Power converter

Abstract

To provide a power conversion device that maintains high cooling performance while offering excellent safety in the event of abnormal heat generation. [Solution] A power conversion device 100 that houses a power unit 31 inside, comprising a power conversion section 23 that houses the power unit 31, a tank 25 disposed above the power conversion section 23, a cooling pipe 41 routed from the tank 25 to the power conversion section 23 to guide cooling water from the tank 25 to the power unit 31 for cooling, and a detection means for detecting the internal temperature of the power conversion section 23, wherein the cooling pipe 41 is equipped with an emergency release valve 47 that opens when the detection means detects that the internal temperature of the power conversion section 23 has reached a preset temperature.

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses a power conversion device including a plurality of power units each having a power conversion circuit, a plurality of electric wires for power input / output to the plurality of power units, a cooling device for supplying a liquid refrigerant to the plurality of power units, and a plurality of pipes for connecting the plurality of power units and the cooling device. In this power conversion device, the power units are cooled by the supplied liquid refrigerant.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, due to the increasing power demand, the demand for various chargers has been increasing. For example, a power conversion device is installed together with a charger for a battery electric vehicle (BEV), a home battery, or a solar power generator. On the other hand, due to the increasing power supply and demand, the usage frequency of these devices has increased, the burden on the power conversion device has become large, and excessive heat generation may occur. Moreover, in the power conversion device, the internal power energy is also high, and the amount of heat generation is further increasing. Therefore, abnormal heat generation may occur in the internal power units of the power conversion device.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a power conversion device that maintains high cooling performance and is excellent in safety during abnormal heat generation.

Means for Solving the Problems

[0006] To achieve the above objective, the power conversion device of the present invention is A power conversion device that houses high-voltage components internally, A power conversion unit housing the aforementioned high-voltage components, A tank is provided above the power conversion unit, A cooling pipe is routed from the tank to the power conversion unit, and guides the cooling water from the tank to the high-voltage component for cooling. A detection means for detecting the internal temperature of the power conversion unit, Equipped with, The cooling pipe is equipped with an opening valve that opens when the detection means detects that the internal temperature of the power conversion unit has reached a preset temperature. Power converter.

[0007] With this configuration of power converter, when the internal temperature of the power converter reaches the set temperature, the release valve of the cooling pipe is opened. Therefore, for example, in an emergency, the cooling water discharged from the tank through the opened release valve can accelerate the cooling of the inside of the device. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a power conversion device that maintains high cooling performance while offering excellent safety in the event of abnormal heat generation. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic diagram of the power conversion device according to this embodiment. [Figure 2] Figure 2 is a schematic perspective view of the lateral piping of a cooling system equipped with an emergency release valve. [Figure 3] Figure 3 is a schematic diagram illustrating the flow of cooling water. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described in detail below with reference to the drawings. Figure 1 is a schematic diagram of the power converter 100 according to this embodiment.

[0011] As shown in Figure 1, the power converter 100 according to this embodiment includes a housing 11, and each device is housed inside this housing 11. This power converter 100 is a device that converts DC / AC by switching the current. This power converter 100 can be installed, for example, in a charger for an electric vehicle (BEV: Battery Electric Vehicle), a home battery storage system, or a solar power generation system.

[0012] The power conversion device 100 comprises a cooling drive unit 21 and a power conversion unit 23. The cooling drive unit 21 includes a tank 25, which is located above the power conversion unit 23.

[0013] The power conversion unit 23 comprises multiple power units (high-voltage components) 31. Each power unit 31 is a unit equipped with a power conversion circuit, such as a power semiconductor element. The power conversion unit 23 also comprises a high-voltage input circuit section (high-voltage component) 33 and a high-voltage output circuit section (high-voltage component) 35. The high-voltage input circuit section 33 and the high-voltage output circuit section 35 are arranged side by side at the bottom of the power conversion unit 23, and multiple power units 31 are arranged above these high-voltage input circuit section 33 and high-voltage output circuit section 35. In this example, the power units 31 are arranged in two horizontal rows and six vertical rows when viewed from the front. The power conversion unit 23 converts the high-voltage current input from the high-voltage input circuit section 33 into power using each power unit 31 and outputs it from the high-voltage output circuit section 35.

