CN113246769A

CN113246769A - Method for operating a cooling system

Info

Publication number: CN113246769A
Application number: CN202110101860.4A
Authority: CN
Inventors: R·德尔达; U·哈尔曼; V·布拉霍夫
Original assignee: Volkswagen Automotive Co ltd
Current assignee: Volkswagen Automotive Co ltd
Priority date: 2020-01-28
Filing date: 2021-01-26
Publication date: 2021-08-13
Also published as: DE102020200972A1

Abstract

Method for operating a cooling device. The invention relates to a method for operating a cooling device (6) having a fan (14) and at least one microphone (8, 8a, 8 b), wherein a sound signal (10) in the surroundings of the cooling device (6) is detected as a microphone signal (24 a, 24 b) by means of the microphone (8, 8a, 8 b); wherein the microphone signal (24 a, 24 b) is compared with the registered threshold value; and wherein the rotational speed of the fan (14) is reduced when the threshold value is reached or lowered.

Description

Method for operating a cooling system

Technical Field

The invention relates to a method for operating a cooling system. The invention also relates to a cooling device and to the use of such a cooling device.

Background

Electric drives or electric drivable or electric motor-driven motor vehicles, such as electric vehicles or hybrid vehicles, usually have an electric machine as drive motor, which is coupled to an on-board electrical system in the vehicle interior in order to supply electrical energy. Such onboard power systems are usually supplied with power by means of an energy store, for example in the form of an electrochemical battery.

In this case, an electrochemical battery is to be understood in particular as a so-called secondary battery (Sekund ä rbatterie) of a motor vehicle, in which the chemical energy consumed can be recovered by means of a charging process. "charging an electric drive or an electrically drivable or motor-driven vehicle" is understood here and in particular below to mean charging such a secondary (traction) energy store of the vehicle with electrical energy.

For charging a motor vehicle or a vehicle battery, for example, it is possible: the battery pack is connected by wire to a power supply point (charging point) or to a power supply grid by means of a charging cable. In this case, for example, so-called charging stations or charging posts are used as charging stations or power supply units.

In this case, such charging stations or charging posts are usually connected to a power supply grid, in particular a public low-voltage grid, using electrical connection terminals. In this case, the charging post often has power electronics for voltage conversion and/or voltage adaptation in order to adapt the voltage of the power supply system to the desired charging voltage or to the desired voltage level.

Due to the need to be connected to the power supply grid, the charging post connected to the grid is usually stationary, i.e. static, fixed in position or immobile. This means that: the charging post is installed at a predetermined location and can only be removed and re-installed at another location with high expenditure.

DE 102017215882 a1 discloses a motorized charging post having a housing and having a battery energy store integrated in the housing. Due to the battery energy store, the charging post is adapted and configured for charging an electrically driven or drivable motor vehicle substantially autonomously or independently of the power supply grid. The charging post is thus mobile, i.e. can be reversibly erected and dismantled in different positions relatively simply. In this case, the charging post also has a connection (Plug-In) for the power supply system In order to charge a battery energy store inside the charging post.

In this case, such mobile or fast charging poles (AFC) usually have integrated power electronics. In this case it is necessary to: the power electronics and the battery energy store are mounted as compactly as possible in the housing of the rapid charging pile. During operation of the rapid charging post, the power loss of the power electronics is formed, which must be dissipated as waste heat from the interior of the housing into the surroundings of the rapid charging post. For this purpose, such rapid-charging piles are equipped with cooling devices.

For example, fans with electrically driven or motor-driven impellers or fan impellers are used as cooling devices, which fans as ventilators discharge the waste heat to the surroundings by means of the generated air flow. Such cooling devices are space consuming and expensive, so that fans of smaller dimensions are often used. In the case of such fans, however, it is necessary to drive the fan or the fan wheel at as high a rotational speed as possible in order to generate a correspondingly stronger air flow, thereby causing a not insignificant noise emission (noise).

