Directly cooled inverter

Abstract

The invention relates to a directly cooled inverter (1) comprising: a cooling circuit (5) for cooling components (2A, 2B, 2C) of the inverter (1); a cooling fluid (7) which at least in part flows through and / or around the components (2A, 2B, 2C) of the inverter (1) and is in direct contact therewith; and at least one sensor (8) which is arranged in the cooling circuit (5), wherein the sensor (8) is designed to detect properties of the cooling fluid (7).

Description

[0001] Description

[0002] Direct-cooled inverter

[0003] The invention relates to a directly cooled inverter.

[0004] Power electronic components in inverters are often mounted decentrally on a PCB and cooled using fans. Air cooling has the advantage that the cooling fluid can relatively easily reach all components requiring cooling. Disadvantages of air cooling include the need for fans, which generate noise. Depending on the application, air filters may also be required, resulting in a higher pressure drop. These filters also need to be replaced.

[0005] Recent developments increasingly utilize directly cooled components. This means that the components are cooled directly by an electrically non-conductive fluid.

[0006] In order to use the power electronics for a long time, it is important to know how long the remaining service life of the individual components is and when coolant needs to be changed.

[0007] The invention is based on the objective of making this possible.

[0008] The problem is solved by claim 1, i.e. a directly cooled inverter, comprising a cooling circuit for cooling components of the inverter, a cooling fluid which at least partially flows through and / or around the components of the inverter and has direct contact with them, at least one sensor which is arranged in the cooling circuit, wherein the sensor is designed to detect properties of the cooling fluid.

[0009] The cooling fluid is advantageously an electrically non-conductive fluid. A biodegradable oil contained in the cooling fluid is particularly preferred. The cooling fluid can also consist entirely of a biodegradable oil. For example, Midel 7131 can be used.

[0010] Because the oil is biodegradable, environmental damage can be avoided in the event of leaks. Furthermore, biodegradability offers another advantage: it reduces the need for containment measures. Since no environmental damage is to be expected in the event of a leak, the safety rating of the housing with regard to leaks can be lowered.

[0011] An advantageous embodiment involves arranging the sensor in close proximity to a circulation pump. This allows for particularly accurate measurement of the cooling fluid's properties.

[0012] Advantageously, the sensor detects the properties of the cooling fluid spectrotopically, chemically and / or physically.

[0013] Several properties of the cooling fluid can be measured. Preferably, these are measured simultaneously. Measured properties include, in particular, water content, oxidation, total base number (TBN), temperature, and / or soot content.

[0014] An increased soot content provides information about, for example, partial short circuits or partially elevated temperatures.

[0015] Elevated water content, for example, indicates leaks in the inverter system. Increased oxidation, for instance, suggests an excess of oxygen molecules, indicating aging of the cooling fluid, particularly the oil. Additional temperature measurements can provide insights into the inverter's operating behavior and its remaining service life.

[0016] An advantageous embodiment also includes a data acquisition and / or data analysis system, preferably based on artificial intelligence. This system is designed to collect data from multiple inverters and / or to predict the service life of one or more inverters and / or to predict when a coolant change is necessary.

[0017] A necessary component replacement can also be advantageously predicted based on the collected data. Artificial intelligence is beneficial for real-time validation through accompanying simulations or evaluations of other performance characteristics of the inverter, such as its efficiency. In production facilities, reliability is crucial. Systems are installed redundantly. If one system fails, the next one takes over. Nevertheless, systems require maintenance. Therefore, maintenance schedules are often defined. If a monitoring system can predict when a power electronic component will fail, maintenance can be planned accordingly. This enables uninterrupted operation. By obtaining real-world customer operating data, the conditions that promote or cause component failure can be identified.

[0018] This data can be interpreted by AI and used to make predictions for specific components.

[0019] Further advantages of the invention include: Noise from fans is avoided. In addition, no filters are required for the fan.

[0020] The invention is aimed in particular at direct cooling of at least those electronic components of the inverter which generate heat during or as a result of the operation of the inverter itself.

[0021] The cooling system is particularly beneficial for those electronic components of the inverter that generate heat and / or hotspots during operation. These are primarily active and passive electronic components.

[0022] Examples of active components include power electronic components, ICs, transistors, and operational amplifiers.