[0014] The power conversion device 100 has a cooling pipe 41, and this cooling pipe 41 is routed inside the power conversion unit 23. The cooling pipe 41 has a vertical pipe 43 and a horizontal pipe 45. The vertical pipe 43 is arranged in the vertical direction, and the horizontal pipe 45 is arranged in the horizontal direction. The upper end of the vertical pipe 43 is connected to the tank 25. Both ends of the horizontal pipe 45 are connected to the vertical pipe 43. As a result, the cooling pipe 41 is routed in a state of being stretched in a grid pattern in the power conversion unit 23.

[0015] In the cooling pipe 41, the cooling water in the tank 25 is supplied to the vertical pipe 43 by the cooling drive unit 21, sent from these vertical pipes 43 to the horizontal pipe 45, and then returned from the vertical pipe 43 to the tank 25. Thus, in the power conversion device 100, the cooling water in the tank 25 is made to flow so as to circulate through the cooling pipe 41. Thereby, the power unit 31, the high-voltage input circuit unit 33, and the high-voltage output circuit unit 35 housed in the power conversion unit 23 are cooled.

[0016] As shown in FIGS. 2 and 3, a plurality of emergency release valves (release valves) 47 are provided in the cooling pipe 41. These emergency release valves 47 are provided in the horizontal pipe 45 constituting the cooling pipe 41 and are arranged at positions spaced apart from each other. When the emergency release valve 47 in the cooling pipe 41 is opened, the cooling water flowing inside discharges from the emergency release valve 47 (refer to the arrows in FIGS. 2 and 3). The power conversion device 100 includes a detection means (not shown) for detecting the internal temperature of the power conversion unit 23. And in the cooling pipe 41, when it is detected by the detection means that the internal temperature of the power conversion unit 23 has reached a preset temperature, the emergency release valve 47 is opened.

[0017] Also, in the power conversion device 100, the area where the power conversion unit 23 is located is a water-stop area As. In the water-stop area As, the housing 11 is water-stopped by a waterproof sheet or the like. Thereby, in the water-stop area As where the power conversion unit 23 is located, water intrusion from the outside to the inside is prevented.

[0018] Next, the operation of the power conversion device 100 according to the present embodiment will be described. (During normal operation) During normal operation, in the power conversion device 100, the cooling water in the tank 25 is circulated through the cooling pipe 41 by the cooling drive unit 21 provided at the upper part. As a result, the power unit 31, the high-voltage input circuit unit 33, and the high-voltage output circuit unit 35 of the power conversion unit 23 are cooled by the circulated cooling water, and high performance is maintained.

[0019] Thus, in the power conversion device 100, since the cooling pipes 41 routed to the power conversion unit 23 are stretched in a grid pattern, the ambient temperature inside the device can be kept constant, the cooling performance of the high-voltage components can be improved, and the expansion stress of the high-voltage components due to the cold and heat temperature difference can be relaxed to improve the lifespan.

[0020] (During abnormal heat generation) In the power conversion unit 23 of the power conversion device 100, when excessive heat generation occurs in high-voltage components such as the power unit 31, the high-voltage input circuit unit 33, and the high-voltage output circuit unit 35, and the internal temperature of the power conversion unit 23 reaches the set temperature, it is detected by the detection means that the power conversion unit 23 has reached the set temperature. Then, a detection signal from the detection means is transmitted to the cooling drive unit 21, and the emergency release valve 47 of the cooling pipe 41 is opened by this cooling drive unit 21. As a result, the cooling water flowing in the cooling pipe 41 is discharged from each emergency release valve 47 of the horizontal pipe 45 (refer to the arrows in FIGS. 2 and 3), and the high-voltage components generating excessive heat are cooled. Also, when there is a fire starting from the high-voltage components due to excessive heat generation, the high-voltage components are extinguished by the cooling water discharged from the emergency release valve 47.

