Power Conversion Equipment

Abstract

To provide a power conversion device whose cooling performance is improved.SOLUTION: A power conversion device obtained by storing a power conversion module in a housing comprises: a heater element included in the power conversion module; a cooling part for cooling the heater element; and an electronic component different from the heater element. In the housing, a vent hole is formed below the cooling part, and the electronic component is arranged in a space between the cooling part and the vent hole.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a power conversion device. [Background technology]

[0002] The following Patent Document 1 discloses a power conversion device having a configuration in which cooling pipes, which are the inlets and outlets of cooling water, and vent holes are at the same height. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-92934 A Summary of the Invention [Problem to be solved by the invention]

[0004] In consideration of the conventional configuration, an object of the present invention is to provide a power conversion device with improved cooling performance in order to more efficiently cool electronic components within the device. [Means for solving the problem]

[0005] The power conversion device is a power conversion device that houses a power conversion module within a housing, and is equipped with a heat-generating element possessed by the power conversion module, a cooling section that cools the heat-generating element, and an electronic component different from the heat-generating element, wherein an air vent is formed in the housing below the cooling section, and the electronic component is disposed in the space between the cooling section and the air vent. Effect of the Invention

[0006] According to the present invention, it is possible to provide a power conversion device with improved cooling performance. [Brief description of the drawings]

[0007] [Figure 1] Diagram of power converter and motor [Diagram 2] Exploded view of the power converter in Figure 1 [Diagram 3] 1 is a cross-sectional view of a power converter according to an embodiment of the present invention; [Figure 4] Exploded view of the current sensor in Figure 3

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The following description and drawings are examples for explaining the present invention, and appropriate omissions and simplifications have been made for clarity of explanation. The present invention can be implemented in various other forms. Unless otherwise specified, each component may be singular or plural.

[0009] In order to facilitate understanding of the invention, the position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings.

[0010] (One embodiment of the present invention and overall configuration of the device) Fig. 1(a) is a diagram of a power converter and a motor, and Fig. 1(b) is a diagram of the power converter and the motor separated from each other. Fig. 2 is an exploded view of the power converter of Fig. 1.

[0011] The power conversion device 1 is fixed to an external device such as a motor 4 with bolts. The direction in which the power conversion device 1 is fixed to the motor 4 in Fig. 2 is the upward direction on the page. A cooling pipe 2, a DC bus bar 8, and an AC bus bar 13 protrude from the outside of the power conversion device 1. The AC bus bar 13 is inserted into the motor 4 so as to be connected to a terminal block 4a of the motor 4, and the vicinity of the joint portion (terminal block 4a) between the AC bus bar 13 and the motor 4 is sealed with a sealing material 4b such as rubber to ensure airtightness.

[0012] The power conversion device 1 is provided with a plurality of power conversion modules 5 with semiconductor elements built in a housing 10. The power conversion modules 5 are provided with semiconductor elements such as IGBTs (Insulated Gate Bipolar Transistors), and DC power from a battery is conducted via a DC bus bar 8, and the DC power is converted to AC power by switching. The converted AC power is transmitted to an external device such as a motor 4 via an AC bus bar 13. The motor 4 drives a rotating body provided inside the motor 4 by the AC power from the power conversion device 1.

[0013] A control board 16 that controls the power conversion module 5 is fixed to a plate-shaped base plate 15. A capacitor element 6 that smoothes ripple current generated by switching of the semiconductor element is fixed by potting resin 7 filled in the housing 10 of a metal case.

[0014] The terminal portion of the power conversion module 5 is electrically connected to a control board 16 through a base plate 15. The control board 16 controls the switching of the power conversion module 5 in response to an instruction from an external higher-level control signal. The current output from the power conversion module 5 to the motor 4 is detected by a current sensor 14 disposed between the power conversion module 5 and the AC bus bar 13, and the detected value is transmitted to the control board 16.

[0015] The water channel cover 11 is joined to the housing 10 to form a refrigerant flow path that cools the power conversion module 5. The housing 10 is provided with a refrigerant inlet 2a and a refrigerant outlet 2b that are connected to this refrigerant flow path and that introduce a refrigerant from the outside.

[0016] The above-mentioned components housed in the housing 10 are fixed inside, and a cover 9 is fixed to the opening end face of the housing 10, which is a metal case, to make the inside of the housing 10 dust-proof. The housing 10 is provided with an air vent 3 into which a waterproof filter 12 is fitted. The waterproof filter 12 is made of a material that allows air to pass through but not water, and prevents water from entering the power conversion device 1 while ensuring ventilation between the air inside and the air outside the power conversion device 1.

