Transverse hydroelectric generator Number:7,088,012 from the United States Patent and Trademark Office (PTO) owispatent A power plant extracts energy from a free flowing motive fluid by means of a transverse mounted generator with its rotor extending downward into the flow. Runner blades with hinges attain the greatest surface area when the flow is tangent to and in the same direction as the rotor rotation. The hinges fold the runner blades to minimize the surface area proportional to drag when the blades oppose the flow. The generator with feedback control charges batteries, produces hydrogen fuel by electrolysis of water, or further couples to a DC motor coupled to an AC generator. Other features optionally perform such tasks as adaptively locating the generator in the maximum velocity flow, controlling and communicating the state of charge of the battery, or gauging and controlling the electrolysis process and communicating the fullness of the hydrogen gas output tanks.<H hydroelectric, Transverse, Transverse, hydr, 7088012.html, Patent, pto, 7088012

Title: Transverse hydroelectric generator

Abstract: A power plant extracts energy from a free flowing motive fluid by means of a transverse mounted generator with its rotor extending downward into the flow. Runner blades with hinges attain the greatest surface area when the flow is tangent to and in the same direction as the rotor rotation. The hinges fold the runner blades to minimize the surface area proportional to drag when the blades oppose the flow. The generator with feedback control charges batteries, produces hydrogen fuel by electrolysis of water, or further couples to a DC motor coupled to an AC generator. Other features optionally perform such tasks as adaptively locating the generator in the maximum velocity flow, controlling and communicating the state of charge of the battery, or gauging and controlling the electrolysis process and communicating the fullness of the hydrogen gas output tanks.

Patent Number: 7,088,012 Issued on 08/08/2006 to Gizara

Inventors: Gizara; Andrew Roman (Lake Forest, CA)
Appl. No.: 10/905,195

Filed: December 21, 2004

Current U.S. Class: 290/43

Current International Class: F03B 7/00 (20060101)

References Cited [Referenced By]

U.S. Patent Documents


2717352	September 1955	Ribner
3604942	September 1971	Nelson
4142832	March 1979	Clifton
4613760	September 1986	Law
4994684	February 1991	Lauw et al.
5083899	January 1992	Koch
5476293	December 1995	Yang
5512787	April 1996	Dederick
6037749	March 2000	Parsonage
6104097	August 2000	Lehoczky
6608397	August 2003	Makino et al.
6670721	December 2003	Lof et al.
6674263	January 2004	Agbossou et al.
6682302	January 2004	Noble
6841893	January 2005	Maiwald et al.
6954004	October 2005	Skeist et al.

Primary Examiner: Waks; Joseph

Claims

What is claimed is:

1. An apparatus of power generation having an impeller which responds to a free flowing motive fluid flowing transverse to the rotor of said apparatus wherein: said impeller mechanically or electro-mechanically or electronically instantaneously adjusts its response to the varying kinetic energy contained in said motive fluid by means of converting said varying kinetic energy to electrical potential for feedback control of withstanding torque on said impeller to avert fatigue on said impeller, said feedback control scales said electrical potential to produce constant voltage for a constant load such as an electrolyzer or a charging battery while simultaneously limiting said withstanding torque to avert fatigue on said impeller over said varying kinetic energy levels of said motive fluid, said electrical potential is scaled within a DC generator by controlling the average field coil excitation current determined by voltage feedback from across the armature winding.

2. The apparatus of claim 1 wherein said free flowing motive fluid is seawater, said seawater is affected by natural or man-made rises in elevation of the ocean floor or any other constriction of the free flow, said elevation or constriction breaks oceanic wave motion such that the wave or tidal energy is transferred into accelerating the water itself, said generator extracts energy from the force of said accelerated water.

3. The apparatus of claim 1 wherein said motive fluid is a free flowing body of water in any form including but not limited to rivers, creeks, inlets, tidal bores, rapids, or waterfalls.

4. The apparatus of claim 1 wherein: said impeller is submerged within the motive fluid, said generator is not submerged within the motive fluid.

5. The apparatus of claim 1 wherein said impeller has a hinge which closes to reduce the runner blade surface area thus reducing drag when the impeller rotates into the direction of said free flowing motive fluid.

6. The apparatus of claim 5 wherein said hinged runner blade has a cupped profile that enables extraction of both impulse force of the impinging motive fluid and reaction force after the motive fluid flows along the surface of said runner blade.

7. The apparatus of claim 1 wherein said impeller has a conic shape with a curvature to change both direction and magnitude of the velocity of flow as it impinges the impeller internal surface enabling extraction of both impulse and reaction forces from said motive fluid.

8. The apparatus of claim 7 wherein said impeller curvature directs said flow towards barrages along the trajectory of the impeller to increase trust.

9. The apparatus of claim 1 wherein said generator system is mounted to a short rail system so that the location of the apparatus can be adaptively located to an optimal location such as the onshore side of the breaking waves, or the location of highest velocity flow in any body of water.

10. The apparatus of claim 9 wherein said location of the apparatus along said rail system is determined by a means of sensing the depth of said apparatus using fluid level sensors mounted at varying heights within the support structure of said apparatus.

11. The apparatus of claim 9 wherein said location of the apparatus along said rail system is determined by an electronic microprocessor system with an almanac in memory indicating tide level and/or relative mean location of the breaking waves with respect to the rail at any given time.

12. The apparatus of claim 9 wherein adjustment of location of the apparatus along said rail system is performed by: means of a singular DC stepper motor with rotor output shaft affixed to, or forged or cast into a beveled pinion, said beveled pinion meshes with a bi-directional anti-backlash and position locking mechanism propelled by a spring loaded solenoid operating synchronously to said DC stepper motor, said beveled pinion synchronously meshing to a gear driving an axel which in turn drives a gear that meshes to a rack gear mounted on said rails.

13. The apparatus of claim 1 wherein said average field coil excitation current is controlled using means of switch mode current control.

14. The apparatus of claim 1 wherein said voltage feedback control system is implemented using means of digital sampling techniques.

