阅读说明：本技术 用于冷却无传动装置的风能设施的方法 (method for cooling a gearless wind energy installation ) 是由 乌尔夫·沙佩尔 卡伊·恩斯科纳图斯 沃伊切赫·京格尔 于 2018-04-05 设计创作，主要内容包括：本发明涉及一种用于控制无传动装置的风能设施(100)的方法,其中风能设施(100)具有发电机(400),所述发电机具有定子(404)和转子(402)以及在其间的气隙(410),所述气隙具有气隙厚度,其中发电机(400)构成为内部转子,具有定子(404)作为外部部件并且具有转子(402)作为内部部件,或者发电机(400)构成为外部转子,具有转子作为外部部件并且具有定子作为内部部件,所述方法包括如下步骤：检测外部部件的温度作为外部部件温度(T<Sub>A</Sub>),检测内部部件的温度作为内部部件温度(T<Sub>I</Sub>),作为外部部件温度和内部部件温度之间的差形成温差,并且根据温差控制发电机(400),使得抵抗气隙厚度(410)因发电机(400)的热膨胀引起的减小。(The invention relates to a method for controlling a gearless wind power installation (100), wherein the wind power installation (100) has a generator (400) having a stator (404) and a rotor (402) and an air gap (410) therebetween having an air gap thickness, wherein the generator (400) is designed as an inner rotor having the stator (404) as an outer part and having the rotor (402) as an inner part, or the generator (400) is designed as an outer rotor having the rotor as an outer part and having the stator as an inner part, comprising the following steps: detecting a temperature of the outer component as an outer component Temperature (TA), detecting a temperature of the inner component as an inner component Temperature (TI), forming a temperature difference as a difference between the outer component temperature and the inner component temperature, and controlling the generator (400) according to the temperature difference such that a reduction of the air gap thickness (410) due to thermal expansion of the generator (400) is resisted.)

1. A method for controlling a gearless wind energy plant (100), wherein the wind energy plant (100) has a generator (400) with a stator (404) and a rotor (402) and an air gap (410) therebetween having an air gap thickness, wherein

-the generator (400) is configured as an inner rotor with the stator (404) as an outer part and the rotor (402) as an inner part, or

-the generator (400) is constituted as an outer rotor, with the rotor as an outer component and with the stator as an inner component, the method comprising the steps of:

-detecting a temperature of the external component as an external component Temperature (TA),

-detecting the temperature of the internal component as an internal component Temperature (TI),

-forming a temperature difference as a difference between the outer component temperature and the inner component temperature, and

-controlling the generator (400) in dependence of the temperature difference such that a reduction of the air gap thickness (410) due to thermal expansion of the generator (400) is counteracted.

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,

Cooling or heating the outer component in accordance with the temperature difference such that a reduction in the thickness of the air gap is resisted.

3. the method according to claim 1 or 2,

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

The outer member is cooled or heated to,

-the outer component temperature is at most an insufficient temperature lower than the inner component temperature,

-making the outer component temperature at least as high as the inner component temperature, or

-causing the outer component temperature to be at least one excess temperature higher than the inner component temperature.

4. The method according to any one of the preceding claims,

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

Electrically heating the outer component and/or thermally unloading the inner component as a function of the temperature difference, wherein in particular

In the case of the generator being designed as an internal rotor, the stator voltage is reduced in order to increase the stator current, so that the stator is warmed up by increased ohmic losses in the stator, or

In the case of the generator being designed as an external rotor, the stator voltage is increased in order to reduce the stator current, so that the stator is warmed up less by the reduced losses in the stator.

5. The method according to any one of the preceding claims,

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

For cooling the external part, the temperature difference and the external part temperature are monitored, and

-when the outer component temperature is at least higher than the inner component temperature by the excess temperature or by an excess temperature, and/or

-when the external component temperature is above a first limit temperature,

The cooling of the outer part is started and,

Preferably, the cooling of the outer part has a variable cooling intensity, and the cooling intensity thereof increases as the temperature of the outer part continues to rise, in particular linearly from an initial cooling intensity to a maximum cooling intensity as the temperature of the outer part continues to rise.

6. The method according to any one of the preceding claims,

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

-performing a heating of the outer component as soon as the outer component temperature is higher than the inner component temperature by less than a minimum difference temperature, wherein preferably the minimum difference temperature is selected to be less than the excess temperature, for example half as large as the excess temperature, wherein preferably,

The heating has a variable heating power and the heating power thereof increases with the outer component temperature which continues to decrease with respect to the inner component temperature, in particular linearly from a starting heating power to a maximum heating power with the outer component temperature which continues to decrease with respect to the inner component temperature.

7. The method according to any one of the preceding claims,

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

The method works adaptively, in particular

-monitoring the thickness of the air gap and triggering a safety measure below a predefinable minimum thickness in order to prevent contact between the outer part and the inner part, and

-increasing the excess temperature or the excess temperature each time the safety measure is triggered, the excess temperature indicating a temperature value: the outer component temperature should be higher than the temperature value of the inner component temperature, wherein preferably,

-gradually reducing the excess temperature again when the safety measure is not triggered within the check time.

