Method for determining temperature information or information related to temperature information assembly

Abstract

The invention relates to a method for determining temperature information related to a static electric induction device assembly (10) or information related to the temperature information. The static electric induction device assembly (10) has a vertical extension in the vertical direction (z). The method comprises performing, for the static electric induction device part (20), the following:-determining a thermal loss value (Q) indicative of a thermal loss of the static electric induction device part (20), the static electric induction device part (20) having a vertical static electric induction device part position (zport) in the vertical direction (z); -determining a liquid temperature value (Tliq (zport)) indicative of the temperature of the liquid (16) in the vertical static electric induction device part position (zport), and-determining the temperature (Tport) of the static electric induction device part (20) or information relating to the temperature information using the liquid pressure difference ([Delta] p), the heat loss value (Q) and the liquid temperature value (Tliq (zport)).

Description

TECHNICAL FIELD

[0001] The present invention relates to a method for determining temperature information related to a static electric induction device assembly or information related to temperature information. Furthermore, the present invention relates to a computer program product, a non-transitory computer readable storage medium and a control unit each. BACKGROUND

[0002] In static electric induction device assemblies, such as assemblies comprising transformers and / or shunt reactors, it is often desirable to determine a temperature of at least a portion of a static electric induction device forming part of such an assembly.

[0003] Purely by way of example, it can be desirable to determine a so-called hot spot temperature of a static electric induction device. A hot spot typically relates to the hottest portion or at least one of the hottest portions of a static electric induction device. Information related to a hot spot temperature can for example be relevant when assessing the aging of the insulation of a static electric induction device.

[0004] However, measuring a temperature in a desired portion of a static electric induction device can be challenging. For example, if a temperature sensor, such as a thermometer or the like, is placed at or near a hot spot, there is a risk that the presence of such a temperature sensor can impair the cooling of the hot spot, for example by impairing the coolant flow around the hot spot. SUMMARY

[0005] In view of the above, it is an object of a first aspect of the present invention to determine temperature information related to a static electric induction device assembly in a straightforward manner. The above object is achieved by a method according to claim 1.

[0006] Thus, a first object of the present invention relates to a method for determining temperature information related to a static electric induction device assembly or information related to temperature information. The static electric induction device assembly has a vertical extension in a vertical direction.

[0007] The static electric induction device assembly comprises an enclosure, a static electric induction device and a liquid, whereby the enclosure accommodates the static electric induction device and the liquid such that the static electric induction device is at least partially, preferably completely, immersed into the liquid. The static electric induction device comprises a static electric induction device portion that is immersed into the liquid. The static electric induction device assembly further comprises an enclosure portion.

[0008] The static electric induction device is at least partially enclosed by an enclosing member, wherein at least one cooling duct is formed between the static electric induction device and the enclosing member and / or wherein the at least one cooling duct at least partially extends through the static electric induction device. The at least one cooling duct is at least partially delimited by the static electric induction device. The at least one cooling duct comprises a lower inlet and an upper outlet as seen in a vertical direction, wherein each of the lower inlet and the upper outlet is in fluid communication with the liquid. The at least one cooling duct is adapted to transport the liquid from the lower inlet to the upper outlet.

[0009] The method comprises determining a liquid pressure difference between a liquid pressure at the upper outlet and a liquid pressure at the lower inlet. The method comprises performing at least for the static electric induction device portion:

[0010] - determining a heat loss value indicative of a heat loss of the static electric induction device portion, the static electric induction device portion having a vertical static electric induction device portion position in a vertical direction;

[0011] - determining a liquid temperature value indicative of a temperature of the liquid in the vertical static electric induction device portion position, and

[0012] - determining a temperature of the static electric induction device portion or information related to temperature information using the liquid pressure difference, the heat loss value and the liquid temperature value.

[0013] The above implies that the temperature of the static electric induction device portion can be determined in a straightforward manner. For example, the above recited method implies that the temperature of the static electric induction device portion can be determined without having to employ a temperature sensor located at or next to the static electric induction device portion.

[0014] Optionally, the method comprises determining a temperature profile indicative of a temperature of the liquid at a plurality of different vertical positions inside the housing but outside the enclosing member between an upper outlet vertical position of the upper outlet and a lower inlet vertical position of the lower inlet.

[0015] The above indicated temperature profile can be useful when determining the temperature of the static electric induction device portion or information related to temperature information. Moreover, since the temperature profile is indicative of a temperature outside the enclosing member, the temperature profile can be determined in a situation where the risk of negatively affecting the liquid flow around the static electric induction device portion, for example, is low.