In this case, the frequency of the fan noise is in the range of human voice, i.e., between about 80 and 4000Hz (hertz), so that the fan noise is in the range of maximum auditory sensitivity. In this case, such fan noise is disadvantageous particularly in relation to the use of the rapid charging pile in a residential area. According to legal regulations, sound levels of up to 35 dBA are only allowed to be measured on bedroom windows at night in residential areas. Thus, the use of such a quick charging pile is disadvantageously limited due to the fan.

In order to reduce noise emissions or noise loads, it is possible, for example: permanently reducing the fan speed or providing the fan outlet on the housing of the rapid-charging post with additional sound-insulating material or a casing. For example, it is likewise conceivable: using a larger fan with a correspondingly reduced rotational speed; or a passive cooling device. The cooling device may also be implemented as a plurality of peltier elements. For example, it is likewise conceivable: the cooling device is spatially separated or spaced apart from the rapid charging pole, wherein the waste Heat is discharged from the housing via Heat Pipes (Heat-Pipes) or water cooling onto the cooling device. Such a spatial separation is described, for example, in EP 3428000 a 1. It is also possible to: noise emission is reduced by corresponding active countermeasures within the fast charging post, such as helmholtz resonators or active noise reduction (active noise cancellation).

The cost of larger sized fans, passive cooling devices, heat pipes or water cooling is expensive. The cooling power is disadvantageously reduced due to the reduction of the fan speed or additional sound insulation to the housing. Helmholtz resonators require additional structural space within the rapid charging pole, wherein such additional resonators are not required outside of populated areas, such as when used on highways. Fan noise is a combination of narrow-band noise, such as the gap flow between the fan wheel and the surrounding fan nacelle, and broad-band radiation, such as that due to vortices or wakes, making active noise reduction relatively complex and costly to implement.

Disclosure of Invention

The invention is based on the task of: a particularly suitable method for operating a cooling device is described. In particular, a method should be specified which makes it possible to achieve the lowest possible hardware expenditure and the use of as many common parts as possible with different variants or points of use of the cooling device. The invention is also based on the task of: a particularly suitable cooling device and a particularly suitable use of such a cooling device are described.

This object is achieved by the method according to the invention, the cooling device according to the invention and the use according to the invention. Advantageous embodiments and further developments are the subject matter of the respective dependent claims.

As long as the method steps are described subsequently, an advantageous embodiment of the cooling device is obtained in particular by: the cooling device is configured to carry out one or more of the method steps.

The method according to the invention is provided for operating a cooling device and is suitable and designed for this purpose. In this case, the cooling apparatus has: especially electric or electromechanical fans; and at least one microphone, i.e. a sound sensor or a noise sensor, in particular an electroacoustic transducer for converting a sound input signal into an electrical output signal. In this case, the at least one microphone is expediently arranged substantially in a position facing the surroundings, depending on the usual installation position of the cooling device.

According to the method, during operation of the cooling device, sound signals in the surroundings of the cooling device, i.e. ambient noise or ambient sound, are detected as microphone signals by means of the at least one microphone. The detected sound signal is in this case converted into an electrical microphone signal, for example. The microphone signal (or a signal derived therefrom) is compared with the registered threshold value. According to the method, when the threshold is reached or lowered, the (fan) speed of the fan is reduced. In other words, according to the invention, the fan speed is controlled and/or regulated in dependence on the ambient noise.

Thus, according to the method, the fan is not only controlled and/or regulated in dependence on the required cooling power, but additionally in respect of sound emission or in dependence on ambient noise. In other words, by the method according to the invention, an optimization of the acoustic or sound emission of the fan is brought about, which is dependent on the ambient noise. In particular, the fan speed is set during the method in such a way that the resulting fan noise is not acoustically noticeable within the ambient noise. A particularly suitable method for operating the cooling device is thereby achieved.

In this case, the threshold value is a prescribed measure for the noise load in the surroundings or for the sound emission. That is, according to this method, the fan speed is limited or reduced in the case of low ambient noise and strict emission regulations and correspondingly increased in the case of high ambient noise. Suitably, in this case, a low (first) threshold value is defined for low ambient noise and/or strict emission regulations and a higher (second) threshold value is defined for high ambient noise, wherein the fan speed, and thus the cooling power and the fan noise, is reduced when the low threshold value is reached or below and increased when the higher threshold value is reached or exceeded.

