WO2010054365A2

WO2010054365A2 - System and methods for magnetic induction power generation for powering elements in high temperature rotating systems

Info

Publication number: WO2010054365A2
Application number: PCT/US2009/063847
Authority: WO
Inventors: David Patrick Arnold; Shuo Cheng
Original assignee: University Of Florida Research Foundation, Inc.
Priority date: 2008-11-10
Filing date: 2009-11-10
Publication date: 2010-05-14
Also published as: WO2010054365A3

Abstract

Magnetic induction power generation systems in high temperature rotating systems are disclosed. In an embodiment, the subject power generation system can provide power to embedded sensors in gas turbines or other high temperature rotating systems. A magnetic array can be disposed on a stationary portion of the gas turbine and a coil can be disposed on a rotating portion of the gas turbine to provide power to a sensor disposed on the rotating portion.

Description

DESCRIPTION

SYSTEM AND METHODS FOR MAGNETIC INDUCTION POWER GENERATION FOR

POWERING ELEMENTS IN HIGH TEMPERATURE ROTATING SYSTEMS

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims the benefit of U.S. Provisional Application Serial No. 61/112,977, filed November 10, 2008, which is hereby incorporated by reference in its entirety, including any figures, tables, or drawings.

BACKGROUND OF THE INVENTION

Providing power to devices within a high temperature rotating system can be difficult due to the harsh environment and rotating parts. However, it has become important to embed or locate sensors and other such devices within a rotating system for optimization, diagnostics, and maintenance. For example, wireless sensors are often embedded within gas turbines to monitor activity within the gas turbine. The power generation elements used to power the sensors can be difficult to provide in the high temperature rotational systems, not only because of the temperatures, but because moving parts make wiring a challenge.

Currently, batteries are used to provide power to sensors and other devices in the rotational systems. However, batteries have a short lifespan and require frequent replacement, which can be difficult and/or expensive.

Therefore, to be able to power rernotely-located wireless devices, energy harvesting technologies are being researched.

Accordingly, there is a need in the art for an energy harvesting technology that can power remotely-located sensors or other devices located within a rotating system while withstanding high temperatures.

BRIEF SUMMARY

Embodiments of the present invention relate to power generation using energy harvesting technologies to provide power to embedded devices in high temperature rotating systems. The present invention provides magnetic induction techniques that can be utilized in high temperature rotating systems. According to one embodiment, the magnetic induction between an array of high temperature permanent magnets and a planar coil is used to generate power for embedded sensors on a rotating system such as a gas or steam turbine. The magnets can be affixed to a stationary portion within the turbine and a coil can be attached to the rotating portion having the sensors. During turbine operation, as the coil passes the magnets, the time-varying magnetic field induces a voltage onto the coil and can be used to generate power to an electrical load. Accordingly, it is possible to generate power for wireless sensors disposed in turbine engines and other rotating systems.

Advantageously, the coil can be provided at a rotating part of the system while a magnet array is provided at a stationary part of the system. Therefore, power can be provided to devices on the rotating portion of a system.

BRIEF DESCRIPTION OF THE DRAWINGS

Figures IA and IB show a magnetic induction system and flux-voltage relationship plots, respectively.

Figures 2A-2C show electromagnetic fields according to magnet polarity for (a) alternating poles; (b) opposing poles; and (c) Halbach configuration.

Figure 3 shows a plot of flux density versus displacement for the magnet configurations of Figures 2A-2C. Figures 4A and 4B show a representation of a magnetic induction power generation system for a rotating system according to an embodiment of the present invention.

Figures 5A-5C show plots indicating characteristics of a magnetic induction power generation system for a rotating system according to an embodiment of the present invention.

Figure 5A is a plot of flux density versus displacement: Figure 5B is a plot of voltage over time; and Figure 5C is a plot of RJVlS Voltage of a single turn coil verses gap space between the coil and the magnets.