15. The apparatus of claim 1 wherein said charging of a battery, including gauging and communicating the fullness of the battery is controlled by an electronic microprocessor.

16. The apparatus of claim 1 wherein said process of electrolysis of water to produce hydrogen fuel, including gauging and communicating the fullness of the output gas tanks is controlled by an electronic microprocessor.

17. The apparatus of claim 16 wherein said hydrogen electrolyzer has an anode or a plurality of anodes comprising manganese dioxide plating in order to reduce the formation of sodium chloroxide by-product.

Description

BACKGROUND OF INVENTION

1. Field of the Invention

The present invention is generally in the field of power plants. More specifically, the present invention is in the field of hydrokinetic generators with means to adapt to changes in streamline direction and magnitude of a free flowing motive fluid.

2. Description of Prior Art

For over two thousand years mankind has known of harnessing the kinetic energy in flowing water to perform mechanical endeavors. In the past two hundred years the pace in which developments emerged in the practice of hydraulics has accelerated. The advent of the turbine in the first half of the nineteenth century culminated in the present advancements in hydroelectric generation, with this period of innovation and intense interest peaking in the first quarter of the twentieth century. Since then, fossil fuels have dominated as the high net energy, readily available energy source in the production of electricity and other conveyors of power. With known fossil fuel reserves at what presently appears to be arguably half depleted, as well as the environmental impact of using a polluting energy source, there is a strong need to develop a renewable and sustainable source of energy to support humankind.

Presently the hydroelectric power plant industry earns revenues of approximately thirty billion dollars annually, but unfortunately is in a state of decline mainly due to the environmental and civic costs of implementing the existing technology. Environmental impact of the prior art hydroelectric power plant threatens extinction to aquatic species living downstream from the proposed power plant infrastructure, and also displaces all human inhabitants that live in what would become the flood plane of the infrastructure. It is estimated that over sixty million people have been displaced in the past century due to hydraulic power plant development with no mention of the number of species of plant and animal that have gone extinct. Furthermore, given the prior art technology, there still exists the possibility of life threatening flooding occurring downstream from the site of the hydraulic power plant infrastructure. Overall these costs have weighed heavily in civic planners' decisions in adopting hydroelectric power generation to the point of putting the industry in a state of such decline that leading companies involved in this business are contemplating other areas of endeavor.

Inherent problems in the prior implementation of hydroelectric power generation have exacerbated the present state of declining interest in this technology. The earliest implementation of hydrokinetic systems, commonly known as waterwheels, allowed less impact to the natural flow of the body of water from which these systems drew energy. With the greater efficiency gained by enclosing the impeller within the turbine came the need for more sophisticated penstock arrangements, which included greater infrastructure in the form of dams incurring the majority of the civil and environmental costs. The penstock, gate and impeller arrangements for these systems are physically coupled to sustain a given range of flow velocities and pressures over varying head and load so to maintain required synchronization to the end electrical alternating current output. This requirement imposes on these systems almost exclusive implementation in freshwater systems with large scale infrastructure, increasing impingement on human habitats, and for the most part, neglecting the significant kinetic energy recoverable from one or more of various forms of oceanic flow.

Other prior art exists where the motive fluid is ocean water, but still requires significant infrastructure. In one form, dam like structures known as barrages compel tidal flow to affect a turbine. Some turbines exist that operate in free flow, but do not adapt to changes in direction and have limited capacity, typically less than a kilowatt. In another recently developed form, offshore platform structures behave as pistons on waves at medium depths, in turn pumping a motive fluid through a turbine and then requiring a long distance power cable generally carrying high voltage direct current back to shore, to be further processed. This likely incurs significant maintenance costs for the offshore platforms. Fully implementing this prior technology would likely impede shipping lanes as a farm of these platforms effectively fences the shoreline. This stands as one of several known environmental impacts of this prior technology with others hypothetically existing.

When one amortizes the total amount of energy that goes into building and maintaining a prior art hydroelectric power installation, it becomes obvious that it takes a considerable amount of time before the plant becomes net energy positive, or in other words, the point when the total investment of energy compared to the total recovery of energy is at the breakeven point. As a further example, fossil fuel, not being a renewable resource, requires mining or drilling deeper and pumping farther to obtain a lower yield and lower quality of fuel incurring more costly refining to recover the remaining reserves at the end-of-life of a mine or a well. Thus, fossil fuel as an energy source clearly diminishes in net energy as time goes on, until it obviously becomes a sink, no longer a source. This latter example reinforces the inevitability of mankind's undeniable need for a sustainable and renewable source of energy. Contemplating the net energy curves of a renewable energy source and fossil fuel indicates a sense of urgency for the development of a renewable source. The timing of the crossover point of when one source becomes net energy positive as the other becomes net energy negative will dictate the severity of the ensuing energy crisis and thus the impact on humanity. As time goes on it will be less likely an option to expend a great deal of energy as an investment while more mundane needs are no longer being met. Despite this sense of urgency in the need to develop renewable, sustainable sources of energy, as previously stated hydroelectric power plant development is actually declining.

Therefore, there exists a fundamental need for developing renewable and sustainable sources of energy including further exploitation of readily available known resources. More specifically, there exists a need for a novel approach to ensure low impact to environment and low civic infrastructure costs such that the energy investment return is most quickly realized. Utmost, to optimally exploit oceanic energy, such as that which arrives onshore, adaptability to inherently unsteady flow is prerequisite of any such system. A system that can achieve the above-specified goals would readily attain a relatively high net energy soon after its inception.

SUMMARY OF INVENTION

The present invention achieves the goals of overcoming existing limitations of present day hydroelectric power generation systems by foremost having the ability to extract power from a free flowing fluid. While prior art exists which functions in free flowing bodies of water, the novelty of this invention lies in its ability to respond and adapt to any change in the magnitude and direction of the streamlines of the free flowing motive fluid. This enables this invention to extract energy from breaking ocean waves, presently an untapped but readily available known source of energy.