8. The method according to any one of the preceding claims,

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

-distinguishing between normal operation and derated operation of the wind energy plant, and

In the reduced-speed operation, the wind energy installation is operated at a reduced rotational speed with the same wind conditions as compared to the normal operation, and

The method for cooling the generator uses different parameter values in the normal operation than in the reduced speed operation, in particular different parameter values for the excess temperature and/or the first limit temperature.

9. The method according to any one of the preceding claims,

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

-different cooling media and/or cooling types are provided for the inner part and the outer part, in particular,

-the inner part is provided with an air cooling device and/or a passive cooling device, and/or

-said outer part is provided with water cooling means.

10. A gearless wind energy installation having a generator with a stator and a rotor and an air gap therebetween, the air gap having an air gap thickness, wherein

The generator is designed as an inner rotor with the stator as an outer part and the rotor as an inner part, or

The generator is designed as an outer rotor, with the rotor as an outer component and with the stator as an inner component, the wind energy installation comprising:

An external component temperature detection mechanism for detecting a temperature of the external component as an external component temperature,

An internal component temperature detection mechanism for detecting a temperature of the internal component as an internal component temperature,

-a difference mechanism for forming a temperature difference as a difference between the outer component temperature and the inner component temperature, and

-a control mechanism configured to control the generator as a function of the temperature difference such that a reduction of the air gap thickness due to thermal expansion of the generator is counteracted.

11. The gearless wind power installation according to claim 10,

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

-is provided with an internal cooling device for cooling the internal components, and/or

-an external cooling device is provided for cooling the external component, wherein preferably,

-providing the internal cooling device and the external cooling device with different cooling media and/or cooling types, in particular,

the internal cooling device is designed as an air cooling device and/or a passive cooling device, and/or

The external cooling device is designed as a water cooling device.

12. gearless wind power installation according to claim 10 or 11,

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

the wind energy plant is designed for carrying out the method according to any one of claims 1 to 9.

Technical Field

The invention relates to a method for controlling a gearless wind energy installation. The invention also relates to a wind energy installation.

background

Wind energy plants are known and convert kinetic energy coming out of the wind into electrical energy. For this purpose, the wind power installation uses a generator. In the case of gearless generators, these have a rotor which is directly coupled to the aerodynamic rotating body of the wind power installation. The rotor thus rotates slowly as the aerodynamic rotating body of the wind power installation rotates. This results in such gearless wind energy installations being usually extremely multipolar and having large air gap diameters, which can be several meters and in the largest gearless wind energy installations of today, i.e. E-126, even in the range of 10 meters, i.e. in the range of 30 feet.

At the same time, however, such an air gap should also have as small a thickness as possible, which is only a few millimeters even with the large air gap diameters mentioned. If the rotor is close to the stator during operation, i.e. during its rotation, i.e. the air gap becomes too small at a certain point, a risk of damage occurs. To prevent this, the air gap thickness can be monitored. If it is detected that the air gap thickness is too small in a certain area, protective measures can be taken, such as reducing the power of the generator or also stopping the wind energy installation in an emergency.

In this case, in gearless wind energy installations, changes in the air gap thickness also occur as a result of thermal expansion of the internal components of the generator, i.e. when the generator is an internal rotor, for example as a result of expansion of the rotor. Thus, a reduction in the thickness of the air gap does not necessarily indicate a defect in the generator.

however, even in the case of such thermal expansion of the internal components, sensors monitoring the air gap thickness may also function and introduce protective measures. But this situation is in principle undesirable and should be avoided.

Disclosure of Invention

the present invention is thus based on the object of solving at least one of the above-mentioned problems. In particular, a solution should be proposed which avoids protective measures due to thermal expansion of the internal components of the generator, in particular the shutdown of the generator of a gearless wind power installation. At least one alternative to the hitherto known solutions should be proposed.

The german patent and trademark office retrieves the following prior art in the priority application of the present PCT application: DE 102014208791 a1 and US 2014/0054897 a 1.

according to the invention, a method for controlling a gearless wind power installation according to claim 1 is proposed. The wind power installation has a generator with a stator and a rotor. Due to the gearless wind power installation, the rotor is thereby directly coupled to the aerodynamic rotating body of the wind power installation. The term rotor is therefore used for a generator in order to distinguish it in terms also better from the aerodynamic rotating body of a wind energy installation. The use of the term rotor should therefore not contain a limitation on the type of generator.

the generator can be configured not only as an inner rotor but also as an outer rotor. If it is designed as an internal rotor, the rotor conventionally rotates inside the electron, viewed in the radial direction. That is, the stator is then the outer component with respect to the rotor, while the rotor is the inner component.

if the generator is constructed as an outer rotor, the rotor conventionally rotates, viewed radially, outside the stator so that the rotor forms the outer part and the stator forms the inner part.

