A wind-responsive vertical-axis photovoltaic tracker system with resonance mitigation

Abstract

A wind-responsive photovoltaic tracker system for single-post foundations is disclosed. Each tracker yaw-rotates about a vertical axis and supports modules feathering passively about a horizontal hinge. Directional bracing raises swing-mode frequency, while a pretensioned flexible drive with bounded compliance and wind-aligned yaw control reduces aerodynamic loading, detunes resonances, and dissipates gust energy.

Description

[0001] WIND-RESPONSIVE VERTICAL-AXIS SOLAR TRACKER WITH RESONANCE MITIGATION

[0002] FIELD OF THE DISCLOSURE

[0003] The disclosure relates to photovoltaic trackers that rotate about a substantially vertical axis and allow for some rotation about a horizontal axis, with particular emphasis on mitigating wind induced loads and dynamic instabilities on single post, rotation friendly superstructures.

[0004] BACKGROUND OF THE INVENTION

[0005] Related Art and Technical Context

[0006] Photovoltaic tracking systems continue to evolve from single-post heads that rotate about a vertical axis and tilt about a horizontal hinge to follow the sun. The art spans yawing heads with tilt linkages, stow strategies that lock the array under wind, drives that distribute motion, and foundation schemes that add substructure to resist storm loads. These approaches improve tracking and survivability but tend to treat each post as a standalone unit. Coordinated wind response across neighboring yawing posts with controlled elastic compliance remains less developed.

[0007] Single post photovoltaic ("PV") tracker heads that yaw about a vertical axis and also provide horizontal articulation for tilt are known. For example, U.S. Patent 8,242,424 discloses a tracker mounted to a base that rotates about a vertical axis while the panel frame is supported by horizontal articulations and adjustable ties that set the tilt angle. This establishes the general architecture of vertical axis yaw combined with a horizontal hinge.

[0008] When wind is the governing load case, some systems prioritize stow locks / brakes that hold the array in a fixed attitude during storms. For instance, U.S. Patent 8,671,930 describes a single axis tracker equipped with wind lock devices that secure the structure at a neutral (e.g., horizontal) position during strong winds. Such strategies address survivability by immobilizing the superstructure at a particular attitude.

[0009] Other disclosures emphasize actuation topologies rather than wind response. For example, U.S. Patent 9,995,506 (and its published application US 2015 / 0107583) teaches a cable drive tracking system in which a flexible tensile member is wrapped around drive / driven pulleys to transmit motion among multiple rotatable PV assemblies. These references focus on motion transfer and layout flexibility for tracking, not on coordinated wind response behavior across yawing posts.

[0010] At the foundation level, prior solutions often add structure under the mast to resist storm loads and moments. Representative examples include A frame or "earth truss" foundations used with trackers, as taught in U.S. Patent 10,615,739 and U.S. Patent 11,121,671— systems that employ angled helical anchors and trussed adapters so lateral and overturning loads are reacted by multimember foundations. These approaches increase capacity by adding material and anchorage complexity beneath the tracker head. Array level mechanical linkage between multiple trackers is also known. For example, EP 2 997 316 A2 describes arrangements in which multiple trackers are mechanically linked to operate in unison from a common drive. Such teachings address synchronous motion and drive efficiency but do not describe coordinated wind energy dissipation via controlled elastic give between neighboring yawing posts.

[0011] Wind Induced Problems Particular to Vertical Axis Tracker Heads

[0012] For single post, vertically yawing PV heads carrying a broad panel, wind creates three interrelated challenges that have been observed in analysis and practice:

[0013] 1. Panel lift / beam "bounce" mode: Gust-induced lift on the panel excites an up and down oscillation about a horizontal line through the rotating superstructure.

[0014] 2. Mast sway in two orthogonal planes: Because the yawing head bears on a single foundation point, lateral wind loads must be carried in both X and Y directions by the slender mast and its footing.

[0015] 3. Yaw torque (twist about the vertical axis): Quartering winds tend to rotate the head toward broadside; the resulting torsion is transmitted into the mast and footing, potentially exciting low frequency modes.

[0016] These behaviors correspond to well documented aerodynamic mechanisms— buffeting, vortex induced response, and panel "galloping" at unfavorable attitudes— and are sensitive to angle of attack and structural damping. Industry guidance likewise recognizes that stow attitude and dynamic (not just static) wind effects govern tracker survivability.

[0017] Limitations of Representative Approaches The references above illustrate the state of the art, but each addresses only part of the wind problem:

[0018] Fixed or locked stow (e.g., wind locks) prevents motion but can leave the panel presenting a large effective area to unsteady flow; this reduces motion but does not actively reduce the aerodynamic input when wind direction or turbulence evolves during the event.

[0019] Heavy trussed foundations increase resistance at the base but add cost and do not address the source of excitation aloft; torsional and lift mode energy can still be injected into the mast and footing, only then resisted by added steel and deeper anchors.

[0020] Flexible tensile drives used for actuation (e.g., cable driven trackers) emphasize traction, layout, and multi table motion transfer; they do not, by themselves, disclose a coordinated wind response scheme that purposefully combines panel level feathering, in head directional bracing, and bounded elastic give between yawing posts to disrupt array scale torsional excitation.

[0021] Vertical axis yaw with a separate horizontal articulation is known as a geometry, but prior art does not describe a windresponsive hinge placed relative to the aerodynamic center and tuned to feather under storm winds as part of an integrated damping / decoupling strategy.

[0022] The references above show progress but each addresses only part of the wind problem. Fixed or locked stow reduces motion yet can leave a large effective area exposed to unsteady flow, and it does not actively trim aerodynamic input as wind direction or turbulence changes during an event. Heavy trussed foundations increase resistance at the base but add cost and do not treat the source of excitation aloft. Torsional and lift energy can still enter the mast and footing and are only resisted by added steel and deeper anchors. Flexible tensile drives used for actuation focus on traction, layout, and multi-table motion transfer. They do not disclose a coordinated wind response that combines panel-level feathering, in-head directional bracing, and bounded elastic give between yawing posts to disrupt array-scale torsional buildup. Vertical-axis yaw with a separate horizontal hinge is known. The state of the art does not combine a wind-responsive hinge, positioned relative to the aerodynamic center and tuned to feather under storm winds, with a rotatable structure that optimizes the wind's angle of attack as part of an integrated damping and decoupling strategy. Resulting Need

[0023] Accordingly, there remains a need for an integrated architecture that, within a single post, rotation friendly tracker head:

[0024] - reduces aerodynamic input at the panel (e.g., via hinge geometry that naturally feathers under wind),

[0025] - raises stiffness only where rotation allows it (directional bracing inside the rotating head), and

[0026] - introduces controlled, bounded compliance along the azimuth drive path (via tensioned flexible elements with positive traction and pretension) so neighboring posts do not excite each other at shared torsional frequencies— while also employing wind aware yaw alignment to minimize yaw torque during storms.

[0027] This combined approach targets the three problematic modes simultaneously and avoids reliance on multipoint trusses or deep foundations to survive gusts.

[0028] SUMMARY OF THE INVENTION

[0029] The present invention relates to photovoltaic trackers. In particular, the invention concerns a wind-responsive solar tracker in which a module support assembly yaw-rotates about a substantially vertical axis carried by a rotatable mast, and in which a horizontally hinged module is coordinated with internal bracing, a flexible azimuth coupling, and wind-aware yaw control to reduce aerodynamic loading, detune structural resonances, and dissipate gust energy while remaining compatible with a single-post foundation.

[0030] According to a first aspect of the present invention, there is provided a photovoltaic tracker system distributed across a plurality of yawing masts, configured to prevent coupled resonance, comprising: a plurality of rotatable masts, each carrying a rotating superstructure rotatable about a substantially vertical axis by a yaw drive under a yaw motor and supporting at least one photovoltaic module mounted by a horizontal hinge assembly defining a substantially horizontal axis located windward of the aerodynamic center, such that wind on the rear face feathers the module toward a reduced angle of attack, the horizontal hinge assembly permitting substantially free feathering of the module together with a rest-tilt limiter that stops downward rotation below a defined rest tilt; directional bracing disposed within each rotating superstructure and oriented to raise a swing-mode natural frequency about the horizontal axis while preserving free yaw about the vertical axis; a controller configured, upon a wind condition exceeding a threshold, to command the yaw motor to maintain a rear-to-wind orientation of each module within a bounded wind-aligned cone so that feathering proceeds in the permitted rotational sense and the module feathers away from the directional bracing; and a flexible azimuth group drive interconnecting the rotatable masts, including on each rotatable mast a rotating traction element having a wheel body and carrying at least four flexible tensile runs reeved as two opposed pairs of a pretensioned flexible element, each run being fixed to the rotating traction element by a positive locking member so torque is transmitted by positive locking, a first opposed pair being operatively connected locally to the yaw motor and a second opposed pair being routed toward a neighboring rotating traction element; wherein the system is configured such that the frequency of oscillation of the at least one module about the horizontal axis is spectrally separated from the frequency of the rotatable masts about the vertical axis, thereby avoiding mode coupling while preserving feathering torque relief.

[0031] According to another aspect of the present invention, the threshold is a three-second wind gust speed of at least about 25 m-s-1, and when the wind condition exceeds the threshold a leeward one of the flexible tensile runs in one of the opposed pairs relaxes toward a loss-of-tension condition while a windward one remains tensioned, interrupting coherent bi-directional torque transmission within a gust half-cycle, permitting at least one rotatable mast to rotate partially in yaw about the vertical axis relative to neighboring rotatable masts within a bounded range, and routing substantially all wind-induced yaw torque along the tensioned run to the rotating traction element that is locally driven by the yaw motor to be reacted at the corresponding rotatable mast.

[0032] According to another aspect of the present invention, the horizontal hinge assembly defining the horizontal axis is positioned within -10% to +20% of panel chord measured from a wind-leading edge toward a leeward edge of the photovoltaic module such that wind on the rear face produces a lifting moment that passively feathers the module toward a reduced angle of attack.

[0033] According to another aspect of the present invention, the hinge assembly is configured to provide damping, thereby suppressing wind-induced small-amplitude chatter about the horizontal axis while permitting quasi-static feathering under rear-face wind.

[0034] According to another aspect of the present invention, an upper stop is positioned to arrest upward rotation of the module about the horizontal axis at a feathered extreme within about ±10° of horizontal under strong rear-face wind. According to another aspect of the present invention, a counterweight on an arm is disposed with respect to the horizontal axis to provide a gravity bias that reduces a gravity-derived restoring gradient in the feathering direction and improves passive feathering response under gusts.

[0035] According to another aspect of the present invention, the flexible azimuth group drive comprising the pretensioned flexible element is divided into multiple short loops, each short loop coupling two or a few of the rotatable masts through their rotating traction elements, thereby bounding cumulative stretch and heading drift while preserving local compliance.

[0036] According to another aspect of the present invention, the directional bracing disposed within each rotating head or superstructure is dimensioned and oriented to raise a first swing-mode natural frequency about the horizontal axis to at least 4 Hz, thereby shifting that mode outside a low-frequency wind-excitable band.

[0037] According to another aspect of the present invention, installation tuning yields a spectral separation between a first yaw natural frequency about the vertical axis and a first panel pitch natural frequency about the horizontal axis of at least about twenty percent, as verified during commissioning by an impulse or gust-response test.

[0038] According to another aspect of the present invention, the directional bracing is disposed entirely within the rotating head or superstructure in a selected plane that increases stiffness in that plane while imparting negligible resistance to yaw about the vertical axis, thereby preserving substantially free yaw of the tracker head.

[0039] According to another aspect of the present invention, the directional bracing comprises two diagonal brace members arranged in a common plane within the rotating head or superstructure and positioned to selectively stiffen the head against sway / bounce deflection in that plane while not constraining motion orthogonal thereto.

[0040] According to another aspect of the present invention, the directional bracing cooperates with drivetrain compliance in the azimuth group drive, comprising elastic extension of the flexible element and / or an inline compliance module, to detune and damp array-level torsional response, whereby wind-induced yaw oscillations about the vertical axis are attenuated and not coherently transmitted between coupled masts.

[0041] According to another aspect of the present invention, each rotating traction element comprises a wheel body with grooves, the flexible element being reeved about the wheel body for at least 1.0 wraps, and a positive locking or anchoring member fixes the flexible element to the wheel such that torque is transmitted by positive locking rather than by capstan friction along the wraps, the wraps being provided to accommodate angular travel.

[0042] According to another aspect of the present invention, the flexible azimuth group drive comprising the pretensioned flexible element is divided into multiple short loops, each short loop coupling two or a few of the rotatable masts through their rotating traction elements, thereby bounding cumulative stretch and heading drift while preserving local compliance.

[0043] According to another aspect of the present invention, a nondriven run of the pretensioned flexible element includes a sacrificial overload release calibrated to fail within a predetermined tension band prior to structural yielding elsewhere, and a backup tether is provided to retain loop continuity upon such release.

[0044] According to another aspect of the present invention, baseline pretension applied to the flexible element by a tensioner is set within a site-tunable range of 0.4-2.0 kN per tracker unit in each drive group such that, for a three-second gust > 25 m-s-1, a leeward-directed run relaxes toward a loss-of-tension condition while the windward-directed run remains tensioned, thereby interrupting coherent bi-directional torque transmission within the gust half-cycle and routing net yaw torque to be reacted predominantly at the motorized mast with minimal torsional propagation to neighboring posts.

[0045] According to another aspect of the present invention, an inline compliance module is disposed in a non-driven span of the flexible element, the compliance module being configured to elastically extend under transient gust-induced tension spikes, thereby absorbing load peaks in the flexible drive and limiting peak loop tension during extreme winds.

[0046] According to another aspect of the present invention, the yaw actuator and controller are configured to maintain a rear-to-wind orientation of each tracker during storm operation by keeping the rear face within a wind-aligned cone having a half-angle of less than ±30°.

[0047] According to another aspect of the present invention, during storm mode the controller applies staggered heading offsets among neighboring trackers, adjacent headings being intentionally offset in alternating positive and negative increments of no more than 15° while each tracker's rear face remains within its respective cone, thereby disrupting array-level aerodynamic symmetry and preventing phase-locked excitation.

[0048] According to another aspect of the present invention, wind-speed threshold logic enters storm mode when a higher gust threshold is exceeded and exits only after wind falls below a lower threshold for a dwell time, the logic being configured, by way of example, to trigger wind-aligned stow when a 3-second gust is at least 15 m-s-1and to revert to normal tracking only after the gust is no more than 12 m-s-1for at least about 60 s, thereby providing entry / exit hysteresis to avoid chatter.

[0049] According to another aspect of the present invention, the system further comprises a rotary electrical interface or an internal cable-routing path through the yaw drive about the vertical axis to preserve electrical connectivity during azimuth rotation.