Secondly, because adapting to change of both magnitude and direction of the streamlines of a free flowing motive fluid formed the basis of the guiding concepts of the present invention; this also avails the present invention the applicability to other bodies of water besides the ocean. Having been conceived for free flowing motive fluid use obviates the prior art's inherent need for large-scale infrastructure and thus eliminates two fundamental disadvantages presently challenging the hydroelectric power industry. The present invention does not require this scale of infrastructure and therefore greatly diminishes the environmental impact while attaining a positive net energy earlier upon implementation.

Overcoming the conceptual need for synchronization to the electric power grid positions the present invention as desirable for implementation in gathering energy for the emerging power conveyance systems, especially hydrogen fuel and fuel cell technology.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 illustrates a general perspective view of an exemplary apparatus in accordance with a preferred embodiment of the present invention.

FIG. 2 illustrates a perspective view of an apparatus of simplified mounting in a fixed position relative to the free flowing motive fluid.

FIG. 3 illustrates a bottom view along the generator rotor in FIG. 1 according to a preferred embodiment of the present invention.

FIG. 4 illustrates a view along the beam orthogonal to the axis of the rotor, cross sections of two positions of the runner blade within the free flowing motive fluid according to an alternate embodiment of the present invention.

FIG. 5 illustrates a perspective view orthogonal to the axis of the rotor, cross sections of two positions of an alternate impeller within the free flowing motive fluid according to one embodiment of the present invention.

FIG. 6 illustrates a perspective view orthogonal to the axis of the rotor, cross sections of two positions of an alternate impeller within the free flowing motive fluid according to one embodiment of the present invention.

FIG. 7 illustrates a perspective view orthogonal to the axis of the rotor, cross sections of two positions of an alternate impeller within the free flowing motive fluid according to one embodiment of the present invention.

FIG. 8 illustrates a perspective view orthogonal to the axis of the rotor, cross sections of two positions of an alternate impeller within the free flowing motive fluid according to one embodiment of the present invention.

FIG. 9 illustrates a perspective view orthogonal to the axis of the rotor, two positions of an alternate impeller within the free flowing motive fluid according to one embodiment of the present invention.

FIG. 10 illustrates a perspective view orthogonal to the axis of the rotor, two positions of an alternate impeller within the free flowing motive fluid according to one embodiment of the present invention.

FIG. 11 illustrates the mounting system affixed to a rail system in accordance to the preferred embodiment.

FIG. 12 illustrates the preferred means of bidirectional anti-backlash and position locking mechanism for the bevel drive gear within the gearbox in FIG. 11.

FIG. 13 illustrates the flowchart for synchronizing the bi-directional anti-backlash and position locking solenoid to the motor, both in FIG. 12.

FIG. 14 represents a schematic view of a DC generator directly coupled to the output shaft of the fluid coupler according to one embodiment.

FIG. 15 illustrates the flowchart for control of the complete system according to the preferred embodiment of the present invention.

DETAILED DESCRIPTION

The present invention is directed to a transverse hydroelectric generator comprising hinged runner blades for adaptively extracting energy from a free flowing motive fluid that continuously changes direction and magnitude of flow. The following description contains specific information pertaining to various embodiments and implementations of the present invention. One skilled in the art will recognize that the present invention may be implemented in a manner different from that specifically depicted in the present specification. Furthermore, some of the specific details of the invention are not described in order to maintain brevity and to not obscure the invention. The specific details not described in the present specification are within the knowledge of a person of ordinary skills in the art. Obviously, some features of the present invention may be omitted or only partially implemented and remain well within the scope and spirit of the present invention.

The following drawings and their accompanying detailed description are directed as merely exemplary embodiments of the invention. To maintain brevity, some other embodiments of the invention that use the principles of the present invention are specifically described but are not specifically illustrated by the present drawings, and are not meant to exhaustively depict all possible embodiments within the scope and spirit of the present invention.

FIG. 1 illustrates a general perspective view of an exemplary apparatus in accordance with one embodiment of the present invention. Arrow 101 indicates direction of the approaching flow of the free flowing motive fluid 100, impinging upon one of a plurality of runner blades 102 of the impeller of the hydroelectric generator shown covered with a chassis 108. The plurality of runner blades 102 couple to the generator rotor 106 through corresponding beams 105 orthogonal to the axis of the generator rotor 106. The orthogonal beams 105 and corresponding runner blades 102 are shown in FIG. 1, FIG. 2, FIG. 3, and FIG. 4, though the drawings are not necessarily to scale of the preferred embodiment. The length of the orthogonal beam 105 and dimensions of corresponding runner blades 102 shown throughout the drawing figures obviously determine the torque delivered to the rotor 106 and force extractable from a motive fluid of given pressure, respectively. These design parameters present a means of scalability by design to adjust the power output from the generator. The orthogonal beam 105 primarily serves the purpose of mechanical clearance, i.e. preventing the runner blades 102, in their open 103 and closed 104 positions from obstructing one another, whereby field excitation control in the generator may compensate for increased torque brought about by the lengthened orthogonal beams 105 which inherently do not increase power output themselves. Further elaboration on the scalability and regulation of the output power will follow in subsequent paragraphs describing FIG. 14. Next, this specification will immediately address the operating positions of the runner blades 102, illustrated in FIG. 1, FIG. 2, FIG. 3 and FIG. 4, in open 103, and closed 104 positions attached to their corresponding orthogonal beams 105.

