Cooling system for superconducting generator

Abstract

An electric machine includes a shaft, a carrier structure disposed circumferentially about the shaft and defining a circumferential surface, a plurality of conductive coils secured to the carrier structure, and a cooling system. The cooling system includes an inlet manifold for providing cooling fluid to the electric machine, an outlet manifold for removing cooling fluid from the electric machine, and at least one channel in fluid communication with the inlet manifold and the outlet manifold. At least one channel is disposed between two adjacent ones of the plurality of conductive coils. The at least one channel defines an inlet portion including a fluid inlet in fluid communication with the inlet manifold, an outlet portion including a fluid outlet in fluid communication with the outlet manifold, and a return portion disposed between the inlet portion and the outlet portion. The return portion defines a length such that the inlet portion and the outlet portion are arranged in contact with each other along the respective lengths of the inlet portion and the outlet portion such that the conduction potential of the at least one channel is reduced.

Description

[0001] STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] This invention was made with Government support under Contract No. DE-EE0008787 awarded by the Department of Energy (DOE). The Government has certain rights in this invention. Technical Field

[0003] The present disclosure relates generally to cooling systems, and more particularly to cooling systems for superconducting generators. Background Art

[0004] Wind energy is considered to be one of the cleanest and most environmentally friendly energy sources currently available, and in this regard, wind turbines have received increased attention. Modern wind turbines typically include a tower, a generator, a gearbox, a nacelle, and a rotatable hub having one or more rotor blades mounted thereto. The rotor blades are typically mounted to the hub via corresponding pitch bearings that allow each of the rotor blades to rotate around the pitch axis. Therefore, the rotor blades use the known airfoil principle to capture the kinetic energy of the wind. For example, the rotor blades typically have a cross-sectional profile of an airfoil so that during operation, air flows through the rotor blades, creating a pressure difference between the sides. Therefore, a lift force directed from the pressure side to the suction side acts on each of the rotor blades. The lift force generates a torque on the main rotor shaft, which can directly drive a generator or a transmission (gear) to a generator for generating electricity.

[0005] Generally, a generator or electric motor (collectively referred to herein as a conductive rotating machine) includes a plurality of conductive coils for generating a static magnetic field or a rotating magnetic field and at least one armature coil for generating a rotating magnetic field or a static magnetic field associated with the armature motion, which interacts with the field from the conductive coils.

[0006] Such conductive rotating machines typically utilize alternating magnetic polarity established by conductive coils of field windings. That is, the North Pole is located between the South Pole to produce a regular field pattern of North, South, North, South, etc. These alternating polarities are generated by conductive coils of field windings constructed by conductors that generate current in opposite directions. The magnetic field generated by the field coils interacts with the magnetic poles of the conductive coils of the armature to produce torque. Torque is generated by the interaction of the two magnetic fields that attempt to align. The magnitude of the torque is related to the strength of the magnetic field and the radius at which they interact.

[0007] Many such generators may also include a cooling system to assist in cooling the conducting coils to maintain the conducting coils and surrounding insulation at a suitable temperature.

[0008] Generator cooling systems may require several mechanical connections to effectively provide cooling to each of the conductive coils. However, as the number of mechanical connections increases, the likelihood of failure of the overall cooling system may increase. In addition, the cost of manufacturing the mechanical connections may result in an increase in the overall cost of producing the generator.

[0009] In addition, such cooling systems may also experience increased heat due to being placed close to other components of the generator. This may occur when magnetic flux passes through the cooling system and causes eddy currents to be generated within the cooling system. These eddy currents may cause the cooling system to conduct current along the cooling system. Such conduction of current may cause the overall resistance of the cooling system (particularly the materials used to construct the cooling system) to increase. With the increase in resistance, the heat load imposed on the cooling system increases. This increased heat load will cause the cooling system to heat up, which will cause a reduction in the overall ability of the cooling system to cool components external to the cooling system. If the capacity of the cooling system is reduced, the components to be cooled may also operate less efficiently due to the components operating at suboptimal temperatures.

[0010] Therefore, the industry is continually seeking new and improved cooling systems for generators that address the aforementioned problems. Summary of the invention

[0011] Aspects and advantages of the disclosure will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the disclosure.

[0012] In one aspect, the present disclosure is directed to an electric machine. The electric machine includes a shaft, a carrier structure arranged circumferentially around the shaft and defining a circumferential surface, a plurality of conductive coils fixed to the carrier structure, and a cooling system. The cooling system includes an inlet manifold for providing a cooling fluid to the electric machine, an outlet manifold for removing the cooling fluid from the electric machine, and at least one channel in fluid communication with the inlet manifold and the outlet manifold. At least one channel is arranged between two adjacent conductive coils in the plurality of conductive coils. At least one channel defines an inlet portion including a fluid inlet in fluid communication with the inlet manifold, an outlet portion including a fluid outlet in fluid communication with the outlet manifold, and a return portion arranged between the inlet portion and the outlet portion. The return portion defines a length such that the inlet portion and the outlet portion are arranged to contact each other along the respective lengths of the inlet portion and the outlet portion, so that the conduction potential of at least one channel is reduced. These and other features, aspects, and advantages of the present disclosure will become better understood with reference to the following description and the appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present disclosure and are used together with the description to explain the principles of the present disclosure.