Figures 6A-6E show magnet/coil spacing configurations for a magnetic induction power generation system for a rotating system according to embodiments of the present invention. Figures 7 A and 7B show a representation of a magnetic induction power generation system for a rotating system according to an embodiment of the present invention.

Figures 8A and 8B show plots indicating RMS Voltage and Power generation performance, respectively, for a magnetic induction power generation system for a rotating system according to an embodiment of the present invention based on gap spacing between the magnets and the coil.

Figures 9A and 9B show plots indicating RMS Voltage and Power generation performance, respectively, based on rotation speed for a magnetic induction power generation system for a rotating system according to an embodiment of the present invention.

Figure 10 shows a relationship between magnet geometry and voltage adjustment according to an embodiment of the present invention.

Figure 11 shows a relationship between spacing/magnet location and voltage adjustment according to an embodiment of the present invention. Figure 12 shows a block diagram of a magnetic induction power generation system according to an embodiment of the present invention.

DETAILED DISCLOSURE Embodiments of the present invention relate to magnetic induction power generation for powering sensors in high temperature environments having rotating structures. System configurations and methods of magnetic power generation are provided.

When the terms "on" or "over" are used herein, when referring to layers, regions, patterns, or structures, it is understood that the layer, region, pattern or structure can be directly on another layer or structure, or intervening layers, regions, patterns, or structures may also be present. When the terms "under" or "below" are used herein, when referring to layers, regions, patterns, or structures, it is understood that the layer, region, pattern or structure can be directly under the other layer or structure, or intervening layers, regions. patterns, or structures may also be present.

In addition, when the terms such as "first" and "second" are used to describe members, the members are not limited by these terms. For example, a plurality of members may be provided. Therefore, when terms such as '"first^1" and "second" are used, it will be apparent that the plurality of such members may be provided. In addition, the terms "first" and "second" can be selectively or exchangeably used for the members. In the figures, a dimension of each of the elements may be exaggerated for clarity of illustration, and the dimension of each of the elements may be different from an actual dimension of each of the elements. Not all elements illustrated in the drawings must be included and limited to the present disclosure, but the elements except essential features of the present disclosure may be added or deleted. The figures and descriptions of embodiments of the present invention have been simplified to illustrate elements that arc relevant for a clear understanding of the invention, while eliminating, for purposes of clarity, other elements that may be well known. Those of ordinary skill in the art will recognize that other elements may be desirable and/or required in order to implement the present invention. However, because such elements are well known in the art, and because they do not facilitate a better understanding of the present invention, a discussion of such elements is not provided herein.

According to embodiments of the present invention, power generation is accomplished in high temperature rotating systems using magnetic induction techniques. In one embodiment, the subject power generation system can power embedded sensors in gas turbines.

Electromagnetic induction can be used to generate power by the generation of magnetic field and flux between magnets (see e.g. magnetic array 10 of Figure IA) and a wire coil (see e.g. reference 11 of Figure IA). Figures IA and IB illustrate this basic theory. A voltage can be generated from a magnetic flux created by the coil 11 in the presence of a fluctuating magnetic field. This relationship is given by the following equations:

_{Λ T} dΦ , _rc, dB . _τa dθ dB .

V = -N = -NS — = -NS . and dt dt dt dθ ^'

Φ = BS , where V is the voltage given at the transformer connected to the coil, which changes over time /; Φ is the magnetic flux, which changes over time t; N is the number of turns of the coil; S is the surface area of the loop; and B is the magnetic flux density.

In addition to the alternating poles (S, N) of the magnetic array 10 shown in Figure

IA, other magnetic array configurations can be utilized for various implementations of the invention. Figure 2 illustrates three magnetic arrays: (a) alternating poles; (b) opposing poles; and (c) Halbach. The Halbach array is a particular magnetic array incorporating alternating and opposing poles. The Halbach array augments the magnetic field on one side and cancels the field to near zero on the other side. Figure 3 shows the flux density profile of the three different magnetic arrays. As indicated by Figure 3, the opposing poles configuration and the alternating poles configuration provide a similar flux density profile across the magnetic array, while the Halbach configuration provides larger flux density amplitude. With the generated voltage being proportional to the magnetic flux density and power being proportional to the voltage squared, the power available from the magnetic arrays is proportional to the magnetic flux density squared (i.e., V ∞ B, P <x V² => P ∞ B²).