A fundamental and significant departure from prior art that provides considerable novelty in this invention is the implementation of the hinged runner blades 102, shown in FIG. 1, FIG. 2, FIG. 3, and FIG. 4 in both open 103 and closed 104 positions. The rotor direction 107 of rotation remains constant regardless of the direction 101 of flow of the free flowing motive fluid 100 strictly due to the orientation of the hinge of the hinged runner blade 102 with respect to its corresponding orthogonal beam 105. As seen best from the bottom view depicted in FIG. 3, because the direction 101 of flow of the free flowing motive fluid 100 causes the hinged runner blade 102 to open 103 as shown, the force imparted upon the face of the runner blade 102 creates torque coupled through the orthogonal beam 105 causing the generator rotor 106 to rotate in the direction 107. Likewise, the force imparted by the free flowing motive fluid 100 causes the hinged runner blade 102 to close 104 when the rotor 106 rotates the runner blade 102 into the direction of flow 101. The runner blade 102 in the closed position 104 clearly occupies less area normal to the direction of flow 101 of the free flowing motive fluid 100, and thus will incur significantly less torque counter to the direction 107 of the generator rotor 106, and therefore the entire impeller will incur significantly less drag. As an example of the ability of the present invention to respond to change in direction of the free flowing motive fluid 100, as the free flowing motive fluid 100 changes direction 101 of its streamlines parallel to the horizontal plane by any arbitrary angle, this change in direction results in the position where the hinged runner blade 102 opens 103 tracking the change of the direction 101 whereby the runner blades 102 continuously open 103 where the orthogonal beam 105 is normal to the new direction of flow 101. Thus the present invention adapts to any change in direction of the streamlines of a free flowing motive fluid. Obviously, any change in type, position or orientation of the hinge of the runner blade 102, or number or length of orthogonal beams 105 employed within the preferred embodiment of the present invention does not constitute a substantial departure beyond the scope of the invention.

Proceeding further with the features depicted in FIG. 1, the chassis 108 of the generator is affixed to horizontal support beams 109, which are affixed to the vertical support struts 110. The support struts 110 are shown in FIG. 1 mounted to the base 111. Under the base is a system of rollers 112 riding on a set of rails 114 driven from under the base 111 through the drive axle 113. Further detail of the drive system will be described in FIG. 11, FIG. 12, FIG. 13, and in subsequent paragraphs. This rail system serves the primary purpose of optimally locating the entire generator system adaptively to an area of flow where maximum energy may be extracted, particularly, preventing the generator chassis 108 from becoming submerged which subjects the entire support structure 109, 110 to undue mechanical stress and reduces the energy extractable from the free flowing motive fluid 100 as the flow becomes turbulent in the vicinity of the submerged chassis 108. Preventing the generator chassis 108 from becoming submerged by design presents another advantage in simplifying the required chassis type to a splash-proof or water-resistant class versus a completely waterproof design. The rail system exists for the secondary purpose of facilitating maintenance on any part of the system at a more convenient location than its in-service location. The rail system serves a third purpose of allowing for moving the generator out of the way of any vessel needing to pass in the present vicinity of the generator. Clearly any deviation from the above stated system, such as a winch and pulley system, which continues to allow the generator system to be adaptively positioned, does not constitute a substantial departure beyond the scope of the present invention. Maximum energy extraction location for the unit has been initially considered the onshore side of breaking ocean waves but can be any area of highest velocity of flow in any body of motive fluid. One alternate example of this includes any body of water that has flow patterns that vary diurnally or seasonally.

Let it be known that the aforementioned features that enable the generator to namely: adapt to any change in the direction of the streamlines of a free flowing motive fluid; or, adaptively position the generator in an optimal flow location using the rail system; while originally conceived for accommodating use in breaking ocean waves, obviously are advantageous for use in other bodies of water such as, but not limited to rivers, creeks, inlets, tidal bores, rapids, or waterfalls. Therefore, use of the present invention in any body of water other than breaking ocean waves does not constitute a substantial departure beyond the scope of the present invention.

FIG. 2 illustrates a perspective view of an alternate embodiment simplified by comprising a mounting system of fixed position with respect to the free flowing motive fluid 100. The apparatus of FIG. 2 is essentially the same as FIG. 1 with the exception of the omission of the base 111, the rollers 112, the drive axle 113, and the rails 114. As previously stated, the fundamental goal of the present invention is to attain the highest possible net energy, in other words, highest return on investment in terms of energy, through implementing the simplest design. At the time of writing this specification the inventor had yet to determine for the general case whether the cost of replacing the parts of the generator system that may receive mechanical damage during instances of excessively high energy in the free flowing motive fluid is greater or less than the cost of implementing the aforementioned parts of the rail system that prevents said damage. Factors specific to the scale and location of the installation decide between these two configurations. Therefore, FIG. 2 likely very well represents the preferred embodiment of the present invention in the majority of installations.

This specification now refers to FIG. 4, a view along the orthogonal beam 105, cross sections of two positions of an alternate embodiment of the runner blade. The runner blade 102 previously described differs from the runner blade 402 portrayed in FIG. 4 in that the previous runner blade 102 simply comprises flat sheets bent at the hinges whereas the alternate runner blade 402 is cast in a similar cupped form as that of a Pelton wheel impeller. The dashed line ending in points 400 and 401 indicates two positions of the alternate runner blade 402 such that the position to the left of the dashed line 400 401 occurs when the runner blade 402 is in the open 103 position, and in the view on the right of the dashed line 400 401 the runner blade 402 is closed 104. The direction 101 of the motive fluid is shown breaking off into streamlines 403 to the left of the dashed line 400 401 to impart greater forces, both impulse and reaction, on the runner blade 402 in the open position 103 with the reaction force due to the change of direction of the streamlines 403 by the cupped runner blade 402 compared to only the impulse force exerted on the sheet runner blade 102. To the right of the dashed line 400 401 the direction 101 of the motive fluid is shown breaking into streamlines 404 which pass over the runner blade 402 in the closed 104 position imparting significantly less force to oppose rotor rotation caused by the prime mover, the streamlines 403. Ultimately, the choice of which type of runner blades, whether the flat sheet runner blade 102 versus the cupped cast runner blade 402 once again likely depends on specific conditions of the installation such as scale of power system, i.e. length of the orthogonal beam 105 and the dimensions of corresponding runner blades, and especially water pressure, as the Pelton wheel has traditionally excelled in high head, in other words high pressure applications, and particularly if the return in additional extracted energy pays for the cost of tooling the more sophisticated cast runner blade 402. Another factor in choosing the alternate cast runner blade 402 over the sheet runner blade 102 includes the possibility of cavitation in the motive fluid which results in not only diminished extractable energy but also increased wear on the runner blade, the choice here once again ultimately depending on net energy and cost of replacement differences.