[0013] In an embodiment, the carrier structure is an armature or yoke of a field assembly.

[0014] In further embodiments, the motor further comprises a first divider disposed along respective lengths of the inlet manifold and the outlet manifold for providing flow separation between the inlet manifold and the outlet manifold.

[0015] In additional embodiments, the first separator is constructed of a material having a thermal conductivity less than about 45 Watts per meter-Kelvin (W / mK).

[0016] In other embodiments, the first separator is constructed of a non-metallic material.

[0017] In yet further embodiments, the electric machine further comprises a cooling inlet and a cooling outlet, wherein the cooling system defines modules, wherein at least one module is connected to the cooling inlet and the cooling outlet.

[0018] In other additional embodiments, the cooling inlet is connected to the inlet manifold of at least one module, and the cooling outlet is connected to the outlet manifold of at least one module.

[0019] In yet additional embodiments, the connections between the cooling inlet and cooling outlet and the inlet and outlet manifolds include flexible connectors.

[0020] In still other embodiments, the motor further includes a second divider disposed along respective lengths of the inlet portion and the outlet portion for providing flow separation between the inlet portion and the outlet portion.

[0021] In yet another embodiment, the second spacer is constructed of a material having a thermal conductivity less than about 45 Watts per meter-Kelvin (W / mK).

[0022] In further embodiments, the second separator is constructed of a non-metallic material.

[0023] In additional embodiments, the cooling fluid includes at least one of water, coolant, antifreeze, gas, or a combination thereof.

[0024] In other embodiments, the inlet and outlet manifolds and the inlet and outlet portions are constructed of electrically conductive materials.

[0025] In yet further embodiments, the cooling system further includes at least two channels in fluid communication with the inlet manifold and the outlet manifold, the at least two channels being disposed between two adjacent conductive coils of the plurality of conductive coils.

[0026] In another aspect, the present disclosure is directed to a method for cooling an electric machine having a plurality of conductive coils. The method includes arranging at least one channel between two adjacent conductive coils of the plurality of conductive coils, the at least one channel being in fluid communication with an inlet manifold that provides cooling fluid to the electric machine and an outlet manifold that removes cooling fluid from the electric machine. The at least one channel defines an inlet portion including a fluid inlet in fluid communication with the inlet manifold, an outlet portion including a fluid outlet in fluid communication with the outlet manifold, and a return portion arranged between the inlet portion and the outlet portion. The return portion defines a length such that the inlet portion and the outlet portion are arranged to contact each other along respective lengths of the inlet portion and the outlet portion so as to provide electrical insulation thereto. The method also includes operating the inlet manifold and the outlet manifold to provide cooling fluid to the at least one channel so as to cool two adjacent conductive coils of the plurality of conductive coils.

[0027] In yet another aspect, the present disclosure is directed to a wind turbine. The wind turbine includes a generator including an axis, a carrier structure arranged circumferentially around the axis and defining a circumferential surface, a plurality of conductive coils fixed to the carrier structure, and a cooling system. The cooling system includes an inlet manifold for providing a cooling fluid to the motor, an outlet manifold for removing the cooling fluid from the motor, and at least one channel in fluid communication with the inlet manifold and the outlet manifold. At least one channel is arranged between two adjacent conductive coils in the plurality of conductive coils. At least one channel defines an inlet portion including a fluid inlet in fluid communication with the inlet manifold, an outlet portion including a fluid outlet in fluid communication with the outlet manifold, and a return portion arranged between the inlet portion and the outlet portion. The return portion defines a length such that the inlet portion and the outlet portion are arranged to contact each other along the respective lengths of the inlet portion and the outlet portion, so that the conduction potential of at least one channel is reduced. These and other features, aspects, and advantages of the present disclosure will become better understood with reference to the following description and the appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present disclosure and are used together with the description to explain the principles of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] A complete and enabling disclosure of the present disclosure, including the best mode thereof, to one of ordinary skill in the art is set forth in the specification with reference to the accompanying drawings, in which:

[0029] Figure 1 shows a side perspective view of an embodiment of a wind turbine having a generator according to the present disclosure;

[0030] Figure 2 Show Figure 1 An interior perspective view of an embodiment of a nacelle of a wind turbine, particularly showing a generator housed in the nacelle according to the present disclosure;

[0031] Figure 3 A perspective view showing an embodiment of a generator according to the present disclosure;

[0032] Figure 4 A schematic diagram showing an embodiment of a cooling system for a generator according to the present disclosure;

[0033] Figure 5 Showing the content of the present disclosure Figure 4 A side view of a cooling system of FIG. 1 , particularly showing channels of the cooling system;

[0034] Figure 6 A schematic diagram showing another embodiment of a cooling system for a generator according to the present disclosure;

[0035] Figure 7 Showing the content of the present disclosure Figure 6 A side view of a cooling system of FIG. 1 , particularly showing channels of the cooling system;

[0036] Figure 8 A side view showing yet another embodiment of a cooling system for a generator according to the present disclosure, particularly showing a plurality of channels of the cooling system;

[0037] Fig. 9 A side view showing yet another embodiment of a cooling system for a generator according to the present disclosure, particularly showing channels of the cooling system;

[0038] Fig.10 a schematic diagram showing another embodiment of a cooling system for a generator, in particular showing the connection of a separate cooling system; and

[0039] Fig.11 A flow chart illustrating an embodiment of a method of cooling a generator having a plurality of conductive coils according to the present disclosure. DETAILED DESCRIPTION

[0040] Reference will now be made in detail to the embodiments of the present disclosure, one or more examples of which are shown in the drawings. Each example is provided by way of illustrating the present disclosure rather than limiting the present disclosure. In fact, it will be apparent to those skilled in the art that various modifications and variations may be made in the present disclosure without departing from the scope or spirit of the present disclosure. For example, a feature shown or described as a part of an embodiment may be used together with another embodiment to produce yet other embodiments. Therefore, it is intended that the present disclosure covers such modifications and variations as fall within the scope of the appended claims and their equivalents.