The method provides for detecting the temperature of the outer component as the outer component temperature and for detecting the temperature of the inner component as the inner component temperature. In particular, in this case, the slot temperature, i.e. the temperature in the slot in which the stator winding runs, can be detected for the stator. This is then a temperature sensor for registering the temperature of the outer component in the case of the inner rotor or a temperature sensor for registering the temperature of the inner component in the case of the outer rotor.

The temperature can be recorded on the rotor, for example, in the region of one or more pole shoes. Accordingly, it is possible to record the inner component temperature in the case of an inner rotor and the outer component temperature in the case of an outer rotor thereby.

It is then proposed to control the generator according to the temperature difference between the external component temperature and the internal component temperature, that is to say so as to counteract a reduction in the air gap thickness due to thermal expansion of the generator.

This provides a control device which does not or only observes the absolute temperature, but also the temperature difference between the outer part temperature and the inner part temperature. In this case, it is recognized in particular that a reduction in the air gap thickness occurs when the inner part is thermally expanded more strongly than the outer part. That is, in this case it may be disadvantageous to cool the external components as well as possible. Although it is often advantageous to cool the generator in order to improve its characteristics, at least the temperature difference in the thickness of the air gap is critical.

According to one embodiment, it is thus provided that the outer component is cooled or heated as a function of the temperature difference, so that a reduction in the thickness of the air gap is counteracted. Cooling the external component so as to resist such a reduction in the thickness of the air gap can be expressed, inter alia, in that: reducing its cooling, or in other words, cooling the outer component weakly or not at all, so that a reduction of the air gap thickness is counteracted. That is, attention is directed to: the outer part can also expand thermally. At least considering this aspect together. However, it is also conceivable to heat the outer part even actively, in order to thereby achieve a thermally induced expansion of the outer part.

That is, if, for example, the internal components thermally expand and the thermal expansion can no longer be resisted by further cooling, the reduction in the air gap thickness can be prevented or resisted by: the external component is heated.

According to one embodiment, the outer part is cooled or heated such that the outer part temperature is at most a deficiency temperature lower than the inner part temperature. That is, the temperature difference between the outer component temperature and the inner component temperature is observed. The insufficient temperature is then taken into account as a limit value. That is, the outer component is only allowed to cool so that it cools down to a maximum value that is less than the inner component temperature by an insufficient temperature. If its temperature drops to a value lower than the temperature of the internal part by an insufficient temperature even without cooling, the external part is heated.

It is proposed that the deficiency temperature is selected or preset depending on the application or, if necessary, also preferably adaptively adjusted during ongoing operation. The insufficient temperature can also assume the value zero. In this case, the outer part is cooled or heated such that the outer part temperature is at least as high as the inner temperature. This variant, that is to say, according to which the outer component temperature should in any case be reduced to the inner component temperature, is thus a specific special case in which the deficiency temperature has a value of zero.

The deficiency temperature may also take a negative value and this may mean that the outer component temperature must be hotter than the inner component temperature. This case is considered exclusively by: it is proposed that the outer component temperature is at least one excess temperature higher than the inner component temperature. That is, it is assumed in this case that: the excess temperature takes a positive value. In this case, the outer component is thus brought to a higher temperature than the inner component.

According to one embodiment, it is proposed that the outer part is electrically heated and/or the inner part is electrically relieved depending on the temperature difference. For this purpose, it is proposed to reduce the stator voltage when the generator, in particular the synchronous generator, is designed as an inner rotor, i.e. when the outer part forms the stator. The stator current can thereby be increased, so that the stator is thereby warmed up by increased ohmic losses in the stator. In other words, the voltage at the respective stator terminal of the stator is reduced in this case and this results in the stator outputting a higher stator current. The output power, which is represented in a simplified manner, i.e. the product of the stator voltage and the stator current, can in this case remain substantially unchanged. That is to say that the generator always produces as much power, which is always preset essentially by the available wind power and the corresponding setting of the aerodynamic body of revolution. However, due to the increased stator current, the ohm-mode losses in the stator increase, i.e. the power losses in the stator windings increase. Whereby the stator warms up more strongly.

in other words, the stator, in which its output voltage at the stator terminals is reduced, can thereby be heated in a simple manner.

in the case of a passive rectifier connected to the stator, which rectifies to a first direct voltage intermediate circuit, this can be set or controlled, for example, in the following manner: reducing the voltage of the first direct voltage intermediate circuit. This can be done, for example, by a step-up chopper which is arranged between the first direct voltage intermediate circuit and a second direct voltage intermediate circuit having a higher intermediate circuit voltage, to name but one example.

If the generator is designed as an external rotor, i.e. the external component is a rotor, the rotor current is increased according to one embodiment, so that the rotor is warmed up by increased ohmic losses in the rotor. This can be achieved, for example, by: an externally excited synchronous generator is used as a generator, the rotor being excited by an excitation current. Now, the field current can be increased in order to heat or to heat the rotor more strongly. This can be done, for example, as follows: the excitation current is generated by a current regulator and the current regulator increases the excitation current accordingly.

it is also conceivable here to reduce the power loss of the stator by increasing the stator voltage instead of or in addition to increasing the power loss of the rotor. In this case, the generator is designed as an external rotor, whereby according to a variant it is proposed to increase the stator voltage in order to reduce the stator current, so that the stator is heated to a lesser extent by the reduced losses in the stator.

according to a further embodiment, it is provided that for cooling the outer part, the temperature difference and the outer part temperature are monitored and that the cooling of the outer part is started when the outer part temperature is at least higher than the inner part temperature by an excess temperature or the outer temperature is higher than a limit temperature.