One skilled in the art may recognize the runner blade 402 in this alternate embodiment of the present invention as a hinged variation of the impeller invented by Pelton. FIG. 5 illustrates a more obvious variation of a Pelton impeller affixed to the rotor 106, not shown, inward where inner concave edge reference 504 is shown, the present invention having the fundamental difference of comprising a generator of transverse orientation to a free flowing motive fluid 100 in which the impeller is completely submerged. The simplicity of construction presents one advantage the impeller 502 of FIG. 5 holds over the hinged runner blade 402 impeller of FIG. 4, while maintaining response to impulse and reaction force shown by streamlines 503. The components needed to manufacture this impeller 502 simply include a longitudinal cross section of a pipe of non-corrodible material of large outside radius to form the convex surface 505, conjoined with two likewise longitudinal cross sections of a pipe of non-corrodible material of small inside radius to form the concave surfaces 504. Greater resistance compared to the hinged runner blade 402 when opposing the streamlines 506 of flow 101 as shown to the right of dashed line 500 501 decreases the energy extractable from the impulse and reaction forces, though. The fact that streamlines 506 travel a greater distance than streamlines 507 and therefore have higher relative velocity and thus lowered pressure against their surface to create dynamic lift 508 somewhat mitigates the loss of extractable energy due to opposing the flow 101 shown on the right of dashed line 500 501. As before, the choice of this impeller 502 versus the previously described hinged runner blade impellers depends on specific conditions of the installation such as scale of power system, i.e. length of the orthogonal beam 105 and the dimensions of corresponding runner blades, and particularly if the return in additional extracted energy pays for the cost of tooling and manufacture of the more sophisticated runner blade 402.

FIG. 6, FIG. 7, and FIG. 8 illustrate perspective cross sections of progressively simpler impeller constructions abandoning the design principals of mitigating drag forces opposing the prime mover by means of hinged runner blades, and extracting energy from reaction force by similar means as the Pelton impeller, in favor of minimal initial investment. The components required to manufacture the impeller 602 of FIG. 6 simply include two concentric longitudinal cross sections of a pipe of non-corrodible material such that the pipe forming the convex surface 605 is of smaller radius than the pipe forming the concave surface 604. Like the impeller 502 of FIG. 5, the design of impeller 602 to the right of dashed line 600 601 of FIG. 6 attempts to take advantage of dynamic lift by virtue of the streamlines 606 traveling a relatively longer distance than streamlines 607 and therefore having a higher relative velocity and thus lower pressure to provide some dynamic lift 608 on the convex surface 605 when the impeller 602 opposes the direction 101 of flow, although cavitation in the vicinity of concave surface 604 is more likely with this simpler construction in this position. Streamlines 603 on the left of the dashed line 600 601 depict the position of the impeller 602 responding to the prime mover, mostly impulse force impinging upon the concave surface 604, with significantly less reaction force.

Like FIG. 6, FIG. 7 also depicts a two-piece construction; only in FIG. 7 a flat surface 704 replaces the concave surface 604 of FIG. 6. There still exists a convex surface 705 which a longitudinal cross section of a pipe of non-corrodible material constitutes. As shown to the right of dashed line 700 701, while the flat surface 704 of the impeller 702 allows for a minimal distance for the streamline 707 to travel implying streamline 706 has a relatively greater distance compared to similar streamlines in previously described impellers, thus facing into the direction 101 of flow creates the greatest dynamic lift 708 for this impeller 702. Conversely, to the left of the dashed line 700 701, as depicted the streamline 703 impinges upon the flat surface 704 providing only limited impulse force extracted from the prime mover. At the time of writing this specification, the inventor has not determined under what conditions this impeller 702 provides an optimal balance between the design parameters of power scale, motive fluid pressure, cavitation, impulse force plus dynamic lift versus prime mover resistance combined for a plurality of runners 702 simultaneously, and the cost of implementation versus net energy extracted. Therefore this impeller 702 style is merely illustrative of a possible embodiment within the scope of this invention, though likely less optimal than the aforementioned preferred embodiments because of its abandoning the principals of mitigation of prime mover resistance by means of a hinge and extraction of energy from reaction force.

FIG. 8 illustrates the simplest construction of an impeller manufactured from a single piece longitudinal cross section of a pipe of non-corrodible material. To the left of dashed line 800 801 the direction 101 of the prime mover is shown breaking into streamlines 803 as it impinges the concave surface 804 of the impeller 802. To the right of dashed line 800 801, the impeller 802 in this position opposes the direction 101 of the prime mover breaking into streamlines 806 and 807. Streamlines 806 appear to be marginally longer than streamlines 807 depending on thickness of the pipe used to construct the impeller 802. So in theory while some dynamic lift 808 exists at the convex surface 805 in the position to the right of dashed line 800 801, it is likely of significantly less magnitude and cavitation is most likely to occur in the vicinity of the concave surface 804 than in previously described impeller embodiments. As in the previously described embodiment of impeller 702, the impeller 802 is merely illustrative of a possible embodiment within the scope of this invention, though likely less optimal than the aforementioned preferred embodiments because of its abandoning the principals of mitigation of prime mover resistance by means of a hinge and extraction of energy from reaction force.

