System for quench protection of superconducting machines such as superconducting wind turbine generators

Abstract

A quench protection system for a superconducting machine, such as a superconducting generator, having a plurality of superconducting coils arranged in series includes at least one switching heater electrically coupled to each of the superconducting coils. A quench protection switch is arranged in series with the coils, wherein each switching heater is in thermal contact with the quench protection switch. A heater network is configured in parallel with the quench protection switch and in thermal contact with each of the coils. A quench in any one of the coils triggers a quench in the quench protection switch, wherein the heater network then triggers a quench in all remaining coils.

Description

Technical Field

[0001] The present disclosure relates generally to superconducting machines, such as superconducting wind turbine generators, and more particularly to quench protection systems and methods for such machines. Background Art

[0002] In general, superconducting generators are made by constructing the generator field coils from superconducting materials ("superconductors") rather than the usual copper materials (which typically carry a substantially direct current). Superconductors are typically lighter and smaller in size (e.g., relative to current carrying capacity) than traditional conductors such as copper, and are more efficient at conducting current (particularly at lower frequencies). Consequently, the use of superconductors in power applications such as wind turbine generators offers benefits such as more efficient performance, lower generator weight, gearbox-less direct drive operation, and lower manufacturing and installation costs. These benefits are particularly applicable to offshore wind turbine applications.

[0003] Superconducting generators are equipped with protection circuits to protect the superconducting magnets from damage that would otherwise occur during a quench. A quench occurs when a superconductor reverts to a resistive state due to localized heating in a portion of the superconductor. When that portion is no longer superconducting and enters a resistive state, any current flowing through the resistive portion will result in localized (Joule) heating. This, in turn, causes adjacent portions of the superconductor to quench, resulting in a larger resistive volume, which in turn causes further heating. Thus, in a rapid cascade, the superconductor enters a resistive state, where potentially very large currents continue to flow.

[0004] Before a quench, the coil retains a large amount of stored energy, which after the quench is dissipated in the resistive volume of the conductor. If the quench process is not properly managed and the energy is dissipated only in a confined area (such as the initial quench site), such an area can experience a rapid and large temperature spike, which can damage the coil area at or near the initial quench location.

[0005] One well-known quench protection approach is to spread the quench process over substantially the entire mass of the superconductor to avoid local heating and dissipate the stored energy across as much of the available superconductor as possible. For certain types of superconducting machines, such as MRI machines, this quench protection is achieved by intentionally initiating a quench in the remaining superconducting coils after an initial quench by applying current to one or more heaters in thermal contact with each coil. For a group of coils, the heaters are configured in series, with the series arrangement being parallel to the coils. Therefore, when one of the coils quenches, a rapid voltage rise is generated across that coil and also across the series-connected heaters. Consequently, current will then flow through the series-connected heaters. The temperature rise caused by the heaters will initiate a quench in the coil attached to the heaters. Thus, by initiating a quench in all coils, energy is dissipated relatively evenly across all coils.

[0006] The quench protection methods discussed above are typically implemented by a cross-linked heater matrix, where for a magnet having N coils, a cross-linked N×N heater matrix is ​​used. However, for large superconducting generators, such as direct-drive superconducting wind turbine generators having a relatively large number of poles (e.g., more than 30 poles, where each pole corresponds to a superconducting excitation coil), implementing an N×N heater matrix for quench protection can be very expensive.

[0007] Therefore, the industry needs an improved quench protection system and method that reduces the complexity and cost of conventional heater matrices for larger superconducting generators, such as direct drive wind turbine generators. Summary of the Invention

[0008] Aspects and advantages of the invention 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 invention.

[0009] According to aspects of the present disclosure, a quench protection system is provided for a superconducting machine having multiple superconducting coils arranged in series. At least one switching heater (e.g., a resistor or a resistor network) can be electrically coupled across each of the superconducting coils. A quench protection switch is arranged in series with the superconducting coils, with each of the switching heaters in thermal contact with the quench protection switch. The heater network can be configured in parallel with the quench protection switch and also in thermal contact with each of the superconducting coils. With this unique configuration, a quench in any one superconducting coil activates the switching heater coupled thereto, and the activated switching heater triggers a quench in the quench protection switch. This quench in the quench protection switch then activates the heater network to trigger a quench in all remaining superconducting coils.