[0016] Optionally, the step of determining the liquid temperature value comprises using the temperature profile and the vertical static electric induction device portion position of the static electric induction device portion in the vertical direction.

[0017] The above implies that the liquid temperature value can be determined in a straightforward manner.

[0018] Optionally, determining the characteristic of the temperature profile comprises using a plurality of temperature sensors arranged inside the housing but outside the enclosing member between the upper outlet vertical position and the lower inlet vertical position.

[0019] Using a plurality of temperature sensors arranged outside the enclosing member implies a suitably low risk that the temperature sensors can hamper the liquid flow around the static electric induction device part.

[0020] Optionally, determining the characteristic of the temperature profile comprises each of:

[0021] - determining measured temperature data comprising a temperature in each of a plurality of different positions of the static electric induction device assembly as a function of time within a reference time range when the static electric induction device assembly is in a state in which at least a part of the static electric induction device generates heat during at least a part of the reference time range,

[0022] - generating a temperature model of estimated temperature data corresponding to an estimated temperature in each of the plurality of different positions of the static electric induction device assembly as a function of time, the temperature model comprising a learning model representing the estimated temperature data and the measured temperature data, and

[0023] - training the learning model using the measured temperature data to thereby obtain the temperature model, and

[0024] - determining the temperature profile using the temperature model.

[0025] The above implies a general embodiment for determining a temperature profile.

[0026] Optionally, the learning model comprises a neural network, preferably a multi-layer neural network.

[0027] Optionally, the measuring assembly comprises an optical fiber sensor located within the enclosing member. Preferably, the static electric induction device comprises a winding, and the optical fiber sensor is at least partially located in the winding.

[0028] The use of an optical fiber sensor implies an accurate determination of the measured temperature data.

[0029] Optionally, the step of determining the liquid pressure difference between the liquid pressure at the upper outlet and the liquid pressure at the lower inlet comprises using the temperature profile and information related to the density of the liquid as a function of temperature.

[0030] Using the temperature profile for determining the liquid pressure difference implies that the liquid pressure difference can be determined without necessarily requiring the use of e.g. pressure sensors. Furthermore, using the temperature profile implies that a suitably accurate value of the liquid pressure difference can be obtained.

[0031] Optionally, the method comprises determining a fluid flow rate of the liquid flowing in the pipe based on the liquid pressure difference and a factor indicative of a flow resistance of the at least one cooling pipe.

[0032] The above embodiments for determining the fluid flow rate can provide suitably accurate results.

[0033] Optionally, the step of determining the heat loss value comprises determining a value indicative of the electrical power fed to the static electric induction device portion.

[0034] The heat loss value can be proportional to the electrical power fed to the static electric induction device portion. Thus, determining a value indicative of the electrical power fed to the static electric induction device portion for determining the heat loss value implies that the heat loss value can be determined with suitable accuracy.

[0035] Optionally, the step of determining the temperature of the static electric induction device portion using the liquid pressure difference, the heat loss value and the liquid temperature value comprises determining a heat transfer coefficient between the static electric induction device portion and the liquid. The heat transfer coefficient is a function of the fluid flow rate, wherein the temperature of the static electric induction device portion is determined as the sum of the liquid temperature value and a parameter proportional to the ratio between the heat loss value and the heat transfer coefficient.

[0036] Optionally, the static electric induction device comprises a winding, wherein the static electric induction device portion is a part of the winding.

[0037] Optionally, the winding comprises a plurality of discs, the method comprising executing the method according to any of the preceding claims for each of a group of discs of the plurality of discs.

[0038] Optionally, the static electric induction device portion is associated with a region of the static electric induction device having a relatively high temperature compared to its surroundings.

[0039] Optionally, the liquid comprises, preferably consists of, a dielectric liquid.

[0040] Optionally, the static electric induction device comprises a transformer and / or a shunt reactor.

[0041] A second aspect of the present invention relates to a computer program product comprising program code for performing the method of the first aspect of the present invention when executed by a processor device.

[0042] A third aspect of the present invention relates to a non-transitory computer readable storage medium comprising instructions which, when executed by a processor device, cause the processor device to perform the method of the first aspect of the present invention.

[0043] A fourth aspect of the invention relates to a control unit arranged to perform the method of the first aspect of the invention. Attached Figure Description

[0044] Referring to the accompanying drawings, a more detailed description of embodiments of this disclosure, which are cited as examples, follows.