One skilled in the art may recognize the impeller 902 in FIG. 9 as common to the typical weather vane. In view of the invention of the weather vane this hydrokinetic impeller represents little significant novelty alone, but considering the subsequent description of the scalability of power and adaptive control for changes in dynamic energy of the motive fluid, illustrates other novel features of the present invention, and can serve this discussion to elicit the advantages of the hinged runner blade impeller previously described, and introduce the impeller of FIG. 10. On the left side of dashed line 900 901 in FIG. 9, the impeller is shown mounted on the end of the orthogonal beam 105 with the internal surface 903 facing the direction 101 of flow. On the right side of dashed line 900 901, the ellipsoidal exterior surface 902 is shown opposing the direction 101 of flow. For the impeller 902, the orthogonal beams 105 once again only provide mechanical clearance from one ellipsoidal exterior surface 902 to the next, as the additional moment arm does not enhance power output, but increases torque on the rotor. Furthermore, under conditions of high energy within the motive fluid, the orthogonal beams 105 for the impeller 902 of FIG. 9 have a higher probability of mechanical fatigue than the orthogonal beams 105 of the hinged runner blades 102 or 402 of the preferred embodiments because the preferred embodiments implement the hinge which mitigates the resistive force, in other words drag, opposing the prime mover, which impinges upon the ellipsoidal exterior surface 905 as shown to the right of dashed line 900 901 in FIG. 9. Although the preferred embodiment comprises moving parts, the embodiment of FIG. 9 likely has relatively less reliability due to the fatigue caused by drag during instances of high energy within the motive fluid. Nonetheless, given the feedback control of field excitation subsequently described with FIG. 14, the present invention sustains effective generator operation within an extended dynamic energy range in the motive fluid while implementing even the most obvious impeller of FIG. 9, and therefore displays novelty even in this embodiment. As the impeller 902 is cast, and obviously costs more than the sheet runner blade 102, the impeller 902 necessarily needs to extract energy at a rate greater than the cupped cast runner blade 402 to justify the additional tooling and manufacturing cost along with factoring compromised reliability.

FIG. 10 presents an adaptation derived from the impeller 902 of FIG. 9 enabling higher performance as a hydrokinetic impeller. As before in FIG. 9, on the left side of dashed line 1000 1001, FIG. 10 depicts a cast impeller mounted at the end of the orthogonal beams 105 with the interior surface 1003 facing the direction 101 of flow. The external surface 1002 differs from the previous external surface 902 in that the impeller with external surface 1002 has a curvature to change both direction and magnitude of the velocity of flow as it impinges the internal surface 1003. The arrow 1004 depicts this change of magnitude and direction of the velocity of the flow as it exits the interior surface 1003 of the impeller. These changes in velocity of the flow serve the purpose of providing a reaction force in addition to the impulse force on the impeller. The output flow 1004, at a greater velocity than the prime mover 101 since the area at the exit is less than the area at the entrance, further impinges the barrages 1005, a cross sectional view in FIG. 10, mounted on the base 111 in a circular trajectory with the barrage surfaces always normal to the output flow 1004. These barrages 1005 form a high-density medium onto which the output flow 1004 impinges thus increasing the thrust transferred to the impeller. To the right of dashed line 1000 1001, the additional curvature on the exterior surface 1002 compared to the exterior surface 902 of FIG. 9 incurs negligible additional area to oppose the flow 101, therefore this attribute renders this adaptation upon the impeller of FIG. 9 relatively beneficial. As with the previous impeller 902, since this impeller 1002 is cast, and obviously costs more than the sheet runner blade 102, the impeller 1002 necessarily needs to extract energy at a rate greater than the cupped cast runner blade 402 to justify the additional tooling and manufacturing cost along with factoring compromised reliability.

Let it hereafter be known that implementation of runner blades, whether or not responsive to impulse and reaction forces or which may or may not mitigate resistive force when rotating within the motive fluid, which do respond to changes in direction and magnitude of the streamlines of a free flowing motive fluid in any manner similar to that of the present invention does not constitute a substantial departure beyond the scope of the present invention. In light of the aforementioned, the modification of Pelton runner blades in the preferred embodiment is purely exemplary, illustrative and not restrictive. Furthermore, it may be advantageous to implement the present invention with an impeller of recent advent which claims of being bladeless, as it is well known that seawater is particularly corrosive to metals, breaking waves notably high in particulates, and thus a bladed runner highly susceptible to pitting on the blades and perhaps costly in terms of maintenance. Thus, regardless of the size or shape of the impeller with hinged runner blades or bladeless, an implementation of any such transverse-mounted hydroelectric generator that responds to changes in direction and magnitude of the streamlines of a free flowing motive fluid in any manner similar to that of the present invention does not constitute a substantial departure beyond the scope of the present invention.

FIG. 11 details the base 111 and associated mechanical components below it. The broken line defined by points 1100 and 1101 indicate alternate views. The left side of the broken line 1100 1101 views from underneath the center of the base 111 looking outward orthogonal to the rails, while the right hand side of the broken line 1100 1101 views underneath the base 111 from a distance parallel to and in between the rails 114. The base 111 rests on the supports 1108 coupled to the axle of the rollers 112. The rollers 112 rotate freely on the rails 114. The rails 114 are secured to a foundation 1102. In the preferred embodiment, this foundation 1102 is formed reinforced concrete, though it alternatively consists of the local natural rock formation depending upon where the application of this invention occurs. Ideally this foundation 1102 is located on the tip of a headland formation where wave energy is most focused, and is sloped of adequate angle with respect to the true horizon so to elicit breaking waves of the plunging or surging type that transfer wave energy into particle velocity in a most concentrated location and succinct time frame. The rails 114 have cutouts 1103 that permit cross flow and thus prevent sand from drifting to the point of obstructing the movement of the drive gears 1105 that meshes with the rail rack gear 1104. When stationary, the drive gears 1105 lock indirectly by coupling through its axle 113 to an internal drive gear not shown locked by a means such as the subsequently described bi-directional anti-backlash and position-locking mechanism to hold the drive gears 1105 steady in the path along the rail which also create tension to hold the system upright against any lateral tilting force. In the preferred embodiment, the means of driving the gears, most easily implemented as a DC stepper motor, will likely occupy the gearbox 1107 or perhaps a compartment not shown under the base 111. The rotor shaft of this motor therefore occupies a location concentric to the drive shaft housing 1106 and has a bevel gear not shown on its end occupying the gearbox 1107. Said bevel gear meshes with the internal drive gear, not shown inside the gearbox 1107, but parallel to the gears 1105 and mounted such that it directly drives the axle 113. The bi-directional anti-backlash and position locking mechanism not shown also occupies the gearbox 1107 and mates and locks the internal drive gear not shown inside the gearbox 1107. A detailed discussion of exemplary sensor input means and the control algorithm itself for the above rail system follows in subsequent paragraphs describing FIG. 15.