[0050] According to another aspect of the present invention, the tracker system is implemented in a grouped-drive configuration in which only one mast of the plurality is directly motorized with the yaw motor driving a powered traction element, and all other yawing posts in the group are coupled via the flexible element to rotate in unison with commanded azimuth, thereby enabling coordinated wind-aligned stow across multiple posts with a single actuator.

[0051] According to another aspect of the present invention, each tracker assembly is mounted on a single-point foundation configured as a shallow anchor, including one or more of a driven pile, ground screw, or ballast footing, without multi-anchor footings, A-frame bracing, or earth-truss structures beneath the mast.

[0052] According to another aspect of the present invention, the combination of a wind-responsive off-center hinge about the horizontal axis, wind-aligned yaw within the cone, and compliant inter-post coupling via the flexible element collectively reduces wind-load excitation such that deep piers or multi-point guyed foundations are unnecessary, whereby a single-post shallow foundation for each mast is sufficient across a range of soil conditions and wind exposure classes.

[0053] According to another aspect of the present invention, only the motorized mast equipped with the yaw motor requires additional anchoring or reinforcement to react aggregate drive torque, the motorized mast optionally including a torque-reaction frame tied to anchors, while non-motor posts utilize standard single-point foundations without enlarged footings or special reinforcements.

[0054] According to another aspect of the present invention, under design storm conditions the peak overturning moment and base shear transmitted into each foundation are reduced by at least about 30% relative to an otherwise-equivalent tracker lacking the disclosed wind-relief features, owing to feathering about the horizontal axis, wind-aligned yaw about the vertical axis, and flexible-drive compliance that limit the magnitude and duration of load transfer into the mast and footing. According to another aspect of the present invention, each tracker assembly is capable of withstanding design storm loads on a single-post foundation without supplemental bracing structures or multi-anchor footings, the wind-responsive hinge, controller-maintained cone, and compliant azimuth group drive attenuating dynamic loads so that conventional shallow anchors may be used.

[0055] BRIEF DESCRIPTION OF THE DRAWINGS

[0056] FIG. 1 is a perspective view of a single-post solar tracker assembly with a rotatable mast, a yaw drive, and a horizontal hinge for supporting a photovoltaic module.

[0057] FIG. 2 is a perspective view of a tracker assembly showing internal directional bracing arranged inside the rotating head.

[0058] FIG. 3 is a side view of a tracker assembly showing the off-center horizontal hinge, a rest-tilt limiter, and an optional upper stop.

[0059] FIGS. 4A-4C are detail views of travel limiters and stops that define rest and feathered positions for the module.

[0060] FIG. 5 is a perspective view of two tracker posts linked by a flexible element forming an azimuth group drive.

[0061] FIG. 6 is a perspective view of a rotating traction element on a mast showing a wheel body configured to engage a flexible drive element.

[0062] FIG. 7 is a perspective view of a two-post loop arrangement including a pretensioner and an optional compliance module.

[0063] FIG. 8 is a perspective view of a chain-and-sprocket variant of the flexible drive.

[0064] FIG. 10 is a schematic plan view of a two-post loop showing routing of the flexible element and placement of a compliance module.

[0065] FIG. 11 is a schematic plan of multiple short loops driven from a single motor to bound cumulative stretch.

[0066] FIG. 12 is a diagram showing a wind-aligned cone policy with a preferred rear-to-wind posture.

[0067] FIG. 13 is a diagram illustrating yaw correction when wind direction falls outside the allowed cone. FIG. 14 is a bird's-eye view of grouped trackers showing elastic coupling within loops and staggered azimuth offsets between groups.

[0068] FIG. 15 is a perspective view of a rotating traction element carrying four flexible runs arranged as opposed pairs.

[0069] FIG. 16 is a schematic of the traction element in fully wound and unwound positions across its angular travel range.

[0070] FIG. 17 is a perspective view of a powered traction element on a motorized mast with a torque-reaction frame tied to anchors.

[0071] FIG. 18 is a perspective view of a solar panel mounting system with rotatable vertical support and upper and lower supports.

[0072] FIG. 19 is a view of the system of FIG. 18 showing the panel feathering under wind load.

[0073] FIG. 20 is a view of the system of FIG. 18 showing the panel oriented to expose the front face.

[0074] FIG. 21 is a perspective view of a variant with dampening members on the lower support.

[0075] FIG. 22 is a perspective view of a variant with vertical and diagonal support members for increased rigidity.

[0076] FIG. 23 is a schematic of a variant with a horizontal support member and lifting arms coupled to upper and lower supports.

[0077] FIG. 24 is a schematic of a variant with the rotatable vertical support directly attached to an upper support.

[0078] FIG. 25 is a schematic of a wheel-and-wire drive arrangement showing a motorized wheel and a passive wheel.

[0079] FIG. 26 is a detail view of a locking member that secures a wire on a wheel.

[0080] FIG. 27 is a plan schematic of multiple arrays of solar panels driven by a single motor through a wire loop.

[0081] FIG. 28 is a detail view of a release mechanism in a wire loop to protect against overload.

[0082] FIG. 29 is a detail view of an adjustment mechanism using a fastening member to fine-tune panel heading.

[0083] FIG. 30 is a schematic of a dual-motor arrangement mounted on a common frame to counteract torque. FIG. 31 is a schematic of a release mechanism positioned on a non-driven run of the wire loop.

[0084] FIG. 32 is a schematic of adjustable wheel placement on a mast to accommodate uneven terrain.

[0085] DETAILED DESCRIPTION OF THE INVENTION

[0086] To assist in the understanding of the present invention, the following list of terms and numerals is provided. It is intended that these terms be used to guide the reader in their understanding of this document, and it is not intended that these terms be limiting on the interpretation of this document.

[0087] Consolidated Definitions (alphabetical)

[0088] 3-second gust — Peak wind speed averaged over three seconds used for survivability and storm entry checks.

[0089] Aerodynamic center (AC) — The center of pressure in the limit as the panel's angle of attack relative to the oncoming wind approaches 0°. For a thin, approximately flat rectangular plate, AC is typically located near the quarter-chord, i.e., about 0.25-c measured from the wind-leading edge along the chord. AC is used herein as a datum for describing hinge placement and offsets.

[0090] Azimuth — The horizontal bearing of the tracker head about the substantially vertical axis. Expressed as the tracker heading and set by the azimuth drive during operation.

[0091] Bounded relative yaw — Limited, controlled differential rotation between neighboring posts that occurs under gusts due to elastic stretch and sag straightening in the flexible element and any compliance module. Example ranges include about 1° to about 5° between neighbors. Values are illustrative.

[0092] Compliance module — An inline extension element in series with the flexible drive that provides controlled extension under transient loads to limit peak loop tension while preserving noslip traction at the wheel.

[0093] Controller - a controller receives windspeed and direction inputs or equivalent site feeds and computes a yaw heading to, for example, keep the rear face (500B) within cone C during storm mode. Counterweight - in some embodiments a counterweight on an arm biases the module behavior with respect to H-H.

[0094] Counterweight bias — A gravity generated moment about the horizontal hinge that helps the panel feather under rear wind and reduces the gravity derived restoring gradient in the opposite direction.

[0095] Directional bracing — Bracing, including guy wires, within the rotating head oriented to raise stiffness and modal frequency in a selected sway plane while preserving free yaw about the vertical axis.

[0096] Embedment depth — The axial depth of a pile, screw, or footing measured from grade to the deepest loadbearing element.

[0097] Feathering — Passive rotation of the panel about the horizontal hinge toward a lower angle of attack under rear face wind, typically approaching horizontal during strong winds.

[0098] Flexible group drive — A wire rope or chain loop with wraps and a positive lock that transmits azimuth actuation among posts without designed slip in normal service and that provides compliance through elastic stretch and sag straightening under gusts.

[0099] Flexible element — A bending compliant, loadbearing member, such as wire rope or chain, that transmits azimuthal motion between tracker posts via traction on a wheel or sprocket. Rigid shafts and tubes are excluded.

[0100] Foundation - A single point footing or anchor supporting the mast (102).

[0101] Gravity "spring" effect — The effective restoring torque about the hinge due to gravity acting on the panel mass distribution, which can contribute to oscillation if not conditioned.

[0102] Group drive — A looped flexible member drive that couples two or more trackers so commanded yaw is shared while wind induced local motions remain elastically bounded.

[0103] Hinge damping pack — Friction and preload elements at the horizontal hinge that provide some resisting torque at small angular velocities to dissipate gust energy while permitting quasistatic feathering.

[0104] Locking or anchoring member — A positive mechanical feature that fixes the flexible element to the rotating traction element to inhibit slip under service loads.

[0105] Lower stop bar — A version of a rest tilt limiter that is a unidirectional mechanical abutment that holds the panel at a desired rest tilt in low to moderate winds while allowing unimpeded upward feathering under rear wind. Module — A photovoltaic module (500) that converts sunlight to electricity. It includes the laminated cell stack and a perimeter frame if present. The sun facing surface is the front face 500A. The opposite surface is the rear face 500B. The term "module" is used interchangeably with "panel" in this specification. Unless stated otherwise, "module" excludes the panel carrier 107, the upper support 105, and the hinge assembly 121. This definition covers monofacial and bifacial constructions.

[0106] Pretension — Initial tension applied to the flexible element to stabilize elongation and ensure traction under service loads.

[0107] Rest tilt — The nominal tilt angle the panel assumes in low to moderate winds when seated against the rest tilt limiter.

[0108] Rest tilt limiter - A limiter used so the panel assumes a rest tilt angle in low to moderate winds, for example a lower stop bar or a front limit stop wire.

[0109] Rotating superstructure — Members rigidly coupled above the yaw bearing that carry the module or modules and the horizontal hinge.

[0110] Rotating traction element — A wheel or sprocket keyed to the azimuth drive and configured to receive or interface with the flexible element and transmit torque without slip when used with wraps and a locking or anchoring member.

[0111] Shallow anchor — A single point foundation that can be realized as a driven pile, ground screw, or ballast, enabled by reduced and damped load transmission under the disclosed wind relief operation.

[0112] Single post architecture — A tracker supported by one rotatable vertical member and one ground interface point, with no ground anchored cross bracing from the rotating head.

[0113] Soft end stop — A compressible, energy absorbing contact at the rest position that cushions impact.

[0114] Stability envelope — The set of tilt, yaw, and windspeed combinations in which no sustained aeroelastic instability is observed for the disclosed assembly.

[0115] Staggered headings — Small, bounded azimuth offsets assigned per group of trackers during storm operation so adjacent tracker groups hold different headings within their wind aligned cones to break array scale symmetry. Storm mode — A controller state in which sun tracking is suspended and the controller maintains the trackers in a rear to wind posture within a defined wind aligned cone with entry and exit hysteresis.

[0116] Substantially vertical axis — The tracker's yaw axis that is nominally vertical with small allowable deviation from true vertical due to installation tolerances.

[0117] Tracker - A single rotatable photovoltaic unit that yaw rotates about a substantially vertical axis V-V. A tracker includes the mast 102, the yaw bearing / drive 120, the rotating head 150 with panel support 105. A tracker may operate alone or be coupled to neighboring trackers by an azimuth group drive, but the term "tracker" refers to one rotatable unit rather than a group of linked units.

[0118] Upper stop — A mechanical limit that arrests motion at or near the feathered extreme under strong winds to stabilize the assembly in a low force state.

[0119] Wind aligned cone (C) — A bounded angular sector about the wind direction within which the controller maintains the tracker's rear face orientation during storm mode. A half angle of about ±15° is preferred. Narrower or broader cones are encompassed.

[0120] Wind aligned policy — The rule that specifies how closely each tracker's rear face is held to the wind direction during storm mode, for example exact alignment, within ±10°, or within ±30°.

[0121] Wind-leading edge — The panel edge that faces the oncoming wind vector W at the operating instant (e.g., during wind-aligned stow). All chordwise distances (including xh) are referenced from this edge toward the opposite edge.

[0122] Wind responsive horizontal hinge — A hinge whose axis is positioned forward of the panel aerodynamic center so rear face wind produces a lifting moment that feathers the panel upward.

[0123] Yaw — Rotation of the tracker head about the substantially vertical axis that changes the azimuth heading and is commanded for wind alignment or sun tracking.

[0124] Symbols & Variables (nonnumerical)

[0125] • V-V — Mast yaw axis (substantially vertical).

[0126] • H-H — Horizontal hinge axis.

[0127] C — Windaligned cone W — Wind direction vector.

[0128] • IJJ — Tracker heading.

[0129] • AQJ — Staggered heading offset applied in storm mode.

[0130] • AC — Aerodynamic center: the limiting center of pressure as the module's effective angle of attack relative to the oncoming wind W approaches 0°, typically near the quarter-chord (=0.25-c) for thin plates; used herein as the chordwise datum for hinge offset O.

[0131] • Lc — Panel chord: the distance measured along the wind-normal depth of the module from the windward edge to the leeward edge; all chordwise percentages in this specification are referenced to the windward edge unless stated otherwise.

[0132] • O — Chordwise hinge offset: the signed distance from AC to the hinge axis H-H measured along the chord Lc toward the windward edge; expressed as a fraction of Lc (e.g., O = +0.05-C indicates H-H is 5% of Lc windward of AC;

[0133] • G — Panel center of gravity.

[0134] Master List of Reference Numerals

[0135] Structure & hinge neighborhood

[0136] • 100 — Tracker assembly (singlepost); 100' — Adjacent tracker assembly.

[0137] • 102 — Vertical mast / rotatable support (yaw about V-V).

[0138] • 105 — Panel support (upper cross-member).

[0139] • 107 — Panel carrier / crossmember.

[0140] • 108 — Rest tilt limiter.

[0141] • 110 — Soft pad / damper at stop interface.

[0142] • 112 — Upper stop (feathered fixation / top seating).

[0143] • 120 — Non-rotating base that holds the rotating head 150 about the substantially vertical axis V-V.

[0144] • 121 — Hinge assembly (bracket / knuckle); axis H-H (symbol).

[0145] • 130 — Footing / anchor (single point foundation).

[0146] • 150 — Rotating head / superstructure. • 160 — Directional brace(s) within rotating head.

[0147] Flexible group drive (capstan / wheel + loop)

[0148] • 206 — Idler pulley; 208 (not shown in figures) — Fairlead (antichafe).

[0149] • 210 — Compliance module (spring / elastic / reel).

[0150] • 218 — Load / tension indicator.

[0151] • 230 — Wheel body

[0152] • 232 — Groove(s) on capstan / wheel.

[0153] • 240 — Tensioner (inline).

[0154] • 250 — Rotating traction element on mast, including 230. Also referred to as "wheel".

[0155] • 251 - Powered traction element.

[0156] • 252 — Sprocket (chain variant).

[0157] • 254 - Torque reaction frame

[0158] • 260 — Flexible element (wire rope or chain).

[0159] • 262 — Chain / roller chain.

[0160] • 268 — Segment coupler (loop to loop).

[0161] • 270 — Positive locking / anchoring member (tail capture on wheel).

