Method and device for operating wind turbine generator in heating mode

Abstract

The invention relates to a method for operating a wind turbine generator in a heating mode, the wind turbine generator having a rotor and a stator, the stator having a first three-phase system and a second three-phase system. The first three-phase system has at least one first switch for short-circuiting the first branch in the closed state and for idle-running the first branch in the open state, and the second three-phase system has at least one second switch for short-circuiting the second branch in the closed state and for idle-running the second branch in the open state. The heating operation comprises a first phase in which the first switch is connected or remains connected into the closed state and the second switch is connected or remains connected into the open state or the first switch is connected or remains connected into the open state and the second switch is connected or remains connected into the closed state. The invention also relates to a wind turbine generator system having a wind turbine generator and to a wind turbine.

Description

Technical Field

[0001] The invention relates to a method for operating a wind power plant generator of a wind power plant in heating mode, as well as a wind power plant generator system and a wind power plant which are configured to carry out the method. Background Art

[0002] Wind energy installations are widely known. They generate electrical power from dynamic wind energy by means of a wind energy installation generator, which is also referred to as generator in the following text. Such wind energy installations are not used continuously, but it may happen that they have to be maintained or there is not enough wind. Therefore, longer periods of time may occur during which the wind energy installation is not in operation. During such periods of time, which can also be referred to as downtimes, the wind energy installation cools down and moisture may condense in the cooling area.

[0003] Wind power plants are subject to climatic influences. For this purpose, certain components of wind power plants are sealed airtight to prevent moisture from entering. This involves, for example, electronic components housed in encapsulated cabinets. However, in the area of ​​the pod in which the generator is arranged, sealing against moisture can only be achieved with difficulty.

[0004] However, it happens that the generators of wind power plants include large masses, which, for example, are areas with a high risk of accumulating moisture when the temperature rises the next day in the case of night cooling. Since warm air can store more moisture than cold air, the moisture-rich warm air enters the nacelle and encounters the cold generator there. The moisture then hits the generator and condenses into water, which can appear in large quantities.

[0005] Wet generators can cause problems if moisture hits the insulation and conductors of the electrical coils and causes a reduction in the insulation effect there. The resins used in the insulation absorb moisture as a result. There is therefore the risk that ground faults may occur in the generator due to the ingress of moisture after the wind power plant generator has been put back into operation after a long downtime. Such ground faults may lead to damage to the generator.

[0006] Thus, a generator heating device for heating a generator after a long downtime is already known from document EP 2 431 604 B1 in order to remove the ingress of moisture by heating the generator. The method described therein comprises the creation of a short circuit in the stator in order to generate a short-circuit current in the stator by the rotation of the excited rotor. The short-circuit current causes a heat release due to the resistance present in the winding. However, due to the magnitude of the short-circuit that can be generated in this way during such a heating operation, the heat release is small, so that a long heating period, which can last for several hours, is required.

[0007] Therefore, after each long downtime, it is necessary to carry out a long heating process until the wind energy plant can actually switch to normal operation in order to feed energy into the power grid. During the time when the wind energy plant generators are being heated up, losses occur due to lost revenues, since no energy can be fed in. In addition, no grid services can be provided to support the grid. Summary of the invention

[0008] The object of the present invention is to solve the problems of the prior art. In particular, to find a possibility to reduce the duration of the heating operation of a wind power plant generator after a longer downtime compared to known solutions. At least to find an alternative to the known solutions from the prior art.

[0009] To this end, the present invention proposes a method for operating a wind energy facility generator of a wind energy facility in heating operation. The wind energy facility generator includes a rotor and a stator. The stator has a first three-phase system with three first branches, which can also be referred to as the first phase, and a second three-phase system with three second branches, which can also be referred to as the second phase. The rotor is configured to generate a magnetic field and feed current into the first three-phase system and the second three-phase system of the stator during rotation. The first three-phase system preferably corresponds to a system linked by three first branches, wherein the ends of each first branch in the first branch are preferably conductively connected in a star point. The second three-phase system corresponds to a system linked by three second branches, wherein the ends of each second branch in the second branch are conductively connected in the star point or another star point.

[0010] Preferably, each branch comprises a plurality of sub-branches connected in parallel. Preferably, the stator comprises a plurality of slots, wherein in each slot or at least in the majority of the slots a branch or sub-branch of a three-phase system is introduced which corresponds to a three-phase system different from the three-phase system associated with the branch or sub-branch in the adjacent slot. In summary, it is therefore applicable for a plurality of slots that the branches or sub-branches in the adjacent slots are therefore associated with different three-phase systems of the two three-phase systems.