[0045] In the attached diagram:

[0046] Figure 1 This is a schematic diagram of a static inductive device assembly;

[0047] Figure 2 This is a schematic diagram of a static inductive device, and a graph showing the heat loss value and the temperature of the liquid, each of which is expressed as a function of the vertical position of the static inductive device.

[0048] Figure 3 This is a schematic illustration of a portion of an implementation of a static inductive device. Detailed Implementation

[0049] Preferred embodiments of this disclosure will be discussed below with reference to the accompanying drawings.

[0050] Figure 1 An embodiment of the static inductor assembly 10 is schematically illustrated. The static inductor assembly 10 has a vertical extension along the vertical direction z. Furthermore, as... Figure 1 As indicated, the static inductive device assembly 10 may also have extensions along the longitudinal direction x and the lateral direction y. The longitudinal direction x and the lateral direction y may form a horizontal plane.

[0051] like Figure 1 As indicated, the static inductance device assembly 10 includes a housing 12, a static inductance device 14, and a liquid 16. For example only, the housing 12 may be referred to as a tank. Furthermore, again for example only, the housing 12 may include a heat sink 18. The heat sink 18 is in fluid communication with the interior of the housing 12, allowing the liquid 16 to be conveyed through the heat sink 18, thereby cooling the conveyed liquid and returning it to the interior of the housing 12. The above capabilities are provided by... Figure 1 The arrow in the text indicates this.

[0052] In addition, such as Figure 1 As indicated, the housing 12 accommodates the static induction device 14 and the liquid 16, such that the static induction device 14 is at least partially, preferably completely, immersed in the liquid 16. Furthermore, as... Figure 1 As indicated, the static inductor 14 includes a static inductor portion 20 immersed in the liquid 16. Typically, and as... Figure 1As indicated in the above, the static electric induction device portion 20 is completely immersed into the liquid 16. Furthermore, as indicated in the above Figure 1 As indicated in the above, the static electric induction device portion 20 has a vertical static electric induction device portion position z port .

[0053] The static electric induction device assembly 10 further comprises an enclosure member 22. At least one cooling duct 24 is formed between the static electric induction device 14 and the enclosure member 22 and / or the at least one cooling duct 24 extends at least partially through the static electric induction device 14. The at least one cooling duct 24 is at least partially delimited by the static electric induction device portion 20.

[0054] In an embodiment of the static electric induction device assembly 10, the at least one cooling duct 24 is formed between the static electric induction device 14 and the enclosure member 22. However, it is also envisaged that in other embodiments of the static electric induction device assembly 10, the at least one cooling duct 24 can extend through one or more other portions of the static electric induction device assembly 10. As a non-limiting example, the at least one cooling duct 24 can extend at least partially through the static electric induction device 14, such as at least partially through a core portion (not shown) of the static electric induction device 14. Figure 1

[0055] The at least one cooling duct 24 comprises a lower inlet 26 and an upper outlet 28 as seen along the vertical direction z, wherein each of the lower inlet 26 and the upper outlet 28 is in fluid communication with the liquid 16. The at least one cooling duct 24 is adapted to transport the liquid 16 from the lower inlet 26 to the upper outlet 28.

[0056] Furthermore, although purely by way of example, an embodiment of the static electric induction device assembly 10 comprises a temperature sensor assembly 30, the details of which will be further discussed hereinafter. However, it is also envisaged that other embodiments of the static electric induction device assembly 10 do not necessarily need to comprise the temperature sensor assembly 30. Figure 1

[0057] As a non-limiting example, the liquid 16 can comprise, preferably consist of, a dielectric liquid, such as a mineral oil.

[0058] Furthermore, although purely by way of example, the static electric induction device 14 can comprise, or even consist of, a transformer or a shunt reactor.

[0059] A first object of the present invention relates to a method for determining temperature information or information related to temperature information related to the static electric induction device assembly 10. In particular, the first object of the present invention relates to a method for determining a temperature T of the static electric induction device portion 20.​​port Or methods for providing information related to temperature.

[0060] By way of example only, the static inductor portion 20 may be associated with an area of ​​the static inductor 14 that has a relatively high temperature compared to its surrounding environment. As a non-limiting example, the static inductor portion 20 may be a so-called hot spot of the static inductor 14.