In an advantageous embodiment, the detected sound signals or microphone signals are filtered by means of a frequency filter before they are compared with a threshold value. In particular, in this case, the known frequency of the fan, i.e. the fan noise or the fan sound, is filtered out. In other words, the fan noise generated by the fan is filtered or removed from the microphone signal, i.e. the fan noise in the microphone signal is cleaned, such that the microphone signal substantially only compares the microphone signal corresponding to the ambient noise with the threshold value. For example, a band-pass filter or a band-stop filter and/or a notch filter is used as the frequency filter. The conjunction "and/or" is to be understood here and in the following such that the features associated by means of the conjunction can be configured not only jointly but also as alternatives to one another. By filtering the microphone signal with respect to the fan noise, a particularly reliable evaluation of the acoustic environment conditions, i.e. the noise load present at present, can be achieved, so that a particularly effective acoustic optimization of the rotational speed of the fan is achieved.

The frequency spectrum of the fan varies with different fan speeds, so that in a preferred embodiment of the method the frequency filter is adjusted in dependence on the speed of the fan. In other words, the frequency filtered by means of the frequency filter is changed depending on the fan speed. This means that: the frequency filter is preferably constructed in an adjustable manner.

In one expedient refinement, the threshold value is determined or adjusted as a function of the navigation data and/or the time of day. In this case, the term "navigation data" is to be understood as meaning, in particular, data of the navigation device, such as GPS data (Global Positioning System). In this case, the term "time of day" should also be understood as a date or a working day, in addition to time. This means that: the cooling device is adapted or adaptable to the respective surroundings or to the respective point of use as a function of a threshold value. In other words, the surroundings are classified according to a threshold value, so that for example different threshold values are defined for the surroundings on a highway or within an industrial area or within a residential area. This means that: the sound classification of the possible erection sites is defined by means of different thresholds. It is thereby possible to: the operation of the cooling device is adapted to different applications substantially purely on a software basis without hardware changes.

An additional or further aspect of the invention provides software on a medium or data carrier for performing or implementing the above described method. This means that: the software is resident on a data carrier and is arranged for carrying out the method described above and is suitable and designed for this purpose. A particularly suitable software for operating the cooling device is thus realized, with which the functionality for carrying out the method according to the invention is implemented in a program-technical manner. The software is thus, in particular, operating software (Firmware), the data carrier being, for example, a data memory of the controller.

In contrast, the advantages and embodiments mentioned in connection with the method described above can also be transferred to the cooling device according to the invention and vice versa.

The cooling device according to the invention has an electric or electromechanical fan and at least one microphone. In this case, the fan and the microphone are coupled to a controller (that is to say a control unit). A particularly suitable cooling device is thereby achieved.

In this case, the controller is generally designed, in program and/or circuit terms, to carry out the method according to the invention described above. The controller is therefore set up in particular to: comparing the microphone signal to the registered threshold value; and adjusting and/or regulating the speed of the fan based on the threshold comparison.

In a preferred embodiment, the controller is formed at least in terms of its core by a microcontroller with a processor and a data memory, wherein the functionality for carrying out the method according to the invention is implemented in the form of operating software (firmware) in a program-technical manner, so that the method is carried out automatically when the operating software is implemented in the microcontroller, optionally interacting with a user of the device. Within the scope of the invention, however, the controller may alternatively also be formed by non-programmable electronic components, such as application-specific integrated circuits (ASICs), in which the functionality for carrying out the method according to the invention is implemented by means of circuit-technology devices.

The cooling device according to the invention therefore has a particularly low hardware expenditure. In particular, a common part can be used for different variants or locations of use of the cooling device, wherein the adaptation to different applications is set, in particular, as a function of the control unit, in particular by means of operating software of the control unit, preferably as a function of a threshold value.

In an advantageous embodiment, the at least one microphone is designed as a directional microphone. In other words, the at least one microphone has at least some directional characteristic or directivity. This means that: the microphones have an angular dependence such that the sound signal is not detected or detected equally strongly over the whole solid angle. For example, the microphone in this case has a directional characteristic in the form of a heart (Cardioid) or a hypercardioid (hypercardioid). Thus, for example, it is possible to: the microphone detects no fan noise or at least less fan noise.