Accordingly, the Halbach magnetic array configuration can be used to provide more power than the purely alternating and the purely opposing configurations.

Figures 4A and 4B show a schematic representation of a magnetic induction power generation system that can be used in a gas turbine in accordance with one embodiment of the present invention. A magnetic array 20 can be disposed on a stationary, or stator, portion of the turbine, and a coil 21 can be disposed on a rotating portion of the turbine. For example, the coil 21 can be disposed on a blade of the turbine. Using this configuration, devices, such as sensors, on the blade can be powered through their connection to the coil. As described above, the magnetic flux induced in the coil 21 due to the electromagnetic fields created by the magnet array 20 generates power that can be used by devices attached to the coil.

Referring to Figure 4A, the magnet array 20 can be a Halbach array with magnet polarities shown as being into the page (® ), out of the page ( • ), left (<— ), and right (→). The coil can be a single turn square coil, but embodiments are not limited thereto. For example, the coil may be a single turn circular coil, rectangular coil, or hexagonal coil. Figure 4B shows a cross-sectional view, where the magnets 20 are disposed on the stationary side and the single turn square coil 21 is disposed on the rotating side. In a specific embodiment, a side length of the coil has the same length as the length of a magnet of the magnet array. In addition, a bottom side of the coil can have a longer length than the width of the magnet of the magnet array.

Figures 5A-5C show plots indicating performance estimations for the design shown in

Figures 4A and 4B. In particular, for a Halbach array using 24 mm x 10 mm x 10 mm magnets and a single turn square coil (American Wire Gage (AWG) of 33) sized 24 mm x 24 mm, the RMS voltage (V_ms ) is given as 0.26 V for a gap of 13.5 mm and the coil resistance

(Rcoii) is given as 61 mΩ (at 450 ⁰C). Thus the average power (P_avg) is 277 mW based on the following equation: p _ V ^γ R²MS a^vg 4R It should be noted that the simulations may not reflect values of actual designs.

However, experimental results indicate corresponding characteristics and trends. Referring to Figure 5C, as the gap between the magnet array and the coil becomes larger, the induced voltage decreases. Accordingly, the strength of the magnetic induction depends on the gap between a magnet of the magnet array and the coil. As indicated by the plot in Figure 5C, the smaller the gap, the higher the voltage generated. The gap can be set to be a distance suitable for a higher voltage generation while providing space for exhaust or air to pass through the turbine. Of course, smaller gaps can be provided in applications requiring less space between the stationary side and the rotating side. Accordingly, in one embodiment, the gap is set to be between about 1 mm and about 25 mm. In one implementation, the gap is between 3 mm and 15 mm. In another implementation, the gap is between 2 mm and 7 mm. The gap spacing can be accomplished using particular sized magnets and/or spacers.

Figures 6A-6E illustrate configurations that can be used to ensure an appropriate gap between the magnets 30 and the coil 31. Referring to Figure 6A, in one embodiment, a spacer 32 can be disposed between the magnets 30 of the magnet array and a surface of the stationary side, while the coil 31 is disposed on a surface of the rotation side. Referring to Figure 6B, in another embodiment, spacers can be omitted and the thickness (U) of the magnets of the magnet array can be selected in order to provide sufficiently close spacing between the magnets 30 and the coil 31. For example, in one embodiment where a magnet would have a first thickness of U and a spacer 32 would have a second thickness of t₂. the spacer 32 can be omitted and the thickness t₃ of the magnet 30 can be selected to be ti + t₂. Of course, embodiments are not limited thereto. Referring to Figure 6C, in yet another embodiment, a spacer 33 is disposed between the coil 31 and a surface of the rotation side, while the magnets 30 of the magnet array are disposed on a surface of the stationary side. Referring to Figure 6D, the spacing between the rotation side and stationary side can be utilized without additional modification to the gap between the sides such that the magnets 30 are disposed on the surface of the stationary side and the coil 31 is disposed on the surface of the rotation side. Referring to Figure 6E. a first spacer 34 can be disposed between the magnets 30 of the magnet array and a surface of the stationary side and a second spacer 35 can be disposed between the coil 31 and a surface of the rotation side. In certain embodiments, such configurations can be implemented to retro-fit existing turbines. In other embodiments, the magnets 30 and coil 31 can be embedded in the sidewall surfaces of the structure.