[0041] As used herein, the terms “first,” “second,” and “third” may be used interchangeably to distinguish one component from another and are not intended to indicate the position or importance of individual components.

[0042] The terms “coupled,” “fixed,” “attached to,” and the like refer to both directly coupled, fixed, or attached as well as indirectly coupled, fixed, or attached through one or more intermediate members or features, unless otherwise specified herein.

[0043] As used herein throughout the specification and claims, approximating language is used to modify any quantitative representation that is permissible to vary without causing a change in the underlying function to which it relates. Accordingly, values ​​modified by one or more terms such as "about," "approximately," and "roughly" are not limited to the exact values ​​specified. In at least some instances, approximate language may correspond to the accuracy of an instrument used to measure a value, or the accuracy of a method or machine used to construct or manufacture a component and / or system. For example, approximate language may refer to within a 10 percent margin.

[0044] Here and throughout the specification and claims, range limitations are combined and interchanged, such ranges are identified and include all sub-ranges contained therein unless context or language indicates otherwise. For example, all ranges disclosed herein include the endpoints, and the endpoints are independently combinable with each other.

[0045] In general, the present disclosure is directed to an energy conversion system, such as a wind turbine power system, which includes an electrical machine, such as a superconducting generator or motor. The present disclosure is generally described herein with reference to a superconducting generator, and more particularly with reference to a wind turbine superconducting generator, but is not limited to a superconducting generator. For example, the present disclosure is directed to a generator that includes a shaft, a carrier structure, a plurality of conductive coils, and a cooling system. The cooling system may include an inlet manifold for providing a cooling fluid to the generator, an outlet manifold for removing the cooling fluid from the generator, and a channel in fluid communication with the inlet manifold and the outlet manifold. In addition, a channel may be arranged between two adjacent conductive coils in the plurality of coils.

[0046] Thus, an advantage of the present disclosure is that the total required mechanical connections required for the cooling system needed to provide proper cooling to the generator are reduced. Another advantage of the present disclosure is that the reliability of the cooling system can be improved due to the reduction in the number of overall required mechanical connections. In addition, the overall manufacturing cost of the cooling system can be reduced because fewer parts and mechanical connections are required. Yet another advantage of the present disclosure is that the cooling system can be more resistant to temperature increases caused by the formation of eddy currents within the cooling system.

[0047] Now refer to the figure, Figure 1A side perspective view of an embodiment of a wind turbine 100 having a superconducting generator 114 according to the present disclosure is shown. As shown, the wind turbine 100 generally includes a tower 108 extending from a support surface, a nacelle 102 mounted on the tower 108, and a rotor 104 coupled to the nacelle 102. The rotor 104 includes a rotatable hub 110 and at least one rotor blade 112 (three are shown) coupled to the hub 110 and extending outwardly from the hub 110. Each rotor blade 112 may be spaced around the hub 110 so as to facilitate rotating the rotor 104 about the axis of rotation 106 to enable kinetic energy from the wind to be converted into usable mechanical energy, and subsequently into electrical energy. For this purpose, the rotor 104 is coupled to the generator 114 via a shaft (not shown). For the purposes of the present disclosure, the generator 114 is a direct drive superconducting generator. Superconducting generators are distinguished from non-superconducting generators by the presence of coils constructed of superconducting materials ("superconductors") rather than of normally conductive materials (e.g., copper, aluminum, etc.) having electrical resistance. However, in order for the material of a superconductor to exist in a non-resistive superconducting state, the superconductor must be kept below a certain temperature (the "critical temperature"). Thus, an improved cooling system (which is used, for example, for non-superconducting coils) may be particularly useful within a superconducting generator by reducing the overall temperature of the generator (thereby minimizing heat leakage into the superconducting conducting coils). However, it should be understood that the improved cooling system may also provide utility to generators having non-superconducting coils.

[0048] Now refer to Figure 2 , Figure 1 A simplified internal view of an embodiment of a nacelle 102 of a wind turbine 100 shown in FIG. 1 is shown in accordance with the present disclosure. As shown, a generator 114 is housed within the nacelle 102 and includes an excitation assembly 120 and an armature 118. In addition, as shown, the generator 114 is generally coupled to the rotor 104 for generating electrical power from the rotational energy generated by the rotor 104. For example, as shown in the illustrated embodiment, the rotor 104 may include a rotor shaft 122 coupled to the hub 110 for rotation therewith. The rotor shaft 122 may in turn be rotatably coupled to the armature 118 of the generator 114. As generally understood, the rotor shaft 122 may provide a torque input to the armature of the generator 114 in response to the rotation of the rotor blades 112 and the hub 110. As shown, the armature 118 is within the excitation assembly 120 of the generator 114. However, it should be understood that the armature 118 may be external and the field assembly 120 may be internal.