In an additional or alternative embodiment, the cooling device has a plurality of microphones, i.e., at least two microphones, which are arranged, for example, spatially offset from one another. These microphones are each embodied, for example, as a directional microphone, so that an envelope measurement can be carried out. In this way, a particularly precise detection of the ambient noise or ambient sound can be achieved, as a result of which a reliable and efficient operation of the cooling device in accordance with the method can be achieved.

In one conceivable embodiment, a wind sensor, preferably a sonar anemometer, is provided, which is coupled to the controller. It is thereby possible to detect the current wind speed in the region of the cooling device in addition to the acoustic environmental conditions and to use this wind speed for controlling and/or regulating the fan speed. This construction is based on the following recognition: wind noise is similar to fan noise, so that strong fan noise-and therefore high fan speeds-can also occur in the presence of strong winds without significant negative impact on the acoustic environmental conditions. In this case, the sonar anemometer has, for example, two integrated microphones.

Additionally or alternatively, it is possible, for example: the current wind speed is invoked online at a meteorological service via an internet connection.

The cooling device described above is particularly suitable for the industrial sector with sound emission. The cooling device can be used, for example, for cooling a dedicated central heating station, a power station or a wind turbine. Use in air conditioning systems, heating systems or ventilation systems is likewise conceivable.

In a preferred application, the cooling device is in particular part of a power supply unit for charging an electrically driven or electrically drivable motor vehicle, such as an electric vehicle or a hybrid vehicle. In this case, the power supply unit is to be understood as a charging pile or rapid charging pile, a mobile charging robot or a service station, among others.

According to the invention, the cooling device described above is used in particular for cooling or tempering a motorized power supply unit. Here, by contrast, the embodiments associated with the method and the cooling device are also applicable to the application according to the invention, and vice versa.

An "electrical power supply system" is understood here and in the following in particular to be an electrical power supply system in which electrical power or electrical energy is supplied to an electrical consumer via a charging interface. Preferably, the electrical consumer is charged with electrical energy in this case.

A "mobile power supply system" is to be understood here and in the following as a mobile or mobile, i.e. not fixedly installed or not stationary, power supply system, in particular a charging post or a rapid charging post for an electrically driven or electrically drivable motor vehicle. This means that: the power supply system according to the invention can be implemented, for example, as an islanded system or as an Off-Grid system, i.e. as a Grid-independent, self-sufficient islanded system.

In this case, the cooling device is embodied, for example, as a cooling module which is at least partially integrated into the housing of the power supply unit. In this way, a particularly effective and acoustically optimized cooling or temperature control of the motorized power supply unit can be achieved by the cooling device according to the invention. In particular, the noise emission or the noise of the fan operation is thus dynamically adapted to the acoustic environmental conditions, so that the legal requirements are complied with simply and reliably. Thereby, the flexibility and user comfort of the power supply unit is significantly improved. In particular, it is therefore possible to use a motorized power supply unit even in residential areas, so that vehicle users can charge their motor vehicles with a minimal noise load for the residents even at night.

In one conceivable embodiment, the power of the motorized power supply unit is reduced if the cooling power of the cooling device is insufficient at the fan speed set according to the method. This means that: the electrical output power of the power supply unit is reduced or lowered as long as the cooling power with the fan speed limited or lowered is not sufficient to reliably discharge waste heat from the power electronics and/or the battery energy storage of the power supply unit. Thereby ensuring that: before the power of the power electronics of the power supply unit is limited, a maximum value of the cooling power is extracted from the cooling device.

Drawings

Subsequently, embodiments of the invention are further elucidated on the basis of the drawing. In which, in a schematic and simplified illustration:

fig. 1 shows a motorized power supply unit with a cooling device; and

fig. 2 shows a block diagram of the cooling device.

Parts and parameters corresponding to each other are provided with the same reference numerals throughout the figures.