[0061] The method includes determining the liquid pressure difference Δp between the liquid pressure at the upper outlet 28 and the liquid pressure at the lower inlet 26. As a purely example, a pressure sensor could be used. Figure 1 (Not shown in the image) to determine this type of liquid pressure difference Δp. Alternatively, as will be further discussed below, information indicating the temperature of liquid 16 can be used to determine the liquid pressure difference Δp.

[0062] The method according to the first aspect of the invention comprises: performing at least the following on the static inductive device portion 20:

[0063] - Determine the heat loss value Q, which indicates the heat loss of the static induction device section 20, which has a vertical static induction device section position z along the vertical direction z. port ,

[0064] - Determine the liquid temperature value T liq (z port The liquid temperature value indicates the position z of the vertical static inductive device. port The temperature of liquid 16 in the middle,

[0065] -Use the liquid pressure difference Δp, heat loss value Q, and liquid temperature value T. liq (z port To determine the temperature T of the static induction device section 20. port Or information related to temperature.

[0066] The liquid temperature value T can be determined in several different ways. liq (z port The liquid temperature value indicates the position z of the vertical static inductive device. port The temperature of the liquid 16 in the liquid. As a non-limiting example, a single temperature sensor (such as a thermometer) can be used to determine the liquid temperature value T. liq (z port This temperature sensor is suitable for measuring the position z of a vertical static inductive device. port The temperature of liquid 16 in the solution.

[0067] However, purely by way of example, the method can comprise determining a temperature profile indicative of a temperature of the liquid 16 at a plurality of different vertical positions inside the enclosure 12 but outside the enclosing member 22 between an upper outlet vertical position z upper of the upper outlet 28 lower and a lower inlet vertical position z liq of the lower inlet 26. Purely by way of example, the temperature profile can be indicative of a temperature of the liquid 16 at least 10 mm (as seen in a horizontal direction formed by the longitudinal direction x and the transverse direction y) inside the enclosure 12 but outside the enclosing member 22.

[0068] To this end, reference is made to Figure 2 which illustrates a temperature T liq of the liquid 16 in the enclosure 12 as a function of the vertical position z liq . Since colder liquid has a higher density than hotter liquid, the temperature profile is indicative of a temperature T liq increasing with increasing vertical position z port .

[0069] Figure 2 The temperature profile illustrated in port may be used for a variety of purposes. As a non-limiting example, the step of determining a liquid temperature value T liq (z port ) can comprise using the temperature profile and a vertical static electric induction device portion position z liq of the static electric induction device portion 20 along the vertical direction z port . Figure 2 The above example is indicated in port which indicates a liquid temperature value T liq (z port ). Purely by way of example, the liquid temperature value T liq (z port ) can be determined by interpolation of the temperature profile for different vertical positions, so as to obtain a liquid temperature value T liq (z port ) at the vertical static electric induction device portion position z liq .

[0070] The temperature profile can be determined in a variety of different ways. As a non-limiting example, determining the temperature profile comprises using a plurality of temperature sensors arranged inside the enclosure 12 but outside the enclosing member 22 between an upper outlet vertical position z upper and a lower inlet vertical position z lower .

[0071] To this end, reference is again made to Figure 1 which illustrates an embodiment of the static electric induction device assembly 10 comprising a temperature sensor assembly 30. Figure 1The temperature sensor assembly 30 comprises a plurality of temperature sensors 32, 34, 36, 38, 40 located at different vertical positions between the outlet vertical position z upper and the lower inlet vertical position z lower As a non-limiting example, each of the temperature sensors 32, 34, 36, 38, 40 can be any one of the following types of sensors: thermocouple, thermistor, resistance thermometer, and fiber-optic temperature sensor.

[0072] As a non-limiting example, the temperature sensor assembly 30 can comprise an elongated member 41, such as a rod, to which each of the temperature sensors 32, 34, 36, 38, 40 is attached. Purely by way of example, the elongated member 41 can be made of an insulating material.

[0073] Purely by way of example, the temperature sensor assembly 30 can be located outside the enclosing member 22, such that the minimum distance between the enclosing member 22 and the temperature sensor assembly 30 (as seen in a horizontal direction in a horizontal plane formed by the longitudinal direction x and the transverse direction y) is at least 10 mm. For any embodiment of the application, a distance of at least 10 mm can be used.

[0074] It is noted, however, that the temperature profile does not need to be determined using the temperature sensors 32, 34, 36, 38, 40 as indicated above.