[0162] Controls & signals

[0163] • 300 — Yaw motor (azimuth actuator).

[0164] Limiters (variations of 108 / 112)

[0165] • 460 — Front limit stop wire (a version of 108).

[0166] Modules & general

[0167] 500 — PV module / panel (500A front face; 500B rear face).

[0168] Overview of the present invention The present invention relates to a tracker assembly (100) having a traction element (250) capable of being rotated via a flexible element (260). In such a system, problems with torque handling between groups of trackers (100) can occur, as previously described.

[0169] Therefore, according to one aspect of the present invention, there is provided a tracker assembly (100) comprising a rotatable mast (102), a yaw bearing / drive (120) that rotates a superstructure (150) about vertical axis V-V, an upper support (105) carrying a module (500) on a horizontal hinge assembly (121) defining horizontal axis H-H, and an azimuth group drive formed by a rotating traction element (250) and a flexible tensile element (260) that couples neighboring posts.

[0170] In this configuration, the modules (500) are allowed to rotate independently of one another about axis H-H, thereby reducing the torque that would otherwise be transferred between adjacent modules and skew the tracker assembly (100). The decoupling of the modules gives rise to four characteristic phenomena:

[0171] 1. Wind-feathering effect: When exposed to wind loading, the modules rotate away from the wind direction, thereby reducing the aerodynamic force acting on the tracker.

[0172] 2. Torque-collapse effect: The decoupling eliminates torque transfer along the horizontal axis H-H, disabling coupling effects between modules in that axis.

[0173] 3. Swing-mode effect: Each module can exhibit pendulum-like motion about the horizontal hinge axis H-H, with amplified back-and-forth oscillations. This phenomenon is herein termed swing mode.

[0174] 4. Pole-resonance effect: When modules are decoupled, oscillatory motion can also develop in resonance with the vertical mast (102), producing back-and-forth swinging relative to the vertical support. This phenomenon is herein termed mast resonance.

[0175] The present invention seeks to overcome these problems, using some or all of the following elements:

[0176] 1. Directional bracing 160 inside the rotating head 150 to raise the panel swing-mode frequency. In one implementation, it raised this frequency from a vulnerable band near 1.7- 2.0 Hz to above about 5 Hz while preserving free yaw about V-V.

[0177] 2. Wind-aligned yaw control that holds the rear face 500B within a cone C about the wind direction so feathering occurs in the permitted direction set by the resttilt limiter 108. 3. A flexible azimuth group drive using a tensioned flexible element 260 on rotating traction elements 250 to transmit commanded azimuth with no designed slip in service while allowing bounded elastic give between neighboring masts, where such elastic give reduces risk of pole-resonance effect.

[0178] 4. Ability to tune the system installation (including tuning the pretension of the flexible element 260) so that some of the strands of the flexible element 260 reach a low-tension state at high yaw torque, which helps decorrelate vertical mast frequency from the frequency of oscillating feathering panels at strong winds.

[0179] Together these features cut aerodynamic input at the module, separate swing mode from mast resonance, and decorrelate torsional impulses along the array. These elements and their use will be made readily apparent in the following description.

[0180] Aspects of the present invention will now be described with reference to the high level architecture of the system.

[0181] According to one aspect of the present invention, there is provided a tracker assembly (100) which comprises a rotatable mast (102), a yaw bearing / drive (120) that rotates a superstructure (150) about axis V-V, an upper support (105) carrying a module (500) on a horizontal hinge assembly (121) defining axis H-H, and an azimuth group drive formed by a rotating traction element (250) and a flexible element (260) that couples neighboring posts. Within the rotating head (150), directional bracing (160) is arranged in a selected plane. In strong wind, a controller commands a rear to wind orientation inside cone C while the hinge geometry feathers the module, and the flexible loop provides compliance and damping. Reference is made to Fig. 1 and 3, which illustrate the tracker assembly 100 including the rotatable mast 102, the yaw bearing / drive 120 that turns the rotating head 150 about axis V-V, the upper support 105, and the hinge assembly 121 that defines the horizontal axis H- H. Fig. 5 shows a two post loop in which a flexible element 260 is reeved about rotating traction elements 250 to form an azimuth group drive that couples neighboring posts. Figs. 5, 6, and 10 show traction details using a rotating traction element (wheel body 230 with grooves 232) that positively locks the flexible member into the wheel via locking / anchoring member 270, so torque is transmitted without slip. A tensioner 240 sets baseline pretension.

[0182] A photovoltaic module (500) mounted to the upper support (105) by a hinge assembly (121) defining a substantially horizontal axis H-H positioned forward of the aerodynamic center AC so that rear face wind (500B) feathers the module. Stops include a rest tilt limiter (108) for rest tilt and optionally an upper stop (112) for feathered seating; a rest tilt limiter may be a stop bar, a front limit stop wire (460) or similar constructions that mechanically stops the photovoltaic module (500) from rotating beyond a rest tilt angle (see Fig. 1).

[0183] According to a further aspect of the present invention relating to an off-center hinge for passive feathering, as shown in Fig. 3, the hinge assembly (121) is positioned such that, under rear face wind (500B), the hinge permits upward feathering toward a low drag attitude without motor intervention, while the optional upper stop (112) provides a defined feathering limit and the rest tilt limiter (108) establishes a rest tilt for low-wind stability.

[0184] The wind-feathering effect previously referred to provides a primary advantage in that it reduces aerodynamic torque along one axis by allowing the modules (500) to rotate away from the incident wind. This reduces the risk of resonance build-up along that axis. However, the swing-mode effect that results from this same freedom of rotation increases the risk of resonance about the horizontal hinge axis H-H, since modules can undergo pendulum-like oscillations that couple with gust energy.

[0185] To address this, a bracing element (160) is introduced which increases the stiffness of the tracker head superstructure (150), thereby suppressing the swing-mode resonance. Analysis has shown that inclusion of the bracing element shifts the natural frequency of the system in a typical implementation from 1.7 Hz to well above 5 Hz, a regime in which excitation from wind energy is not capable of driving resonance.

[0186] While the braces (160) effectively suppress swing-mode resonance by stiffening the structure, they also limit the range of independent rotation of the panels (500). As a result, the modules can only feather in a single direction relative to the wind. To preserve the beneficial wind-feathering effect, the assembly further comprises a yaw motor that rotates the mast (102) and superstructure (150) about axis V-V such that the incident wind is always directed from behind the modules. In this way, the modules retain their ability to rotate away from the wind in the permitted direction, while still being protected from resonance risks.

[0187] According to a further aspect of the present invention relating to directional bracing, two braces (160) are disposed within the superstructure (150) in a plane selected to raise the frequency of the most vulnerable sway / "bounce" mode while not tying the head to ground. This bracing is compatible with continuous yaw about V-V and is shown in Fig. 2. A particular challenge arises in connection with the previously presented swing-mode effect and the mast-resonance effect. Each of these dynamic modes can independently introduce oscillatory motion of the modules (500). However, when the modal frequencies of swing mode and mast resonance are proximate, mode coupling may occur, whereby oscillations about the horizontal hinge axis H-H (swing mode) excite oscillations of the vertical mast (mast resonance), and vice versa. Such coupled resonance produces mutual amplification of displacements and imposes destructive structural loads.

[0188] It is therefore of critical importance that the tracker assembly (100) maintains a vertical torque modal frequency separation between swing-mode and mast-resonance modes. In preferred embodiments, this is achieved by introducing the bracing element (160), which increases the effective stiffness of the superstructure (150) and shifts the swing-mode natural frequency. This establishes a frequency margin sufficient to ensure that the swingmode frequency is spectrally isolated from the mast-resonance frequency, thereby preventing dynamic coupling and resonance amplification.

[0189] According to a further aspect of the present invention, relating to flexible element coupling, adjacent tracker assembly heads are coupled by a flexible element (260) reeved around traction elements (250) with about 1.0-2.0 wraps to enable rotation, and a positive locking member (270) that provides an anti slip fixation; baseline pretension is maintained by a tensioner (240), and an optional compliance module (210) in a nondriven run provides elastic extension under gust load. Routing and clearance is shown in Fig. 5 and Fig. 6. The flexible loop transmits commanded azimuth while permitting small, bounded relative yaw between neighbors by elastic stretch and sag straightening, thereby reducing torsional lock in.

[0190] With reference to Figs. 12 and 13, cone C represents a bounded angular sector centered on the current wind direction W. During storm mode the controller yaws the tracker about the vertical axis so the rear surface 500B remains inside this cone. A preferred half angle is in some implementations variable and calculated based on specific wind speed, current variations in wind direction and other factors. In some implementations a cone C of for instance ±15° is applied. Keeping the rear surface 500B within cone C reduces the aerodynamic yaw torque that would otherwise act on the mast.

[0191] In the "within-cone" case the wind direction indicator W shown by the arrow lies inside the cone boundaries in Figs. 12 and 13. The tracker heading is therefore acceptable. The rear surface 500B faces generally downwind, the horizontal hinge works in its favorable feathering sense, and the panel tends toward a low-drag attitude. Only small heading corrections are required to keep the arrow inside cone C.

[0192] When the wind shifts or gusts push the arrow beyond the cone boundary, the controller detects that the rear surface 500B is no longer inside cone C. The controller then commands a corrective yaw rotation to bring the arrow back into the cone. Once the arrow re-enters the cone, heading changes are minimized to avoid hunting while the rear surface 500B is held within the allowed range.

[0193] These examples help visualize correct and incorrect alignment. If the arrow is clearly inside cone C, the tracker is properly wind-aligned and the hinge can feather the panel toward the upper stop in strong rear winds. If the arrow is clearly outside cone C, the tracker is pointed the "wrong" way for wind relief, yaw torque rises, and the system promptly re-aligns so the rear surface 500B is again held within cone C.

[0194] Aspects of the present invention will now be described with reference to wind responsive off-center horizontal hinge behavior.

[0195] According to one aspect of the present invention, as shown in Fig. 1 and Fig. 2, a wind responsive off center horizontal hinge axis H-H is provided. Each panel 500 is mounted to the panel support 105 by a hinge assembly 121 establishing a horizontal hinge axis H-H. The axis H-H is placed forward of the panel aerodynamic center AC so that wind incident on the rear face 500B produces a lifting moment urging the panel to rotate upward (toward a lower angle of attack), thereby passively feathering under rear wind conditions. In representative implementations, the hinge axis AC H-H is placed within -5% to +10% of the windward end (percentages measured along the chord Lc from the windward edge). Where "windward to leeward direction" is the in-plane panel direction normal to the hinge axis H-H, measured from the edge of the panel (500) that faces the incident wind vector W (windward edge) toward the opposite edge (leeward edge) in the stowed orientation used for hinge placement. For rear-wind operation the windward edge is the rear edge that faces the wind on the rear face (500B). This off center placement and the associated rotation sense are depicted in Fig. 1 and Fig. 2. Optionally, the hinge may employ a friction damped characteristic with an approximate Coulomb torque in the range of 5-25 N-m per meter of module width to suppress chatter while allowing quasistatic feathering, and the optional upper stop (112) preferably caps feathering within -10° to +10° of horizontal. The hinge geometry is arranged so that, under increasing wind, the panel moves along a controlled path from a rest tilt position toward a feathered extreme that may be limited by an upper stop 112. The overall assembly layout, including the relationship of H-H to the support 105, the presence of directional braces 160 within the rotating head 150, and the location of limiters 108 / 112 relative to the carrier 107, is shown in Figs 1-3. Optional hinge region damping elements may be included but are not required in the preferred embodiments of the present invention.

[0196] Aspects of the present invention will now be described with reference to rotation and tilt limiters.

[0197] Further aspects of the present invention relating to rotation limiters that bound the panel's motion about H-H and provide (i) a stable rest tilt for low and moderate winds and (ii) a defined feathered extreme for strong rear winds, will now be described.

[0198] According to one aspect of the present invention, relating to a rest tilt limiter, in one embodiment, a rest tilt limiter 108 on the rotating head 150 or support 105 establishes the rest tilt by providing a seated contact for the panel frame. Optionally, a soft pad 110 may be placed at the contact to protect the module frame. In an alternative embodiment, an adjustable front limit stop wire 460 sets the rest tilt by length between an attachment point located on the panel (500) or some other part of the structure that rotates around the horizontal axis, and the mast (102) or some other part of the structure that is fixated in relation to the horizontal axis. See Fig. 3. Both embodiments allow free upward feathering under rear wind toward the optional upper stop.

[0199] In an alternative embodiment, the rest-tilt limiter 108 is formed above the hinge H-H as a contact stop between the panel carrier 107 and the upper support 105. A stop tab fixed to an upper portion of the carrier 107 advances toward an abutment mounted on the upper support 105. As the module 500 rotates downward toward its production attitude, the stop tab bears against the abutment and prevents further rotation past a defined rest tilt.

[0200] The soft pad (110) is an energy absorbing interface, for instance an EPDM or polyurethane pad of 50-70 mm and 6-20 mm thickness, sized to limit peak contact stress and rebound. An upper stop 112 is positioned so that, when the panel feathers upward under rear wind, the upper frame or carrier 107 seats against 112 at a chosen storm angle. A detail of the upper stop interface, including the pad 110 where used, is shown in Fig. 4A, 4B and 4C. Limiter settings may be field adjustable and locked using a jam nut and cotter or crimp sleeve to maintain tolerance over life.

[0201] The functional role of the rest tilt limiter will now be described. The rest tilt limiter, such as bar 108 or wire 460 stabilizes the panel posture in low / moderate winds and during production; the upper stop 112 provides a repeatable feathered fixation in strong rear winds. These limiters cooperate with the off center hinge 121 to bound motion, while permitting the passive feathering action elsewhere described. This can be seen in Fig. 4B.

[0202] The foregoing ranges are configured to produce a net aerodynamic moment about H-H under rear face winds W so that the module 500 tilts upward (feathers) toward a reduced angle of attack and optionally settles against the limiter (112) when required. In some embodiments, the offset selection is co tuned with any gravity bias element (e.g., a counterweight) and the chosen rest tilt limiter so that feathering onset and end stop engagement occur within site target wind bands without chatter.

[0203] Aspects of the present invention will now be described with reference to drive train compliance and coupling.

[0204] In one aspect of the present invention, adjacent tracker assemblies 100 are azimuth-coupled by a flexible element 260 reeved around a rotating traction element 250 on each mast 102. The traction element includes grooves 232 and a positive locking or anchoring member 270 so the flexible element is fixed to the wheel with no designed slip under service loads. Each traction element carries at least about one to one and a half wraps to maintain traction in normal operation. The resulting loop provides an equivalent torsional compliance and damping effect between tracker posts.