Cooling is thereby effected in dependence on the difference temperature so that an excessively large difference temperature is counteracted. However, in addition, an absolute temperature, i.e. a first limit temperature, is monitored, which is likewise preset and optionally adjustable, in particular adaptively variable. By this additionally monitoring the absolute temperature, overheating of external components is thereby prevented. That is to say that the cooling acts such that it first controls the outer component temperature on the basis of the inner component temperature, i.e. in particular allows slightly higher temperatures, but then intervenes in a cooling manner. Thereby avoiding: cooling results in a reduction of the air gap thickness. However, overheating of external components is additionally prevented.

Preferably, it is provided for this purpose that the cooling of the outer part has a variable cooling intensity and that the cooling intensity thereof increases with a further increasing outer part temperature. Preferably, the cooling increases linearly with a further increasing temperature of the external component from the initial cooling intensity to the maximum cooling intensity. This not only relates to the case where the temperature of the external part is above the final temperature by an excess temperature, i.e. in the case of a relative temperature increase, but also to the case where the temperature of the external part is above the first limit temperature, i.e. in the case of an absolute temperature increase. Preferably, a further target temperature is set from the start of the cooling, that is to say from a temperature which is higher than the temperature of the internal components by an excess temperature, or from the first limit temperature, which can be, for example, 10K or 20K higher. It should be mentioned preventively that it is naturally also possible to consider that the relative and absolute temperature monitoring functions simultaneously.

According to one specific embodiment, it is provided that the heating of the outer part takes place as soon as the outer part temperature rises above the inner part temperature by less than a minimum difference temperature. Preferably, the minimum temperature is selected to be less than the excess temperature.

It is for example expedient to select the minimum difference temperature to be half the excess temperature. By this measure, first a clear criterion is determined: when the heating of the external part is performed. This heating is also controlled in relation to the difference temperature or temperature difference. Particularly advantageous in combination with cooling control. Thus, once the difference temperature has reached a value exceeding the temperature, the difference temperature is monitored and cooling is switched on. This achieves, in particular: the cooling of the external part is not performed in advance, but is performed from the time when the temperature interval exists between the external part temperature and the internal part temperature. If the difference is less than the temperature interval, then it does not cool because the external components become too hot.

However, if the outer component temperature then drops such that it is only slightly warmer than the inner component temperature, it is proposed to heat the outer component. But this is only done when the outer component temperature is higher than the inner component temperature by less than the minimum difference temperature. That is, if the outer component temperature is higher than the inner component temperature by a value greater than the minimum difference temperature but less than the excess temperature, then the outer component is neither heated nor cooled.

Preferably, the heating is variable, that is to say has a variable heating power, and its heating power increases with a further decrease in the temperature of the outer component, this also being observed relative to the temperature of the inner component. Preferably, this increase proceeds linearly from the starting heating power to the maximum heating power with a further reduced external component temperature. In the predetermined difference temperature, i.e., for example, below the internal component temperature of 10K, the maximum heating power can then be achieved. For example, when the external component is a stator, the setting of the heating power can be achieved by reducing the stator voltage while the stator power remains unchanged.

preferably, it is provided that the method works adaptively. In particular, the predefinable values are adapted or set here. Preferably, this process of adaptation starts with a relatively meaningful starting value, which is subsequently adjusted.

in particular, it is proposed to monitor the air gap thickness and to trigger safety measures below a predefinable minimum thickness in order to prevent contact between the outer part and the inner part. That is to say, if the minimum thickness is undershot, a safety measure is triggered and the predeterminable or variable excess temperature is increased each time the safety measure is triggered. The predeterminable excess temperature can be increased by, for example, 1K or 5K each time a safety measure is triggered. That is, the trigger is evaluated as an indication that the temperature interval is not yet large enough, i.e. that the cooling of the external component is still too early.

It is also preferably provided that the excess temperature is reduced again in steps if the safety measure is not triggered within the checking period. That is, if the safety measures are not triggered, for example, in a day, a week or a month, the excess temperature may be sufficient and may drop at least slightly again, in order to be able to cool the generator slightly better overall.

according to a further embodiment, it is provided that a distinction is made between normal operation and reduced-speed operation of the wind energy installation. In the case of reduced-speed operation, the wind power installation is operated at a reduced rotational speed in the case of the same wind conditions compared to normal operation. The rundown operation can for example involve a reduction of the rotational speed for noise reduction purposes. For this purpose, it is proposed that the method for cooling the generator uses different parameter values in normal operation than in reduced-speed operation. In particular, it is proposed that the excess temperature and, in addition or alternatively, the limit temperature are selected differently. For this purpose, alternative parameter sets can be stored. The proposed adaptation method can also be applied, wherein the adaptation relates to the current parameter set of the current operating type. That is to say, if the wind energy installation is operated, for example, in a reduced-speed operation and an adaptation is made which should reduce the excess temperature, only the excess temperature values of the data records for such a reduced-speed operation are adapted. In this way, the respective characteristics of normal operation or reduced-speed operation can be taken into account in a simple manner.