[0023] Examples of passive components include chokes, capacitors (especially DC-link capacitors), and resistors.

[0024] A particularly advantageous embodiment is a directly cooled inverter comprising at least one component that actively generates heat during operation of the inverter, wherein the inverter has:

[0025] - a cooling circuit with a cooling fluid for directly cooling the component generating heat during operation of the inverter, wherein the cooling fluid at least partially flows through and / or around the component generating heat during operation of the inverter and has direct contact with the at least one component, - at least one sensor arranged in the cooling circuit, wherein the sensor is designed to detect properties of the cooling fluid.

[0026] The problem can also be solved by a method for monitoring a directly cooled inverter, wherein properties of the cooling fluid are detected by means of a sensor. The properties are advantageously detected spectroscopically, chemically, and / or physically; preferably, the properties of the cooling fluid are detected simultaneously. In particular, water content, oxidation, total base number (TBN), temperature, and / or soot content are detected. The detected properties are advantageously compared with defined values ​​for the respective property. An indicator is advantageously output when a value of a detected property is higher than the previously defined value.

[0027] An increased soot content preferably serves as an indicator of partial short circuits or partially elevated temperatures. An increased water content serves as an indicator of leaks. Increased oxidation advantageously serves as an indicator of the aging of the cooling fluid. An elevated temperature advantageously serves as an indicator of the operating mode of the inverter and / or the remaining service life.

[0028] Artificial intelligence and the collected data can be used to draw advantageous conclusions about the lifespan and cooling fluid change intervals. Based on this data, recommendations can be made for replacing individual components.

[0029] The sensor can be installed, for example, in the coolant line upstream of the pump. This ensures particularly good monitoring of the coolant properties and allows for the timely detection of potential damage to the inverter. Additionally, the aforementioned AI approaches can be used to learn from the data and to suggest suitable components for replacement.

[0030] The invention is described and explained below with reference to the figures in the exemplary embodiments.

[0031] They show:

[0032] FIG 1 shows an inverter with a cooling circuit,

[0033] FIG 2 a method and FIG 3 a system for data acquisition and / or data analysis.

[0034] FIG 1 shows an inverter 1 and a cooling circuit 5. The cooling circuit 5 carries a cooling fluid 7 to cool, in particular, those components 2A, 2B, 20 of the inverter 1 that generate heat during regular operation of the inverter 1, i.e., even when no fault is present, which can, for example, result in hotspots. Such heat-generating components 2A, 2B, 20 during operation of the inverter 1 can be active components and / or passive components. Active components can be, for example, power electronic components or power modules, ICs, transistors, operational amplifiers, etc. Passive components can be, for example, resistors, capacitors (e.g., DC link capacitors), inductors, chokes, etc. In contrast, for example, housing parts of the inverter, structural components, and other components are not considered passive components.The cooling circuit itself or other cooling devices are not to be considered as heat-generating components in the operation of converter 1.

[0035] The cooling fluid 7 can, for example, be introduced into the inverter 1 at an inlet point 3 and exit again at an outlet point 4. In the figure, the cooling fluid 7 flows through and / or around components 2A, 2B, and 2C and is in direct contact with them. Due to this direct contact, it is advantageous if the cooling fluid 7 is electrically non-conductive.

[0036] The cooling circuit 5 advantageously runs through or past components of the inverter, this serves to cool the components.

[0037] FIG 1 further shows a sensor 8 arranged in the cooling circuit 5. The sensor 8 is designed to detect properties of the cooling fluid 7. The sensor 8 is advantageously arranged in the vicinity of a circulation pump 10.

[0038] FIG 1 further shows a system 20 for data acquisition and / or data analysis.

[0039] System 20 can collect data, even from multiple inverters 1, 1B, 1C, see FIG. 3. This allows for predictions of necessary coolant changes based on Kl. It is also possible to predict the service life of at least one inverter 1, 1B, 1C.

[0040] The sensor 8 advantageously measures the properties of the cooling fluid 7 spectroscopically, chemically, and / or physically. The sensor 8 advantageously detects water content, oxidation, total base number (TBN), temperature, and / or soot content in the cooling fluid 7.

[0041] FIG 2 shows a method.

[0042] In process step S1, the properties of the cooling fluid 7 are recorded.