[0021] Thus, according to the power conversion device 100 according to the present embodiment, when the internal temperature of the power conversion unit 23 reaches the set temperature, the emergency release valve 47 of the cooling pipe 41 is opened. Therefore, for example, in an emergency, the cooling inside the device can be promoted by the cooling water from the tank 25 discharged from the opened emergency release valve 47. Also, after detecting leakage and disconnecting from the system, the heat generation inside the power conversion unit 23 due to residual power can be suppressed, and maintenance can be performed safely.

[0022] Furthermore, the power converter 100 is equipped with a leakage current detector to detect leakage current and a circuit breaker to interrupt overcurrent as protective devices in the event of an abnormality, and is also equipped with a discharge resistor to reduce internal power energy, thereby enhancing safety in the event of an abnormality. Herein, it is conceivable that the protective devices and discharge resistor may be damaged and cease to function in the event of an abnormality, but in this embodiment, the power converter 23 is cooled and extinguished by cooling water, so the device can be made to have an excellent fail-safe function.

[0023] Furthermore, in the power converter 100, the power conversion unit 23 is designated as a watertight region As, where water ingress from the outside is prevented by a waterproof sheet or the like. Therefore, in the event of an abnormality, leakage of cooling water discharged from the emergency release valve 47 to the outside is suppressed in the watertight region As. As a result, in the event of an abnormality, the power conversion unit 23 is cooled and extinguished with cooling water, and forced discharge by the cooling water is performed in the high-voltage input circuit unit 33 and the high-voltage output circuit unit 35, and electric shock damage due to leakage of cooling water to the outside is avoided. In addition, since leakage of cooling water discharged from the emergency release valve 47 to the outside is suppressed in the event of an abnormality, cooling water is stored in the power converter 23. Therefore, even if the high-voltage input circuit unit 33 and the high-voltage output circuit unit 35 are not at the bottom but are located, for example, in an intermediate position in the vertical direction, forced discharge by the cooling water is possible in the high-voltage input circuit unit 33 and the high-voltage output circuit unit 35.

[0024] Furthermore, in the power conversion device 100 according to this embodiment, the cooling water storage tank 25 is located at the top, so that the cooling water in the tank 25 can be sent to the power conversion unit 23 below by gravity. Moreover, by locating the tank 25 at the top, the tank 25 acts as a water jacket to suppress radiant heat from the sun. Note that if a pump is provided, the tank 25 does not need to be located at the top. Also, the tank 25 may be provided as a single case covering the entire upper surface of the power conversion unit 23 of the housing 11, or it may be configured as multiple divided cases arranged on the top of the power conversion unit 23.

[0025] Furthermore, the emergency release valve 47 may be made of rubber, for example, which melts and opens at high temperatures. In this case, a detection means for detecting the internal temperature of the power conversion unit 23 becomes unnecessary. Also, if a cooling pipe 41 made of a molten material such as rubber that melts at high temperatures is used, only the part of the cooling pipe 41 close to the high-temperature part of the heated high-voltage component will melt, and cooling water will be discharged from this molten area. Therefore, the area from which the cooling water is discharged can be kept small. [Explanation of symbols]

[0026] 23 Power Conversion Unit 25 tanks 31 Power Unit (High Voltage Components) 33. High-voltage input circuit section (high-voltage components) 35. High-voltage output circuit section (high-voltage components) 41 Cooling piping 47. Emergency release valve (release valve) 100 Power converter

Claims

[Claim 1] A power conversion device that houses high-voltage components internally, A power conversion unit housing the aforementioned high-voltage components, A tank is provided above the power conversion unit, A cooling pipe is routed from the tank to the power conversion unit, and guides the cooling water from the tank to the high-voltage component for cooling. A detection means for detecting the internal temperature of the power conversion unit, Equipped with, The cooling pipe is equipped with an opening valve that opens when the detection means detects that the internal temperature of the power conversion unit has reached a preset temperature. Power converter.

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