[0049] In an embodiment, electrical power may then be generated using well-known induction principles by applying a torque input to the armature 118 of the generator 114. The armature 118 may then rotate within a magnetic field provided by the excitation assembly 120 of the generator 114 (eg, in an inside rotor configuration).

[0050] However, in other embodiments, the outer member may be the armature 118 of the generator 114, and the inner member may be the field assembly 120 of the generator 114 (e.g., in an outer rotor configuration). Moreover, as shown, additional space may be defined between the outer member and the inner member to allow movement (e.g., rotation) therebetween. In other embodiments, it should be understood that the armature 118 may also be a stationary element that operates within the rotating magnetic field established by the rotation of the field windings.

[0051] Still refer to Figure 2 , the magnetic field generated by the armature 118 is due to the magnetomotive force (MMF) setting created by the current flowing through the armature 118. The MMF has both spatial and temporal harmonics associated with it due to the discretization of the coils and the magnetic saturation within the steel structure.

[0052] Now refer to Figure 3 , a cutaway perspective view of an embodiment of a generator 114 according to the present disclosure is provided. In particular, as shown, the generator 114 may include a housing 116 for housing its internal components, such as an armature 118 that may be fixed to a rotor shaft 122 and an excitation assembly 120 that may be fixed to the stationary housing 116, such as described herein. In addition, as shown, the generator 114 may also include at least one winding set. For example, as shown, the winding set may include one or more current-carrying conductors formed into coils 124, which may be attached to a carrier structure 126. As shown, the carrier structure 126 may be arranged circumferentially around the rotor shaft 122 and define a circumferential surface. In addition, the carrier structure 126 may be a yoke for the excitation assembly 120. Alternatively, if the armature 118 is outside the excitation assembly 120, the carrier structure 126 may be a circumferential surface of the armature 118 instead.

[0053] Additionally, the coils 124 may be spaced apart from one another such that there is a space 128 between adjacent coils 124. By leaving a space 128 between each of the coils 124, a generated opposing magnetic field (e.g., a second common polarity) may be generated in that space 128 by forcing the laws of nature that conserve the magnetic flux generated by the coils 124.

[0054] Now refer to Figure 4 and Figure 5, various views of an embodiment of a cooling system 200 for a generator 114 according to the present disclosure are shown. As shown, the cooling system 200 generally includes an inlet manifold 202, an outlet manifold 204, a channel 208, and a core 206. Thus, in an embodiment, the inlet manifold 202 may be configured to provide a cooling fluid 210 to the generator 114. Additionally, the outlet manifold 204 may be configured to remove the cooling fluid 210 from the generator 114. The outlet manifold 204 may also be placed at a length L1 from the inlet manifold 202 such that a gap 209 is formed therebetween. Thus, the channel 208 may be in fluid communication with the inlet manifold 202 and the outlet manifold 204. More specifically, as shown, the channel 208 may be arranged between two adjacent coils 124 of the plurality of conductive coils 124. For example, if the generator 114 includes only two adjacent coils 124, one channel 208 may be placed between the two coils 124. Furthermore, if there are four or more coils 124 in the generator 114 , two or more channels 208 may be placed between each pair of coils 124 , respectively.

[0055] The passages 208 may be constructed of a selected selection of materials useful in the provision of a cooling system for the generator 114. For example, the passages may be constructed of a metal such as copper or aluminum, a metal alloy such as a copper alloy or an aluminum alloy, a non-metallic material, or a combination thereof.

[0056] With particular reference Figure 5 , the channel 208 may also include an inlet portion 212, an outlet portion 214, and a return portion 216. The inlet portion 212 includes a fluid inlet 218 connected to the inlet manifold 202 so that the cooling fluid 210 can flow out of the inlet manifold 202 and the channel 208. Similarly, the outlet portion 214 includes a fluid outlet 220 connected to the outlet manifold 204 so that the cooling fluid 210 can flow from the channel 208 to the outlet manifold 204. In particular, as shown, the return portion 216 generally refers to the area of ​​the channel 208 disposed between the inlet portion 212 and the outlet portion 214.

[0057] Additionally, the fluid inlet 218 and the fluid outlet 220 may include connectors, such as flexible connectors. In such embodiments, the flexible connectors allow for expansion and / or contraction to occur in the cooling system 200 when the temperature therein changes. Furthermore, in embodiments, by forming the fluid inlet 218 and the fluid outlet 220 from flexible connectors, effects on the connection between the channel 208 and the inlet manifold 202 and / or the outlet manifold 204 caused by expansion and / or contraction of the cooling system 200 may be avoided.

[0058] Still refer to Figure 5, the return portion 216 may define a length L2. The length L2 may be such that a gap 222 is formed between the inlet portion 212 and the outlet portion 214, so that the inlet portion 212 and the outlet portion 214 are separated from each other.