In more detail, the components of FIG. 12 include the rotor, the bevel gear, and the components previously introduced in FIG. 11 and the foregoing paragraph, with the addition of a solenoid 1200 with a plunger 1202 that engages between the teeth of the internal drive bevel gear 1206 to stop motion in the actuated members. FIG. 12 omits the actuated members for sake of clarity though one may presume the actuated members such as the drive gears 1105 are situated as depicted in FIG. 11. The mounting of the solenoid core 1200 and the stops 1203 cast or forged on the inner surface of the gearbox 1107, or perhaps a compartment not shown under the base 111 contains the torque translated back to the plunger 1202 from the actuated members. The solenoid core 1200 is shown spring loaded, with the solenoid spring 1201 compressed by the retracted plunger 1202 when the solenoid coil 1204 has current flowing as depicted by arrows 1205, in accordance to the right-hand rule. The physical positioning of the solenoid 1200 core and the DC stepper motor 1209 and its shaft 1207 is displayed in a collinear orientation to attest the importance of mounting these components concentric to the drive shaft housing 1106 in such a manner as to not disrupt the balance necessary, otherwise mechanical oscillation may occur thereby harming the system efficiency and possibly causing fatigue and shortened life of various components.

Several fundamental advantages arise from employing a DC stepper motor 1209, in actuating motion to traverse the rail system 114. The stepper motor is inherently a precise means of translating rotational displacement and therefore requires no feedback, or in other words may be implemented in an open-loop configuration affording more circuit complexity devoted to higher-level control of the system. Secondly, given the preferred means of bi-directional anti-backlash and position locking mechanism for the bevel gear 1206 as illustrated in FIG. 12, the stator coils 1210, 1211 of the DC stepper motor need powering only in the instances of performing an adjustment, serving to improve the overall efficiency of the generator. Also, because this adjustment period comprises an exceedingly short duty cycle, in the order of one to five percent in the most transitory installations, the current for the stator coils 1210, 1211 is limited by the breakdown voltage of the coil winding insulation, not the thermal wear of the coil itself, as the average power dissipated by its resistive losses are averaged over a much longer period than its duty period. With the use of higher energizing currents, depicted by arrows 1212, comes the advantage of greater torque deliverable to the actuated members in a more space efficient sized DC stepper motor.

FIG. 13 illustrates the flowchart for synchronizing the bi-directional anti-backlash and position locking mechanism to the bevel gear mechanism of FIG. 12. From the start, the DC stepper motor stator coils 1210, 1211 and the bi-directional anti-backlash and position locking solenoid coil 1204 are in the de-energized state 1300. When the aforementioned rail position requires an adjustment, assuming the present position coincides with the position of the DC stepper motor rotor shaft 1207 when its stator coil 1210 is energized, the stator coil 1210 is once again energized, state 1301. Upon energizing the stator coil 1210, the solenoid coil 1204 is energized with a current as depicted by arrows 1205, thereby causing the solenoid plunger 1202 to retract and to unlock the present position by disengaging the plunger 1202 from the teeth of the bevel drive gear 1206, state 1302. Then to affect the necessary adjustment, assuming the position of the next step corresponds to energizing stator coil 1211, a current depicted in FIG. 12 by the arrows 1212 energizes stator coil 1211 while stator coil 1210 is de-energized. This actuates the motion in the rotor shaft 1207 depicted by arrow 1208; the direction of this arrow is arbitrary as implied by the term bi-directional anti-backlash and position locking mechanism. This completes states 1303 and 1304 for this example, though the system permissibly continues to step in this manner through an arbitrary number of stator coils on the DC stepper motor 1209, by reiterating state 1303 for successive coils as necessary to achieve the desired set point position of the rotor shaft for this adjustment. Upon obtaining the desired position, the solenoid coil 1204 is de-energized by interrupting the current depicted by arrows 1205, thereby permitting the solenoid spring 1201 to decompress causing the solenoid plunger 1202 to re-engage the teeth of the drive bevel gear 1206 at the new position, performing the operation of anti-backlash and position locking, state 1305. Since this internal bevel drive gear 1206 is further coupled to plural actuated members through gears 1104, and 1105, and there remains some play in the gears, this results in some motion associated with backlash in the actuated members. But the drive bevel gear 1206 has precision fine enough that this resultant motion in the actuated members is negligible for the overall system response. In the final state 1306, the stator coil 1211 is de-energized and the new position of the actuated member and of the corresponding stator coil is placed in a register, of discrete logic or microprocessor register or memory space, as DC stepper motors are amenable to digital control due to their discrete means of determining rotational displacement. More detail of the higher-level system control will follow in subsequent paragraphs and FIG. 15.

While this means of actuating motion in the rail system presents a novel departure from prior art, this preferred means is purely discussed in an exemplary manner, illustrative, not restrictive, and therefore any deviation from the above specification does not constitute a significant departure beyond the scope of the present invention.