it is preferably provided that different cooling media and additionally or alternatively different types of cooling are provided for the inner part and the outer part. With these different cooling media or cooling types, the characteristics of the outer and inner components can be taken into account. In addition, different cooling powers and in particular different cooling results can also be achieved by different cooling media or cooling types. However, by taking into account the difference temperature between the external component temperature and the internal component temperature, different cooling results can thus be taken into account. In particular, effects can be counteracted in which, for example, the cooling of the interior operates less efficiently, in particular a smaller cooling result is achieved, which can lead to a greater thermal expansion of the interior components. The effect can be specifically counteracted by taking account of the differential temperature.

here, the following results in particular as advantages: when using the method according to the invention, different cooling types are used for the inner part on the one hand and the outer part on the other hand.

As different cooling media, air is considered on the one hand and a liquid cooling medium, such as water or water with an additive, on the other hand. As different cooling types, active cooling is considered in particular, in which the cooling medium is actively moved along the component to be cooled, on the one hand, and passive cooling, on the other hand, in which in particular an air flow along the component to be cooled can be achieved, but not necessarily conveyed by an additional actuator.

Preferably, air cooling and/or passive cooling is provided for the inner part and water cooling is provided for the outer part, in particular active cooling is provided for this purpose.

According to the invention, a wind energy installation is also proposed. The wind energy installation has a generator with a stator and a rotor and an air gap therebetween, which has an air gap thickness. The generator can be designed as an inner rotor or as an outer rotor. If the generator is designed as an internal rotor, it has a stator as an external component and a rotor as an internal component. If the generator is designed as an external rotor, it has a rotor as an external component and a stator as an internal component.

In any case, an external component temperature measuring mechanism for detecting the temperature of the external component as the external component temperature is provided. Further, an internal component temperature measuring mechanism for detecting the temperature of the internal component as the internal component temperature is provided. Each of the temperature measuring devices can have one or more temperature sensors, respectively, which are preferably arranged distributed over the circumference of the generator and thus of the outer or inner part in each case.

Furthermore, a difference mechanism for forming a temperature difference as a difference between the outside component temperature and the inside component temperature is provided. A difference can thereby be formed from the outer component temperature and the inner component temperature, which difference forms a temperature difference. In principle, the temperature difference, which thus forms the difference between the external component temperature and the internal component temperature, can also be referred to synonymously as a component temperature difference. That is, the difference in temperature between the two components, i.e., the outer component and the inner component, is expressed by a temperature difference. When a plurality of temperature sensors are used for the external component temperature measuring means and the internal component temperature measuring means, respectively, the average value of the detected temperatures can be used, or the maximum detected value can be used, respectively.

Finally, a control device is provided, which is configured to control the generator as a function of the temperature difference, such that a reduction in the air gap thickness due to thermal expansion of the generator is counteracted.

the control takes place in particular as explained above with reference to at least one embodiment of the method for controlling a wind energy installation.

Preferably, the wind power installation has an internal cooling device for cooling the internal components, and additionally or alternatively the wind power installation has an external cooling device for cooling the external components. Cooling devices are thus provided for the outer part and the inner part, respectively.

Preferably, different cooling media and/or cooling types are provided for the internal cooling device and the external cooling device. In particular, it is proposed that the interior cooling device is designed as an air cooling device and, in addition or alternatively, as a passive cooling device. Preferably, provision is made for the external cooling device to be designed as a water cooling device.

A gearless wind power installation is therefore proposed, which is characterized in that it is designed to carry out a method according to at least one of the above-described embodiments.

in particular, the method described is implemented for this purpose completely or partially in a control unit. The proposed difference mechanism can also be implemented as software, in particular in the control mechanism or in a separate device.

The temperature difference can also be shown differently, as for example as a factor. If, for example, there is a temperature range of 80 to 120 degrees celsius, this corresponds to an absolute temperature of 352 to 392K. The temperature difference of 3.5K can then also be approximately shown by a factor of 1.01.

Drawings

the invention is explained in detail below with reference to the drawings, by way of example, according to at least one specific embodiment.

Fig. 1 shows a perspective view of a wind energy installation.

Fig. 2 shows an exploded view of a portion of the generator.

fig. 3 schematically shows different possible conditions of the air gap.

fig. 4 schematically shows the control device.

Detailed Description

Fig. 1 shows a wind energy plant 100 with a tower 102 and a nacelle 104. A rotor 106 having three rotor blades 108 and a fairing 110 is provided on the nacelle 104. Rotating body 106 is placed in rotational motion by the wind during operation to drive a generator in nacelle 104.