[0010] The heater network can have various configurations. For example, in one embodiment, the heater network includes a plurality of heaters connected in parallel, wherein each superconducting coil is in thermal contact with at least one of the heaters.

[0011] In another embodiment, the heater network may include a plurality of heaters connected in series, wherein each superconducting coil is in thermal contact with at least one of the heaters.

[0012] In yet another embodiment, the heater network may include a plurality of heaters connected in parallel and a plurality of heaters connected in series, wherein each superconducting coil is in thermal contact with at least one of the heaters.

[0013] In yet another embodiment, the heater network may include a single heater, wherein each superconducting coil is in thermal contact with the single heater.

[0014] It may be desirable to include a voltage clamping device across the heater network to limit the voltage applied across the heaters.

[0015] It may also be desirable to include a shielding coil applied to the quench protection switch to accelerate quenching of the heater network.

[0016] The present disclosure also includes a superconducting generator comprising a plurality of superconducting field coils and a quench protection system as discussed above. The superconducting generator may be configured as a superconducting wind turbine generator, for example.

[0017] The present invention includes a wind turbine power generation system comprising: a tower; a hub and a plurality of blades connected to the hub; a rotor connected to the hub; and a superconducting generator coupled to the rotor. The superconducting generator can be configured according to any combination of the embodiments of the quench protection system and generator discussed above.

[0018] The present invention also comprises various methods for operating a superconducting generator, in particular a superconducting wind turbine generator, according to the aspects discussed above.

[0019] Technical Solution 1. A quench protection system for a superconducting machine having a plurality of superconducting coils arranged in series, comprising:

[0020] at least one switching heater electrically coupled across each of the superconducting coils;

[0021] a quench protection switch configured in series with the superconducting coil, each of the switch heaters being in thermal contact with the quench protection switch;

[0022] a heater network configured in parallel with the quench protection switch, the heater network being in thermal contact with each of the coils;

[0023] causing the quench of any one of the superconducting coils to activate the switch heater coupled thereto, and the activated switch heater to trigger the quench of the quench protection switch; and

[0024] The quench of the quench protection switch activates the heater network to trigger a quench of all remaining superconducting coils.

[0025] Technical Solution 2. The quench protection system according to Technical Solution 1 is characterized in that the heater network includes a plurality of heaters connected in parallel, wherein each superconducting coil is in thermal contact with at least one of the heaters.

[0026] Technical Solution 3. The quench protection system according to Technical Solution 1 is characterized in that the heater network includes a plurality of heaters connected in series, wherein each superconducting coil is in thermal contact with at least one of the heaters.

[0027] Technical Solution 4. The quench protection system according to Technical Solution 1 is characterized in that the heater network includes a plurality of heaters connected in parallel and a plurality of heaters connected in series, wherein each superconducting coil is in thermal contact with at least one of the heaters.

[0028] Technical Solution 5. The quench protection system according to Technical Solution 1 is characterized in that the heater network includes a single heater, wherein each superconducting coil is in thermal contact with the single heater.

[0029] Technical Solution 6. The quench protection system according to Technical Solution 1 is characterized in that it also includes a voltage clamping device across the heater network.

[0030] Technical Solution 7. The quench protection system according to Technical Solution 1 is characterized in that it also includes a shielding coil applied to the quench protection switch to accelerate the quench of the heater network.

[0031] Technical Solution 8. A superconducting generator comprising:

[0032] a plurality of superconducting excitation coils arranged in series;

[0033] The quench protection system further comprises:

[0034] at least one switching heater electrically coupled across each of the field coils;

[0035] a quench protection switch configured in series with the superconducting coil, each of the switch heaters being in thermal contact with the quench protection switch;

[0036] a heater network configured in parallel with the quench protection switch, the heater network being in thermal contact with each of the coils;

[0037] causing the quench of any one of the superconducting coils to activate the switch heater coupled thereto, and the activated switch heater to trigger the quench of the quench protection switch; and

[0038] The quench of the quench protection switch activates the heater network to trigger a quench of all remaining superconducting coils.

[0039] Technical Solution 9. The superconducting generator according to Technical Solution 8 is characterized in that the heater network includes a plurality of heaters connected in parallel, wherein each superconducting coil is in thermal contact with at least one of the heaters.