FIG. 14 depicts a coupling configuration and energy extraction means from the impeller through to the output conditioning circuitry of the electric generator. FIG. 14 shows the generator rotor shaft 106 directly coupling to a DC generator 1400. The impeller, not shown in FIG. 14 in order to maintain simplicity, physically occupies the space within the free flowing motive fluid as depicted in FIG. 1 and FIG. 2, while the shaft 106 extends upward into the generator chassis 108. The DC generator 1400 may be any of available forms of DC generator, including but not limited to a commutated or semiconductor-rectified generator, and as shown preferably with a separately-excited or else self-excited shunt field winding 1421 configuration chosen for its combined simplicity and relatively constant voltage independent of load current. The DC generator 1400 thus produces a speed-dependent DC voltage across its armature leads, positive 1401 and negative 1402, that feeds the power filtering elements, the inductor 1403 and the capacitor 1405. Though two armature leads 1401, 1402 imply a single-phase machine, this is purely exemplary, and no predetermination is placed on the number of phases of the machine in the preferred embodiment. The filtering performed by the inductor 1403 and the capacitor 1405 minimizes spurs in the electrical waveform caused by commutation. The preferred embodiment of this invention samples the filtered DC waveform at point 1404 filtered by inductor 1403 and capacitor 1405 referencing the negative armature lead 1402 to local ground 1407 to form feedback that controls the average current through the field winding 1421 and thus controlling the torque opposing the impeller rotation and ultimately the armature voltage depending on impeller rotational velocity and load current.

As previously mentioned, this form of feedback regulation allows by design scaling of the mechanical parameters such as orthogonal beam 105 length affecting torque, and the dimensions and area of the impeller or runner blades 102 ultimately affecting the power extractable in a given installation. For power output means that draw a constant load current, this feedback control of field winding current can compensate for variation in the velocity of the free flowing motive fluid to produce a relatively constant armature voltage and respond accordingly to changes in the free flowing motive fluid that impart varying levels of torque on the impeller, to avert potentially fatigue-inducing torque on the impeller during extreme conditions. For instance, when the average voltage of the sampled, filtered DC waveform 1404 exceeds a given threshold, the feedback control will reduce the average current passing through the field coil 1421 which in turn, reduces the torque on the impeller while reducing the average armature voltage. Likewise, when the average voltage of the sampled, filtered DC waveform 1404 recedes below a given threshold, the feedback control increases the average current passing through the field coil 1421, which in turn, increases the torque on the impeller for the benefit of increasing the average armature voltage. While load or armature current, i.e. the electrical current leaving the filtered node 1404 and entering the output power conditioning means 1424 may vary, responding to load current change may take a subordinate priority compared to responding to changes in free flowing motive fluid in order to avert fatigue on the impeller. In one case, an increase in energy within the free flowing motive fluid coincides with an increase in demand for load current, therefore necessitating little change in average current passing through the field coil 1421. Similarly, a decrease in energy within the free flowing motive fluid coincides satisfactorily with a decrease in demand for load current again necessitating little change in average current drawn through the field coil 1421. However, given the energy within the free flowing motive fluid increases or decreases contrary to a decrease or increase in demand for load current, these situations can elicit limitations in the control loop response. These limitations may manifest in terms of delayed response time, that is, control loop parameters such as loop bandwidth and damping factor that primarily concern stability may slow a response time, producing inadequate transient output voltage or else excessive transient output voltage given a lesser bandwidth or incorrect damping factor. Also the design must take into careful consideration the overall headroom for meeting system demands during such instances, and thus varying loads require more design complexity. Therefore the preferred embodiment of this invention powers output means drawing constant current for optimal power conditioning for application to loads as described in subsequent paragraphs.

Proceeding further along the path of the feedback loop, FIG. 14 depicts two points on the filtered node 1404 where sampling occurs. The path including the resistors 1410, 1412 and the capacitor 1411 constitute the voltage sampling node of a typical feedback loop with frequency compensation. The network of these resistors 1410, 1412 and the capacitor 1411 along with the error amplifier 1409 and its own feedback loop represented by the capacitors 1414, 1415 and the resistor 1416 form the feedback section of prior art switch mode power supply design. Given the fixed internal reference voltage 1413 into the non-inverting input of the error amplifier 1409, resistor 1410 along with resistor 1408 compose a voltage divider that sets the optimal voltage on the filtered node 1404 that feeds the output power conditioning means 1424 while this control loop responds to variations in the velocity of the free flowing motive fluid. The reference voltage 1413 multiplied by the quantity of one plus the ratio of resistor 1410 over resistor 1408 determines the optimal value of the output voltage of the filtered node 1404 that the control loop maintains despite changes in input energy. The other sampling point includes the Zener diode 1406 that quickens the response to over-voltage conditions at the sampling point 1404. Resistor 1408 must be of correct value in order to allow the Zener current to flow through the diode 1406 given this over-voltage condition. The design of the frequency compensation of this error amplifier must also take into account the junction capacitance, though often negligibly small, seen across the Zener diode 1406 and parallel to resistor 1410. Resistors 1412 and 1416 and capacitors 1411, 1414, 1415 form the frequency compensation of the error amplifier 1409 within the feedback loop of the traditional switch mode power supply. While tuning these frequency compensation components is not germane to the specification of the present invention and is elsewhere covered in greater detail, this specification will now disclose some general observations regarding it. Uncompensated, the filter components, the inductor 1403 and the capacitor 1405 produce a complex pole pair at their resonant frequency given by one over the quantity of two times pi times the square root of inductance times the capacitance. The filter capacitor 1405 also places a zero above the pair of poles at a frequency given by one over the quantity of two times pi times the capacitance and the value of the capacitor's 1405 equivalent series resistance, "ESR". Generally as a goal in compensation, two zeroes are added near the filter resonant frequency to correct the sharp change in phase near that frequency and an open-loop unity gain frequency is chosen to exist at a frequency about ten times greater than the resonant frequency but less than about 10% of the switching frequency. The overall gain of the error amplifier 1409, the filter components comprising the inductor 1403 and capacitor 1405, the two zeroes added plus the gain of the integrator created by the compensation network that sets open-loop unity gain frequency preferably sums to zero at the unity gain frequency. The integrator gain is given by 1/(2(pi)(Fo)(R1410(C1414+C1415))) where Fo is the open-loop unity gain frequency. The frequency of the output filter compensating zeroes equals 1/(2(pi)(R1416)(C1415)) and 1/(2(pi)(R1410+R1412)(C1411)) and these zeroes are understood to add to 40 dB per decade of gain. A pole also exists in the compensation network and its frequency is chosen to coincide with the zero formed by the output capacitor 14