[0075] To this end, although purely by way of example, determining the temperature profile can comprise the following:

[0076] - determining measured temperature data using a measurement assembly (42, see Figure 2 ), the measured temperature data comprising a temperature in each of a plurality of different positions of the static electric induction device assembly as a function of time within a reference time range when the static electric induction device assembly is in a state in which at least a portion of the static electric induction device generates heat during at least a portion of the reference time range,

[0077] - generating a temperature model of estimated temperature data corresponding to an estimated temperature in each of the plurality of different positions of the static electric induction device assembly as a function of time, the temperature model comprising a learning model representing the estimated temperature data and the measured temperature data, and

[0078] - training the learning model using the measured temperature data to thereby obtain the temperature model,

[0079] - determining the temperature profile using the temperature model.

[0080] As a non-limiting example, the learning model can comprise a neural network (not shown), preferably a multi-layer neural network.

[0081] Purely by way of example, using a learning model comprising a neural network to determine the characteristics of the temperature profile can use the learning model to solve a partial differential equation, such as the partial differential equation presented below:

[0082]

[0083] wherein:

[0084] T = T(x, t) represents the temperature in each of a plurality of different locations (x) in the liquid 16 as a function of time (t);

[0085] D(T) represents a temperature-dependent material property of at least a portion of the enclosure 12, such as a thermal conductivity, and

[0086] q(I(t), T) represents the heat generated by the static electric induction device 14.

[0087] It is noted that the above partial differential equation according to equation 1 is merely used as an example of a partial differential equation that can be used as a temperature model for determining the estimated temperature data. In other implementations of determining the temperature profile, the partial differential equation can comprise more terms, such as for example additional source terms. As a non-limiting example, the additional source terms can be related to heat losses through the walls of the enclosure 12 and / or to stray losses in the metallic parts of the static electric induction device 14.

[0088] With reference to Figure 2 , the measurement assembly 42 can comprise an optical fiber sensor located within the enclosing member 22. Preferably, the static electric induction device comprises a winding (not shown in Figure 2 ) and the optical fiber sensor is at least partially located in the winding. Alternatively, as a non-limiting example, the measurement assembly 42 can comprise a temperature sensor (not shown) for measuring the temperature of the liquid 16 in one or more locations within the enclosure 12, such as an uppermost location of the enclosure 12. As another non-limiting alternative, the measurement assembly 42 can comprise a temperature sensor adapted to measure the ambient temperature of the enclosure 12. Further, purely by way of example, the measurement assembly 42 can comprise a thermographic camera (not shown) adapted to capture a thermal image of the outside of the enclosure 12 or a thermocouple attached to the outside of the enclosure 12. Purely by way of example, the measurement assembly 42 can comprise one or more of the examples presented above.

[0089] Irrespective of how the temperature profile has been determined, the step of determining the liquid pressure difference Ap between the liquid pressure at the upper outlet 28 and the liquid pressure at the lower inlet 26 can comprise using the temperature profile and information related to the density of the liquid as a function of temperature.

[0090] Purely by way of example, the liquid pressure difference Ap can be determined according to:

[0091]

[0092] wherein:

[0093] g is the acceleration of gravity, and

[0094] δ(z) = δ(T(z)) is the density of the liquid as a function of the temperature of the liquid.

[0095] Furthermore, the method of the first aspect of the application can comprise determining the fluid flow rate of the liquid flowing in the pipe based on the liquid pressure difference Δp and a factor k indicative of the flow resistance of the at least one cooling pipe.

[0096] As a non-limiting example, the fluid velocity can be the volumetric flow rate Q v (e.g. expressed in volume per unit of time, such as m 3 / s), which can be determined according to the following formula:

[0097]

[0098] wherein the exponent n is in the range of 0.5-1 (such that 0.5 < n < 1), and wherein the value of the exponent n depends on the implementation of the cooling pipe 24. As a non-limiting example, when the cooling pipe 24 is a straight single pipe, the exponent n can be equal to 0.5, and for two parallel pipes, the exponent n can be close to or even equal to 1.

[0099] As regards the heat loss value Q indicative of the heat loss of the static electric induction device portion 20, the step of determining the heat loss value Q can comprise determining a value P indicative of the power fed to the static electric induction device portion 20. Purely by way of example, the value P indicative of the power fed to the static electric induction device portion 20 can be expressed as a current component I (e.g. expressed in A) relative to the power actually fed to the power fed to the static electric induction device portion 20 (e.g. expressed in W or kW). As another non-limiting alternative, the value P indicative of the power fed to the static electric induction device portion 20 can be expressed as a voltage U (e.g. expressed in V) relative to the power actually fed to the power fed to the static electric induction device portion 20 (e.g. expressed in W or kW). The latter example can use the assumption that the voltage U is known, possibly even fixed.