[0040] Technical Solution 10. The superconducting generator according to Technical Solution 8 is characterized in that the heater network includes a plurality of heaters connected in series, wherein each superconducting coil is in thermal contact with at least one of the heaters.

[0041] Technical Solution 11. The superconducting generator according to Technical Solution 8 is characterized in that the heater network includes a plurality of heaters connected in parallel and a plurality of heaters connected in series, wherein each superconducting coil is in thermal contact with at least one of the heaters.

[0042] Technical Solution 12. The superconducting generator according to Technical Solution 8 is characterized in that the heater network includes a single heater, wherein each superconducting coil is in thermal contact with the single heater.

[0043] Technical Solution 13. The superconducting generator according to Technical Solution 8 is characterized in that it also includes a voltage clamping device across the heater network.

[0044] Technical Solution 14. The superconducting generator according to Technical Solution 8 is characterized in that it also includes a shielding coil applied to the quench protection switch to accelerate the quench of the heater network.

[0045] Technical Solution 15. The superconducting generator according to Technical Solution 8 is characterized in that the superconducting generator is a wind turbine generator.

[0046] Technical Solution 16. A wind turbine power generation system comprising:

[0047] tower;

[0048] a hub, and a plurality of blades connected to the hub;

[0049] a rotor connected to the hub;

[0050] a superconducting generator coupled to the rotor, the superconducting generator further comprising:

[0051] a plurality of superconducting excitation coils arranged in series;

[0052] The quench protection system further comprises:

[0053] at least one switching heater electrically coupled across each of the field coils;

[0054] a quench protection switch configured in series with the superconducting coil, each of the switch heaters being in thermal contact with the quench protection switch;

[0055] a heater network configured in parallel with the quench protection switch, the heater network being in thermal contact with each of the coils;

[0056] causing the quench of any one of the superconducting coils to activate the switch heater coupled thereto, and the activated switch heater to trigger the quench of the quench protection switch; and

[0057] The quench of the quench protection switch activates the heater network to trigger a quench of all remaining superconducting coils.

[0058] These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims.The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] A full and enabling disclosure of the invention, including the best mode thereof, to one of ordinary skill in the art is set forth in the specification which proceeds with reference to the accompanying drawings in which:

[0060] Figure 1 A perspective view showing an embodiment of a wind turbine having a superconducting generator according to the present disclosure;

[0061] Figure 2 is a cross-sectional view of a superconducting generator;

[0062] Figure 3 is a schematic diagram of a quench protection system for a superconducting machine according to aspects of the present invention;

[0063] Figure 4 is used in Figure 3 Schematic diagram of an embodiment of a heater network used in a quench protection system;

[0064] Figure 5is a schematic diagram of an alternative embodiment of a heater network;

[0065] Figure 6 is a schematic diagram of another embodiment of a heater network; and

[0066] Figure 7 is a schematic diagram of an alternative embodiment of a quench protection system. DETAILED DESCRIPTION

[0067] Reference will now be made in detail to embodiments of the present invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explaining the present invention rather than limiting the present invention. In fact, it will be apparent to those skilled in the art that various modifications and variations may be made to the present invention without departing from the scope or spirit of the present invention. For example, features shown or described as part of one embodiment may be used together with another embodiment to produce another embodiment. Therefore, the present invention is intended to cover such modifications and variations as fall within the scope of the appended claims and their equivalents.

[0068] The present disclosure encompasses a wide variety of superconducting machines and is not limited to superconducting generators.For purposes of explanation, the present quench protection system is described herein generally with reference to superconducting generators, and more particularly with reference to wind turbine superconducting generators.

[0069] Referring now to the accompanying drawings, Figure 1 A perspective view of one embodiment of a wind turbine power generation system 10 is shown. As shown, wind turbine 10 generally includes a tower 12 extending from a support surface 14, a nacelle 16 mounted on tower 12, and a rotor 18 coupled to nacelle 16. Rotor 18 includes a rotatable hub 20 and at least one rotor blade 22 (three shown), with rotor blades 112 coupled to hub 20 and extending outwardly from hub 110. Each rotor blade 22 may be spaced about hub 20 to facilitate rotating rotor 18, thereby enabling kinetic energy to be converted from wind energy into usable mechanical energy, and subsequently into electrical energy. To this end, rotor 18 is coupled to generator 24 via shaft 26. For the purposes of this disclosure, generator 24 is a direct drive superconducting generator.