Fig. 2 shows a generator 200 having a rotor 202 and a stator 204. The generator 200 is designed here as an internal rotor and the rotor 202 is pushed into the stator 204 for conventional use so as to rotate within this stator 204. A thin air gap is then formed between the rotor 202 and the stator 204.

Furthermore, a stator carrier 206 is shown, on which stator 204 is conventionally fastened. The three elements, i.e. rotor 202, stator 204 and stator carrier 206 are then, in normal use, substantially surrounded by a cladding 208, which is also shown.

Fig. 3 illustrates four basic conditions of the air gap 310, which is denoted by the same reference numeral in all four views. Likewise, all four states are thus also shown in a manner illustrated by the inner circle for the rotor 302 and in a manner illustrated by the larger outer circle for the stator 304 or the inner boundary of the stator 304.

In fig. 3, condition a shows a desired or ideal state, in which rotor 302 is ideally concentrically disposed within stator 304. Thus, the air gap 310 also extends uniformly between the two members. Further, the air gap 310 is not too thin.

Case B shows an eccentric condition, in which the rotor 302 is no longer precisely concentrically disposed in the stator 304. As a result, the air gap 310 no longer has the same thickness everywhere, but becomes relatively thin in one area and relatively thick in another area. Condition B, although not optimal, allows continued operation of the generator involved.

Condition C shows a condition in which the rotor 302 is arranged substantially concentrically in the stator 304, wherein however the air gap 310 is in any case reduced with respect to condition a. This can be the result of the rotor 302 expanding while the stator 304 does not expand or does not expand as strongly. However, the generator is still operational even in condition C.

Condition D then shows a condition in which the air gap 310 is thinned at one location so that a safety measure is triggered. In condition D, not only does air gap 310 decrease overall, as a result of expansion of rotor 302, but rotor 302 is no longer disposed concentrically within stator 304. This very thin air gap 310 thus occurs in one area and the safety trigger mentioned, which can also be referred to as an air gap switch trigger, occurs.

fig. 3 illustrates only the different possibilities of the state of the air gap 310. This is described for the case of an inner rotor, where rotor 302 forms the inner part and stator 304 forms the outer part. However, the same applies to the generator constructed as an external rotor, i.e. when the rotor is located outside and the stator is located inside. This may correspond to fig. 3 with the following differences: the rotor 320 is a stator and the stator 304 is a rotor.

Fig. 4 illustrates a control design or control structure for controlling, in particular cooling, a generator 400 shown diagrammatically in cross section. Here, an inner rotor is also used as an example as a generator 400, which has a rotor 402 and a stator 404. The rotor 402 is rotatably supported on a journal 412 by two bearings 414. A stator carrier 406 is fastened to the journal 412, which stator carrier fixedly carries the stator 404. The stator carrier 406 is finally held on a machine carrier, which is not shown here. Journal 412 and stator carrier 406 are shown shaded for illustration purposes where they are the primary load-bearing elements. Other elements, such as the stator 404 and the rotor 402, in principle also have a profile, which is not shown in shadow here, since it is not critical in detail for the specific construction.

Furthermore, a hub 416 is firmly connected to the rotor 402, which hub can carry three spinner blades in order to thereby rotate the hub 416 and thus the rotor 402 in the respective wind.

An air gap 410 is formed between the rotor 402 and the stator 404. Further, an external sensor 418 and an internal sensor 420 are shown, respectively. The external sensor 418 is arranged in the region of the stator lamination stack 422 of the stator 404 and represents an external component temperature measuring device here, which can also comprise further sensors.

The internal sensor 420 is arranged in the region of a pole shoe 422 of the rotor 402 and represents an internal component temperature measuring device here, which can also comprise further sensors.

The external sensor 418 detects the external component temperature TA and the internal sensor 420 detects the internal component temperature TI. These two temperatures are subtracted from one another at the adding element 426, so that a difference temperature Δ T is obtained as a difference or differential temperature, which can also be referred to as a component differential temperature. The temperature difference Δ T is derived from the external component temperature TA and the internal component temperature TI according to the following equation:

ΔT＝T-T

The differential temperature Δ T, as well as the external component temperature TA and the internal component temperature TI are input as input variables to the control mechanism 428. The adding element 426 furthermore serves as a difference mechanism.

the control means 428 can now control the cooling of the generator 400 by means of two separate temperatures depending on the difference temperature Δ T or temperature difference. For this purpose, a liquid cooling device is provided for the stator 404, which has a cooling pump 430, a cooling channel 432 and a cooling coil 434. The cooling coils 434 are here arranged in a stator carrier ring 436 of the stator 404 in the manner illustrated. The stator carrier ring 436 held by the stator carrier 406 holds the stator lamination stack 422 again in respect of it, which is sketched here only in an illustrative manner.

If the difference temperature Δ T is now higher than a predefinable excess temperature or the absolute value of the external component temperature TA is greater than a first limit temperature, the cooling pump 430 is operated by the cooling signal KA for external cooling and pumps the liquid cooling medium through the cooling coil 423 according to the arrow shown at the cooling channel 432. If the difference temperature Δ T or the absolute external component temperature TA still continues to rise, the pump power can continue to increase linearly with the rise and thus the delivery power of the cooling pump 430 also continues to increase. The control mechanism 428 is capable of performing such control.