[0017] FIG. 3 is a cross-sectional view of a power converter according to an embodiment of the present invention, where FIG. 3(a) is an external view from above of the power converter, and FIG. 3(b) is a cross-sectional view taken along line AA of FIG. 3(a).

[0018] In the power conversion device 1, the internal parts that generate heat due to the inherent resistance of the bus bars 8 and 13 during power conduction are controlled to within a guaranteed temperature range by the coolant introduced from the outside via the cooling pipes 2. In addition, the coolant flow path 2c shown in Fig. 3(b) mainly serves to cool the semiconductor elements of the power conversion module 5 that generate a large amount of heat.

[0019] However, the temperature inside the sealed power conversion device 1 varies depending on the location inside the device 1, and if high heat accumulates in an area where low heat-resistant electronic components such as the current sensor 14 are installed, this component may be adversely affected. Therefore, it is necessary to efficiently cool low heat-resistant electronic components such as the current sensor 14.

[0020] Therefore, in the present invention, the vent hole 3 blocked by the waterproof filter 12 described above is formed on the lower side of the refrigerant flow path 2c, which is the cooling part, in the housing 10. Furthermore, a current sensor 14, which is an electronic component separate from the semiconductor element of the power conversion module 5, which is the heat generating element, is disposed in the space between the refrigerant flow path 2c and the vent hole 3.

[0021] In this manner, air convection 17 is generated inside the housing 10 as shown by the arrows, and air is exhausted 17a through the air vent 3. By generating a flow of air that is exhausted from the inside of the housing 10 to the outside, the air inside the device 1 that has been cooled by the cooling water circulates, and the internal components and electronic components of the housing 10 can be efficiently cooled.

[0022] Although the present invention has been described using the current sensor 14 as an example of an electronic component other than a semiconductor element, which is a heat-generating element, the same method can be used to cool not only the current sensor 14 but also substrates that tend to generate heat, resistors and chips mounted on the substrate, and the electronic component that needs to be cooled primarily can be determined by any desired positional relationship between the refrigerant flow path 2c and the ventilation hole 3.

[0023] (Principle of the Invention) In the upper part (upper part of the drawing) of the device 1 cooled by the cooling water, the density of the air is higher than the density of the air around the heat-generating components. This causes air convection in the device 1. In addition, the housing 10 has a vent hole 3 that communicates with the outside air, located at a position away from the refrigerant flow path 2c and on the lower side. The internal air around the vent hole 3 expands due to the heating of the heat-generating components, and the air of the convection current 17 tries to go to the outside toward the vent hole 3 in response to the flow discharged to the outside of the housing 10. This series of flows causes the air cooled by the refrigerant flow path 2c to spread throughout the power conversion device 1. This allows electronic components with low heat resistance that need to be cooled, such as the current sensor 14, to be efficiently cooled.

[0024] When the refrigerant flow path 2c, which is a cooling unit, is located far from the housing wall on which the ventilation holes 3 are formed, with respect to the center of the housing 10 as a reference, the air cooled by the refrigerant flow path 2c can be spread throughout the power conversion device as described above, and the entire space of the housing 10 can be cooled evenly. Also, when the refrigerant flow path 2c is located near the housing wall on which the ventilation holes 3 are formed, with respect to the center of the housing 10 as a reference, the cooling effect of low heat-resistant electronic components placed between them is increased. Note that when the housing 10 is divided into an upper space and a lower space, the refrigerant flow path 2c is located on the upper space side, and the ventilation holes 3 are formed on the lower space side.

[0025] In this way, it is possible to control convection and determine the part to be actively cooled by arbitrarily setting the arrangement of the cooling part according to the position of the vent hole 3. Note that it is also possible to use a method in which the part to be actively cooled is determined by arbitrarily setting the position of the vent hole 3 relative to the cooling part.

[0026] FIG. 4 is an exploded view of the current sensor of FIG.

[0027] In the current sensor 14, a magnetic core 18 with a gap formed in a portion thereof is housed in an overmolded case 23 and fixed by a sensor cover 22. The circuit board 20 is mounted so that a detection element 19 is disposed in a portion of the gap in the magnetic core 18, and is fixed to the overmolded case 23 by a base 21.