Figures 7A and 7B show a schematic representation of a magnetic induction power generation system that can be used in a gas turbine according to an embodiment of the present invention. A magnetic array 40 can be disposed on a stationary, or stator, portion of the turbine, and a coil 41 can be disposed on a rotating portion of the turbine. For example, the coil 41 can be disposed on a blade root of the turbine. Using this configuration, devices, such as sensors, on the blade can be powered through their connection to the coil. As described above, the magnetic flux induced in the coil 41 due to the electromagnetic fields created by the magnet array 40 generates power that can be used by devices attached to the coil. Referring to Figure 7A, the magnet array 40 can be a Halbach array with magnet polarities shown as being into the page (® ). out of the page (• ), left (•*—), and right (→). The coil 41 can be a multi-turn planar spiral coil. The multi-turn coil can have 2 or more spiral turns. In one embodiment, the coil has 5 spiral turns. In further embodiments, the coil has 6 or more spiral turns. The number of turns and surface area of the coil can be selected to affect the generated power in accordance with the mathematical relationships described above. Figure 7B shows a cross-sectional view, where the magnets 40a are disposed on the stationary side and the multi-turn planar spiral coil 41a is disposed on the rotating side. In a specific embodiment, a side length of the planar coil has the same length as the length of a magnet of the magnet array. In another embodiment, the side length of the planar coil has a larger length than the length of the magnet of the magnet array. In addition, a bottom side of the coil can have a longer length than the width of the magnet of the magnet array.

For a Halbach array using 24 mm x 10 mm x 10 mm magnets and a multi-turn planar spiral coil (AWG 33) sized 24 mm x 24 mm and spaced apart with a 13.5 mm gap, the RMS voltage (V_mis) is given as 8.49 V and the average power (P_aVg) is given as 8.2 W.

Figures 8A and 8B show plots indicating performance estimations for the design of Figures 7A-7B based on gap spacing between the magnets and the coil. Simulations for the gap range of 25 mm and less are provided. Referring to Figure 8Λ, as the gap between the magnet array and the coil becomes larger, the induced voltage (RMS voltage) decreases. In addition, referring to Figure 8B, as the gap between the magnet array and the coil becomes larger, the power generated from the planar spiral coil decreases. Accordingly, the strength of the magnetic induction depends on the gap between a magnet of the magnet array and the coil. In one embodiment, the gap can be set to be between 25 mm and about 1 mm. In another embodiment, the gap can be set to between 1 mm and 15 mm. In yet another embodiment, the gap can be set to between 10 mm and 20 mm. Of course, smaller gaps or can be provided in applications requiring less space between the stationary side and the rotating side and larger gaps can be provided in applications utilizing stronger magnets. Figures 9A and 9B show plots indicating RMS Voltage and Power generation performance, respectively, for the design of Figures 7A-7B based on rotation speed of the rotating system. As shown in Figure 9A, as the rotation speed increases, the RMS voltage increases. Referring to Figure 9B, it can be seen that the power generation capabilities increase exponentially as the rotation speed of the system increases.

As described above, according to embodiments of the present invention, power and voltage of the power generation system can be adjusted through adjusting the number of turns of the coil, the speed of the system, and/or the gap between the magnets and the coil. In further embodiments, the magnet array can be modified to further control power and voltage of the power generation system.