[0011] Furthermore, the first three-phase system comprises at least one first switch for short-circuiting the first branch in the closed state of the first switch and for idling the first branch in the open state of the first switch. The second three-phase system further comprises a second switch for short-circuiting the second branch in the closed state of the second switch and for idling the second branch in the open state of the second switch.

[0012] A short circuit of a branch of a three-phase system corresponds to an electrical connection of ends of the branch of the three-phase system that are not already electrically conductively connected to one another via a star point. No-load corresponds to a state of the switch in which current cannot flow from one of the ends of a branch of the three-phase system that is not connected to the star point to the other of the ends of the branch of the three-phase system that is not connected to the star point.

[0013] Furthermore, the heating operation has a first phase. According to the method, in the first phase of the heating operation, the first switch is switched to a closed state and the second switch is switched to an open state, or the first switch is switched to an open state and the second switch is switched to a closed state.

[0014] According to the invention, it is known that the current flowing into one of the three-phase systems by the short circuit is supplemented by the current that cannot flow into the other three-phase system in the no-load state due to the lack of a reverse field in the other three-phase system. In addition, there is a quadratic relationship between the induced current and the thermal power, so that in the short-circuited three-phase system, a current with an amplitude of the second power of the amplitude of the current that respectively occurs in each of the three-phase systems when the two three-phase systems are short-circuited occurs. The power loss or thermal power increased in this way therefore causes a faster temperature rise. Therefore, by the alternating short circuit of the two three-phase systems, a faster temperature rise process is possible overall.

[0015] According to a first embodiment, an insulation value is determined for each three-phase system of a three-phase system, which insulation value preferably indicates the insulation of the three-phase system, in particular a branch of the three-phase system, relative to the ground potential. For example, a voltage, for example in the range of 300 volts, for example a DC voltage, is applied between one of the branches and the ground potential, and the resistance between the branch and the ground potential is determined. For this purpose, for example, the amplitude of the current generated by the applied voltage in the branch is measured. If the resistance is below a predefined threshold value (which can also be referred to as insulation threshold), then it is preferably assumed that the insulation is insufficient. The insulation threshold is preferably 100 kΩ. According to this embodiment, in a first phase, the switch of the three-phase system whose branch has the determined insulation value showing the minimum insulation is switched to the closed state.

[0016] Preferably, the three-phase system with the worst insulation is heated first. It is possible to dispense with heating of the hitherto unheated three-phase system, in particular when all other insulation values ​​in a further measurement are above a predefined insulation threshold value. A further acceleration of the heating of the generator stator is thus possible.

[0017] According to another embodiment, the first phase is implemented or only implemented if only one of the determined insulation values ​​is below the insulation threshold and the other of the two determined insulation values ​​is at the insulation threshold or above the insulation threshold. Preferably, a heating operation is implemented before the first phase in the case of both insulation values ​​being below the insulation threshold, in which the first switch and the second switch are switched or remain switched to the closed state. Such a pre-phase preceding the first phase is preferably implemented in a time period that is predefined or related to one or more insulation values. After the pre-phase, the insulation values ​​can then be re-determined for each of the three-phase systems, and the first phase can only be implemented if only one of the insulation values ​​is below the insulation threshold.

[0018] It has been recognized that if two three-phase systems can be operated in no-load at the same time, the no-load voltage in the no-load three-phase system during the short circuit of the other three-phase system is very small compared to the no-load voltage of these three-phase systems. When the pre-defined or suitable spatial arrangement of the branches of the two three-phase systems is performed as shown in the subsequent embodiment, the effect can preferably also be maximized. The relatively small no-load voltage in the no-load three-phase system is caused by the reverse field of the current flowing in the short-circuited three-phase system. Through the drop of the no-load voltage, it is possible that one of the three-phase systems can be operated in no-load even when the insulation values ​​of the two three-phase systems are reduced, and there is no danger of grounding of the no-load three-phase system. However, if both insulation values ​​are below the insulation threshold, then preventively implement normal heating operation when the three-phase system is not no-loaded, so as to completely exclude grounding.

[0019] According to another embodiment, a minimum insulation threshold is defined or defined. The minimum insulation threshold is below the insulation threshold. The insulation threshold is, for example, 100 kΩ, while the minimum insulation threshold is, for example, 50 kΩ. According to the embodiment, if one determined insulation value or two determined insulation values ​​are below the insulation threshold and both determined insulation values ​​are above the minimum insulation threshold, then the first phase is implemented or the first phase is implemented only in this case. Preferably, in the case where both insulation values ​​are below the minimum insulation threshold, a heating operation is implemented before the first phase, wherein the first switch and the second switch are switched to or remain switched to a closed state. The pre-phase before the first phase is preferably implemented in a predefined time period or in a time period associated with one or more insulation values. After the pre-phase, the insulation values ​​of the two three-phase systems are then re-determined respectively, and the first phase can be implemented when two of the insulation values ​​are above the minimum insulation threshold.