[0100] Figure 2 A curve of the heat loss value Q as a function of the vertical position z is illustrated.

[0101] Purely by way of example, the curve of the heat loss value Q can have been determined by determining a value P indicative of the power fed to the static electric induction device 14. As can be seen from Figure 2It is appreciated that the heat loss value Q at the vertically uppermost portion and the vertically lowermost portion of the static induction device 14 can be greater than the heat loss value Q at the vertically central portion of the static induction device 14.

[0102] Furthermore, Figure 2 The curve of heat loss values Q and the temperature curve in FIG. 6 indicate that the portion of the static induction device associated with the region of the static induction device having a relatively high temperature compared to its surroundings is often found in the vertically uppermost portion of the static induction device 14. This is because the vertically uppermost portion is associated with a relatively high heat loss value Q and a relatively high liquid temperature. Thus, the relatively hot liquid at the vertically uppermost portion of the static induction device 14 can cool the vertically uppermost portion of the static induction device 14 only to a limited extent, whereby the vertically uppermost portion of the static induction device 14 becomes relatively hot. Thus, any hot spot of the static induction device 14 is typically found in the uppermost portion of the static induction device 14.

[0103] As a non-limiting example, the temperature T of the static induction device portion 20 is determined using the liquid pressure difference Δp, the heat loss value Q, and the liquid temperature value T(z) as follows: liq (z port ) to determine the temperature T of the static induction device portion 20. port The step of determining the temperature T of the static induction device portion 20 can include determining a heat transfer coefficient h between the static induction device portion 14 and the liquid 16.

[0104] The heat transfer coefficient h is a function of the fluid flow rate Q v . Purely by way of example, the current fluid flow rate Q v A lookup table can be used to determine the value of the heat transfer coefficient h. As a non-limiting example, such a lookup table can depend on the material of the static induction device portion 20. The temperature T of the static induction device portion 20 is determined as the sum of the liquid temperature value T(z) and a parameter proportional to the ratio between the heat loss value Q and the heat transfer coefficient h. port liq (z port ) to determine the temperature T of the static induction device portion 20.

[0105] As a non-limiting example, the temperature T of the static induction device portion 20 can be determined according to the following equation: port

[0106]

[0107] where the factor A can indicate the cooling surface area of the static induction device portion 20.

[0108] The static induction device 14 can be implemented in a variety of different ways. Reference is made to Figure 3 ​​Although, purely by way of example, a static inductor may include a winding 44, wherein the static inductor portion is part of the winding.

[0109] In fact, in the static inductance device 14 Figure 3 In this embodiment, the winding 44 includes a plurality of discs 46, 48. Furthermore, as... Figure 3 As indicated, the liquid may be adapted to flow from the lower inlet 26 and the upper outlet 28, and thus through one or more sides of each of the plurality of discs 46, 48. In the static induction device 14 Figure 3 In this embodiment, the hot spot of the static inductor 14 can be associated with the uppermost disk 46. Therefore, in Figure 3 In one embodiment, the static induction device portion 20 may form part of the uppermost disk, or be equivalent to the uppermost disk.

[0110] However, in other embodiments of the first aspect of the invention, the method may include: determining the temperature of each of a set of the plurality of disks 46, 48.

[0111] The second aspect of the invention relates to a computer program product comprising program code that, when executed by a processor device, performs the method of the first aspect of the invention.

[0112] A third aspect of the invention relates to a non-transitory computer-readable storage medium comprising instructions which, when executed by a processor device, cause the processor device to perform the method of the first aspect of the invention.

[0113] Furthermore, it should be noted that the fourth aspect of the present invention relates to a control unit 50 (see...) Figure 1 The control unit 50 is arranged to perform the method of the first aspect of the invention. For this purpose, although purely illustrative, the control unit 50 may be adapted to receive information from one or more portions of the static inductive device assembly 10. As a non-limiting example, see reference to... Figure 1 In one embodiment, the control unit 50 may be adapted to receive information from the temperature sensor assembly 30.