For example, referring to Figure 10. the thickness and length of the magnets can be adjusted. Λ reduced magnet thickness or length can reduce the generated electric field, and thus, the induced voltage.

Referring to Figure 11, frequency and duty cycle can be adjusted by modifying the arrangement of the magnets of the magnet array instead of modifying the rotating properties of the rotating system. The adjustments to frequency and duty cycle can be particularly useful in turbine engines or other rotating systems where the rotation of the system is set to a particular speed for the applications required of the system. According to an embodiment, the frequency can be adjusted by creating a sparse IIalbach array configuration where the magnets of the array are spaced apart from each other about the stationary portion of the rotating system (see top configuration of Figure 11). The sparse Halbach array can provide a decreased electric field, voltage, and frequency.

In an embodiment, the duty cycle can be adjusted by utilizing partial coverage of the stationary portion of the rotating system. As a coil disposed at a rotating side moves around the stationary portion, voltage can be induced in the coil at regions having the magnet array.

For example, a 50% duty cycle can be accomplished by positioning the magnet array to cover half the stationary portion.

Although certain embodiments are described utilizing planar coils or multi-turn coils, the invention is not limited thereto. For example, in yet another embodiment, the coil can be a solenoid coil.

In certain applications, the subject magnetic power generation system can be retrofitted into current engines to supply power to embedded sensors in the engines. As described above, positioning of the magnet array can be used to modify frequency and duty cycle irrespective of engine system constraints. In addition, proper spacings can be accomplished using spacers at the magnet side, the coil side, or both the magnet side and coil side.

In other applications, the power generation elements can be embedded during manufacturing (and design) of the engine into the stator and rotational parts. In one embodiment, the coil(s) can be disposed on a blade or rotating component using "direct- write" technologies.

It can be difficult to incorporate permanent magnets in the harsh, high temperature environment of a turbine engine. Previous magnetic power induction designs have not been directed to use in high temperature systems, in part because of the known difficulty of permanent magnets to function properly at high temperatures. In certain embodiments of the present invention, high temperature magnetic materials are utilized to provide the permanent magnets of the magnet array. For example, ultra high temperature samarium cobalt (SmCo) magnets can be utilized. In particular, the ultra high temperature SmCo magnets have currently indicated maximum operational temperatures between 400 ⁰C and 550 ⁰C.

In further embodiments, soft magnets can be utilized. For example, portions of the stationary portion of the high temperature rotating system can include materials that create a magnetic field when current is applied. The soft magnets can be arranged in addition to the permanent magnets. In one embodiment, the rotating system includes materials exhibiting "soft'^" magnetic properties. For example, regions of the rotating system can include iron or iron alloys. The regions having soft magnetic properties can be disposed behind the permanent magnets and/or coils. The soft magnets can be used to improve temperature sensitivity of the voltage generation.

According to an embodiment of the present invention, the subject coil is connected to elements in high temperature rotating systems to provide power to the elements. For example, where the element in the high temperature rotating system is a sensor, the coil may be physically attached to the sensor. In another embodiment, the coil can be connected to power or rectification electronics of a system for providing power for the elements in the high temperature rotating system. For example, referring to Figure 12, mechanical to electrical induction occurs between magnets 50 on the stator side and a coil 51 on the rotor side. The coil 51 is connected to power electronics 52 (such as rectification electronics and voltage regulators) to provide power generation for devices, such as a sensor 53, on the rotor. In one embodiment, the power electronics 52 can supply power to a wireless sensor module on the rotor. In a specific embodiment, AC power is provided from the coil 51 to the power electronics 52, which converts the AC power from the coil to DC power, for signal processing 54 and wireless transmitter 55 circuits connected to a sensor 53 on a rotor. The sensor 53 may also be connected to receive DC power from the power electronics 52. In one implementation, the coil 51 is disposed on a high-temperature compatible circuit board where the coil is connected to the power conditioning electronics 52.

Accordingly, power can be provided to devices on a rotating portion of a system.