[0059] In further embodiments, the channel 208 may also include one or more insulators 224 and one or more ground wires 226 arranged therewith. Thus, as shown, the insulator 224 may be placed on the inlet portion 212, the outlet portion 214, or both. The insulator 224 may be particularly important when the channel 208 or the inlet manifold 202 and the outlet manifold 204 are made of a conductive material, such as a metal material having optimal thermal conductivity properties. For example, if the channel 208 or the inlet manifold 202 and the outlet manifold 204 are made of an electrically conductive material, the insulator 224 may prevent current from being conducted from the manifolds 202, 204 into the channel 208 or from the channel 208 into the manifolds 202, 204. This benefit may be particularly important due to the characteristics of the cooling system 200. For example, if the cooling system 200 is composed of an electrically conductive material, eddy currents may be generated due to the proximity of the magnetic flux generated by the conductive coil 124. These eddy currents will induce localized electrical losses in the material of the channels 208 or manifolds 202, 204, which will cause these components to heat up. Furthermore, the generated eddy currents may then cause the channels 208 or manifolds 202, 204 (each of which has conductive properties) to act as a conductor through which the eddy currents may flow through the cooling system 200 along the channels 208 or manifolds 202, 204. Since the internal resistance of the cooling system 200 increases when current flows through the cooling system 200, this movement of current will cause the internal temperature to increase further. To address this issue, the insulator 224 is configured to block the path for the current to flow into the inlet manifold 202 or the outlet manifold 204 and throughout the cooling system 200.

[0060] Similarly, an insulator 224, a ground wire 226 may be placed on either the inlet portion 212 or the outlet portion 214. Alternatively, the inlet portion 212 and the outlet portion 214 may be naturally electrically grounded via a device (not shown) in which they are mounted within the generator 114. In this configuration, the ground wire 226 attached to 204 may not be required.

[0061] Additionally, a ground wire 226 may also be placed on the inlet manifold 202 or the outlet manifold 204. Alternatively, the inlet portion 212, outlet portion 214, and channel 208 may be grounded at one point via the ground wire 226. By placing the ground wire 226 in any of these configurations, a known voltage for the inlet / outlet manifolds 202, 204 or the inlet / outlet portions 212, 214 may be established.

[0062] In additional embodiments, the cooling fluid 210 may be any suitable cooling fluid, such as a cooling liquid (eg, water, a refrigerant, or an antifreeze compound such as propylene glycol) or a cooling gas (eg, air or hydrogen), or a combination thereof.

[0063] Now refer to Figure 6-7 , showing various views of another embodiment of a cooling system 300 for a generator 114 according to the present disclosure. As shown in the illustrated embodiment, the cooling system 300 may have the same Figure 4 and Figure 5 For example, cooling system 300 may include a passage 308 having an inlet portion 312 , an outlet portion 314 , and a return portion 316 .

[0064] However, with Figure 4 and Figure 5 In contrast to the embodiment of the present invention, the inlet manifold 302 and the outlet manifold 304 are in contact with each other. In addition, the separator 306 can be placed between the inlet manifold 302 and the outlet manifold 304. The separator 306 can be composed of a variety of materials, such as materials with particularly low thermal conductivity. For example, the material can be a metallic material such as steel having a thermal conductivity at or below 45 watts per meter-Kelvin (W / mK). Alternatively, the material can be a non-metallic material having a thermal conductivity much lower than that of steel. For example, the non-metallic material can be a polymer material in which the thermal conductivity is approximately 2% of the thermal conductivity of steel or in which the thermal conductivity is between about 0.6 W / mK and about 1 W / mK. Although the inlet manifold 302 and the outlet manifold are placed in such close proximity to each other, when the material of the separator 306 is selected, heat transfer from the outlet manifold 304 to the inlet manifold 302 can be reduced or prevented.

[0065] In such embodiments, by placing the inlet manifold 302 in contact with the outlet manifold 304, the conduction potential of the cooling system 300 can be reduced because the inlet manifold 302 and the outlet manifold 304 no longer exist as a conduction loop or circuit. This is because any current that may be generated in the inlet manifold 302 or the outlet manifold 304 will no longer have a path through which the current can flow. Instead, when magnetic flux passes through the materials of the inlet manifold 302 and the outlet manifold 304, eddy currents will be able to be generated, but because the manifolds 302, 304 are in contact with each other, the voltages of the inlet manifold 302 and the outlet manifold 304 will remain similar. Because the voltages are similar between the manifolds 302, 304, current will not flow from the inlet manifold 302 to the outlet manifold 304 or vice versa.

[0066] In addition, now refer to Figure 7, the inlet portion 312 and the outlet portion 314 may also be placed in contact with each other, similar to the inlet manifold 302 and the outlet manifold 304. The separator 318 may also be placed between the inlet manifold and the outlet manifold 304 for providing flow separation. Like the configuration of the inlet manifold 302, the outlet manifold 304, and the configuration of the separator 306, the inlet portion 312, the outlet portion 314, and the separator 318 may be able to reduce the conduction potential of the channel 308. For example, by placing the inlet portion 312 and the outlet portion 314 in contact with each other, the voltage across these portions 312, 314 may be similar or the same, thereby reducing the amount of current or preventing current from passing through the channel 308. In addition, like the separator 306, the separator 318 may be formed of a metallic material (such as steel) or a non-metallic material (such as a polymer material) to reduce heat transfer from the outlet portion 314 to the inlet portion 312. It should be appreciated that while divider 306 and divider 318 are discussed as separate components, divider 306 and divider 318 may be integrated with one another to form a single divider that separates inlet and outlet manifolds 302 and 304 and inlet and outlet portions 312 and 314 .