[0205] In a two-post loop the two runs of the flexible element 260 act like a spring that resists relative twist between posts 100. The loop is stiffer when the flexible element 260 is larger or made from a higher-modulus material, and when the effective wheel radius at the rotating traction element 250 is larger. It is softer when the free span length is longer. For small relative yaw angles the shared torque rises roughly in proportion to the angle. At rest there is often a small catenary sag. The first part of a gust straightens that sag, so the loop stiffens smoothly as the sag is pulled out. This allows small, bounded relative yaw between neighbors while keeping traction at 250. Optionally, a compliance module may be added, and in a non-driven run behaves like another spring in series with the loop. It lowers the effective stiffness, limits peak loop tension during gusts, and still preserves positive traction at 250. However, it is an object of the present invention that inherent compliance in a flexible element 260 is often times sufficient.

[0206] With a 6 mm flexible element 260, a wheel radius of about 0.15 m, and a free span of about 12 m per run, a 5° differential yaw produces about 0.55 kN-m of shared torque while still allowing gust-relief motion. These numbers are illustrative only and can be scaled with rope size, material, wheel radius, and span.

[0207] Fig. 15 is a perspective view of a rotating traction element 250 mounted on the mast 102. The element includes a wheel body 230 fixed to the mast through an upper plate 220 and a bolt circle. Four separate runs of the flexible element 260 are shown as strands 260A, 260B, 260C, and 260D. Each strand sits in a circumferential groove on the wheel body and approaches from opposed directions to form two opposed pairs.

[0208] A positive locking or anchoring member 270 captures each strand to the wheel. The lock guides the strand around an end-rotation point 283 where the strand terminates while remaining positively held. Traction is provided by this positive capture and by baseline pretension in the loop, not by capstan friction along the groove. The arrangement maintains no-slip torque transfer at the wheel in normal service.

[0209] The figure depicts a neutral, half-wound condition. Each of the four strands is partially wrapped so the wheel can rotate in either direction from this state. When the wheel turns, one strand of an opposed pair winds while its mate unwinds, and at least one opposed pair remains in tension to apply torque. Because each strand is locked at 270 and terminates at 283, the strand does not release when it reaches the unwound limit. Commanded azimuth is therefore transmitted reliably while the flexible element outside the wheel provides elastic give for gust relief.

[0210] The four-strand layout illustrated in Fig. 15 supports the group-drive usage described elsewhere. Two strands can be routed locally for the powered post and two onward to a neighboring post, with bounded differential yaw permitted by elastic stretch and sag straightening in the free spans.

[0211] In the clockwise excursion from neutral (Fig. 16, rotation +200°), strand 260b becomes fully wound while the opposed strand 260a becomes fully unwound and is constrained from further payout by the associated locking / anchoring 270 at the end rotation point 283. The remaining strands 260c and 260d assume mirrored states. In the counterclockwise excursion (Fig. 16, rotation -200°), strand 260a is fully wound and strand 260b is fully unwound and positively held at 270 / 283, with 260c / 260d again assuming mirrored positions. This four run arrangement maintains a bidirectional pul l / pull capability: for any commanded direction, one of a first opposed pair is tensioned to apply torque while its mate provides opposed tension and positional stability; the second pair simultaneously provides either a power take off to an adjacent post or a return path as described below.

[0212] Referring to Fig. 17, two strands (260c, 260d) are routed locally to a powered traction element 251 (i.e., the motorized wheel assembly coupled to the yaw drive 300 on the same post), and two strands (260a, 260b) are routed onward as a group drive link to a downstream rotating traction element 250' on an adjacent tracker assembly 100'. In this configuration the powered traction element 251 supplies the commanded azimuth rotation to its own post while simultaneously distributing motion through the onward pair (260c, 260d) so that the adjacent post tracks azimuth with bounded relative yaw permitted by the elastic characteristics of the loop and any intentional compliance module 210 placed in a nondriven span. Throughout the travel range (about ±200° from neutral, total travel on the order of 400°), at least one of the four strands is always in tension, and no designed slip occurs between the strands and the traction element because each strand is positively locked at 270 and terminated about 283.

[0213] Referring to Fig. 17, when a post employs the powered traction element 251, the torque reaction that would otherwise be distributed along a rigid shaft is localized to the motorized post and is reacted to ground via the mast base and auxiliary torque reaction anchors. In the embodiment shown, a torque reaction frame 254 coupled to the mast 102 is tied to four ground anchors 56 (e.g., ground screws). This localized reaction enables the array to accommodate high transient motor torque without requiring enlarged foundations at nonmotor posts: additional anchoring is only necessary around the motorized unit where the traction drive torque accumulates. The remainder of the posts employ the fourrun wheel architecture for motion transmission and gusttolerant compliance without heavy foundation upgrades.

[0214] The four run wheel with positive tail locking 270 and endrotation points 283 provides (i) bidirectional torque transfer with continuous availability of at least one tensioned strand, (ii) large angular travel ("'±200° from neutral) without loss of capture at the fully unwound condition, and (iii) selective localization of torque reaction at the powered traction element 251, enabling singlepost trackers with modest anchoring at nonmotor sites while maintaining robust drive control. Because traction is assured by positive locking rather than capstan friction, the architecture is tolerant of environmental variability (e.g., wet or icy strands) and service pretension can be set by 240 for accurate heading control while preserving elastic give where 210 is specified.

[0215] A two post loop arrangement is illustrated in Fig. 7, in which opposed runs of the flexible element 260 couple the traction elements 250 of neighboring masts 102, with an inline tensioner 240 for pretension and fine heading trim. An optional compliance module 210 can be placed in a nondriven run to absorb transient tension rise. The loop is routed below the lowest panel edge to avoid interference with the module 500 and limiters 108 / 112 / 460.

[0216] Fig. 6 is a perspective view of the rotating traction element 250 mounted on the tracker mast 102. A wheel body 230 is fixed to the mast by a bolted mounting plate 220. The wheel body carries circumferential grooves 232 sized to receive a flexible element 260 that forms the azimuth group drive between neighboring posts.

[0217] The view illustrates a neutral, partially wound condition that allows rotation in either direction. From this state the wheel can rotate through its operating travel while one opposed run remains tensioned to apply torque. Elastic stretch and straightening of small catenary in the free spans of the flexible element provide bounded compliance under gusts while the locked interface at 270 preserves position control.

[0218] The assembly shown in Fig. 7 represents the two-post loop arrangement described elsewhere. A tensioner on a non-driven span sets baseline pretension and can be used for fine heading trim, though it is not visible in this view.

[0219] For scalability, several short loops can be driven from a single actuator by segmenting the array into groups; one embodiment is shown in Fig 11, in which multiple short loops are powered and managed as discrete segments to bound accumulated stretch and maintain controllability.

[0220] The coupling is configured so that compliance arises from elastic extension of the tensile element 260 and straightening of its small catenary sag under gust loading, rather than from wheel slip. Overload protection may be provided on nondriven runs by an overload release or equivalent weak link element, optionally paired with a backup tether.. , as described in the drawings package; segment couplers 268 may be used to define loop boundaries for group coordination. According to one aspect of the present invention, as shown in Fig. 8, a chain implementation uses a sprocket 252 and chain 262 with functionally equivalent locking and termination details. Fig. 10 shows an aspect of the present invention where two post loop plans are depicted, in which the flexible element 260 is pretensioned using a tensioner 240, guided by an idler or a fairlead 208 where needed, and may include a compliance module 210 placed in a nondriven span to limit peak tension rises under gusts. Multiloop group drives— where one motor drives several short loops for scalability— are illustrated in Fig 11, with segment routing and per loop tensioners 240 facilitating installation and service.

[0221] Fig. 14 is a bird's eye view of three groups of tracker assemblies 100. The center group includes three trackers carried on masts 102 that are shown at an oblique heading. A flexible element 260 runs between the center trackers in two opposed spans. Each span is reeved over a rotating traction element 250 mounted on the mast 102.

[0222] A tensioner 240 is positioned in a non-driven run of the flexible element 260 to set baseline pretension. Traction at each mast is maintained by a wheel body 230 with grooves 232 and a positive locking member 270 that fixes the flexible element to the wheel so normal service is no-slip.

[0223] Small angle differences between the three center heads 150 indicate bounded relative yaw within the group. Elastic extension and straightening of small catenary in the flexible element 260 permit a few degrees of differential rotation under gusts while commanded azimuth remains shared across the loop.

[0224] The trackers 100 shown to the left and right represent neighboring groups that are held at different azimuth headings by the controller using staggered offsets AIJJ. Each group remains within its own wind-aligned cone C during storm operation, not shown in plan for clarity.

[0225] Under wind loading, the flexible element 260 behaves as a compliant link. Compliance arises from the element's inherent axial elasticity and from geometric effects along its path, including small curvature changes where it wraps the rotating traction element 250, seating of the strand lay and terminations, an d straightening of any initial sag. These mechanisms act with or without added slack or discrete springs. They admit small, bounded differential yaw between neighboring trackers while traction at 250 remains positive and noslip. The compliant coupling reduces and decorrelates torsional impulses transmitted between posts. It works together with the wind-aligned cone control as previously described and the feathering hinge as previously described. Optional features may be included without departing from the scope, such as an overload release, a backup tether, segment couplers 268, loop connectors 266 and segment decouplers.

[0226] Aspects of the present invention relating to yaw control will now be described.

[0227] According to a further aspect of the present invention, relating to wind aligned yaw control, in some embodiments, a controller commands a yaw motor 300 to rotate the tracker about the substantially vertical axis V-V such that, when wind exceeds a site configured storm threshold, the rear face 500B of the module 500 is maintained within a wind aligned cone C about the instantaneous or filtered wind direction W. The cone half angle is selectable. By way of nonlimiting examples, Fig 12 and 13 illustrates a preferred ±15° cone (C15) boundary. Enter / exit hysteresis may be applied in firmware so that the stow state persists until winds decay, thereby avoiding chatter, while remaining implementation agnostic with respect to the exact thresholds.

[0228] The wind aligned cone strategy reduces yaw torque about V-V by keeping the array oriented with its rear to the wind, while the off center hinge, as previously described, feathers the module toward a low angle of attack about the hinge axis H-H. In operation, the controller receives a wind direction input and issues commands through an actuator driver to the motor 300. The controller may maintain a state machine associated with storm mode without limiting the scope of the claimed mechanics.

[0229] In one embodiment, torque transmission between posts is accomplished by dual wire ropes extending from the drive motor to successive wheels. When wind forces act upon the panels (500), the aerodynamic loading generates a net yaw torque that tends to rotate the panels in a unified direction about the vertical axis V-V. This unified tendency produces differential loading of the rope pair: the windward rope run is placed into increased tension while the leeward rope run correspondingly slackens. Because the dual ropes are continuous along the array, the tightening rope transmits the torque through the system directly back to the motor, while the slackening rope has reduced tension.

[0230] In a preferred embodiment, dual wire ropes are employed as the transmission medium specifically configured to achieve vertical-axis torque modal frequency separation is achieved by establishing a baseline pretension within a commissioning window, for example between about 0.4 kN and 2 kN per tracker unit, tunable to site conditions. Under high-wind events (e.g., site winds > 25 m / s), the leeward tensile run is permitted to momentarily relax toward zero tension when wind-induced torque subtracts from the baseline pretension, while the windward run remains in tension. This interrupts coherent bi-directional torque transmission within a gust half-cycle. In preferred embodiments, an optional compliance module (210) is provided to furnish bounded extension and hysteretic damping, thereby capping peak tension rise. Collectively, these features establish modal decoupling between the principal panel feathering mode (about horizontal axis H-H) and the azimuthal torsion mode (about vertical axis V-V), enforce desynchronization of inter-post excitations, and suppress array-level lock-in.

[0231] Furthermore, the wind-induced torque acting on each panel is aggregated and conveyed through the tensioned rope path. In aggregate, substantially all wind-induced torque is transmitted back to and resisted by the motor, thereby preventing destructive torque accumulation on the tracker units in the array and ensuring that the motor serves as the sole reaction point for group-wide wind loading.

[0232] Because wind-induced torque acting on the panels (500) is transmitted through the dual wire rope system back to the motor, no individual post or pole along the array is subjected to large unbalanced torque. Each non-motor pole carries only localized vertical and bearing loads, permitting such poles to be stabilized by a single-point anchoring arrangement without risk of torque overload. By contrast, at the motor location, where substantially all wind-induced torque is aggregated and resisted, two or more poles are employed in parallel. This multi-pole foundation provides the structural capacity to absorb the accumulated torque while the motor serves as the sole reaction point for array-wide torsional loading.

[0233] In a multi tracker installation, to prevent array level symmetry that can promote resonance, neighboring trackers may be assigned small, bounded azimuth offsets AIJJ while each remains within its own cone C. Fig 14 depicts an embodiment in which adjacent posts receive alternating +AI|J / - AIJJ offsets so that headings are desynchronized while still back to wind. In coupled groups using the flexible loop previously described, this heading staggering cooperates with the elastic coupling to disrupt narrowband torsional lockin. Fig. 14 schematically illustrates gusty wind behavior in which trackers remain within their cones yet exhibit noncoherent responses due to turbulence and the compliant coupling.

[0234] The above yaw control primarily addresses azimuthal torque; absolute aerodynamic force reduction occurs by the hinge induced feathering and by the distributed compliance in the wire / chain loop as described elsewhere in this document. The combined action of (i) wind aligned azimuth via the controller and motor 300, (ii) passive feathering about H-H, and (iii) compliant inter post coupling provides coordinated mitigation of torsional excitation about

[0235] V-V. Aspects of the present invention will now be described with reference to suitable inputs and signal conditioning.

[0236] The controller receives wind data from at least one wind input, optionally fused with a forecast input. The wind input may include a local anemometer (cup, ultrasonic, or equivalent) installed at a representative height, be derived from other sensors, and / or an external feed. The controller conditions the signals using (i) vector averaging for direction, (ii) dual timescale magnitude filters— e.g., a short window 2-3 s) to detect gusts and a longer window 30-60 s) to follow background wind— and (iii) outlier rejection / fallback rules if data are missing or implausible. Direction is maintained as a wrapped azimuth; speed is handled as both mean and peak gust estimates.

[0237] According to a further aspect of the present invention, relating to a storm threshold for entry and exit logic the controller uses a parameter set, any source of weather information may be utilised, encompassing sensor data such as wind speed, wind direction, wind turbulence etc, or further it may be based on historical weather information or forecasted information, alternatively it may even be based on opinion or speculation from an individual or individuals. By way of example only, the following information is provided: entry threshold Hl, an exit threshold H2, and a dwell time td. Hl and H2 may be based on one or more of the following:

[0238] 1. Mean wind criterion. Enter storm mode when the filtered mean speed is at or above Hlmean (for example, 8-10 m / s). Exit when the filtered mean speed is at or below H2mean (for example, 6-8 m / s).

[0239] 2. Gust criterion. Enter when a short-window gust estimate is at or above Hlgust (for example, a 3-second equivalent of 12-15 m / s). Exit when the gust estimate is at or below H2gust (for example, 8-10 m / s).

[0240] 3. Hybrid criterion. Enter when either the mean or gust criterion meets Hl. Exit when both the mean and gust fall below H2 for at least td (for example, 60-180 s) to avoid chatter.