[0070] The present invention includes a wind turbine power generation system 10 as described above, wherein the generator 24 is configured as a superconducting generator having a quench protection system as set forth below.

[0071] The present invention also includes various methods of operating a superconducting generator, particularly a wind turbine superconducting generator, having a quench protection system according to the method aspects set forth below.

[0072] Figure 2 Shown from Figure 1FIG2 is an exemplary cross-sectional view of a superconducting generator 24. As depicted, the generator 24 includes an outer concentric member 104, which may be a stator, and an inner concentric member 106, which may be a rotor (e.g., in an inner rotor configuration). However, in other embodiments, the outer member 104 may be the rotor of the generator 24, and the inner member 106 may be the stator of the generator 24 (e.g., in an outer rotor configuration). A gap (or "air gap") 105 is defined between the outer member 104 and the inner member 106 and allows movement (e.g., rotation) therebetween.

[0073] The generator 24 also includes a first set of one or more current-carrying conductors ("coils") 108 attached to the outer member 104 and a second set of one or more current-carrying conductors ("coils") 110 attached to the inner member 106. During operation of the generator 24, these coils 108, 110 are in electromagnetic communication. The coils 108 may be armature coils, and the coils 110 may be field coils of the generator 24. In other embodiments, the coils 108 may be field coils, and the coils 110 may be armature coils of the generator 24. The field coils are connected to a source of excitation current (e.g., an "exciter"), where current flowing through the field coils generates a magnetic field on the field coils, and the armature coils are connected to the output of the generator 24 (e.g., via output terminals) to conduct output current and electrical power output. Although several coils 108 , 110 are depicted, in various embodiments, there may be more or fewer coils 108 , 110 and / or windings thereof around the outer member 106 and the inner member 108 , for example, to configure the number of poles of the generator 24 , and thereby the power generation frequency and / or other operating characteristics of the generator 24 .

[0074] The field coils (e.g., coil 110) are constructed from a superconducting material, such as niobium-titanium (NbTi), niobium-tin (Nb3Sn), or magnesium-boron (MgB2). Typically, the armature coils 108 are constructed from copper. However, in some embodiments, the armature coils may be constructed from a superconducting material, such as NbTi, Nb3Sn, or MgB2. In some embodiments, the superconducting material may also be a high-temperature superconductor, such as YBCO or ReBCO.

[0075] Figure 3 FIG2 is an illustration of an embodiment of a quench protection system 200 according to aspects of the present disclosure. The system 200 can be incorporated into a superconducting machine, such as an MRI machine or a superconducting generator (e.g., a superconducting wind turbine generator). The superconducting magnet includes a plurality of coils 202, depicted as SCG Coil #1 through SCG Coil #N, connected in series. Each of these coils 202 has a corresponding switching heater 204 (labeled as Switching Heater #1 through Switching Heater #N) electrically coupled thereto, for example, in a parallel configuration.

[0076] An electrical circuit including leads 218, which may be fixed or retractable, is provided for connection to a main power source 226. When connected to the main power source 226, the superconducting coils 202 are supplied with current via the ends 224 of the coils 202 arranged in series.

[0077] A superconducting main switch 216 is configured in parallel with coil 202 in system 200. As is known in the art, main switch 206 can be, for example, a ramping switch having a superconducting wire portion and a heater portion impregnated in epoxy resin. By controlling the heater portion, the wire portion can be switched between a resistive state and a superconducting state. This type of switch 206 is typically used to switch a superconducting coil between a superconducting continuous mode of operation and a non-continuous superconducting mode. Generally, switch 206 is used to "ramp up" coil 202 to continuous mode and purposefully "ramp down" the coil from continuous mode. When system 200 is connected to a current source (power supply 226) via lead 218, current flows through coil 202 and main switch 216. When magnet / coil 202 is ramped to the desired current, main switch 216 becomes superconducting and closes. As the power supply connected to lead 218 ramps down, the current through main switch 216 increases by substantially the same amount as the external power supply current decreases. Once the external power source is fully ramped down, the leads 218 are disconnected from the external power source.At this point, the superconducting coil 202 is in a continuous operation mode.

