the vertical direction (Z) ,
The cooler (22) has a refrigerant flow path for circulating a cooling medium therein,
The power converter (1), wherein the lower end (B) of the high-voltage energization unit is located above the lower end of the cooler in the vertical direction (Z ).   The low-voltage energization unit has a signal connector unit (5) for electrically connecting the control circuit unit (3) to the outside, and the signal connector unit (5) is a lower end (B) of the high-voltage energization unit. The power conversion device (1) according to claim 1, wherein the power conversion device (1) is arranged below the vertical direction (Z).   The power conversion device (1) according to claim 2, wherein the signal connector part (5) is arranged below the control circuit part (3) in the vertical direction (Z).

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