[0020] Compared to the previous embodiments, a staged protection against ground faults is achieved by providing a minimum insulation threshold. When the insulation value is below the insulation threshold but above the minimum insulation threshold, the first stage can therefore already be implemented, thereby accelerating the heating process as a whole. The minimum insulation threshold also serves to prevent a possible ground fault in the three-phase system when the unloaded three-phase system would have an insulation value below the minimum insulation threshold.

[0021] According to another embodiment, the method comprises a second phase. The second phase follows the first phase. In the second phase, the first switch and the second switch are switched, i.e., switched from the state they had in the first phase to a corresponding other state. Thus, if the first switch is in the closed state in the first phase, the first switch is transferred to the open state in the second phase, and if the second switch is in the open state in the first phase, the second switch is transferred to the closed state in the second phase. If the first switch is in the open state in the first phase, the first switch is transferred to the closed state in the second phase, and if the second switch is in the closed state in the first phase, the second switch is transferred to the open state in the second phase. In the second phase, therefore, the three-phase system that was not used for heating in the first phase is used to heat the stator. Thus, if the stator is heated using the first three-phase system in the first phase, the stator is heated using the second three-phase phase in the second phase, or vice versa.

[0022] According to another embodiment, further insulation values ​​are determined after the first phase, in particular for each three-phase system in the three-phase system, and the second phase is only carried out if at least one of the further insulation values ​​is below an insulation threshold value, for example 100 kΩ. Thus, the implementation of the second phase can be omitted if the insulation value of the system not used for heating is sufficient anyway and therefore no heating of the other three-phase system is required in the second phase.

[0023] According to another embodiment, a further insulation value is determined after the first phase and in a further phase following the first phase, the switch of the three-phase system with the smallest insulation value is switched to the closed state. The further insulation value is preferably determined like the insulation value determined before the first phase.

[0024] According to another embodiment, the humidity of the stator is determined by determining at least one humidity value, and the method is only implemented when the measured humidity value is above a humidity threshold value. The humidity value can be determined directly via a measuring device, such as a hygrometer. Alternatively, the humidity value is determined as a function of the temperature of the stator and the temperature of the air in or outside the pod in which the stator is arranged. Preferably, the humidity value corresponds to the difference between the determined temperature of the stator and the air. Particularly preferably, the humidity threshold value is determined as a value such that a humidity value that shows the difference between the measured temperatures and that shows an air temperature that is colder than the temperature of the stator is below the humidity threshold value. Whereas a humidity value that shows that the temperature of the stator is below the external temperature of the pod indicates a humidity value that is above the humidity threshold value. Preferably, the humidity threshold value is therefore in a range of humidity values ​​that show that there is no temperature difference between the stator and the air.

[0025] By determining the humidity value and comparing it with the humidity threshold value, the wind energy plant is started without heating if the humidity value does not indicate humidity at the stator. Thus, the stator is heated only if the humidity value indicates the possibility of humidity at the stator.

[0026] According to another embodiment, the first phase is implemented in a duration also referred to as the first duration. The duration of the first phase is determined according to the insulation value determined, in particular the insulation value having the minimum insulation. Preferably, the longer the duration of the first phase, the smaller the insulation value determined. Alternatively or additionally, the duration of the first phase is related to a determined humidity value indicating the humidity of the stator. Additionally or alternatively, the second phase also has a duration. The second phase is therefore implemented in a duration also referred to as the second duration. The duration of the second phase is related to another insulation value determined, in particular another insulation value showing the minimum insulation, and additionally or alternatively to a determined humidity value or another humidity value, which is determined as another humidity value after the first phase, as the humidity value before the first phase.

[0027] By providing a variable first duration and / or a variable second duration, it is possible that the first phase can be chosen to be very short if insulation problems due to moisture are only small at the stator. Only if insulation problems due to high humidity at the stator are very large is a long duration of heating required.

[0028] The invention further relates to a wind energy plant generator system having a wind energy plant generator. The wind energy plant generator system is configured to implement a method according to one of the above-described embodiments. The wind energy plant generator thus has a rotor and a stator, wherein the stator has a first three-phase system with three first branches and a second three-phase system with three second branches. The rotor is configured to generate a magnetic field and to feed current into the first three-phase system and the second three-phase system during rotation.