[0078] System 200 includes a superconducting quench protection switch (QPS) 206 configured in series with coil 202 and main switch 216. The QPS switch 206 can be the same type of switch as the main switch 216 discussed above. The main switch 216 requires a relatively long length of superconductor to provide a resistance of several ohms when the switch is resistive so that Joule heating on the main switch during ramping is manageable (not too high). The QPS switch 206 is generally similar in size or smaller in size than the main switch 216 having similar superconducting properties.

[0079] In the continuous operating mode, the QPS 206 is also superconducting, and therefore closed. Each of the switching heaters 204 is in thermal contact with the QPS 206, such as by gluing or otherwise affixed directly to a surface of the QPS 206.

[0080] When one of the coils 202 quenches, a voltage rapidly develops across the coil 202 and therefore across the associated switching heater 204 to which it is electrically coupled, causing current to flow through the switching heater 204. The switching heater 204 is in thermal contact with the QPS 206, thus causing the QPS 206 to quench.

[0081] The heater network 208 is configured in parallel with the QPS 206 and in thermal contact with each of the coils 202. With this unique configuration, a quench in any one of the coils 202 also triggers a quench in the QPS 206. The resulting voltage induced across the QPS 206 triggers the heater network 208 (causing current to flow through each heater 210 in the network 208). This activation of the heater network 208 thus results in a subsequent rapid quench in all of the remaining coils 202.

[0082] Another particular advantage of the system 200 is that, because the QPS 206 is placed in series with the coil 202 and the main switch 216 , quench protection is provided during the ramp-up to the continuous mode and during the continuous mode of operation.

[0083] The heater network 208 may have various configurations of individual heaters 210, with each coil 202 in thermal contact with at least one of the heaters 210. For example, in Figure 3 In the embodiment of FIG. 5 , N heaters 210 are configured in parallel within the heater network 208 , with a respective heater 210 associated with each coil 202 .

[0084] exist Figure 4 In another depicted embodiment, the heater network 208 includes N heaters 210 connected in series, with there being a respective heater 210 associated with each coil 202 .

[0085] In another embodiment, the heater network 208 may include heaters 210 configured in parallel and in series. Figure 5 In the embodiment of FIG. 5 , a first branch 220 in the heater network 208 includes a plurality of heaters 210 connected in series within separate circuits, wherein the circuits are connected in parallel. The first branch 220 is connected in parallel with a similarly configured second branch 222 .

[0086] Figure 6 An embodiment of a heater network 208 is depicted having a single heater 210 , with each of the coils 202 being in thermal contact with the single heater 210 .

[0087] For example, as in Figure 3 In the embodiment of system 200 depicted in FIG, a voltage clamping device, such as a diode configuration or a shunt resistor, may be arranged across the heater network to limit the voltage applied across the heaters.

[0088] It may be desirable to position the QPS 206 in a high magnetic field (e.g., approximately 2-4 T field region) relatively close to the superconducting field coils 202 in the generator to further increase the quench propagation speed in all coils 202. In this case, Figure 7An embodiment of the quench protection system 200 is depicted in which a shield coil 214 is added, which shields the QPS 206 from high field strengths (e.g., shielding to less than about 0.5 T). The shield coil 214 is self-shorting (not connected to the main current supply circuit). Each of the superconducting excitation coils 202 has a shield coil heater (not shown) electrically coupled thereto and in thermal communication with the shield coil 214. The shield coil 214 quenches similarly to the QPS switch 206. Once any one of the coils 202 quenches, the QPS coil 206 and the shield coil 214 will quench. When coil 214 quenches, the QPS 206 is exposed to high field strengths and spontaneously quenches, which results in accelerated triggering of the heater network 208 and subsequent quenching of the remaining coils 202.

[0089] The embodiments described herein provide a relatively simple, reliable and cost-effective quench protection system 200. Instead of the (N×N) switching heater matrix used in conventional quench protection systems, the present system can be implemented with a matrix of approximately 2×N heaters (e.g., Figure 6 ) or a 3×N heater matrix (e.g., Figure 7 ), QPS and voltage clamping devices (if required). As discussed above, the quench protection system provides protection during ramp-up as well as in sustained mode.