[0241] 4. Alert or forecast criterion. Enter or pre-stow on a designated external alert, such as a site-specific severe-wind advisory, or when a forecast peak gust for the next interval exceeds a configured bound. Return to normal when the alert clears and measured winds remain below H2 for at least td.

[0242] All numerical values are examples only and may be set per site. According to one aspect of the present invention, relating to vertical axis yaw and wind aligned operation, each tracker assembly 100 is rotatable about a substantially vertical yaw axis V-V carried by a yaw bearing / drive 120 on mast 102, the rotation being driven by a yaw motor 300 under control of a controller receiving windspeed and wind direction inputs. As used herein, "storm mode" is a controller state in which sun tracking is suspended and the controller commands a rear-to-wind heading within a bounded wind-aligned cone C based on wind speed and wind direction inputs, with hysteresis on exit. By way of example, when a gust, such as a 3 second gust measured from a local wind input (322) and / or a site SCADA feed exceeds an entry threshold Hl (e.g., 15 m / s), the controller commands a heading IJJ such that the rear face (500B) remains within a wind aligned cone C centered on the vector averaged wind direction. Storm mode exits only after wind falls below a lower threshold H2 (e.g., 12 m / s) for a dwell time td (e.g., 60 s). Preferred embodiments employ a half angle of about ±15° (illustrated as C), while other embodiments use exact alignment (0° half angle) or a wider cone (e.g., ±30°). Wind direction is computed as a 3-10 s vector average sampled at >1 Hz; upon loss of valid wind input the controller defaults to a conservative downwind heading based on the last reliable prevailing wind estimate. Entry / exit hysteresis and dwell, which are implemented in the controller state logic so that the storm mode heading is maintained stably without chatter.

[0243] Yaw alignment by the controller and yaw motor 300 reduces aerodynamic yaw torque about the vertical axis V-V by holding the module 500, and specifically the rear face 500B, within a wind-aligned cone C. Yaw alignment does not by itself reduce face pressure when the panel is broadside. Force at the panel is reduced by the wind-responsive horizontal hinge assembly 121 about axis H-H, as shown elsewhere in this document. Remaining torsional content is attenuated by the flexible azimuth group drive including the rotating traction element 250, the flexible element 260, the tensioner 240, and an optional compliance module 210, demonstrated elsewhere. Fig. 12 and 13 shows the cone policy C and the rear-to-wind posture that keep the hinge 121 operating in its favorable feathering sense.

[0244] In some embodiments, the tracker assembly (100) includes a rotary electrical interface or an internal cable routing arrangement that preserves electrical continuity during azimuth rotation about axis V-V. In one approach, DC and signal wiring from the photovoltaic module (500) enters at the top of the rotating superstructure (150), passes through the yaw drive (120), and exits through, or below, the non-rotating portion of the mast, thereby preventing cable twist while the mast rotates. A rotary slip-ring may be provided at the yaw joint, or alternatively, an internal routing path with controlled slack or helical service loops Cmay be arranged inside the yaw drive (120) so that continuous azimuth motion is permitted without stressing the conductors. These provisions ensure that electrical connectivity to the module (500) is maintained irrespective of the yaw orientation of the tracker.

[0245] To disrupt array scale symmetry and avoid phase locked excitation, adjacent tracker assemblies may be intentionally commanded to different headings using bounded stagger offsets AIJJ while each remains inside its own cone C. In one implementation, neighboring trackers receive alternating positive / negative offsets with magnitudes selected within ±5° to ±15° (example range), thereby desynchronizing aerodynamic inputs without departing from tailwind protection.

[0246] When multiple trackers 100 are coupled by a flexible element 260 wound around rotating wheels 230, commanded yaw is transmitted because each run of the flexible element is positively locked to the wheel. Controlled wraps of flexible element 260 around wheels 230 are provided only to package angular travel: as a wheel 230 turns, one run of flexible element 260 winds while the opposite run unwinds until the end of the wrap is reached, which sets the available rotation window. Elastic stretch in the free spans of flexible element 260 permit small, bounded relative yaw under gusts.

[0247] Control behavior once in storm mode will now be described. Upon Hl entry, the controller transitions its state register to STORM_ALIGN and commands a yaw setpoint that maintains the module rear face within a selected wind aligned policy. In preferred embodiments the policy is a narrow cone (halfangle ±15°) about W; alternatives include exact alignment (0°) or a wider cone (e.g., ±30°) to reduce motor activity in highly variable winds. Within that policy the controller may apply small, bounded heading offsets AIJJ between neighboring trackers to break array scale symmetry while each unit remains inside its cone. Feedback regarding the yaw position of the tracker may be fed into the decision making to ensure optimal position is achieved.

[0248] To illustrate this aspect of the present invention, an example embodiment will now be described. A representative configuration used in prototypes set Hlmean ~ 13 m / s OR Hlgust ~ 20 m / s, H2mean ~ 9 m / s AND H2gust ~ 15 m / s, with t ~ 120 s and a ±15° cone policy. Direction was filtered with a 5-10 s vector average; speed used parallel 3 s and 30 s windows. Heading staggering AIJJ was assigned randomly in the range ±5-12° per unit identity to suppress coherent excitation. These values are examples only and are not limiting. Aspects of the present invention will now be described with reference to single post and shallow anchoring.

[0249] Because aerodynamic input is reduced at the panel by feathering about H-H and azimuthal torque is minimized by wind aligned stow and the compliant group drive, the residual loads transmitted through the mast 102 into the footing 130 are reduced in magnitude and rate of change. As a result, in many sites a single post superstructure with a single point foundation is sufficient without resorting to heavy trussing. A single-post tracker may use a shallow anchor 130, such as a driven pile, ground screw, or ballast. Under wind-relief operation, loads are transferred through the structure into element 130 along representative load paths. Selection of the foundation type and the embedment depth for element 130 follows geotechnical practice and site-specific codes, and this disclosure does not prescribe any embedment geometry. In representative implementations of the disclosed wind relief architecture, measured and simulated responses show material reductions in base shear and overturning moment at 130 relative to fixed panel baselines, as described elsewhere in this document. Rather, the figures explain that the disclosed combination— off center hinge feathering, wind aligned yaw control, and flexible inter post coupling— reduces the excitation that typically drives the need for deep or multipoint foundations, enabling single post layouts in a range of soils and wind classes.

[0250] Aspects of the present invention will now be described with reference to counterweights.

[0251] In some embodiments of the present invention, a counterweight (not shown) is mounted to a counterweight arm (not shown) carried by the rotating superstructure 150 and positioned to act with respect to the horizontal hinge axis H-H so as to provide a gravity bias moment on the module 500. The counterweight is located so that, in low to moderate winds, the module adopts and holds a defined rest tilt against the rest tilt limiter 108, and, in high downwind conditions, the gravity moment assists the hinge to move the module toward a low-drag attitude while avoiding adverse shading.

[0252] The counterweight bias reduces the effective small signal "gravity spring" that would otherwise oppose upward feathering of the module under rear face wind, thereby lowering the tendency for oscillation about H-H as the aerodynamic moment varies. Aspects of the present invention will now be described with reference to hinge tuning and damping.

[0253] The module 500 is supported on a wind responsive hinge assembly 121 defining the horizontal hinge axis H-H. In certain embodiments a hinge damping pack comprising one or more of a friction ring, friction pad, and preload adjuster is employed to add rotational damping about H-H so as to dissipate energy from rapid excursions while maintaining free feathering under sustained rear face wind. An optional torsion spring can be included where a lifting moment about H-H is desired without materially impeding the feathering function.

[0254] Soft end stop interfaces are provided to manage contact at travel limits. In particular, a lower stop bar establishes a production / rest tilt and receives the module or carrier 107 against a soft pad 110; an upper stop 112 is positioned to seat the module or carrier when feathered in high winds, thereby stabilizing the module in a defined position. A front limit stop wire 460, as shown in Fig. 4, can be used as an alternative to the lower stop bar 108. Representative placements and clearances are shown in Figs 1 and 2.

[0255] Aspects of the present invention will now be described with reference to control system details.

[0256] A controller receives windspeed and wind direction inputs and commands a yaw motor 300 to maintain the rear face 500B of the module within a defined directional cone C about the prevailing wind vector W during storm conditions while applying hysteresis between entry and exit thresholds. A preferred cone half angle of ±15° (C15) is illustrated in Fig 12 and 13, with a wider C30 boundary shown as a dashed reference. The controller includes logic to estimate heading IJJ and state and to execute storm mode state transitions.

[0257] To disrupt array scale symmetry and avoid phase locked excitation, the controller can apply bounded staggered heading offsets AIJJ among neighboring trackers while keeping each tracker within its respective cone C. An example of alternating offsets is shown in Fig 14. Where trackers are mechanically coupled in short loops as previously described, the staggered offsets are selected so as to remain compatible with the loop's pretensioned heading while allowing the compliance of the flexible element 260 to absorb gust induced transients.

[0258] In embodiments employing multiple flexible elements 260, controller coordinates the behavior of each segment, such as those shown in Fig. 11, maintains stable headings across loop boundaries, and preserves a no-slip condition at each rotating traction element 250 by maintaining pretension with tensioner 240 and by following the specified wrap count and positive locking scheme using grooves 232 and locking member 270 as shown in Fig. 6. In some embodiments, a controller-implemented method that holds each tracker 100 within a wind-aligned cone C while applying bounded, alternating azimuth offsets Ai to adjacent units constitutes an independent control method irrespective of the particular mechanical realization.

[0259] Under turbulent loading, the disclosed combination of wind-aligned yaw, off-center hinge feathering, directional bracing 160, and drivetrain compliance reduces cyclic stress ranges transmitted to 102 and 130.

[0260] By way of example, the following pseudocode is provided:

[0261] State TRACK: if wind_speed_3s > Hl then goto STORM_ALIGN.

[0262] State STORM_ALIGN: compute target heading from W and policy C (Exact / ±10° / ±30°); apply perunit stagger AIJJ per parameter set; command 300 while holding deadband to avoid hunting; if wind_speed_3s < H2 for >td then goto RESUME.

[0263] State RESUME: return to solar tracking with hysteresis cleared.

[0264] Various methods of operation according to aspects of the present invention will now be described.

[0265] A method of mitigating wind induced loads includes: (i) detecting wind speed and direction and commanding a yaw motor 300 under a controller so a panel rear 500B remains within a wind aligned cone C (Fig 12 and 13); (ii) allowing a panel 500 mounted by hinge 121 about axis H-H to feather toward a reduced angle of attack, bounded by limiters 108 / 110 / 112 and, where provided, a front limit wire 460; and (iii) transmitting azimuth actuation between trackers through a flexible element 260 reeved over traction elements 250, with baseline load set by tensioner 240 and, in some variants, an inline compliance module 210, thereby admitting bounded elastic extension that reduces torsional lockin between adjacent masts. Optional array level staggering of headings ±Ai is applied during storm operation to disrupt symmetry (Fig 12 and 13.

[0266] A method of commissioning and pretension a tracker system 100 includes: (i) prestretching the flexible element 260 to stabilize in service elongation; (ii) fixing the element to the traction element 250 using locking member 270; (iii) setting baseline tension with 240; and (iv) verifying routing / clearances so the loop remains below the lowest panel edge. These steps establish repeatable traction and alignment for normal tracking and storm operation.

[0267] Operability and performance of the present invention was demonstrated by analysis, wind-tunnel campaigns, and field trials on instrumented prototypes. Scale models and full-scale hardware used the rotating head 150, hinge 121 about axis H-H, and the flexible element 260 on traction elements 250. Wind was measured by an anemometer and logged by a data logger. Representative, non-limiting targets included storm entry at a three-second gust of about 15 m / s with exit at about 12 m / s, drag or moment reductions of about 80 to 85 percent versus a fixed panel, stable behavior in tunnels up to about 50 m / s, and braced-plane first-mode frequencies raised from about 1.8 Hz to at least about 5.5 Hz.

[0268] The off-center hinge 121 placed forward of AC caused passive feathering toward low drag and seated at the upper stop 112 under rear wind, with no flutter observed up to about 30 m / s when the controller held a rear-to-wind heading. The flexible azimuth actuation using opposed runs of the flexible element 260 over traction elements 250 or a wheel 230 with grooves 232 and a locking member 270 maintained traction with no designed slip in service. Under gusts the loop stretched elastically and straightened small catenary, allowing small bounded differential yaw and disrupting array-scale torsional lock-in. In combined feathering and tail-wind yaw, scaled base-shear and overturning-moment reductions of about 60 to 75 percent and 65 to 80 percent were recorded. Modal tests identified braced-plane and torsional modes confirmed the braced-plane lift above about 5.5 Hz. Optional elements such as a compliance module 210 and an overload fuse link on a non-driven run with a backup tether further limited tension spikes.

[0269] The system is designed to withstand a three-second wind gust of about 32 m / s measured at 2 meters above ground. Wind-tunnel tests reached about 50 m / s to provide safety margin, and field trials that entered storm mode at about 20 to 25 m / s showed the same behavior. Each site records its terrain and sensor height and converts wind readings to the 10-meter standard. During commissioning, checks confirm that the drive loop is pretensioned using the tensioner and pretension fixture, that the panel feathers to the upper stop in a light breeze, that the controller holds a rear-to-wind stow, and that the transient response shows no sustained torsional oscillation in the event logs. All values are examples and are not limiting.

[0270] Aspects of the present invention relating to site commissioning will now be described. Upon commissioning of a tracker assembly (100) according to one aspect of the present invention, various parameters, including pretension applied to the flexible assembly (260), are set.

[0271] Non-limiting exemplars include 6 mm galvanized 7x19 IWRC wire rope or 10 mm Grade-60 roller chain; wheels of 250-350 mm pitch diameter with 15-20° V-groove lands; and groove lead / pitch selected to maintain > 80% groove contact along 1.0-2.0 wraps.

[0272] A factory or onsite pretension protocol uses the pretension fixture to prestretch the flexible element (260) and seat terminations (214), followed by setting final tension with (240) and marking alignment / length at (270) for service reference. Where posts sit on uneven terrain, height adjustable mounts and the idler / fairlead set are used to maintain correct rope approach. In all installations, the traction elements (250) and flexible element (260) are placed below the module envelope.

[0273] Acceptable rope lays include 7x19 IWRC or 6x36 IWRC galvanized constructions with fiber-core excluded in outdoor service; acceptable chain includes ISO Grade-40 / 60 roller chain with hardened pins and sealed bushings for corrosion protection.

[0274] Further aspects of the present invention will now be described with reference to FIGs. 18 to 24. For the purpose of FIGs. 18 to 24 and the following text, reference numerals shall have the following meanings.