Furthermore, a distance sensor 438 is shown, which measures the air gap thickness of the air gap 410 and is exemplary representative of a wide variety of other such distance sensors that can be provided for detecting the air gap thickness at other locations of the air gap 410. The results can be evaluated in control mechanism 428 as illustrated in fig. 4.

via the cooling pump 430, the cooling channels 432 and the cooling coils 434, whereby the stator 404 and thus the outer components are subjected to cooling by means of a liquid medium. This thus forms an external cooling device. To cool rotor 402 and thus the internal components, a fan 440 is disposed in stator carrier 406. The fans 440 each press an air flow 442 through a stator carrier, which can be designed here as a bell-shaped structure and can also be referred to as a stator bell, toward the rotor 402. There, the air flow can divide and flow through different openings in the rotor 402 and also through the air gap 410.

The fan 440, which thus forms the internal cooling device, can likewise be operated via the control member 428. To this end, the control 428 sends a cooling signal KI for the internal cooling device.

Thereby, the rotor 402 and the stator 404 can be controlled in terms of their cooling independently of each other. Control mechanism 428 assumes such control in the example of fig. 4. Specifically, the external component temperature TA is controlled in accordance with the difference temperature Δ T. The absolute value of the external component temperature TA can nevertheless be taken into account directly. In particular, it is proposed that the cooling of the stator 404 and thus of the outer part only begins when the outer part temperature TA exceeds the inner part temperature TI by an excess temperature. The internal component temperature can in principle be controlled in a conventional manner, that is to say in particular as a function of the detected internal component temperature TI.

That is, the system in principle achieves a higher external component temperature TA compared to the internal component temperature TI. Thereby avoiding: the rotor 402 expands radially more strongly thermally than the stator 404, so that an overall reduction in the air gap thickness is thereby avoided. If an excessively small air gap thickness nevertheless occurs once, this can be detected by the distance sensor 438 and safety measures triggered in the event of an emergency.

but in any case this safety measure can be avoided by the proposed thermal control or a particularly narrow air gap thickness can be arranged. It is also possible to specifically consider special operating modes, in particular noise-reducing operating modes. In particular in the noise-reduced operating mode, it can be provided that, with the maximum possible power, which is of course always desirable, the lowest possible rotational speed is used. This can lead to a relatively strong warming, in particular in air-cooled inner rotors, and thus to a disproportionately large thermal expansion.

Such differentiation considerations cannot be made in particular via conventional generator temperature regulation, in which the cooling is switched on or off only as a function of the absolute temperature.

This ensures, by differential temperature regulation: the stator is always hotter than the rotating body of the generator, which is referred to herein as the rotor. This statement applies to the inner rotor and in the case of the outer rotor is the opposite, i.e. it is ensured by differential temperature regulation: the rotor is always hotter than the stator. The proposed regulation presupposes that the outer part and the inner part have separate cooling or heating systems, at least the outer part being able to be cooled or heated independently of the inner part. That is, the outer part of the generator can be kept hotter than the inner part, so that the outer part is subjected to a higher thermal expansion than the inner part, so that triggering of the air gap monitoring, i.e. safety measures due to an excessively thin air gap, does not occur.

In particular, the proposed solution makes it possible to improve the previous situation in which the stator cooling is controlled as a function of the absolute stator temperature in the case of an internal rotor, wherein only the stator cooling is undertaken as long as the rotor cooling, i.e. the cooling of the rotor, is not effective. In this case it may happen that: if the rotor heats up more strongly than the stator at full cooling power, the rotor expands too strongly and an air gap switch triggering may occur.

This results in a solution in which the generator cooling, in particular the stator cooling, is controlled as a function of the difference between the outer component temperature and the inner component temperature in the case of an inner rotor. Overheating of the stator relative to the rotating body, i.e. the rotor, is thereby ensured.

This enables an improvement: parameters, in particular the switching on and off temperature thresholds, are adaptively tracked as a function of the frequency at which the air gap switch triggering takes place, i.e. as a function of the frequency at which the air gap thickness is identified as being below and the safety triggering is carried out. Thus, in the case of an internal rotor, excessive stator warming with correspondingly higher copper losses cannot be avoided.

On the other hand, if the desired differential temperature cannot be achieved by the controlled cooling alone, it is proposed that: if the stator forms an external part, the stator is additionally heated. This heating can be carried out by lowering the stator voltage, as a result of which the stator current increases and more stator losses occur, which thus heat the stator. Thereby, it is possible to achieve a matching of the stator temperature to the rotor temperature, i.e. the rotor temperature, even when the stator cooling is deactivated.

Thus, another aspect of the invention is that the outer component, e.g. the stator in the case of an inner rotor, operates at least as hot as the inner component, which in the example of an inner rotor is a rotor. It should thus be ensured that: the effect of the reduction of the air gap caused by operation has virtually no effect anymore.