[0090] Various aspects and embodiments of the present invention are defined by the following numbered clauses:

[0091] 1. A quench protection system for a superconducting machine having a plurality of superconducting coils arranged in series, comprising:

[0092] at least one switching heater electrically coupled across each of the superconducting coils;

[0093] a quench protection switch configured in series with the superconducting coil, each of the switch heaters being in thermal contact with the quench protection switch;

[0094] a heater network configured in parallel with the quench protection switch, the heater network being in thermal contact with each of the coils;

[0095] causing a quench in any one of the superconducting coils to activate a switching heater coupled thereto, and causing the activated switching heater to trigger a quench of a quench protection switch; and

[0096] Therein, the quench of the quench protection switch activates the heater network to trigger the quench of all remaining superconducting coils.

[0097] 2. The quench protection system of clause 1, wherein the heater network comprises a plurality of heaters connected in parallel, wherein each superconducting coil is in thermal contact with at least one of the heaters.

[0098] 3. A quench protection system according to any of the preceding clauses, wherein the heater network comprises a plurality of heaters connected in series, wherein each superconducting coil is in thermal contact with at least one of the heaters.

[0099] 4. A quench protection system according to any of the preceding clauses, wherein the heater network comprises a plurality of heaters connected in parallel and a plurality of heaters connected in series, wherein each superconducting coil is in thermal contact with at least one of the heaters.

[0100] 5. A quench protection system according to any of the preceding clauses, wherein the heater network comprises a single heater, wherein each superconducting coil is in thermal contact with the single heater.

[0101] 6. A quench protection system according to any preceding clause, further comprising a voltage clamping device across the heater network.

[0102] 7. The quench protection system according to any of the preceding clauses, further comprising a shielding coil applied to the quench protection switch to accelerate the quench of the heater network.

[0103] 8. A superconducting generator comprising:

[0104] a plurality of superconducting excitation coils arranged in series;

[0105] A quench protection system, the quench protection system further comprising:

[0106] at least one switching heater electrically coupled across each of the superconducting coils;

[0107] a quench protection switch configured in series with the superconducting coil, each of the switch heaters being in thermal contact with the quench protection switch;

[0108] a heater network configured in parallel with the quench protection switch, the heater network being in thermal contact with each of the coils;

[0109] causing a quench in any one of the superconducting coils to activate a switching heater coupled thereto, and causing the activated switching heater to trigger a quench of a quench protection switch; and

[0110] Therein, the quench of the quench protection switch activates the heater network to trigger the quench of all remaining superconducting coils.

[0111] 9. The superconducting generator of clause 8, wherein the heater network comprises a plurality of heaters connected in parallel, wherein each superconducting coil is in thermal contact with at least one of the heaters.

[0112] 10. A superconducting generator according to any of clauses 8 to 9, wherein the heater network comprises a plurality of heaters connected in series, wherein each superconducting coil is in thermal contact with at least one of the heaters.

[0113] 11. A superconducting generator according to any one of clauses 8 to 10, wherein the heater network comprises a plurality of heaters connected in parallel and a plurality of heaters connected in series, wherein each superconducting coil is in thermal contact with at least one of the heaters.

[0114] 12. A superconducting generator according to any of clauses 8 to 11, wherein the heater network comprises a single heater, wherein each superconducting coil is in thermal contact with the single heater.

[0115] 13. A superconducting generator according to any one of clauses 8 to 12, further comprising a voltage clamping device across the heater network.

[0116] 14. A superconducting generator according to any one of clauses 8 to 13, further comprising a shielding coil applied to the quench protection switch to accelerate the quenching of the heater network.

[0117] 15. A superconducting generator according to any one of clauses 8 to 14, wherein the superconducting generator is a wind turbine generator.

[0118] 16. A wind turbine power generation system comprising a superconducting generator according to any one of clauses 8 to 14.

[0119] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention 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 with insubstantial differences from the literal language of the claims.