[0275] Further, terms in the following text shall have the same meaning as terms in the preceding text as follows:

[0276] According to one aspect of the present invention, there is provided a solar panel mounting system containing one or more solar panels. The one or more solar panels sway around a horizontal axis, the horizontal axis attached to a vertical support member around the center of the horizontal axis. The vertical support member is rotatable such that the vertical support member may be rotated to follow the movement of the sun in the sky.

[0277] According to a further aspect of the present invention, there is provided a solar panel mounting system having an inner vertical member fixed to the ground, either directly or via a ground anchoring system. Located over the inner vertical member is a rotatable vertical support member, which rotates around the inner vertical member. Fixedly attached to the rotatable vertical support member is a horizontal axis, preferably the point of attachment of the horizontal axis to the rotatable vertical support member is at or around the center of the horizontal axis. Attached to the horizontal axis are one or more solar panels, these panels are attached such that they may hang from the horizontal axis and sway in the presence of wind. The rotatable vertical support member may be rotated by a motor, the motor may be driven by a computing device which can determine the desired orientation of the solar panels based on measured or predicted wind conditions, or other conditions or requirements. To reduce or limit friction between the inner vertical member and the rotatable vertical support member, bearings may be positioned adjacent the top of the inner vertical member and the bottom of the rotatable vertical support member. In an alternative embodiment, the inner vertical member may be rotatable, while the roatable vertical support member is not rotatable but is rather fixed to the ground as is herein described. According to one aspect of the present invention, as shown in Figures 17 and 18, there is provided a solar panel mounting system X100 comprising a rotatable vertical support member X102, a lower solar panel support member X104, an upper solar panel support member X105, and at least one solar panel X500 having a front surface X500A and a rear surface X500B. Optionally, the rotatable vertical support member X102 may be connected to a motor X300 for driving rotation of the rotatable vertical support member X102.

[0278] The at least one solar panel X500 is attached to one or more connection members X200, which in turn are connected to the upper solar panel support member X105. The connection member X200 is in the form of a hinge or alternative mechanism, that functions to allow one item to rotate relative to another item. In this case, the solar panel X500 rotates relative to the upper solar panel support member X105, while the upper solar panel support member X105 remains static.

[0279] The motor X300 rotates the rotatable vertical support member X102, to place the solar panel mounting system into a desired orientation relative to the position of the sun in the sky, or direction of wind force present. One desired position may be such that the rear surface X500B is facing the direction of any wind force present, upon the wind force contacting the rear surface X500B, the rear surface X500B will rotate around the upper solar panel support member X105 by the connection member(s) X200. Figure 19 demonstrates an example of the solar panel mounting system X100 shown in Figure 18, where the solar panel X500 is rotated in the presence of wind from direction X.

[0280] Figure 20 shows the solar panel mounting system of Figures 17 and 18, where the motor X300 has rotated the solar panel mounting system via the rotatable vertical support member X102. This Figure clearly shows the front surface X500A of the at least one solar panel X500.

[0281] In a further example of the present invention, as shown in Figure 21, there is provided a solar panel mounting system X100 comprising a rotatable vertical support member X102, a lower solar panel support member X104, an upper solar panel support member X105, and at least one solar panel X500 having a front surface X500A and a rear surface X500B.

[0282] Optionally, the rotatable vertical support member X102 may be connected to a motor X300 for driving rotation of the rotatable vertical support member X102.

[0283] The at least one solar panel X500 is attached to one or more connection members X200, which in turn are connected to the upper solar panel support member X105. The connection member X200 is in the form of a hinge or alternative mechanism, that functions to allow one item to rotate relative to another item. In this case, the solar panel X500 rotates relative to the upper solar panel support member X105, while the upper solar panel support member X105 remains static. Provided on the lower solar panel support member X104 are one or more dampening members X110, which function to cushion the contact between the one or more solar panels X500 and the lower solar panel support member X104. The dampening members X110 may be a piece of foam, rubber or similar soft material, alternatively they may be a spring or other elastic component. Any material or component capable of cushioning contact between two items may be suitable for use as a dampening member, as would be readily understood by a person of skill in the art.

[0284] The motor X300 rotates the rotatable vertical support member X102, to place the solar panel mounting system into a desired orientation relative to the location of the sun in the sky, or the direction of wind force present. One desired position may be such that the rear surface X500B is facing the direction of any wind force present, upon the wind force contacting the rear surface X500B, the rear surface X500B will rotate around the upper solar panel support member X105 by the connection member(s) X200.

[0285] In a further example of the present invention, as shown in Figure 21, there is provided a solar panel mounting system X100 comprising a rotatable vertical support member X102, a lower solar panel support member X104, an upper solar panel support member X105, at least one vertical solar panel support member X106, and at least one solar panel X500 having a front surface X500A and a rear surface X500B. Optionally, the rotatable vertical support member X102 may be connected to a motor X300 for driving rotation of the rotatable vertical support member X102.

[0286] The at least one solar panel X500 is attached to one or more connection members X200, which in turn are connected to a vertical solar panel support member X106. The connection member X200 is in the form of a hinge or alternative mechanism, that functions to allow one item to rotate relative to another item. In this case, the solar panel X500 rotates relative to the vertical solar panel support member X106, while the vertical solar panel support member X106 remains static.

[0287] The motor X300 rotates the rotatable vertical support member X102, to place the solar panel mounting system into a desired orientation relative to the direction of wind force present. One desired position may be such that the rear surface X500B is facing the direction of any wind force present, upon the wind force contacting the rear surface X500B, the rear surface X500B will rotate around the vertical solar panel support member X106 by the connection member(s) X200. In a further example of the present invention, as shown in Figure 22, there is provided a solar panel mounting system X100 comprising a rotatable vertical support member X102, a lower solar panel support member X104, an upper solar panel support member X105, at least one vertical solar panel support member X106, at least one diagonal solar panel support member X107, and at least one solar panel X500 having a front surface X500A and a rear surface X500B. Optionally, the rotatable vertical support member X102 may be connected to a motor (not shown) for driving rotation of the rotatable vertical support member X102.

[0288] The lower solar panel support member X104, upper solar panel support member X105, vertical solar panel support member X106, and diagonal support member X107 serve to support the at least one solar panel X500 atop the rotatable vertical support member X102. Generally, the greater the number of support members X104 to X107, the more rigid and stable the solar pane mounting system X100 is in the presence of wind force.

[0289] The at least one solar panel X500 is attached to one or more connection members X200, which in turn are connected to the upper solar panel support member X105. The connection member X200 is in the form of a hinge or alternative mechanism, that functions to allow one item to rotate relative to another item. In this case, the solar panel X500 rotates relative to the upper solar panel support member X105, while the upper solar panel support member X105 remains static.

[0290] The motor X300 rotates the rotatable vertical support member X102, to place the solar panel mounting system into a desired orientation relative to the direction of wind force present. One desired position may be such that the rear surface X500B is facing the direction of any wind force present, upon the wind force contacting the rear surface X500B, the rear surface X500B will rotate around the upper solar panel support member X105 by the connection member(s) X200.

[0291] In a further example of the present invention, the rotatable vertical support member X102 may attach directly to the upper solar panel support member X105. Connected to the upper solar panel support member X105 are solar panels X500, connected via connection members X200, as has been previously described.

[0292] In a further example of the present invention, as shown in Figure 23, there is provided a solar panel mounting system X100 comprising a rotatable vertical support member X102, a lower solar panel support member X104, an upper solar panel support member X105, and at least one solar panel X500 supported by the upper and lower solar panel support members X105, X104. Located at one distal end of the rotatable vertical support member X102 is a horizontal support member X109, while the other distal end of the rotatable vertical support member X102 is secured to the ground via a foundation 50. The rotatable vertical support member X102 may rotate around the foundation 50 using a ball bearing joint. Attached to the horizontal support member X109 are arms X108, which further attach to the upper and lower support members X105, X104. The horizontal support member X109 is rotatable such that rotation of the horizontal support member (such as via wind force) causes the arms X108 to raise, and in turn raise the upper and lower support members X105, X104 which in turn raise the at least one solar panel X500.

[0293] In a further improvement of the present invention, according to any of the examples herein described, a measurement device (not shown) may be used to drive rotation of a solar panel X500 via a motor X300. The measurement device may measure properties of wind or other external force present, these properties include but are not limited to speed, and direction. Upon the measurement device measuring a property at a predetermined threshold, or meeting a different condition, the motor may be directed to rotate the solar panel X500 to a determined orientation. This determination of the required orientation, and control of the motor may be performed by a computing unit (not shown). Ideally, the solar panel X500 is rotated such that the rear surface X500B faces a direction that allows the solar panel X500 to minimize the force excerpted by the wind upon the panel X500 by means of rotating to a position with reduced angle of attack with respect to the wind, the direction of wind force present, such that the wind force causes the solar panel X500 to rotate to a position such as that demonstrated in Figure 19, whereby the solar panel X500 is substantially parallel to the direction of the wind. In this manner, in the presence of high wind or other external forces, the solar panel X500 may rotate to a position whereby wind or other external force is permitted to pass by the solar panel X500, with minimal resistance.

[0294] In all embodiments and examples of the present invention, the solar panel mounting system X100 may be secured to the ground via a ground anchor (not shown) or similar. The ground anchor may be attached to the vertical support member X102. The ground anchor may be in the form of a ground screw as would be understood by a person of skill in the art, preferably the ground screw extends above ground by approximately 20-80cm and contains a hollow aperture within which the vertical support member X102 may be placed. Is this manner, the ground anchor is embedded within the ground, and the vertical support member X102 is secured within it. This provides a solid and stable foundation for the solar panel mounting system X100. Other forms of ground anchors would also be suitable as would be understood by a person of skill in the art., for example multiple ground anchors X103 could be embedded in the ground at different angles, or alternative ballast or weight could be placed atop the ground in the place of a ground anchor. The ground anchors for example may be in the form of a screw which upon rotation into the ground secures the ground anchor within the ground, or they may be in the form of a metal bar having a cross section designed to provide strength, which may include a "C" cross section, "H" cross section, "I" cross section or the like, which may be driven into the ground by force. Further, the ground anchor may have a substantially flat bottom portion.

[0295] The present invention will now be described with regard to the general logic for controlling the solar panel mounting system X100. When wind force meeting a predefined threshold is forecast, the measured wind speed meets a predefined threshold, or other forces meet a predefined threshold, it is optimal for the solar panel mounting system X100 to rotate such that the solar panels to meet a desired condition, for example:

[0296] An angle which allows the solar panels to rotate while avoiding resonance or turbulence.

[0297] • An angle which allows efficient maintenance of the solar panel mounting system to be carried out.

[0298] • An angle which allows for the maintenance, planting, or care of grass or crops located below the solar panel mounting system. For example, in the case of multiple solar panel mounting systems, all panels in a single row of solar panel mounting systems may be rotated to maximize space for machinery, or every second row could be rotated X180 degrees differently. n a further improvement of the present invention, it is possible that any rotated of the solar panel mounting system may be controlled by a remote system, such as via an app on a phone. The app may communicate directly, or via a remote server, with motors which control rotation of individual or a group of solar panel mounting systems.

[0299] The present invention will now be described with reference to solar tracking systems. A solar tracking system moves the solar panels in a solar system to track the sun's movement across the sky to maximize electricity production. Traditionally, there are three forms of solar tracking systems, dual axis trackers, horizontal single-axis trackers (HSAT), and vertical single-axis trackers (VSAT). Dual axis trackers rotate solar panels around both a horizontal and vertical axis, HSAT rotate solar panels around a horizontal axis, and VSAT rotate solar panels around a vertical axis. The present invention relates to solar mounting systems that operate like a VSAT which adapt to the presence of wind, by allowing wind to control rotation of solar panels around a horizontal axis. When wind blows towards rotatable solar panels, with a vertical rotation axis in, or near, the center of the solar panels, the wind will induce torque on the solar panels that will - unless the surface is limited from rotating in some way - rotate the solar panels to face the wind. By making it possible for the solar panels to rotate around a horizontal axis based on the wind, the surface can rotate around this horizontal axis away from the wind and as a result reduce this torque.

[0300] Further when the wind blows toward solar panels, the wind will induce force on the solar panels that can damage or topple the solar panel structure unless it is strong enough to handle this force and attached firmly enough not to topple. By making it possible for the solar panels to rotate around a horizontal axis based on the wind, this will cause less strain on the solar panels and make it harder for the wind to topple the body.

[0301] In order to efficiently operate the solar panel mounting system according to the present invention, it is preferable that the tracking of the sun by the solar panel mounting system is efficient with regard to all variables. For example, in the case of the solar panel mounting system being placed in the northern hemisphere, it is desirable for the solar panels to face toward the southeast in the morning, the south at midday, and southwest in the afternoon and evening. Preferably the configuration of solar panels in the solar panel mounting system are optimised to form as close as possible to a solid line when facing southeast and southwest, while minimising the presence of shadows cast behind them. This optimises land use density. The exact aspect ratio of solar panels can vary depending on latitude and desired land density and shadowing, but for example a ratio of 3:1 width:height may be suitable.

[0302] It should be understood by a person of skill in the art that the material chosen to manufacture the solar panel mounting system X100 from is important, it may be a lightweight material such as aluminium or the like, or portions of the system X100 may be manufactured from a heavier material such as steel to provide ballast to the system X100.

[0303] The solar panel mounting system described herein is versatile and can be used with various types of solar panels. This includes, but is not limited to, crystalline silicon solar panels, thin- film solar panels, and other photovoltaic technologies. The system's design allows for easy adaptation to different panel sizes, shapes, and configurations, ensuring compatibility with a wide range of commercially available solar panels. Whether the solar panels are framed or frameless, the mounting system can securely support and optimize their orientation for maximum sunlight capture and wind resistance. This flexibility makes the invention suitable for diverse applications, from residential rooftop installations to large-scale solar farms.

[0304] Examples of aspects of the present invention will now be listed:

[0305] A first example

[0306] Example 1. A solar panel mounting system for mounting one or more solar panels, including: at least one solar panel, a lower solar panel support member for supporting the at least one solar panel in a rest position, an upper solar panel support member rotatably attached to the solar panel, a rotatable vertical support member supporting a solar panel support member, wherein wind force upon a surface of the at least one solar panel causes the at least one solar panel to rotate around the upper solar panel rotation member out of the rest position.

[0307] Example 2. The solar panel mounting system of Example 1, further comprising a motor connected to the rotatable vertical support member for driving rotation of the rotatable vertical support member.

[0308] Example 3. The solar panel mounting system of Example 2, further comprising a computing unit for controlling the motor.

[0309] Example 4. The solar panel mounting system of Example 3, wherein the computing unit controls the motor to rotate the rotatable vertical support member such that the rear surface of the at least one solar panel faces the direction of incoming wind.

[0310] Example 5. The solar panel mounting system of Example 3, wherein the computing unit determines the future direction of incoming wind.

[0311] Example 6. The solar panel mounting system of Example 5, wherein the computing unit controls the motor to rotate the rotatable vertical support member such that a surface of the at least one solar panel faces the determined future direction of incoming wind.