[0067] Now refer to Figure 8 , showing a side view of yet another embodiment of a cooling system 400 having a plurality of channels 403, 405. In particular, as shown, the cooling system 400 may include a first channel 403 and a second channel 405. However, it should be understood that more than two channels may be placed between two adjacent coils 124. In addition, both the first channel 403 and the second channel 405 may be connected to the inlet manifold 402 and the outlet manifold 404, as shown and described herein. One benefit of providing the first channel 403 and the second channel 405 is that a greater mass flow rate of the cooling fluid may be achieved, resulting in a greater overall cooling power at the same overall pressure between the inlet manifold 402 and the outlet manifold 404. In addition, as shown, the inlet portion 412 and the outlet portion 414 may be placed in contact with each other, with the divider 406 placed therebetween, with Figure 6 and Figure 7 The embodiments are similar.

[0068] Now refer to Fig. 9 , shows a side view of yet another embodiment of a cooling system 500 having a single channel 508 with an inlet portion 512 and an outlet portion 514 defined using a divider 506. As shown, the channel 508 has two return portions 516 to allow cooling fluid entering from the inlet manifold 502 to travel through the channel 508 and return to the outlet manifold 504 through the single channel 508.

[0069] Now refer to Fig.10, a schematic diagram of another embodiment of a cooling system. As shown, the cooling system 600 includes a cooling inlet 604, a cooling outlet 602, and a cooling module 606. The cooling module 606 may be or may include any of the cooling systems 200, 300, 400, 500, or 600 mentioned above. For example, if the cooling module 606 is the cooling system 300, the cooling inlet 604 may be connected to the inlet manifold 302 (which is then connected to the inlet portion 312), and the cooling outlet 602 may be connected to the outlet manifold 304 (which is then connected to the outlet portion 314). The connection between these respective components may be formed using a connector 608. The connector 608 may be a flexible connector similar to the flexible connector used to form the fluid inlet 218 and the fluid outlet 220 of the cooling system 200. In addition, any number of cooling modules 606 may be provided. Furthermore, if the cooling system 600 is to be used with a generator (such as the generator 114), the cooling modules 606 may be placed along the entire perimeter of the generator. By providing cooling inlet 604, cooling outlet 602, and cooling module 606 in this manner, cooling module 606 (which may include cooling system 200, 300, 400, 500, or 600) may be easier to manufacture and arrange within an electric machine (such as generator 114) because cooling module 606 has a shortened circumferential span.

[0070] Now refer to Fig.11 , a flow chart showing an embodiment of a method 700 for cooling a generator having a plurality of conducting coils. It should be understood that the method 700 may be used, for example, as described herein with respect to Figure 4-10 For purposes of illustration and discussion, Fig.11 The steps are depicted as being performed in a particular order. One of ordinary skill in the art using the disclosure provided herein will appreciate that the various steps in method 700 or any of the methods disclosed herein may be adjusted, modified, rearranged, performed simultaneously, or modified in various ways without departing from the scope of the present disclosure.

[0071] As shown at (702), method 700 includes arranging at least one channel between two adjacent conductive coils in a plurality of conductive coils. The channel may be in fluid communication with an inlet manifold that provides cooling fluid to the generator and an outlet manifold that removes cooling fluid from the generator. During this step, at least one channel may define an inlet portion including a fluid inlet in fluid communication with the inlet manifold, an outlet portion including a fluid outlet in fluid communication with the outlet manifold, and a return portion arranged between the inlet portion and the outlet portion. In addition, the return portion arranged between the inlet portion and the outlet portion may define a length such that the inlet portion and the outlet portion are arranged to contact each other along the respective lengths of the inlet portion and the outlet portion to provide electrical insulation. As shown at (704), method 700 also includes operating the inlet manifold and the outlet manifold to provide cooling fluid to the channel to cool two adjacent conductive coils in the plurality of conductive coils.

[0072] Various aspects and embodiments of the present disclosure are defined by the following numbered clauses:

[0073] Clause 1. An electric machine comprising:

[0074] axis;

[0075] a carrier structure disposed circumferentially about the shaft and defining a circumferential surface;

[0076] a plurality of conductive coils secured to the carrier structure; and

[0077] Cooling system, including:

[0078] an inlet manifold for providing cooling fluid to the motor;

[0079] an outlet manifold for removing cooling fluid from the electric machine; and

[0080] at least one channel in fluid communication with the inlet manifold and the outlet manifold, the at least one channel disposed between two adjacent conductive coils of the plurality of conductive coils, the at least one channel defining an inlet portion including a fluid inlet in fluid communication with the inlet manifold, an outlet portion including a fluid outlet in fluid communication with the outlet manifold, and a return portion disposed between the inlet portion and the outlet portion,

[0081] Wherein the return portion defines a length such that the inlet portion and the outlet portion are arranged to contact each other along the respective lengths of the inlet portion and the outlet portion such that a conduction potential of the at least one channel is reduced.

[0082] Clause 2. The electric machine of clause 1, wherein the carrier structure is an armature or yoke of the field assembly.