Claims

1. A quench protection system for a superconducting machine having a plurality of superconducting coils arranged in series, comprising: at least one switching heater electrically coupled across each of the superconducting coils; a quench protection switch configured to be connected in series with the superconducting coil, each of the switch heaters being in thermal contact with the quench protection switch, the quench protection switch comprising a superconducting switch having a superconducting wire portion and a heater portion, wherein the wire portion is switched between a resistive state and a superconducting state by controlling the heater portion; a heater network configured in parallel with the quench protection switch, the heater network being in thermal contact with each of the superconducting coils; The quench of any one of the superconducting coils activates the switch heater coupled thereto, and the activated switch heater triggers the quench of the quench protection switch; and The quench of the quench protection switch activates the heater network to trigger a quench of all remaining superconducting coils.

2. The quench protection system according to claim 1, characterized in that: The heater network includes a plurality of heaters connected in parallel, wherein each superconducting coil is in thermal contact with at least one of the heaters.

3. The quench protection system according to claim 1, characterized in that: The heater network includes a plurality of heaters connected in series, wherein each superconducting coil is in thermal contact with at least one of the heaters.

4. The quench protection system according to claim 1, characterized in that: The heater network includes a plurality of heaters connected in parallel and a plurality of heaters connected in series, wherein each superconducting coil is in thermal contact with at least one of the heaters.

5. The quench protection system according to claim 1, characterized in that: The heater network includes a single heater, wherein each superconducting coil is in thermal contact with the single heater.

6. The quench protection system according to claim 1, characterized in that: Also included is a voltage clamping device across the heater network.

7. The quench protection system according to claim 1, characterized in that: Also included is a shielding coil applied to the quench protection switch to accelerate the quenching of the heater network.

8. A superconducting generator comprising: a plurality of superconducting excitation coils arranged in series; The quench protection system further comprises: at least one switching heater electrically coupled across each of the superconducting field coils; a quench protection switch configured to be connected in series with the superconducting excitation coil, each of the switch heaters being in thermal contact with the quench protection switch, the quench protection switch comprising a superconducting switch having a superconducting wire portion and a heater portion, wherein the wire portion is switched between a resistive state and a superconducting state by controlling the heater portion; a heater network configured to be connected in parallel with the quench protection switch, the heater network being in thermal contact with each of the superconducting excitation coils; enabling the quench of any one of the superconducting excitation coils to activate the switch heater coupled thereto, and the activated switch heater to trigger the quench of the quench protection switch; and The quench of the quench protection switch activates the heater network to trigger the quench of all remaining superconducting excitation coils.

9. The superconducting generator according to claim 8, characterized in that: The heater network includes a plurality of heaters connected in parallel, wherein each superconducting field coil is in thermal contact with at least one of the heaters.

10. The superconducting generator according to claim 8, characterized in that: The heater network includes a plurality of heaters connected in series, wherein each superconducting field coil is in thermal contact with at least one of the heaters.

11. The superconducting generator according to claim 8, characterized in that The heater network includes a plurality of heaters connected in parallel and a plurality of heaters connected in series, wherein each superconducting field coil is in thermal contact with at least one of the heaters.

12. The superconducting generator according to claim 8, characterized in that: The heater network includes a single heater, wherein each superconducting field coil is in thermal contact with the single heater.

13. The superconducting generator according to claim 8, characterized in that Also included is a voltage clamping device across the heater network.

14. The superconducting generator according to claim 8, characterized in that Also included is a shielding coil applied to the quench protection switch to accelerate the quenching of the heater network.

15. The superconducting generator according to claim 8, characterized in that: The superconducting generator is a wind turbine generator.

16. A wind turbine power generation system comprising: tower; a hub, and a plurality of blades connected to the hub; a rotor connected to the hub; a superconducting generator coupled to the rotor, the superconducting generator further comprising: a plurality of superconducting excitation coils arranged in series; The quench protection system further comprises: at least one switching heater electrically coupled across each of the superconducting field coils; a quench protection switch configured to be connected in series with the superconducting excitation coil, each of the switch heaters being in thermal contact with the quench protection switch, the quench protection switch comprising a superconducting switch having a superconducting wire portion and a heater portion, wherein the wire portion is switched between a resistive state and a superconducting state by controlling the heater portion; a heater network configured to be connected in parallel with the quench protection switch, the heater network being in thermal contact with each of the superconducting excitation coils; enabling the quench of any one of the superconducting excitation coils to activate the switch heater coupled thereto, and the activated switch heater to trigger the quench of the quench protection switch; and The quench of the quench protection switch activates the heater network to trigger the quench of all remaining superconducting excitation coils.

Images