[0312] Example 7. The solar panel mounting system of Example 3, wherein the computing unit controls the motor to rotate the rotatable vertical support member such that a surface of the at least one solar panel faces within seventy degrees of the direction of present or predicted incoming wind.

[0313] Example 8. The solar panel mounting system of Example 1, further comprising a ground anchor attached to the rotatable vertical support member for attaching the solar panel structure to the ground.

[0314] Further aspects of the present invention will now be described with reference to FIGs. 25 to 32. For the purpose of FIGs. 25 to 32 and the following text, reference numerals shall have the following meanings.

[0315]

[0316] Further, terms in the following text shall have the same meaning as terms in the preceding text as follows:

[0317] According to one aspect of the present invention as shown in FIG. 1, there is provided a wheel for rotating a solar panel, where the wheel is driven via a wire and second wheel attached to a motor. A rotatable vertical member Y102 supports a solar panel support member Y105. The solar panel support member Y105 holds one or more solar panels Y500. A wheel Y250 is positioned below the solar panel support member Y105 and is connected to a wire Y260. The wire Y260 wraps around the wheel Y250 and extends to a second wheel Y250, which is connected to a motor Y300. The motor Y300 drives the second wheel Y250, which in turn controls the tension and movement of the wire Y260. The wire Y260, by being wrapped around the wheel Y250, enables the rotation of the solar panel support member Y105 and the attached solar panels Y500 around the vertical axis of the rotatable vertical member Y102. The motor Y300, through the second wheel Y250, provides the necessary force to adjust the orientation of the solar panels Y500 by controlling the wire Y260.

[0318] The configuration allows for the solar panels Y500 to adapt to strong winds by rotating around the horizontal axis, thereby reducing the torque exerted on the panels. The wire Y260 ensures that the panels can be rotated in any direction, providing flexibility in panel orientation. The placement of the wire Y260 and the wheel Y250 below the point of the solar panels Y500 ensures that the panels can rotate freely without interference.

[0319] To further elaborate on the above, the solar panels Y500 may rotate freely around the solar panel support member Y105 which reduces force exerted on the panels Y500 and thus the torque exerted on the vertical member Y102. One possible method by which the solar panels Y500 are rotated around the solar panel support member Y105 is via wind force on the solar panels Y500. The solar panels Y500 may be rotatably connected to the solar panel support member Y105 via a rotatable connection such as a hinge, or they may be fixedly connected to the solar panel support member Y105 which may then rotate itself. Any form of rotation of the solar panels Y500 around the solar panel support member Y105 is contemplated and should be understood by a person of skill in the art.

[0320] The rotatable vertical member Y102 is rotatable, typically via mechanical means but may be by any form of force. It may be directly rotated through connection to a motor, which may be achieved via gears or the like as would be understood by a person of skill in the art. One possible method for achieving rotation of the rotatable vertical member Y102 is via a wheelY250 as is further described in this document. Utilising a wheel Y250 to rotate the vertical member Y102 allows the solar panels Y500 to be fixed in a certain orientation to allow for reduced torque on the vertical member Y102 in the presence of certain wind conditions. In an embodiment comprising multiple solar panel systems according to the present invention, each system comprises solar panels Y500, a vertical member Y102, and a solar panel support member Y105, each system may have one or more wheels Y250 to to orient the solar panels Y500 to reduce torque exerted on the respective vertical members Y102. Driving of the wheels Y250 to cause rotation of the vertical members Y102 will be described further herein. In an alternative embodiment, the solar panels are fixed in the horizontal direction but rotate around the rotatable vertical support member Y102. This configuration allows for the solar panels Y500 to adapt to strong winds by rotating around the vertical axis, thereby reducing the torque exerted on the panels. The wire Y260 ensures that the panels can be rotated in any direction, providing flexibility in panel orientation. The placement of the wire Y260 and the wheel Y250 below the point of the solar panels Y500 ensures that the panels can rotate freely without interference.

[0321] As shown in Fig. 8, the rotatable vertical member Y102 rotates around axis A, while the solar panels Y500 attached to the solar panel support member Y105 rotate around axis B. Rotation of the rotatable vertical member Y102 may be driven why a wheel Y250 and wire Y260 as herein described, or by any other suitable method, including direct rotation via the wire Y260. Rotation of the solar panels Y500 around axis B is driven by the wind.

[0322] Additionally, the system can connect multiple wheels Y250 to the same wire Y260, allowing for the control of multiple solar panels Y500 simultaneously. The motor Y300 can control multiple wire loops, each loop managing one or more solar panels Y500, enhancing the scalability and efficiency of the system.

[0323] According to a further aspect of the present invention as shown in FIG. 2, there is provided a locking member for locking the wire into place on the wheel.

[0324] The wheel Y250 is a component in the wire-based rotational control system for wind- responsive solar panels. The wheel Y250 facilitates the movement and positioning of the solar panels by interacting with the wire Y260. The wire Y260 wraps around the wheel Y250, enabling the transmission of rotational force from a motor to the solar panels.

[0325] The wire Y260 is secured onto the wheel Y250 using a locking member Y270. The locking member Y270 ensures that the wire Y260 remains fixed in position on the wheel Y250, preventing any slippage that could disrupt the control and orientation of the solar panels. The locking member Y270 engages with the wire Y260 at a specific point, providing a secure attachment that maintains the wire's tension and alignment.

[0326] The locking member Y270 is designed to hold the wire Y260 firmly against the wheel Y250, ensuring consistent and reliable operation of the solar tracking system. By locking the wire Y260 in place, the locking member Y270 allows the system to accurately control the rotation of the solar panels, even under varying wind conditions. This configuration enhances the stability and responsiveness of the solar tracking system, contributing to the overall efficiency and effectiveness of the solar tracking system. According to another aspect of the present invention, the locking member for securing the wire onto the wheel can be implemented using a screw mechanism. This mechanism allows for the wheel to be adjustable even after the wire has been tightened, providing fine-tuning capabilities for the orientation of the solar panels.

[0327] In one embodiment, the screw mechanism includes screws that can be released slightly to allow the wheel to turn. When the screws are loosened, the wheel can be rotated, which in turn adjusts the orientation of the attached solar panels. The screws are positioned within grooves on the wheel, allowing for free movement within the groove when the screws are loosened.

[0328] If the fine-tuning provided by the groove is not sufficient, the wheel can be further adjusted by utilizing additional holes positioned along the groove. Once the wheel is turned all the way to the end of the groove, another hole becomes visible. The screw can then be unscrewed from its current position and inserted into the next hole, allowing for further adjustment of the wheel and the attached solar panels.

[0329] This screw mechanism is crucial for ensuring that all solar panels face the same direction after the wire has been tightened. During the initial installation and tightening of the wire, the panels may end up pointing in slightly different directions, leading to a loss of production. The ability to fine-tune the direction of the panels using the screw mechanism ensures optimal alignment and maximizes energy capture.

[0330] The locking member Y270, as shown in FIG. 2, is designed to hold the wire Y260 firmly against the wheel Y250, ensuring consistent and reliable operation of the solar tracking system. By locking the wire Y260 in place, the locking member Y270 allows the system to accurately control the rotation of the solar panels, even under varying wind conditions. This configuration enhances the stability and responsiveness of the solar tracking system, contributing to the overall efficiency and effectiveness of the solar tracking system.

[0331] According to one aspect of the present invention, the wire makes at least one and a half full loops around the wheel. This configuration, as shown in FIG. 1, enables the rotation of the solar panel support member Y105 and the attached solar panels Y500 around the vertical axis of the rotatable vertical member Y102. By making at least one and a half full loops (i.e., at least Y540 degrees) around the wheel Y250, the system ensures that the panels can be rotated in any direction, providing flexibility in panel orientation. This design allows the panels to be rotated an additional 90 degrees in either direction, regardless of their initial position, thereby enhancing the system's adaptability to varying wind conditions and sun positions.

[0332] Another aspect of the present invention involves the placement of the wire and wheel below the lowest point of the solar panels. As depicted in FIG. 1, the wire Y260 and the wheel Y250 are positioned below the solar panel support member Y105, which holds the solar panels Y500. This strategic placement ensures that the panels can rotate freely without interference from the wire Y260. By positioning the wire and wheel below the panels, the system avoids potential obstructions and allows for smooth, unobstructed rotation, thereby enhancing the overall efficiency and reliability of the solar tracking system.

[0333] Additionally, the present invention includes at least one wire tensioner configured to adjust the tension of the wire. As shown in FIG. 2, the wire tensioners are integrated into the system to maintain optimal wire tension, which is crucial for precise control of the solar panel orientation. The wire tensioners allow for adjustments to be made to the wire's tension, ensuring that the wire remains taut and responsive to the motor's movements. In an embodiment containing two wire tensioners, by shortening one wire tensioner and lengthening the other, the direction of the panels can be adjusted between the wire tensioners, providing fine-tuned control over the panel orientation. This feature enhances the system's ability to adapt to varying wind conditions and ensures consistent, reliable operation.

[0334] According to a further aspect of the present invention as shown in FIG. 3, there is provided multiple arrays of solar panels Y500, each array driven by a single wheel Y250. The wheel Y250 is driven by a wire Y260 from a wheel Y250 attached to a motor. The motor drives several wheels Y250 using the wire Y260, which each drive their own solar panel array Y500.

[0335] The solar panels Y500 are arranged in multiple arrays, each supported by a solar panel support member. The support members are connected to the wheel Y250, which facilitates the rotation of the solar panels Y500 around a vertical axis. The wire Y260 wraps around the wheel Y250, enabling the transmission of rotational force from the motor to the solar panels Y500.

[0336] The wire Y260 extends from the wheel Y250 connected to the motor to the wheels Y250 of each solar panel array Y500. This configuration allows the motor to control the orientation of multiple solar panel arrays Y500 simultaneously. The wire Y260 ensures that the panels can be rotated in any direction, providing flexibility in panel orientation and allowing the system to adapt to varying wind conditions. The placement of the wire Y260 and the wheel Y250 below the point of the solar panels Y500 ensures that the panels can rotate freely without interference. The system can connect multiple wheels Y250 to the same wire Y260, allowing for the control of multiple solar panels Y500 simultaneously. The motor can control multiple wire loops, each loop managing one or more solar panels Y500, enhancing the scalability and efficiency of the system.

[0337] With reference to FIG. 4, part of the wire Y260 can be seen going inside the wheel Y250. Within the wheel Y250, a release mechanism Y270 is screwed onto the wire Y260 to prevent it from slipping. The release mechanismY270 ensures that the wire Y260 remains securely in place, maintaining the necessary tension and alignment for the rotational control of the solar panels. This configuration enhances the stability and reliability of the solar tracking system by preventing any unwanted movement or slippage of the wire Y260 within the wheel Y250.

[0338] The configuration shown in FIG. 3 demonstrates the ability of the system to manage the movement and orientation of multiple solar panel arrays Y500 using a single motor and wirebased transmission system. This approach reduces the torque exerted on the panels, simplifies the overall design, and makes the system more accessible and cost-effective.

[0339] According to another aspect of the present invention, the apparatus is designed to allow the wheel to be placed at various different heights on the pole, thereby accommodating uneven or hilly ground conditions. This feature provides flexibility in the installation of the solar tracking system, ensuring that the solar panels can be optimally positioned regardle40ss of the terrain.

[0340] The rotatable vertical member Y102, which supports the solar panel support member Y105, is configured to allow the wheel Y250 to be mounted at different heights along its length. This adjustability ensures that the wire Y260 and the wheel Y250 can be positioned to maintain proper alignment and tension, even when the ground is not level.

[0341] By enabling the wheel Y250 to be placed at various heights on the pole, the system can compensate for variations in the terrain, ensuring that the solar panels Y500 remain properly oriented and can rotate freely without interference. This adaptability enhances the overall efficiency and reliability of the solar tracking system, making it suitable for a wide range of installation environments, including those with challenging topographies.

[0342] According to another aspect of the present invention, it is possible to adjust the direction of one or more rotatable vertical members in relation to the other rotatable vertical member after tension has been added to the wire. This feature allows for fine-tuning of the panel orientation, ensuring optimal alignment and maximizing energy capture.

[0343] In a more specific embodiment, this adjustment is achieved by releasing rotatable vertical member Y102 from the wheel Y250 controlled by the wire Y260, allowing the rotatable vertical member Y102 to rotate independently from the wheel Y250. This capability provides the advantage of easily fine-tuning the position of different rotatable vertical members Y102 in relation to each other, enhancing the overall efficiency of the solar tracking system.

[0344] One example of a suitable mechanism, as shown in Fig. 5, for achieving this independent rotation involves a fastening member Y257 that protrudes through a hole Y255 in the wheel Y250. By releasing the fastening member Y257, the rotatable vertical member Y102 can be rotated independently, allowing for precise adjustments to the panel orientation. This mechanism ensures that all panels can be aligned accurately, even after the wire has been tensioned, thereby improving the system's performance and energy output.

[0345] As a further alternative embodiment of the present invention, the wheel Y250 may be integrated directly into the rotatable vertical member Y102, or in other words, the rotatable vertical member Y102 may perform the function of the wheel Y250 directly. For example, the rotatable vertical member Y102 may be formed in a round shape, optionally comprising a channel or groove for the wire Y260 to fit within and fulfil the function of the wheel Y250 as described herein. Any reference to wheel Y250 within this document should be understood to be capable of being fulfilled by a suitably formed rotatable vertical member

[0346] Y102.

[0347] A further alternative embodiment of the present invention is shown in Fig. 6, whereby the system includes two motors Y400 that rotate in opposite directions. All the solar panel structures connected to one of the motors are in a standard wire loop with a wire Y260 that wraps around a wheel Y250 on top of the motor, as well as additional wheels Y250 that cause rotatable vertical members Y102 attached thereto to rotate. The solar panel structures connected to the other motor are linked through a wire loop where the wire Y260 is crossed between the motor and the first wheel Y250.

[0348] The two motors Y400 are mounted atop a common mounting member Y600. This configuration provides a significant advantage, particularly when dealing with a large number of panels. In strong wind conditions, the torque exerted on the mounting member Y600 can be substantial. This is true even when the motors and wire loops are not actively rotating. By crossing some of the wires in this manner, the torque from the crossed wire loops counteracts the torque from the standard loops. As a result, the total torque exerted on the ground is significantly reduced, enhancing the stability and reliability of the system.

[0349] A further alternative embodiment of the present invention is shown in Fig. 7, whereby one or more release mechanisms Y270 are strategically placed on the wire Y260. The release mechanism Y270 is designed to either stretch, break, or otherwise reduce the tension on the wire loop under specific conditions. This serves as a safety feature to prevent excessive force from damaging the system.

[0350] For example, the release mechanism can be a small wire loop connected to the main wire loop formed of wire Y260, where the small wire loop has a smaller diameter than the main wire loop, causing it to break earlier than the main wire loop. Alternatively, the release mechanism can be a mechanical component that breaks at a predetermined force.