Detailed Description

Fig. 1 shows a motorized power supply unit 2 in a schematic and very simplified illustration. The power supply unit 2 is in particular designed as a motor-driven rapid charging post for charging an electrically driven or drivable motor vehicle. The power supply unit 2 has a housing 4 in which power electronics, not shown in detail, are accommodated.

During operation of the power supply unit 2, the power electronics generate waste heat as a result of power losses, which waste heat accumulates in the housing 4. In order to dissipate the waste heat, the power supply unit 2 has a cooling device 6 (fig. 2) which is embodied as a cooling module.

The cooling device 6 has at least one microphone 8 for detecting a sound signal 10, in particular an ambient sound signal, such as ambient noise or ambient sound. In the embodiment of fig. 1, the sound signal 10 is, for example, wind noise, or the leaf of a tree 12, sand noise, or traffic noise of adjacent lanes or roads.

The cooling device 6 also has an electric or electromechanical fan 14, which as a housing fan expels the resulting waste heat of the power electronics by means of the generated air flow 16. For this purpose, the housing 4 has, for example, a side housing opening 18 and/or a floor housing opening 20, through which cold ambient air enters the housing interior. The fan 14 comprises an impeller or a fan impeller, not further designated, which is driven or rotated at (fan) rotational speed during operation. The fan noise 22 is formed as a result of the movement or rotation of the fan 14 and is emitted as sound emissions into the surrounding environment.

Subsequently, the construction of the cooling device 6 is further elucidated on the basis of fig. 2.

In the embodiment of fig. 2, the cooling device 6 has exemplarily two

microphones

8a, 8 b. In operation, the

microphones

8a, 8b receive the (ambient) sound signals 10 and convert these (ambient) sound signals into corresponding

electrical microphone signals

24a, 24 b. The microphone signals 24a, 24b are fed to a frequency filter 26, for example a notch filter and/or a band stop filter.

In this case, the frequency filter 26 filters out, in particular, the frequency of the fan noise 22 from the

microphone signals

8a, 8b and generates a filtered microphone signal 28. In other words, the fan noise 22 is filtered or removed from the filtered microphone signal 28 such that the microphone signal 28 contains substantially only the ambient noise 10. In this case, the microphone signals 28 are, for example, vectors which have, as entries, the respective filtered

microphone signals

8a and 8 b.

The filtered microphone signal 28 is communicated to a controller 30. The microphone signal 28 is analyzed by a controller 30, for example embodied as a microcontroller. In an alternative embodiment, it is likewise conceivable that: the

unfiltered microphone signals

24a, 24b are fed directly into the controller 30.

The

microphones

8a, 8b are, for example, implemented as directional microphones which have a cardioid or hypercardioid directional characteristic. Alternatively, for example, it is likewise conceivable for: the

microphones

8a, 8b are configured as omnidirectional microphones and the corresponding directional characteristic is determined during filtering by the frequency filter 26 and/or when analyzing the microphone signal 28 in the controller 30.

In analyzing the microphone signal 28, the controller 30 performs a threshold comparison with the registered threshold value. In this case, the threshold value is a prescribed measure for the noise load in the surroundings or for the sound emission. The threshold value is determined or adjusted, for example, in dependence on navigation data and/or time of day. Thus, the controller 30 effectively compares the level or volume of the ambient noise or sound signal 10 to the threshold. According to the method, when the threshold is reached or lowered, the (fan) speed of the fan 14 is reduced. In other words, the fan speed is reduced in quiet ambient conditions. In particular, the fan speed is in this case adjusted such that the resulting fan noise 22 is not acoustically noticeable within the ambient noise 10, i.e. has, for example, the same sound level.

In this case, the controller 30 varies the rotational speed of the fan 14 in dependence on the control and/or regulating signal 32. The control and/or regulating signal 32 is, for example, a pulse width modulated signal for actuating and/or regulating the motor of the fan 14. Since the frequency spectrum of the fan noise 22 varies with different fan speeds, the controller 30 sends a frequency signal 34 to the frequency filter 26 so that the filter frequency is varied depending on the fan speed.