[0029] The first three-phase system further comprises a first switch for short-circuiting the first branch in the closed state and for idling the first branch in the open state. The second three-phase system comprises at least one second switch for short-circuiting the second branch in the closed state and for idling the second branch in the open state. The wind energy facility generator system is configured to switch the first switch to the open state and the second switch to the closed state, or to switch the first switch to the closed state and the second switch to the open state in the first phase of the heating operation. The circuit is preferably implemented by a control device of the wind energy facility generator system, which is configured as a switching switch.

[0030] According to one embodiment of the wind energy facility generator system, the wind energy facility generator system has an insulation measuring device and / or a humidity measuring device. The insulation measuring device is configured to determine at least one insulation value of each of the two three-phase systems. Preferably, the insulation measuring device is configured to measure the insulation value relative to the ground potential for each branch of the three-phase system. The insulation value describes, for example, the resistance between the corresponding branch and the ground potential. The insulation value is therefore preferably determined in ohms. The humidity measuring device is configured to determine the humidity of the stator, which is described in the form of a humidity value. Preferably, the wind energy facility generator system has a control device, which is configured to determine the duration of at least the first stage based on the determined insulation value or humidity value.

[0031] According to another embodiment, each of the branches of the two three-phase systems has a plurality of sub-branches connected in parallel. Preferably, each of the branches comprises four sub-branches connected in parallel. Preferably, each of the sub-branches connected in parallel is arranged in a different quarter of the stator. With each of the sub-branches, a plurality of coils connected in series in the stator are formed respectively. Preferably, each sub-branch therefore extends through the slots of the stator associated therewith and forms a plurality of coils. The coils of the sub-branches are arranged here in the region of a quarter of the stator, so that all four sub-branches connected in parallel of a branch are distributed over the entire circumference of the stator.

[0032] According to another embodiment, the stator has a plurality of slots and a branch or subbranch of one of the three-phase systems associated with a different three-phase system than the branch or subbranch introduced in the slot adjacent to the slot is introduced at least in most or all of the slots.

[0033] According to another embodiment, at least one first rectifier is provided, to which a branch of a first three-phase system is connected on the input side. In addition, at least one second rectifier is provided, to which a branch of a second three-phase system is connected on the input side. The first rectifier and the second rectifier are each configured to convert a voltage on the input side into a DC voltage and output the voltage on the output side as a DC voltage at two output potentials, which preferably form a DC voltage output. A first switch is provided in the first rectifier and a second switch is provided in the second rectifier.

[0034] According to another embodiment, the first rectifier and the second rectifier are respectively active rectifiers. The active rectifiers each include six switches, wherein the first rectifier has six first switches and the second rectifier has six second switches. The switches in the respective rectifiers respectively connect each branch in the branch to one of the two potentials forming the output or two output potentials. In the short-circuit state, all switches of the respective rectifiers are closed.

[0035] According to another embodiment, the first rectifier and the second rectifier are each passive rectifiers. The passive rectifiers each include a switch, wherein the first rectifier has a first switch and the second rectifier has a second switch. The switches are each connected between two output potentials, which preferably form a DC voltage output, so that the switches are short-circuited in the short-circuit state and are not connected in the no-load state.

[0036] Furthermore, the invention relates to a wind power plant having a wind power plant generator system according to one of the above-described embodiments. Alternatively or additionally, the wind power plant is configured to carry out a method according to one of the above-described embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Further embodiments are derived from the exemplary embodiments described in detail in the drawings. Here, it is shown:

[0038] Figure 1 A wind energy facility is shown.

[0039] Figure 2 A wind energy facility generator system is shown,

[0040] Figure 3 A section of a wind power plant generator is shown.

[0041] Figure 4 shows the active inverter in no-load state,

[0042] Figure 5 shows the active inverter in a short circuit state,

[0043] Figure 6 shows a passive rectifier,

[0044] Figure 7 shows the switch position of the rectifier in the first phase or the second phase, and

[0045] Figure 8 The steps of a method according to one embodiment are shown. DETAILED DESCRIPTION

[0046] Figure 1 The schematic diagram of a wind power plant 100 according to the invention is shown. The wind power plant 100 has a tower 102 and a nacelle 104 on the tower 102. An aerodynamic rotor 106 with a fairing 110 and three rotor blades 108 is provided at the nacelle 104. The aerodynamic rotor 106 is set into rotational motion by the wind during operation of the wind power plant 100, thereby also rotating an electrodynamic rotor or a rotating body of a wind power plant generator, which is directly or indirectly coupled to the aerodynamic rotor 106. The wind power plant generator is arranged in the nacelle 104 and generates electrical energy. The pitch angle of the rotor blades 108 can be changed by a pitch motor at the rotor blade root of the corresponding rotor blade 108.