[0083] Clause 3. The electric machine of any of the preceding clauses, further comprising a first divider disposed along respective lengths of the inlet manifold and the outlet manifold for providing flow separation between the inlet manifold and the outlet manifold.

[0084] Clause 4. The electric machine of clause 3, wherein the first separator is constructed of a material having a thermal conductivity less than about 45 Watts per meter-Kelvin (W / mK).

[0085] Clause 5. The electric machine of Clause 3, wherein the first separator is constructed of a non-metallic material.

[0086] Clause 6. The electric machine of any of the preceding clauses, further comprising a cooling inlet and a cooling outlet, wherein the cooling system defines modules, wherein at least one module is connected to the cooling inlet and the cooling outlet.

[0087] Clause 7. The electric machine of clause 6, wherein the cooling inlet is connected to an inlet manifold of at least one module and the cooling outlet is connected to an outlet manifold of at least one module.

[0088] Clause 8. The electric machine of clause 7, wherein the connections between the cooling inlet and cooling outlet and the inlet and outlet manifolds include flexible connectors.

[0089] Clause 9. The motor of any of the preceding clauses, further comprising a second divider disposed along respective lengths of the inlet portion and the outlet portion for providing flow separation between the inlet portion and the outlet portion.

[0090] Clause 10. The electric machine of clause 9, wherein the second separator is constructed of a material having a thermal conductivity less than about 45 Watts per meter-Kelvin (W / mK).

[0091] Clause 11. The electric machine of Clause 9, wherein the second separator is constructed of a non-metallic material.

[0092] Clause 12. The electric machine of any of the preceding clauses, wherein the cooling fluid comprises at least one of water, coolant, antifreeze, gas, or a combination thereof.

[0093] Clause 13. The electric machine of any of the preceding clauses, wherein the inlet and outlet manifolds and the inlet and outlet portions are constructed of electrically conductive materials.

[0094] Clause 14. The electric machine of any of the preceding clauses, wherein the cooling system further comprises at least two passages in fluid communication with the inlet manifold and the outlet manifold, the at least two passages being disposed between two adjacent conductive coils of the plurality of conductive coils.

[0095] Clause 15. A method of cooling an electric machine having a plurality of conductive coils, the method comprising:

[0096] disposing at least one channel between two adjacent conductive coils of the plurality of conductive coils, the at least one channel being in fluid communication with an inlet manifold that provides cooling fluid to the motor and an outlet manifold that removes cooling fluid from the motor, wherein the at least one channel defines an inlet portion including a fluid inlet in fluid communication with the inlet manifold, an outlet portion including a fluid outlet in fluid communication with the outlet manifold, and a return portion disposed between the inlet portion and the outlet portion, wherein the return portion defines a length such that the inlet portion and the outlet portion are disposed in contact with each other along respective lengths of the inlet portion and the outlet portion to provide electrical insulation therebetween; and

[0097] The inlet manifold and the outlet manifold are operated to provide cooling fluid to at least one channel to cool two adjacent conductive coils of the plurality of conductive coils.

[0098] Clause 16. The method of Clause 15, further comprising disposing a first divider disposed along respective lengths of the inlet manifold and the outlet manifold for providing flow separation between the inlet portion and the outlet portion.

[0099] Clause 17. The method of clauses 15-16, further comprising disposing a second divider disposed along respective lengths of the inlet portion and the outlet portion for providing flow separation between the inlet portion and the outlet portion.

[0100] Clause 18. The method of clause 16, wherein the first separator comprises a non-metallic material, wherein the non-metallic material comprises a thermal conductivity less than about 45 Watts per meter-Kelvin (W / mK).

[0101] Clause 19. The method of clauses 15-18, further comprising disposing at least two channels between two adjacent conductive coils of the plurality of conductive coils, the at least two channels being in fluid communication with an inlet manifold that provides cooling fluid to the electric machine and an outlet manifold that removes cooling fluid from the electric machine.

[0102] Clause 20. A wind turbine comprising:

[0103] Generator, including:

[0104] axis;

[0105] a carrier structure disposed circumferentially about the shaft and defining a circumferential surface;

[0106] a plurality of conductive coils secured to the carrier structure; and

[0107] Cooling system, including:

[0108] an inlet manifold for providing cooling fluid to the generator;

[0109] an outlet manifold for removing cooling fluid from the generator; and at least one passage in fluid communication with the inlet manifold and the outlet manifold, the at least one passage being disposed between two adjacent conducting coils of the plurality of conducting coils, the at least one passage defining an inlet portion including a fluid inlet in fluid communication with the inlet manifold, an outlet portion including a fluid outlet in fluid communication with the outlet manifold, and a return portion disposed between the inlet portion and the outlet portion,

[0110] Wherein the return portion defines a length such that the inlet portion and the outlet portion are arranged to contact each other along the respective lengths of the inlet portion and the outlet portion such that a conduction potential of the at least one channel is reduced.

[0111] This written description uses examples to disclose the disclosure, including the best mode, and also to enable any person skilled in the art to practice the disclosure, including making and using any device or system and performing any combined method. The patentable scope of the disclosure is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that have insubstantial differences from the literal language of the claims.