In accordance with certain embodiments of the present invention, a system for powering sensors in a high temperature rotating system is provided that includes a coil disposed at a rotating portion of the high temperature rotating system, the coil being connected to at least one sensor disposed at the rotating portion; and an array of magnets disposed at a stationary portion of the high temperature rotating system. The system can further include power electronics receiving a signal from the coil to condition the signal and supply the conditioned signal to the at least one sensor. The coil can be connected to the at least one sensor through the power electronics.

In the system, the array of magnets can be arranged having a Halbach array configuration. In one embodiment, the array of magnets is disposed about an entire circumference of the stationary portion. In another embodiment, the array of magnets is disposed about a circumference of the stationary portion, wherein adjacent magnets of the array of magnets are spaced apart from each other. In yet another embodiment, the array of magnets are disposed about a circumference of the stationary portion, wherein adjacent magnets of the array of magnets are in contact. The array of magnets may be disposed about a portion of a circumference of the stationary portion. The portion of a circumference of the stationary portion can be about half the circumference, less than half the circumference, or more than half the circumference.

In the system, the coil can be a multi-turn planar spiral coil. A side length of the coil can have a same length as the length of a selected magnet of the plurality of magnets or a larger length than the length of a selected magnet of the plurality of magnets. In one embodiment, a bottom side length of the coil has a larger length than the width of a selected magnet of the plurality of magnets. In an alternative embodiment, the coil can be a solenoid coil.

In accordance with certain embodiments of the present invention, a method for powering sensors in a high temperature rotating system is provided that includes mounting permanent magnets and coils in the high temperature rotating system; and using magnetic induction for powering the sensors disposed in the high temperature rotating system. The sensors can be disposed at a rotating portion of the high temperature rotating system, and the mounting of the permanent magnets and the coils can include disposing a coil at the rotating portion and coupled to at least one of the sensors at the rotating portion; and mounting the permanent magnets about a surface of a stationary portion of the high temperature rotating system.

In one embodiment, the coil is directly connected to the at least one of the sensors at the rotating portion. In another embodiment, the coil is coupled to the at least one of the sensors at the rotating portion through power conditioning electronics to provide a conditioned power supply signal to the at least one of the sensors at the rotating portion. The permanent magnets may be mounted in a Halbach array configuration.

A gap between the coil and the permanent magnets can be adjusted by, for example, inserting a spacer between a surface of the rotating portion and the coil, inserting spacers between the surface of the stationary portion and the permanent magnets, or selecting a thickness of the magnets.

In the method, the frequency of the magnetic field between the coil and permanent magnets can be adjusted. Adjusting the frequency of the magnetic field can include adjusting a spacing distance between adjacent permanent magnets. In the method, the duty cycle of the magnetic filed between the coil and permanent magnets can be adjusted. Adjusting the duty cycle of the magnetic field can include mounting the permanent magnets about an entire circumference of the stationary portion and mounting the permanent magnets about only a portion of a circumference of the stationary portion. In further embodiments, soft magnet regions are incorporated in the high temperature rotating system. The soft magnet regions can include iron or iron alloys. The soft magnet regions may be located behind the permanent magnets on the stator side.

Any reference in this specification to "one embodiment," "an embodiment," "example embodiment," etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to effect such feature, structure, or characteristic in connection with other ones of the embodiments.

All patents, patent applications, provisional applications, and publications referred to or cited herein are incorporated by reference in their entirety, including all figures and tables, to the extent they are not inconsistent with the explicit teachings of this specification.

It should be understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and arc to be included within the spirit and purview of this application. In addition, any elements or limitations of any invention or embodiment thereof disclosed herein can be combined with any and/or all other elements or limitations (individually or in any combination) or any other invention or embodiment thereof disclosed herein, and all such combinations are contemplated with the scope of the invention without limitation thereto.

Claims

CLAIMSWe claim:

1. A method for powering sensors in a high temperature rotating system, comprising: mounting permanent magnets and coils in the high temperature rotating system; and using magnetic induction for powering the sensors disposed in the high temperature rotating system.