[0047] Figure 2 A wind power plant generator system 10 is shown, which has a wind power plant generator 12 with a stator 14 and a rotor 16. The rotor 16 generates a magnetic field which, by rotating in a direction of rotation 18, generates currents in the coils, which currents are distributed over the circumference of the stator 14 and are Figure 2 The stator 14 is functionally divided into four quarters 20a, 20b, 20c, 20d in the illustrated embodiment. The distribution of the coils is typically described in Figure 2 20a, 20b, 20c, 20d, by means of which a branch or sub-branch including the coils is formed. The terminals 22a, 22b of the quarter 20a are connected to the rectifiers 24a, 24b and the star point 26, as shown representatively for all other quarters 20b, 20c, 20d. The rectifiers 24a, 24b serve to convert the currents induced in the coils of the stator 14, which flow to the rectifiers 24a, 24b via the branches used to form the coils. The induced currents in the three-phase system correspond to the three-phase alternating currents which are rectified to direct current and provided at the potential output terminals of the rectifiers in normal operation.

[0048] Through each quarter 20a, 20b, 20c, 20d of the generator, six sub-branches 28a, 28b, 28c, 28d, 28e, 28f extend from the star point 26 to the input-side terminals 30a, 30b of the rectifiers 24a, 24b. The quarter 20a of the generator stator 14 thus comprises two three-phase systems, namely a first three-phase system 32a, which is associated with the rectifier 24a, so that the rectifier 24a can also be referred to as a first rectifier 34a. In addition, a second three-phase system 32b is shown, which is associated with the second rectifier 24b, which can therefore also be referred to as a second rectifier 34b.

[0049] Sub-branches 28a, 28b, 28c, 28d, 28e, 28f are associated with one of the branches 36a, 36b, 36c, 36d, 36e, 36f, respectively. The three-phase systems 32a, 32b include three branches 36a, 36b, 36c, 36d, 36e, 36f, respectively, wherein the branches 36a, 36b, 36c of the first three-phase system 32a can also be referred to as phases U, V, W of the first three-phase system 32a. These three branches 36d, 36e, 36f can also be referred to as phases U, V, W of the second three-phase system 32b.

[0050] The branches 36a, 36b, 36c, 36d, 36e, 36f are each divided into four sub-branches for each quarter 20a, 20b, 20c, 20d, wherein only the sub-branches 28a, 28b, 28c, 28d, 28e, 28f are shown for better overview. Corresponding to these branches, the sub-branches 28a, 28b, 28c, 28d, 28e, 28f can also be referred to as sub-phases, i.e. the sub-branches 28b, 28d, 28f are referred to as sub-phases U1, V1, W1 of the first three-phase system 32a, and the sub-branches 28a, 28c, 28e are referred to as sub-phases U2, V2, W2 of the second three-phase system 32b. For a better overview, the terminals 22c, 22d, 22e, 22f, 22g, 22h are indicated for the further quarters 20b, 20c, 20d, and only dots are indicated for the branches 36a, 36b, 36c, 36d, 36e, 36f in the region of the rectifiers 24a, 24b of the correspondingly associated sub-branches. The wiring of the sub-branches, not shown, is carried out in a similar manner to the first quarter 20a with the aid of the rectifiers 24a, 24b in the quarters. Thus, the four sub-branches in each quarter at the rectifier are connected in parallel to form a branch.

[0051] According to another exemplary embodiment (not shown here), a plurality of first rectifiers 34a and a plurality of second rectifiers 34b are provided, which are connected in parallel on the input side by means of their input terminals. Accordingly, a plurality of first rectifiers 34a are connected in an electrically conductive manner by means of their input-side terminals 30a, and all second rectifiers 34b are connected in an electrically conductive manner by means of their input-side terminals 30b.

[0052] Figure 3 The arrangement of sub-branches 28a, 28b, 28c, 28d, 28e, 28f in the slots 40 of the stator 14 is shown. It can be seen that in adjacent slots, sub-branches 28a, 28b, 28c, 28d, 28e, 28f are arranged in each case, which are differently associated with the two three-phase systems 32a, 32b. For improved overview, only the sub-branches 28a, 28b, 28c, 28d, 28e, 28f extending in the slots 40 are shown without their winding heads. The winding heads are indicated by arrows 42a, 42b. The sub-branches 28c extending through the slots twice here form coils in the two slots and the sub-branches 28d extending in the two shown slots also form coils.