Claims

1. A motor, comprising: axis; a carrier structure disposed circumferentially about the shaft and defining a circumferential surface; a plurality of conductive coils secured to the carrier structure; as well as Cooling system, including: an inlet manifold for providing cooling fluid to the electric machine; an outlet manifold for removing the cooling fluid from the electric machine; and at least one channel in fluid communication with the inlet manifold and the outlet manifold, the at least one channel disposed between two adjacent conductive coils of the plurality of conductive coils, the at least one channel defining an inlet portion including a fluid inlet in fluid communication with the inlet manifold, an outlet portion including a fluid outlet in fluid communication with the outlet manifold, and a return portion disposed between the inlet portion and the outlet portion, wherein the return portion defines a length such that the inlet portion and the outlet portion are arranged to contact each other along respective lengths of the inlet portion and the outlet portion such that a conduction potential of the at least one channel is reduced.

2. The motor according to claim 1, wherein: The carrier structure is the armature or yoke of the field assembly. 3 . The electric machine of claim 1 , further comprising a first divider disposed along respective lengths of the inlet manifold and the outlet manifold for providing flow separation between the inlet manifold and the outlet manifold.

4. The motor according to claim 3, wherein: The first separator is constructed of a material having a thermal conductivity less than about 45 Watts per meter-Kelvin (W / mK).

5. The motor according to claim 3, wherein: The first separator is constructed of a non-metallic material.

6. The electric machine according to claim 1, further comprising a cooling inlet and a cooling outlet, wherein: The cooling system defines modules, wherein at least one module is connected to the cooling inlet and the cooling outlet.

7. The motor according to claim 6, wherein: The cooling inlet is connected to an inlet manifold of the at least one module, and the cooling outlet is connected to an outlet manifold of the at least one module.

8. The motor according to claim 7, wherein: The connections between the cooling inlet and the cooling outlet and the inlet manifold and the outlet manifold include flexible connectors.

9. The electric machine of claim 1, further comprising a second divider disposed along respective lengths of the inlet portion and the outlet portion for providing flow separation between the inlet portion and the outlet portion.

10. The electric machine according to claim 9, wherein: The second separator is constructed of a material having a thermal conductivity less than about 45 Watts per meter-Kelvin (W / mK).

11. The electric machine according to claim 9, wherein: The second separator is constructed of a non-metallic material.

12. The electric machine according to claim 1, wherein: The cooling fluid includes at least one of water, coolant, antifreeze, gas, or a combination thereof.

13. The electric machine according to claim 1, wherein: The inlet and outlet manifolds and the inlet and outlet portions are constructed of an electrically conductive material.

14. The electric machine according to claim 1, wherein: The cooling system also includes at least two passages in fluid communication with the inlet manifold and the outlet manifold, the at least two passages being disposed between two adjacent conductive coils of the plurality of conductive coils.

15. A method of cooling an electric machine having a plurality of conductive coils, the method comprising: disposing at least one channel between two adjacent conductive coils of the plurality of conductive coils, the at least one channel being in fluid communication with an inlet manifold that provides cooling fluid to the electric machine and an outlet manifold that removes the cooling fluid from the electric machine, wherein the at least one channel defines an inlet portion including a fluid inlet in fluid communication with the inlet manifold, an outlet portion including a fluid outlet in fluid communication with the outlet manifold, and a return portion disposed between the inlet portion and the outlet portion, wherein the return portion defines a length such that the inlet portion and the outlet portion are disposed in contact with each other along respective lengths of the inlet portion and the outlet portion to provide electrical insulation therebetween; and The inlet manifold and the outlet manifold are operated to provide the cooling fluid to the at least one channel to cool two adjacent conductive coils of the plurality of conductive coils.

16. The method of claim 15, further comprising disposing a first divider disposed along respective lengths of the inlet manifold and the outlet manifold for providing flow separation between the inlet portion and the outlet portion.

17. The method of claim 15, further comprising disposing a second divider disposed along respective lengths of the inlet portion and the outlet portion for providing flow separation between the inlet portion and the outlet portion.

18. The method according to claim 16, wherein: The first separator comprises a non-metallic material, wherein the non-metallic material comprises a thermal conductivity less than about 45 Watts per meter-Kelvin (W / mK).

19. The method of claim 15, further comprising disposing at least two channels between two adjacent ones of the plurality of conductive coils, the at least two channels being in fluid communication with an inlet manifold that provides cooling fluid to the electric machine and an outlet manifold that removes the cooling fluid from the electric machine.

20. A wind turbine comprising: Generator, including: axis; a carrier structure disposed circumferentially about the shaft and defining a circumferential surface; a plurality of conductive coils secured to the carrier structure; and Cooling system, including: an inlet manifold for providing cooling fluid to the generator; an outlet manifold for removing the cooling fluid from the generator; and at least one channel in fluid communication with the inlet manifold and the outlet manifold, the at least one channel disposed between two adjacent conductive coils of the plurality of conductive coils, the at least one channel defining an inlet portion including a fluid inlet in fluid communication with the inlet manifold, an outlet portion including a fluid outlet in fluid communication with the outlet manifold, and a return portion disposed between the inlet portion and the outlet portion, wherein the return portion defines a length such that the inlet portion and the outlet portion are arranged to contact each other along respective lengths of the inlet portion and the outlet portion such that a conduction potential of the at least one channel is reduced.

Images