Claims

1. A method for determining temperature information or information related to temperature information related to a static electric induction device assembly (10) having a vertical extension in a vertical direction (z), The static electric induction device assembly (10) comprises a housing (12), a static electric induction device (14) and a liquid (16), whereby the housing (12) contains the static electric induction device (14) and the liquid (16) such that the static electric induction device (14) is at least partially, preferably completely, immersed into the liquid (16), wherein - the static electric induction device (14) comprising a static electric induction device portion (20) immersed in the liquid (16), the static electric induction device assembly (10) further comprising an enclosure member (22), - the static electric induction device (14) being at least partially enclosed by the enclosure member (22), wherein at least one cooling duct (24) is formed between the static electric induction device (14) and the enclosure member (22), and / or wherein the at least one cooling duct (24) extends at least partially through the static electric induction device (14), the at least one cooling duct (24) being at least partially delimited by the static electric induction device portion (20), the at least one cooling duct (24) comprising a lower inlet (26) and an upper outlet (28) as seen along the vertical direction (z), wherein each of the lower inlet (26) and the upper outlet (28) is in fluid communication with the liquid (16), the at least one cooling duct (24) being adapted to transport the liquid (16) from the lower inlet (26) to the upper outlet (28), wherein the method comprises determining a liquid pressure difference (Ap) between a liquid pressure at the upper outlet (28) and a liquid pressure at the lower inlet (26), wherein the method comprises performing the following for at least the static electric induction device portion (20): - determining a heat loss value (Q) indicative of a heat loss of the static electric induction device portion (20) having a vertical static electric induction device portion position (z port ) along the vertical direction (z). - determining a liquid temperature value (T(z liq (z port )) indicative of a temperature of the liquid (16) in the vertical static electro inductive device portion position (z port ), and - using said liquid pressure difference (Δp), said heat loss value (Q) and said liquid temperature value (T liq (z port )) to determine a temperature (T port ) of said static electric induction device portion (20) or information related to temperature information.

2. The method of claim 1, wherein, The method comprises determining a temperature profile indicative of the temperature (T liq ) of the liquid (16) at a plurality of different vertical positions between an upper outlet vertical position (z upper ) of the upper outlet (28) and a lower inlet vertical position (z lower ) of the lower inlet (26), inside the casing (12) but outside the enclosing member (22).

3. The method of claim 2, wherein, determining the liquid temperature value (T liq (z port )) comprises using the temperature profile and the vertical static electro-inductive device portion position (z port ) of the static electro-inductive device portion (20) along the vertical direction (z).

4. The method of claim 2 or claim 3, wherein, - determining the characteristic of the temperature profile comprises using a plurality of temperature sensors (32, 34, 36, 38, 40) arranged inside the housing (12) but outside the enclosure member (22) and between the upper outlet (28) vertical position and the lower inlet (26) vertical position.

5. The method of claim 2 or claim 3, wherein, - determining the characteristic of the temperature profile comprises the following: - determining measured temperature data using a measurement assembly, the measured temperature data comprising a temperature in each of a plurality of different locations of the static electric induction device assembly (10) as a function of time over a reference time range when the static electric induction device assembly (10) is in a state in which at least a portion of the static electric induction device (14) generates heat during at least a portion of the reference time range, - generating a temperature model of estimated temperature data corresponding to an estimated temperature in each of the plurality of different locations of the static electric induction device assembly (10) as a function of time, the temperature model comprising a learning model representing the estimated temperature data and the measured temperature data, and - training the learning model using the measured temperature data to thereby obtain the temperature model, and - determining the temperature profile using the temperature model.

6. The method of claim 5, wherein, The learning model comprises a neural network, preferably a multi-layer neural network.

2. The method according to claim 1, wherein the method comprises determining a temperature profile of the static electric induction device assembly (10) in the vertical direction (z) and / or in a horizontal direction (x, y) perpendicular to the vertical direction (z), the temperature profile comprising a characteristic of the temperature profile, wherein the method comprises determining the characteristic of the temperature profile.

3. The method according to claim 1 or 2, wherein the method comprises determining a temperature profile of the static electric induction device assembly (10) in the vertical direction (z) and / or in a horizontal direction (x, y) perpendicular to the vertical direction (z), the temperature profile comprising a characteristic of the temperature profile, wherein the method comprises determining the characteristic of the temperature profile.

4. The method according to any one of claims 1 to 3, wherein the method comprises determining a temperature profile of the static electric induction device assembly (10) in the vertical direction (z) and / or in a horizontal direction (x, y) perpendicular to the vertical direction (z), the temperature profile comprising a characteristic of the temperature profile, wherein the method comprises determining the characteristic of the temperature profile.