That is, if an internal rotor is assumed, the stator is heated when it is not hot enough, that is, when it is below a preset delta temperature with respect to the rotor. For this purpose, it is proposed to reduce the stator voltage in order to increase the current while the power remains approximately constant. This increase in current increases the ohmic losses in the stator, which heats up as a result.

it is now preferably provided that a separate difference temperature range for the heating is predefined, i.e. in which the heating is started below a second difference temperature, which is referred to herein as the minimum difference temperature. For this purpose, it is furthermore proposed that the stator voltage be reduced in proportion to a conventional desired value of the stator voltage, that is to say in a proportional manner such that a maximum stator voltage drop is achieved at the end of the second difference temperature range. This second difference temperature range can represent values of the external temperature that are lower than the internal component temperature, for example 10K lower than the current internal temperature value. That is to say, up to this point the stator voltage has dropped by a maximum value in order to achieve a maximum achievable or reasonable heating of the stator.

That is to say, if, for example, the stator temperature is higher than the rotor temperature by a second difference temperature or less, i.e. for example by 5K above the rotor temperature, the heating is carried out in particular by reducing the stator voltage as described. This heating can be increased further as the outer part temperature or temperature difference is further reduced until the end of a second difference range is reached, which can be, for example, 10K below the rotor temperature. In the example mentioned, the stator voltage therefore begins to drop, in particular linearly, from a normal value and at a differential temperature of 5K above the rotor temperature to a value below the current rotor temperature, for example 10K. This also enables, for example, a linear increase in the heating output.

For the cooling control, it is still to be mentioned that the cooling control, for example in the case of an inner rotor, has hitherto been started at an absolute temperature value of the stator slot temperature, such as, for example, 80 degrees celsius, and the maximum cooling power is reached at a slot temperature of 100 degrees celsius. Instead, for this example, the stator cooling is now started when the stator slot temperature exceeds the rotor pole shoe temperature 20K, i.e. exceeds the rotor temperature 20K.

Preferably, the water cooling takes place by means of a settable volume flow for the outer part, i.e. for the stator in the case of the inner rotor. Such a water cooling can, for example, start with a small volume flow at a differential temperature of 20K, which reaches a maximum volume flow at a differential temperature of 30K. Preferably, a linear profile is proposed here.

For reasons of reliability, it is additionally also possible to start the cooling as a function of absolute values, for example a temperature of 130 degrees celsius for the stator. If cooling has not started due to the difference temperature, cooling starts at that value and reaches its maximum value until another value of 140 degrees Celsius. This ensures that: when such high temperatures are reached, the stator is in any case cooled.

That is to say to achieve: the thermal expansion of the outer part, i.e. the stator in the case of the inner rotor, is always as much as possible greater than the expansion of the inner part, i.e. the rotor in the case of the inner rotor.

Furthermore, it is proposed that the parameters of the differential temperature regulation are not fixedly preset, but rather can be learned. It proposes: the differential temperature to be calculated, i.e. the temperature from which cooling is initiated, is increased by each air gap event. If then the air gap event is no longer present, then: a corresponding value is sufficient. This value can then be reduced again if necessary. When the air gap thickness becomes too small, the triggering of a safety measure is understood as an air gap event.

in particular, in noise-reducing operation, it is proposed to learn a set of intrinsic parameters, which differs from the power-optimized operation, i.e., essentially from the normal operation. The proposal is particularly suitable for a separately excited synchronous generator as an inner rotor. However, in this synchronous generator, the wind power installation can be operated with reduced rotational speed with the same power during noise-reducing operation. For this reason, the rotor or rotor requires more excitation power, that is to say a greater excitation current is supplied to the rotor or rotor, which thereby becomes hotter. That is, then, there is a greater risk that: the rotor as the inner member expands more strongly than the stator as the outer member.

In detail, the following can be performed: first, initial setting is performed on the factory side. Preferably, such a factory-side initial setting provides that no differential temperature-related control is performed.

If a safety cut-off is subsequently triggered due to an air gap thickness that is identified to be too small, the proposed differential regulation, i.e. in particular the cooling, can be activated as a function of the differential component temperature. The value of the excess temperature can be set to 20K, for example. That is, it is then set to an initial value such that cooling of the external part is started only when the external part temperature is higher than the internal part temperature by at least 20K.

if subsequently no errors occur after a predetermined reset time, which can be greater than 3 hours, 5 hours or 10 hours, for example, it is proposed to reduce the excess temperature in steps.

However, if a shut-off occurs again, it can be provided that the excess temperature is increased again in steps and the wind energy installation is switched on again. Preferably, the increasing step after the occurrence of the safety trigger is numerically larger than the decreasing step after a long time of non-faulty operation. The decreasing step size can be, for example, 5K, while the increasing step size can be 10K.

The maximum value of the excess temperature can be set if the safety trigger repeatedly occurs due to a detected air gap that is too low.

although it is still possible to stop the wind energy installation as a result of the described safety trigger, the wind energy installation can be automatically switched on again, in particular with changing values which exceed the temperature.