[0043] In process step S2, the recorded properties are compared with defined values ​​of the respective property.

[0044] In process step S3, an indicator is output if a value of the recorded property is higher than the defined value.

[0045] Not shown, but still possible in the further process, is, for example, a recommendation to replace a component based on the collected data.

[0046] An advantage of the invention is that no fans are required, thus enabling quiet operation.

[0047] Depending on the application, air filters are required. Any associated pressure loss is no longer a problem. By eliminating the need for fans, maintenance and replacement are unnecessary.

[0048] The proposed cooling system also has a power density (kW / m²). 3 ) advantageous to the entire unit.

Claims

Patent claims 1. Direct-cooled inverter (1), comprising: - a cooling circuit (5) for cooling components (2A, 2B, 2C) of the inverter (1), - a cooling fluid (7) that at least partially flows through and / or around the components (2A, 2B, 2C) of the inverter (1) and has direct contact with them, - at least one sensor (8) arranged in the cooling circuit (5), wherein the sensor (8) is designed to detect properties of the cooling fluid (7).

2. Directly cooled inverter (1) according to claim 1, wherein the cooling fluid (7) comprises a biodegradable oil.

3. Directly cooled inverter (1) according to one of the preceding claims, wherein the at least one sensor (8) is arranged in the vicinity of a circulation pump (10).

4. Directly cooled inverter (1) according to one of the preceding claims, wherein the sensor (8) spectroscopically, chemically and / or physically detects the properties of the cooling fluid (7).

5. Directly cooled inverter (1) according to one of the preceding claims, wherein the sensor (8) is designed to detect several properties of the cooling fluid (7), preferably simultaneously, in particular water content, oxidation, total base number (TBN), temperature and / or soot content.

6. Direct-cooled inverter (1) according to one of the preceding claims, further comprising at least one system (20) for data acquisition and / or data analysis, preferably based on artificial intelligence (Kl), designed to collect data from a plurality of inverters (1 , 1B, 1C) and / or to predict the lifetime of an inverter (1) and / or to predict a necessary cooling fluid change.

7. Direct-cooled inverter according to claim 6, designed such that a necessary replacement of a component (2A, 2B, 2C) is predictable based on the collected data.

8. Directly cooled converter according to claim 6 or 7, wherein the KL is designed for real-time validation by accompanying simulations and / or evaluations of further performance characteristics of the converter (1), for example, the efficiency.

9. Directly cooled converter (1) according to one of the preceding claims, wherein the components (2A, 2B, 2C) of the converter (1) are such that they generate heat during operation of the converter (1).

10. Direct-cooled converter (1) according to one of the preceding claims, wherein the components (2A, 2B, 2C) are active components, for example power electronic components, ICs, transistors, operational amplifiers, and / or passive electronic components, for example chokes, capacitors, resistors.

11. Directly cooled converter (1) according to one of the preceding claims, wherein the cooling fluid (7) is an electrically non-conductive fluid.

12. Method for monitoring a directly cooled inverter (1) according to one of the preceding claims, wherein properties of the cooling fluid (7) are detected by means of a sensor (8).

13. Method according to claim 12, wherein the properties of the cooling fluid (7) are detected spectroscopically, chemically and / or physically.

14. Method according to one of claims 12 or 13, wherein several properties of the cooling fluid (7) are detected, preferably simultaneously, in particular water content, oxidation, total base number (TBN), temperature and / or soot content.

15. Method according to any one of claims 12 to 14, wherein the detected properties are compared with defined values ​​of the respective property, wherein if a value of the detected property is higher than the defined value, an indicator is output.

16. Method according to claim 15, wherein an increased soot content serves as an indicator for partial short circuits or partially increased temperatures, wherein an increased water content serves as an indicator for leaks, wherein an increased oxidation serves as an indicator for the aging of the cooling fluid (7) and / or wherein an increased temperature serves as an indicator for the operating mode of the inverter (1) and / or a remaining service life.

17. Method according to one of claims 12 to 16, wherein conclusions about lifetime and cooling fluid change are obtained from the collected data on the basis of artificial intelligence.

18. Method according to claim 17, wherein the replacement of individual components (2A, 2B, 2C) is recommended based on the collected data.

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