5. The method according to any one of claims 1 to 4, wherein the method comprises determining a temperature profile of the static electric induction device assembly (10) in the vertical direction (z) and / or in a horizontal direction (x, y) perpendicular to the vertical direction (z), the temperature profile comprising a characteristic of the temperature profile, wherein the method comprises determining the characteristic of the temperature profile.

6. The method according to any one of claims 1 to 5, wherein the method comprises determining a temperature profile of the static electric induction device assembly (10) in the vertical direction (z) and / or in a horizontal direction (x, y) perpendicular to the vertical direction (z), the temperature profile comprising a characteristic of the temperature profile, wherein the method comprises determining the characteristic of the temperature profile.

7. The method according to any one of claims 1 to 6, wherein the method comprises determining a temperature profile of the static electric induction device assembly (10) in the vertical direction (z) and / or in a horizontal direction (x, y) perpendicular to the vertical direction (z), the temperature profile comprising a characteristic of the temperature profile, wherein the method comprises determining the characteristic of the temperature profile.

8. The method according to any one of claims 1 to 7, wherein the method comprises determining a temperature profile of the static electric induction device assembly (10) in the vertical direction (z) and / or in a horizontal direction (x, y) perpendicular to the vertical direction (z), the temperature profile comprising a characteristic of the temperature profile, wherein the method comprises determining the characteristic of the temperature profile.

9. The method according to any one of claims 1 to 8, wherein the method comprises determining a temperature profile of the static electric induction device assembly (10) in the vertical direction (z) and / or in a horizontal direction (x, y) perpendicular to the vertical direction (z), the temperature profile comprising a characteristic of the temperature profile, wherein the method comprises determining the characteristic of the temperature profile.

10. The method according to any one of claims 1 to 9, wherein the method comprises determining a temperature profile of the static electric induction device assembly (10) in the vertical direction (z) and / or in a horizontal direction (x, y) perpendicular to the vertical direction (z), the temperature profile comprising a characteristic of the temperature profile, wherein the method comprises determining the characteristic of the temperature profile.

7. The method of claim 5 or claim 6, wherein, The measuring assembly comprises an optical fiber sensor (42) located inside the enclosing member (22), preferably the static electric induction device (14) comprises a winding (44) and the optical fiber sensor (42) is at least partially located in the winding (44).

8. The method of any one of claims 2 to 7, wherein, The step of determining the liquid pressure difference (Ap) between the liquid pressure at the upper outlet (28) and the liquid pressure at the lower inlet (26) comprises using the temperature profile and information related to the density of the liquid (16) as a function of temperature (d(T(z))).

9. The method of any of the preceding claims, wherein, The method comprises determining a fluid flow rate (Q of the liquid (16) flowing in the at least one cooling pipe (24) based on the liquid pressure difference (Ap) and a factor (k) indicative of a flow resistance of the at least one cooling pipe (24) v ).

10. The method of any of the preceding claims, wherein, The step of determining the heat loss value (Q) comprises determining a value indicative of the electric power (P) fed to the static electric induction device portion (20).

11. The method of any one of claims 9-10, wherein, using said liquid pressure difference (Δp), said heat loss value (Q) and said liquid temperature value (T liq (z port )) to determine said temperature of said static electric induction means portion (20) comprises determining a heat transfer coefficient (h) between said static electric induction means portion (20) and said liquid (16), said heat transfer coefficient (h) being a function of said fluid flow rate, wherein said temperature of said static electric induction means portion (20) is determined as a sum of said liquid temperature value (T liq (z port )) and a parameter proportional to a ratio between said heat loss value (Q) and said heat transfer coefficient (h).

12. The method of any of the preceding claims, wherein, The static electric induction device (14) comprises a winding (44), wherein the static electric induction device portion (20) is a part of the winding (44), preferably the winding comprises a plurality of discs (46, 48) and the method comprises executing the method according to any of the preceding claims for each of a group of discs of the plurality of discs (46, 48).

13. The method of any of the preceding claims, wherein, The static electric induction device portion (20) is associated with a region of the static electric induction device (14) having a relatively high temperature compared to its surroundings.

14. A computer program product comprising program code for performing the method according to any of claims 1 to 13 when executed by a processor device.

15. A control unit (50) arranged to perform the method according to any of claims 1 to 13.

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