In the embodiment shown in fig. 2, the cooling device 6 has, in particular, a sonar anemometer 36, which sends measurement signals 38 to the controller 30 as a wind sensor. Alternatively, the sonar anemometer 36 is, for example, part of the power supply unit 2, wherein the corresponding measurement signals 38 are transmitted to the cooling device 6 or the controller 30 via an interface. The sonar anemometer 36 is set up and established as: the current wind speed in the area of the cooling device 6 or the power supply unit 2 is detected.

The sonar anemometer 36 has, for example, three integrated microphones, in which case the

microphones

8a, 8b are replaced in one possible alternative embodiment by integrated microphones of the sonar anemometer 36. In this case, the acoustically detected wind signal is fed directly as a measurement signal 38 into the controller 30, wherein the microphone signal of the sonar anemometer 36 is conducted via the filter 26 or directly to the controller 30.

The controller 30 is coupled to the power electronics of the power supply unit 2 in a signal-technical manner, so that, depending on the power loss, the cooling power can be adjusted as a function of the fan speed 14 and the corresponding flow speed of the generated air flow 10. However, according to this method, the cooling power is limited in this case by the evaluation or evaluation of the acoustic environment as a superordinate control and/or regulation. In this case, if the required cooling power of the cooling device 6 is insufficient with the fan speed adjusted in accordance with the method, the power of the power supply unit 2 or the power electronics is reduced.

The invention as claimed is not limited to the embodiments described above. Rather, other variants of the invention can also be derived from the person skilled in the art within the framework of the claims disclosed, without departing from the subject matter of the invention claimed. Furthermore, all individual features described in connection with different embodiments can in particular also be combined in other ways within the framework of the disclosed claims without departing from the subject matter of the claimed invention.

List of reference numerals

2 Power supply Unit

4 casing

6 Cooling device

8. 8a, 8b microphone

10 sound signal/ambient noise

12 trees

14 Fan

16 air flow

18. 20 opening of the shell

22 fan noise

24a, 24b microphone signals

26 frequency filter

28 filtered microphone signal

30 controller

32 control/regulation signal

34 frequency signal

36 wind sensor/sonar anemometer

38 measuring signal

Claims

1. A method for operating a cooling device (6) having a fan (14) and at least one microphone (8, 8a, 8 b),

-wherein a sound signal (10) in the surroundings of the cooling device (6) is detected as a microphone signal (24 a, 24 b) by means of the microphone (8, 8a, 8 b);

-wherein the microphone signal (24 a, 24 b) is compared with the registered threshold value; and also

-wherein the rotational speed of the fan (14) is reduced when the threshold value is reached or lower.

2. The method of claim 1, wherein the first and second light sources are selected from the group consisting of,

it is characterized in that the preparation method is characterized in that,

the detected microphone signals (24 a, 24 b) are filtered by means of a frequency filter (26) before comparing them with the threshold value.

3. The method of claim 2, wherein the first and second light sources are selected from the group consisting of,

it is characterized in that the preparation method is characterized in that,

the frequency filter (26) is adjusted in accordance with the rotational speed of the fan (14).

4. The method of any one of claims 1 to 3,

it is characterized in that the preparation method is characterized in that,

the threshold value is determined or adjusted in dependence on the navigation data and/or the time of day.

5. A cooling device (6) having a fan (14) and at least one microphone (8, 8a, 8 b) and a controller (30) for performing the method according to any one of claims 1 to 4.

6. Cooling apparatus (6) according to claim 5,

it is characterized in that the preparation method is characterized in that,

the at least one microphone (8, 8a, 8 b) is a directional microphone.

7. Cooling apparatus (6) according to claim 5 or 6,

it is characterized in that the preparation method is characterized in that,

a plurality of microphones (8, 8a, 8 b) are provided.

8. Cooling apparatus (6) according to any of claims 5 to 7,

it is characterized in that the preparation method is characterized in that,

a wind sensor (36) is provided, which is coupled to the controller (30).

9. Use of a cooling device (6) according to any of claims 5 to 8 for cooling or tempering a motorized power supply unit (2).

10. The use according to claim 9, wherein,

it is characterized in that the preparation method is characterized in that,

-reducing the power of the motorized power supply unit (2) if the cooling power of the cooling device (6) is insufficient.