[0351] Another embodiment of the release mechanism involves a weight that is heavy enough to force the wire to move in a larger loop. When the force becomes large enough to lift the weight, the length of the wire loop is effectively shortened, reducing tension.

[0352] The force at which the release mechanism is designed to activate can range between Y5000N and Y20000N. This range ensures that the system remains protected from forces that could otherwise break the wire or cause one of the solar panel structures to be pulled out of the ground or suffer damage.

[0353] The value of incorporating such a release mechanism Y270 lies in its ability to act as a safety measure. It ensures that the forces exerted by the motor do not exceed a safe threshold, thereby protecting the integrity of the solar panel structures and the overall system.

[0354] A second example

[0355] Example 9. An apparatus for controlling the orientation of solar panels, comprising a rotatable vertical member configured to support a solar panel support member, and a solar panel support member rotatably attached to a solar panel, such that the solar panel may rotate around the solar panel support member.

[0356] Example 10. The apparatus of Example 9, further comprising a wheel connected to the rotatable vertical member.

[0357] Example 11. The apparatus of Example 9, wherein the solar panel may rotate around the solar panel support member. Example 12. The apparatus of Example 10, wherein the solar panel is caused to rotate around the solar panel support member in response to wind force.

[0358] Example 13. The apparatus of Example 9, wherein the solar panel rotates around the rotatable vertical member.

[0359] Example 14. The apparatus of Example 12, wherein the solar panel is caused to rotate around the rotatable vertical member in response to wind force.

[0360] Example 15. The apparatus of Example 10, further comprising a wire configured to wrap around the wheel and extend to a second wheel, and a motor connected to the second wheel, the motor configured to drive the second wheel, which in turn controls the movement of the wire.

[0361] Example 16. The apparatus of Example 15, wherein the wire makes at least one and a half full loops around the wheel, enabling the rotation of the solar panel support member and the attached solar panels around the vertical axis of the rotatable vertical member.

[0362] Example 17. The apparatus of Example 15, wherein the wire and wheel are placed below the lowest point of the solar panels to allow free rotation without interference.

[0363] Example 18. The apparatus of Example 15, further comprising at least one wire tensioner configured to adjust the tension of the wire.

[0364] Example 19. The apparatus of Example 18, wherein there are provided two wire tensioners, where one wire tensioner shortens one wire and the other wire tensioner lengthens a separate wire, to effect rotation of the solar panel.

[0365] Example 20. The apparatus of Example 15, wherein the motor is configured to control multiple wire loops, each loop managing one or more solar panels, allowing for the control of multiple solar panels simultaneously.

[0366] Example 21. The apparatus of Example 15, further comprising a locking member configured to secure the wire onto the wheel to prevent slippage.

[0367] Example 22. The apparatus of Example 10, wherein the wheel is configured to be mounted at various different heights along the rotatable vertical member.

[0368] Example 23. The apparatus of Example 15, further comprising a second rotatable vertical support member attached to a second wheel and capable of being oriented independently of the first solar panel support member. Example 24. The apparatus of Example 23, wherein the second rotatable vertical support member is oriented by adjustment of the tension of the wire around the second wheel.

[0369] The foregoing description includes examples, sample dimensions, parameter values, and numerical ranges to illustrate enablement of the claimed subject matter. Unless expressly stated otherwise in a specific claim, such examples and ranges are illustrative only and are not intended to limit the scope of the claims. A stated numerical value should be understood to encompass approximate values and normal manufacturing tolerances. A stated numerical range includes all sub-ranges and individual values within that range, as well as values outside the range that achieve substantially the same function or result.

[0370] The description includes examples, sample dimensions, operating parameters, and numerical ranges to teach how to make and use the invention. These examples and ranges are illustrative only and do not limit the claims unless a claim explicitly says otherwise.

[0371] Any single numerical value in this document covers its approximate value and normal manufacturing tolerances. Values are understood as reasonable approximations that a skilled person would accept given measurement accuracy and intended function, "approximately," and "substantially" indicate allowable variation consistent with achieving the stated result. A stated numerical range includes each endpoint, every intermediate value, and every sub-range formed from the endpoints and intermediate values. Unless a different meaning is made explicit, phrases like "between X and Y," "from X to Y," and "X-Y" are inclusive of X and Y. Overlapping and adjacent ranges are intended to be combinable.

Claims

CLAIMS1. A photovoltaic tracker system (100) distributed across a plurality of yawing masts, configured to prevent coupled resonance, comprising: a plurality of rotatable masts (102), each carrying a rotating superstructure (150) that is rotatable about a substantially vertical axis V-V by a yaw drive (120) under a yaw motor (300), and supporting at least one photovoltaic module (500) mounted by a horizontal hinge assembly (121) defining a substantially horizontal axis H-H located windward of the aerodynamic center AC, such that wind on the rear face (500B) feathers the module (500) toward a reduced angle of attack, the horizontal hinge assembly (121) permitting substantially free feathering of the module (500), together with a rest-tilt limiter (108) that stops downward rotation below a defined rest tilt; directional bracing (160) disposed within each rotating superstructure (150) and oriented to raise a swing-mode natural frequency about H-H while preserving free yaw about an axis V- V; a controller configured, upon a wind condition exceeding a threshold, to command the yaw motor (300) to maintain a rear-to-wind orientation of each module (500) within a bounded wind-aligned cone (C) so that feathering proceeds in the permitted rotational sense and the module feathers away from the directional bracing (160); a flexible azimuth group drive interconnecting said rotatable masts (102), including on each rotatable mast (102) a rotating traction element (250) having a wheel body (230) and carrying at least four flexible tensile runs (260a-260d) reeved as two opposed pairs of a pretensioned flexible element (260), each run being fixed to the rotating traction element (250) by a positive locking member (270) so torque is transmitted by said positive locking; a first opposed pair being operatively connected locally to the yaw motor (300) and a second opposed pair being routed toward a neighboring rotating traction element (250), wherein the system is configured such that the frequency of the oscillation of the at least one module (500) about H-H is spectrally separated from the frequency of the rotatable masts (102) about V-V , thereby avoiding mode coupling while preserving feathering torque relief.

2. The photovoltaic tracker system (100) of claim 1, wherein the threshold is a three-second wind gust speed of at least about 25 m-s-1, and wherein, when the wind condition exceedsthe threshold, a leeward one of the flexible tensile runs (260a-260d) in one of the opposed pairs relaxes toward a loss-of-tension condition while a windward one of the flexible tensile runs (260a-260d) remains tensioned, interrupting coherent bi-directional torque transmission within a gust half-cycle, permitting at least one of the rotatable masts (102) to rotate partially in yaw about the vertical axis (V-V) relative to neighboring rotatable masts (102) within a bounded range, and routing substantially all wind-induced yaw torque along the tensioned flexible tensile run (260a-260d) to the rotating traction element (250) that is locally driven by the yaw motor (300) to be reacted at the corresponding rotatable mast (102).

3. The photovoltaic tracker system (100) of claim 1, wherein the horizontal hinge assembly (121) defining axis H-H is positioned within -10% and +20% of the panel chord Lc measured from a wind-leading edge toward a leeward edge of the photovoltaic module (500) such that wind on the rear face (500B) produces a lifting moment that passively feathers the module toward a reduced angle of attack.

4. The photovoltaic tracker system (100) of claim 1, wherein the hinge assembly (121) is further comprises a configured to provide a damping, thereby suppressing wind-induced small-amplitude chatter about axis H-H while permitting quasi-static feathering under rear-face wind.

5. The photovoltaic tracker system (100) of claim 1, wherein an upper stop (112) is positioned to arrest upward rotation of the module (500) about axis H-H at a feathered extreme within about ±10° of horizontal under strong rear-face wind.

6. The photovoltaic tracker system (100) of claim 1, wherein a counterweight on an arm is disposed with respect to axis H-H to provide a gravity bias that reduces a gravity-derived restoring gradient in the feathering direction and improves passive feathering response under gusts.

7. The photovoltaic tracker system (100) of claim 1, wherein the flexible azimuth group drive comprising the pretensioned flexible element (260) is divided into multiple short loops, each short loop coupling two or a few of the rotatable masts (102) through their rotating tractionelements (250), thereby bounding cumulative stretch and heading drift while preserving local compliance.

8. The photovoltaic tracker system (100) of claim 1, wherein directional bracing (160) disposed within each rotating head / superstructure (150) is dimensioned and oriented to raise a first swing-mode natural frequency about axis H-H to at least 4 Hz, thereby shifting that mode outside a low-frequency wind-excitable band.

9. The photovoltaic tracker system (100) of claim 1, wherein installation tuning yields a spectral separation between a first yaw natural frequency about axis V-V and a first panel pitch natural frequency about axis H-H of at least about twenty percent, as verified during commissioning by an impulse or gust-response test.

10. The photovoltaic tracker system (100) of claim 1, wherein the directional bracing (160) is disposed entirely within the rotating head / superstructure (150) in a selected plane that increases stiffness in said plane while imparting negligible resistance to yaw about axis V-V, thereby preserving substantially free yaw of the tracker head.

11. The photovoltaic tracker system (100) of claim 1, wherein the directional bracing (160) comprises two diagonal brace members arranged in a common plane within the rotating head / superstructure (150) and positioned to selectively stiffen the head against sway / bounce deflection in that plane while not constraining motion orthogonal thereto.

12. The photovoltaic tracker system (100) of claim 1, wherein the directional bracing (160) cooperates with drivetrain compliance in the azimuth group drive, comprising elastic extension of the flexible element (260) and / or an inline compliance module (210), to detune and damp array-level torsional response, whereby wind-induced yaw oscillations about axis V-V are attenuated and not coherently transmitted between coupled masts.

13. The photovoltaic tracker system (100) of claim 1, wherein each rotating traction element (250) comprises a wheel body (230) with grooves (232), the flexible element (260) beingreeved about the wheel body for at least 1.0 wraps, and wherein a positive locking / anchoring member (270) fixes the flexible element to the wheel such that torque is transmitted by said positive locking rather than by capstan friction along the wraps, the wraps being provided to accommodate angular travel.

14. The photovoltaic tracker system (100) of claim 1, wherein the flexible azimuth group drive comprising the pretensioned flexible element (260) is divided into multiple short loops, each short loop coupling two or a few of the rotatable masts (102) through their rotating traction elements (250), thereby bounding cumulative stretch and heading drift while preserving local compliance.

15. The photovoltaic tracker system (100) of claim 1, wherein a nondriven run of the pretensioned flexible element (260) includes a sacrificial overload release calibrated to fail within a predetermined tension band prior to structural yielding elsewhere, and wherein a backup tether is provided to retain loop continuity upon such release.

16. The photovoltaic tracker system (100) of claim 1, wherein baseline pretension applied to the flexible element (260) by the tensioner (240) is set within a site-tunable range of 0.4-2.0 kN per tracker unit in each drive group such that, for a three-second gust > 25 m-s-1, a leeward-directed run relaxes toward a loss-of-tension condition while the windward-directed run remains tensioned, thereby interrupting coherent bi-directional torque transmission within the gust half-cycle and routing net yaw torque to be reacted predominantly at the motorized mast (102) with minimal torsional propagation to neighboring posts.

17. The photovoltaic tracker system (100) of claim 1, further comprising an inline compliance module (210) disposed in a non-driven span of the flexible element (260), the compliance module being configured to elastically extend under transient gust-induced tension spikes, thereby absorbing load peaks in the flexible drive and limiting peak loop tension during extreme winds.

18. The photovoltaic tracker system (100) of claim 1, wherein the yaw actuator and controller are configured to maintain a rear-to-wind orientation of each tracker during stormoperation by keeping the rear face (500B) within a wind-aligned cone (C) having a half-angle of less than ±30°.

19. The photovoltaic tracker system (100) of claim 1, wherein, during storm mode, the controller applies staggered heading offsets (AIJJ ) among neighboring trackers, adjacent headings being intentionally offset in alternating positive and negative increments of no more than 15° while each tracker's rear face (500B) remains within its respective cone C, thereby disrupting array-level aerodynamic symmetry and preventing phase-locked excitation.

20. The photovoltaic tracker system (100) of claim 1, wherein wind-speed threshold logic enters storm mode when a gust threshold l-h is exceeded and exits only after wind falls below a lower threshold Hzfor a dwell time, the logic being configured, by way of example, to trigger wind-aligned stow when a 3-second gust is at least 15 m-s-1and to revert to normal tracking only after the gust is no more than 12 m-s-1for at least about 60 s, thereby providing entry / exit hysteresis to avoid chatter.

21. The photovoltaic tracker system (100) of claim 1, further comprising a rotary electrical interface or an internal cable routing path through the yaw drive (120) about the vertical axis (V-V) to preserve electrical connectivity during azimuth rotation.

22. The photovoltaic tracker system (100) of claim 1, wherein the tracker system is implemented in a grouped drive configuration in which only one mast of the plurality is directly motorized with the yaw motor (300) driving a powered traction element (251), and all other yawing posts in the group are coupled via the flexible element (260) to rotate in unison with commanded azimuth, thereby enabling coordinated wind-aligned stow across multiple posts with a single actuator.

23. The photovoltaic tracker system (100) of claim 1, wherein each tracker assembly (100) is mounted on a single-point foundation (130) configured as a shallow anchor (including one or more of a driven pile, ground screw, or ballast footing) without multi-anchor footings, A-frame bracing, or earth-truss structures beneath the mast.

24. The photovoltaic tracker system (100) of claim 1, wherein the combination of a wind-responsive off-center hinge (121) about H-H, wind-aligned yaw within cone C, and compliant inter-post coupling via the flexible element (260) collectively reduces wind-load excitation such that deep piers or multi-point guyed foundations are unnecessary, whereby a single-post shallow foundation (130) for each mast is sufficient across a range of soil conditions and wind exposure classes.

25. The photovoltaic tracker system (100) of claim 1, wherein only the motorized mast equipped with the yaw motor (300) requires additional anchoring or reinforcement to react aggregate drive torque, the motorized mast optionally including a torque-reaction frame (254) tied to anchors (56), while non-motor posts utilize standard single-point foundations (130) without enlarged footings or special reinforcements.

26. The photovoltaic tracker system (100) of claim 1, wherein, under design storm conditions, the peak overturning moment and base shear transmitted into each foundation (130) are reduced by at least about 30% relative to an otherwise-equivalent tracker lacking the disclosed wind-relief features, owing to feathering about H-H, wind-aligned yaw about V-V, and flexible-drive compliance that limit the magnitude and duration of load transfer into the mast and footing.

27. The photovoltaic tracker system (100) of claim 1, wherein each tracker assembly (100) is capable of withstanding design storm loads on a single-post foundation (130) without supplemental bracing structures or multi-anchor footings, the wind-responsive hinge (121), controller-maintained cone C, and compliant azimuth group drive (250, 260, 240, 210) attenuating dynamic loads so that conventional shallow anchors may be used.

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