[0053] Figure 4 An active rectifier 50 is shown in an unloaded state 52. In the unloaded state 52, the switches 54a, 54b, 54c, 54d, 54e, 54f are disconnected. The switches 54a, 54b, 54c, 54d, 54e, 54f are in an open state 56 so as to unload the branches 36a, 36b, 36c, 36d, 36e, 36f. The potential output terminal 57 forming the DC voltage output terminal of the rectifier 50 is not short-circuited, i.e., electrically separated. If the active rectifier 50 corresponds to the first rectifier 34a, the switches 54a, 54b, 54c, 54d, 54e, 54f are correspondingly referred to as first switches. Correspondingly, if the rectifier 50 corresponds to the second rectifier 34b, the switches 54a, 54b, 54c, 54d, 54e, 54f are referred to as second switches.

[0054] Figure 5 The active rectifier 50 is shown in a short-circuit state 58, wherein the switches 54a, 54b, 54c, 54d, 54e, 54f are closed. The switches 54a, 54b, 54c, 54d, 54e, 54f are therefore in a closed state 60, so that the branches 36a, 36b, 36c, 36d, 36e, 36f or the potential output 57 are short-circuited, ie connected in an electrically conductive manner.

[0055] Figure 6A passive rectifier 62 is shown with a switch 64 which can be opened or closed in order to be able to short-circuit or unload the voltage rectified via the thyristor 66. When the passive rectifier 62 is the first rectifier 34a, the switch corresponds to the first switch, and when the passive rectifier 62 is the second rectifier 34b, the switch corresponds to the second switch.

[0056] Figure 7 The switch positions in the first phase 70 and in the second phase 71 are shown by way of example, wherein the upper switches 54a, 54b, 54c, 54d, 54e, 54f correspond to the first switches 72a, 72b, 72c, 72d, 72e, 72f of the first rectifier 34a, which is the active rectifier 50. The lower switches 54a, 54b, 54c, 54d, 54e, 54f correspond to the second switches 72b of the second rectifier 34b, which is also the active rectifier 50. It can be seen that the first switches 72a, 72b, 72c, 72d, 72e, 72f are in the open state and the second switch 72b is in the closed state.

[0057] Figure 8 The steps of the method according to an embodiment are shown. In an optional step 80, the humidity of the stator is first determined by measuring the humidity value. If the humidity value is below the humidity threshold, the method ends in step 82. If the humidity value is above the humidity threshold or step 80 is not present, the insulation value is determined for each of the three-phase systems 32a, 32b in step 84. In step 86, the switches 54a, 54b, 54c, 54d, 54e, 54f of the three-phase systems 32a, 32b are closed, and the three-phase system has a branch whose insulation value is the smallest and is particularly below the insulation threshold. In step 88, the switches 54a, 54b, 54c, 54d, 54e, 54f of another three-phase system 32a, 32b are opened, and the other three-phase system particularly has an insulation value at or above the insulation threshold. The first stage is implemented in a duration 90. According to an alternative not shown here, when both insulation values ​​are below the insulation threshold or below the minimum insulation threshold, all switches 54a, 54b, 54c, 54d, 54e, 54f of the two three-phase systems 32a, 32b are closed and step 84 is not performed again until after a predefined time period has expired.

[0058] After the time period 90 has expired, further insulation values ​​are detected in step 92 and, if all insulation values ​​are above the insulation threshold value, the method ends in step 82. In other cases, steps 86 and 88 are carried out again as a second phase. This is repeated until all insulation values ​​are above the insulation threshold value and the method ends in step 82.