2. The method according to claim 1, wherein the sensors are disposed at a rotating portion of the high temperature rotating system, wherein mounting the permanent magnets and the coils comprises: disposing a coil at the rotating portion and coupled to at least one of the sensors at the rotating portion; and mounting the permanent magnets about a surface of a stationary portion of the high temperature rotating system.

3. The method according to claim 2, wherein the coil is directly connected to the at least one of the sensors at the rotating portion.

4. The method according to claim 2, wherein the coil is coupled to the at least one of the sensors at the rotating portion through power conditioning electronics to provide a conditioned power supply signal to the at least one of the sensors at the rotating portion.

5. The method according to claim 2, wherein the permanent magnets are mounted in a Halbach array configuration.

6. The method according to claim 2, further comprising adjusting a gap between the coil and the permanent magnets.

7. The method according to claim 6, wherein adjusting the gap between the coil and the permanent magnets comprises inserting a spacer between a surface of the rotating portion and the coil.

8. The method according to claim 6, wherein adjusting the gap between the coil and the permanent magnets comprises inserting spacers between the surface of the stationary portion and the permanent magnets.

9. The method according to claim 6, wherein adjusting the gap between the coil and the permanent magnets comprises selecting a thickness of the magnets.

10. The method according to claim 2, further comprising adjusting frequency of the magnetic field between the coil and permanent magnets.

11. The method according to claim 10, wherein adjusting the frequency of the magnetic field comprises: adjusting a spacing distance between adjacent permanent magnets.

12. The method according to claim 2, further comprising adjusting duty cycle of the magnetic field between the coil and permanent magnets.

13. The method according to claim 12, wherein adjusting the duty cycle of the magnetic field comprises mounting the permanent magnets about an entire circumference of the stationary portion.

14. The method according to claim 12, wherein adjusting the duty cycle of the magnetic field comprises mounting the permanent magnets about only a portion of a circumference of the stationary portion.

15. The method according to claim 1, further comprising including soft magnet regions in the high temperature rotating system.

16. A system for powering sensors in a high temperature rotating system, comprising: a coil disposed at a rotating portion of the high temperature rotating system, the coil being connected to at least one sensor disposed at the rotating portion; and an array of magnets disposed at a stationary portion of the high temperature rotating system.

17. The system according to claim 16, further comprising power electronics receiving a signal from the coil to condition the signal and supply the conditioned signal to the at least one sensor, wherein the coil is connected to the at least one sensor through the power electronics.

18. The system according to claim 16, wherein the array of magnets are arranged having a IIalhach array configuration.

19. The system according to claim 16, wherein the array of magnets are disposed about an entire circumference of the stationary portion.

20. The system according to claim 16, wherein the array of magnets are disposed about a circumference of the stationary portion, wherein adjacent magnets of the array of magnets are spaced apart from each other.

21. The system according to claim 16, wherein the array of magnets are disposed about a circumference of the stationary portion, wherein adjacent magnets of the array of magnets are in contact.

22. The system according to claim 16. wherein the array of magnets are disposed about a portion of a circumference of the stationary portion.

23. The system according to claim 22, wherein the portion of a circumference of the stationary portion is about half the circumference.

24. The system according to claim 22, wherein the portion of a circumference of the stationary portion is less than half the circumference.

25. The system according to claim 22. wherein the portion of a circumference of the stationary portion is more than half the circumference.

26. The system according to claim 22, wherein the coil comprises a multi-turn planar spiral coil.

27. The system according to claim 26, wherein a side length of the coil has a same length as the length of a selected magnet of the plurality of magnets.

28. The system according to claim 26, wherein a side length of the coil has a larger length than the length of a selected magnet of the plurality of magnets.

29. The system according to claim 26, wherein a bottom side length of the coil has a larger length than the width of a selected magnet of the plurality of magnets.

30. The system according to claim 16, wherein the coil comprises a solenoid coil.