[0028] In such a current sensor 14, by arranging the circuit board 20 on which the detection element 19 is mounted in a position closer to the above-mentioned refrigerant flow path 2c, it is possible to efficiently dissipate heat from the circuit board 20. Note that the same effect can be obtained by placing not only the current sensor 14 but also other components with low heat resistance closer to the refrigerant flow path 2c.

[0029] According to the embodiment of the present invention described above, the following advantageous effects are obtained.

[0030] (1) The power conversion device 1 accommodates a power conversion module 5 in a housing 10, and includes a heat generating element of the power conversion module 5, a cooling unit 2 that cools the heat generating element, and an electronic component different from the heat generating element, and an air vent 3 is formed in the housing 10 below the cooling unit 2, and the electronic component is disposed in the space between the cooling unit 2 and the air vent 3. In this way, it is possible to provide a power conversion device 1 with improved cooling performance.

[0031] (2) The electronic component is a current sensor 14 that detects the output current of the power conversion module 5. This makes it possible to maintain the reliability of the current sensor 14.

[0032] (3) Current sensor 14 has magnetic core 18 with a gap formed in a portion thereof, and circuit board 20 on which detection element 19 is mounted so as to be disposed in the gap, and when current sensor 14 is disposed within housing 10, circuit board 20 is disposed in a position close to cooling unit 2. In this manner, the reliability of current sensor 14 can be maintained.

[0033] (4) The cooling unit 2 is disposed at a position far from the housing wall in which the air vents 3 are formed, with respect to the center of the housing 10. In this manner, the convection current 17 of the air cooled by the cooling unit 2 spreads throughout the device 1, and the internal electronic components can be evenly cooled.

[0034] (5) The cooling unit 2 is disposed at a position close to the wall of the housing in which the ventilation holes 3 are formed, with respect to the center of the housing 10. This allows efficient cooling of electronic components that need to be cooled in a concentrated manner.

[0035] (6) When the space inside the housing 10 is divided into an upper space and a lower space, the cooling unit 2 is disposed in the upper space side, and the air vents 3 are formed in the lower space side. In this way, the convection current 17 of the air cooled by the cooling unit 2 spreads throughout the device 1, and the electronic components inside can be evenly cooled.

[0036] The present invention is not limited to the above-described embodiment, and various modifications and other configurations can be combined without departing from the spirit of the present invention. Furthermore, the present invention is not limited to those having all of the configurations described in the above-described embodiment, and includes those in which some of the configurations are omitted. [Explanation of symbols]

[0037] 1 Power conversion device 2 Cooling pipe 2a Refrigerant inlet 2b Refrigerant outlet 2c Coolant flow path 3. Ventilation holes 4 Motors 4a terminal block 4b Sealing material 5 Power Conversion Module 6 Capacitor elements 7 Potting resin 8 DC busbar 9 Cover 10. Chassis 11 Waterway Cover 12 Waterproof filter 13 AC busbar 14 Current Sensor 15 Base plate 16 Control Board 17 Air convection 17a Air Exhaust 18 Magnetic core 19 Detector element 20 Circuit Board 21 Base 22 Sensor cover 23 Overmolded case

Claims

1. A power conversion device having a power conversion module housed in a housing, The power conversion module includes a heat generating element, a cooling unit that cools the heat generating element, and an electronic component that is different from the heat generating element, When the space inside the housing is divided into an upper space and a lower space, the cooling unit is disposed on the upper space side, and an air vent is formed on the lower space side to ensure ventilation between the air inside the housing and the air outside the housing, the electronic component is disposed in a space in the housing between the cooling unit and the ventilation hole, and is disposed closer to the ventilation hole than other electronic components; the electronic component is a current sensor that detects an output current of the power conversion module, The current sensor includes a magnetic core having a gap formed in a portion thereof, and a circuit board on which a detection element is mounted so as to be disposed in the gap; In the current sensor, the circuit board side faces the cooling unit and is located closer to the cooling unit than the magnetic core. Power conversion equipment.

2. The power conversion device according to claim 1, The cooling unit is disposed at a position far from the housing wall in which the ventilation hole is formed, with respect to the center of the housing. Power conversion equipment.

3. The power conversion device according to claim 1, The cooling unit is disposed at a position close to the wall of the housing in which the ventilation hole is formed, with respect to the center of the housing. Power conversion equipment.

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