[0059] Reference numerals list

[0060] 10 Wind energy facility generator systems

[0061] 12 Generator

[0062] 14 Stator

[0063] 16 rotors

[0064] 18Rotation direction

[0065] 20a-20d quarter

[0066] 22a-22h terminals

[0067] 24a, 24b rectifier

[0068] 26 star contacts

[0069] 28a-28f sub-branch

[0070] 30a, 30b terminal

[0071] 32a, 32b three-phase system

[0072] 34a, 34b rectifier

[0073] Branch 36a-36f

[0074] 40 slots

[0075] 42a, 42b arrows

[0076] 50 Active Rectifier

[0077] 52 No-load state

[0078] 54a-54f switch

[0079] 56 disconnected state

[0080] 57 potential output terminal

[0081] 58 short circuit state

[0082] 60 Closed state

[0083] 62 Passive rectifier

[0084] 64 switches

[0085] 66 thyristor

[0086] 70 First Stage

[0087] 71 Second Stage

[0088] 72a-72f switch

[0089] 80 Determine the humidity of the stator

[0090] 82 Method End

[0091] 84 Determine the insulation value

[0092] 86 switch closed

[0093] 88 switch off

[0094] 90 First Length

[0095] 92 Check other insulation values

[0096] 100 wind energy facilities

[0097] 102 Tower

[0098] 104 Pod

[0099] 106 aerodynamic rotor

[0100] 108 rotor blades

[0101] 110 fairing

[0102] U, V, W phase

[0103] U1, V1, W1 sub-phase

[0104] U2, V2, W2 subphases

Claims

1. A method for operating a wind energy plant generator (12) in heating operation, wherein the wind energy plant generator (12) has a rotor (16) and a stator (14), and the stator (14) has a first three-phase system (32a) with three first branches (36a, 36b, 36c) and a second three-phase system (32b) with three second branches (36d, 36e, 36f), wherein the rotor (16) is configured to generate a magnetic field and to generate a magnetic field by means of the magnetic field. During rotation, current is fed into the first three-phase system (32a) and the second three-phase system (32b), wherein the first three-phase system (32a) has at least one first switch (54a, 54b, 54c, 54d, 54e, 54f, 64) for short-circuiting the first branch (36a, 36b, 36c) in a closed state (60) and for unloading the first branch (36a, 36b, 36c) in an open state (60), and wherein the second three-phase system (32b) has at least one second switch (54a, 54b, 54c, 54d, 54e, 54f, 64) for short-circuiting the second branch (36d, 36e, 36f) in a closed state (60) and for unloading the second branch (36d, 36e, 36f) in an open state (56), and The heating operation comprises a first stage (70), wherein in the first stage (70), a) the first switch (54a, 54b, 54c, 54d, 54e, 54f, 64) is switched or remains switched to a closed state (60) and the second switch (54a, 54b, 54c, 54d, 54e, 54f, 64) is switched or remains switched to an open state (56), or b) The first switch (54a, 54b, 54c, 54d, 54e, 54f, 64) is switched or remains switched to an open state (56) and the second switch (54a, 54b, 54c, 54d, 54e, 54f, 64) is switched or remains switched to a closed state (60).

2. The method according to claim 1, The method comprises: An insulation value of each of the three-phase systems (32a, 32b) is determined and in the first phase (70), switches (54a, 54b, 54c, 54d, 54e, 54f, 64) of the three-phase system (32a, 32b) are switched to a closed state (60), the insulation value of the closed state having a minimum insulation, wherein preferably, The first phase will only be implemented if: a) only one of the determined insulation values ​​is below the insulation value threshold, or b) defining a minimum insulation threshold, and the two determined insulation values ​​being below the insulation threshold and above the minimum insulation threshold, wherein particularly preferably When both insulation values ​​are below the insulation threshold or when a minimum insulation threshold is defined and both insulation thresholds are below the minimum insulation threshold, a heating operation is performed before the first phase, during which the first switch (54a, 54b, 54c, 54d, 54e, 54f, 64) and the second switch (54a, 54b, 54c, 54d, 54e, 54f, 64) are switched to or remain switched to a closed state (60).

3. The method according to claim 1 or 2, In a second phase (71) that follows the first phase (70) in time, the switches (54a, 54b, 54c, 54d, 54e, 54f, 64) that were opened in the first phase (70) are closed and the switches (54a, 54b, 54c, 54d, 54e, 54f, 64) that were closed in the first phase (70) are opened.

4. The method according to claim 3, In which, after the first phase (70), at least one further insulation value in the three-phase system (32a, 32b) is determined, and the second phase is only implemented when at least one absolute value of the further insulation values ​​is below an insulation threshold value, in particular an insulation threshold value of a three-phase system whose switches (54a, 54b, 54c, 54d, 54e, 54f, 64) were opened in the first phase (70).

5. The method according to any one of the preceding claims, A plurality of further insulation values ​​are determined after the first phase (70), and in a phase following the first phase (70), a switch (54a, 54b, 54c, 54d, 54e, 54f, 64) of the three-phase system (32a, 32b) having the smallest further insulation value is switched into a closed state (60).

6. The method according to any one of the preceding claims, A humidity value is determined, which indicates the humidity of the stator (14), and the method is carried out only if the humidity value is above a predefined humidity threshold value.

7. The method according to any one of the preceding claims, The first phase (70) has a first duration (90), during which the first phase (70) is implemented and the first duration (90) of the first phase (70) is related to a determined insulation value and / or a humidity value, in particular with minimum insulation, and the second phase (71) has a second duration, during which the second phase (72) is implemented and the second duration of the second phase is related to a determined further insulation value, in particular with minimum insulation, and / or a determined humidity value.

8. A wind energy plant generator system (10) having a wind energy plant generator (12), wherein the wind energy plant generator (12) has a rotor (16) and a stator (14), and the stator (14) has a first three-phase system (32a) with three first branches (36a, 36b, 36c) and a second three-phase system (32b) with three second branches (36d, 36e, 36f), and wherein the rotor (16) is configured to generate a magnetic field and to feed current into the first three-phase system (32a) and the second three-phase system (32b) during rotation, wherein the first three-phase system (32a) has at least one first switch (54a, 54b, 54c, 54d, 54e, 54f, 64) for short-circuiting the first branch (36a, 36b, 36c) in a closed state (60) and for unloading the first branch (36a, 36b, 36c) in an open state (60), and wherein the second three-phase system (32b) has at least one second switch (54a, 54b, 54c, 54d, 54e, 54f, 64) for short-circuiting the second branch (36d, 36e, 36f) in a closed state (60) and for unloading the second branch (36d, 36e, 36f) in an open state (56), and Wherein the wind energy facility generator system (10) is configured to implement the method according to any one of claims 1 to 7.

9. The wind energy facility generator system (10) according to claim 8 comprises an insulation measuring device for determining at least one insulation value and / or at least one other insulation value and / or a humidity measuring device for determining at least one humidity value, wherein the humidity value indicates the humidity of the stator (14), and preferably comprises a control device for determining a first duration (90) of at least the first phase (70) based on the insulation value and / or the humidity value.

10. A wind energy facility generator system (10) according to claim 8 or 9, Each of the branches (36a, 36b, 36c, 36d, 36e, 36f) has a plurality of, preferably four, parallel-connected sub-branches (28a, 28b, 28c, 28d, 28e, 28f), and a plurality of, preferably series-connected coils in the generator (12) are formed by means of each of the sub-branches (28a, 28b, 28c, 28d, 28e, 28f).

11. A wind energy installation generator system (10) according to any one of claims 8 to 10, The stator (14) has a plurality of slots (40), and a branch (36a, 36b, 36c, 36d, 36e, 36f) or a sub-branch of a three-phase system (32a, 32b) is introduced into each slot of the slots (40) or at least into most of the slots, wherein the branch or sub-branch is associated with a three-phase system (32a, 32b) different from a branch (36a, 36b, 36c, 36d, 36e, 36f) or a sub-branch arranged in an adjacent slot (40).

12. A wind energy installation generator system (10) according to any one of claims 8 to 11, At least one first rectifier (34a) is provided, to which the branches (36a, 36b, 36c, 36d, 36e, 36f) of the first three-phase system (32a) are connected on the input side, and the first rectifier converts the voltage on the input side into a DC voltage and outputs the DC voltage at two output potentials on the output side, wherein the first switch (54a, 54b, 54c, 54d, 54e, 54f, 64) is provided in the first rectifier (34a), and At least one second rectifier (34b) is provided, to which the branches (36a, 36b, 36c, 36d, 36e, 36f) of the second three-phase system (32b) are connected on the input side, and the second rectifier converts the voltage on the input side into a DC voltage and outputs the DC voltage at two output potentials on the output side, wherein the second switch (54a, 54b, 54c, 54d, 54e, 54f, 64) is provided in the second rectifier (34b).

13. A wind energy facility generator system (10) according to claim 12, wherein the first rectifier (34a) and the second rectifier (34b) are respectively active rectifiers (50) and respectively include six first switches or six second switches (54a, 54b, 54c, 54d, 54e, 54f, 64), wherein the branches (36a, 36b, 36c, 36d, 36e, 36f) respectively associated with the corresponding rectifiers (34a, 34b) are respectively connected to each of the two output potentials forming the output end via a first switch among the first switches (54a, 54b, 54c, 54d, 54e, 54f, 64) in the first rectifier (34a) or a second switch among the second switches (54a, 54b, 54c, 54d, 54e, 54f, 64) in the second rectifier (34b).

14. The wind energy facility generator system (10) according to claim 12, The first rectifier (34a) and the second rectifier (34b) are respectively passive rectifiers (62), and a first switch (54a, 54b, 54c, 54d, 54e, 54f, 64) in the first rectifier (34a) is connected between the output potentials so as to short-circuit the output potentials in a closed state and disconnect the output potentials in an open state, and a second switch (54a, 54b, 54c, 54d, 54e, 54f, 64) in the second rectifier (34b) is connected between the output potentials so as to short-circuit the output potentials in a closed state and disconnect the output potentials in an open state.

15. A wind energy facility (100), The wind energy facility (100) is configured to implement the method according to any one of claims 1 to 7 and / or has a wind energy facility generator system (10) according to any one of claims 8 to 14.

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