IES930384A2 - Wind turbine support and array layout - Google Patents

Abstract

A wind turbine support system comprises a lattice steel tower £ stabilized by cables £ and supporting controlled, horizontally rotatable, balanced, steel lattice jibs from which are suspended wind turbines WT1, WT2 of similar weight and construction. The wind turbines may be of the single or double bladed type and, in operation, are arranged to be downwind of the tower and jibs. In a wind farm array, the wind turbines operate at different altitude.

Description

WIND TURBINE SUPPORT SYSTEM AND ARRAY LAYOUT.

The present invention relates to Wind Turbines. The invention is particularly concerned with the provision of a turbine suitable for use in an array of such turbines for commercial production of Electricity, i.e. on larger mu 11i-megawatt Wind Farms, both onshore and offshore.

Among the difficulties which may arise with popular standard type Wind Turbines - which consist of tubular steel tower 30 - 40m high supporting a standard 2 or 3 blade upwind rotar attached to gearbox and generator with appropriate electric control gear, all enclosed in weatherproof nacelle, - are the following:(1) The support tower and rotar may be blown down or damaged in extremely high winds. (2) The generator etc. located at top of tower may be difficult to service and / or replace in case of permanent breakdown. (3) The rotar, if large, may be subject to considerably different wind speeds at top and bottom of rotation circle, causing vibration and damage to rotor. (4) As the rotor blade swings past the tower, the rotor is subject to 'tower shadow' which in the case of large rotors may cause environmentally undesirable low frequency noises, which may also add to destructive vibration problems to rotor.

OPEN TO PUBLIC INSPECTION UNDER SECTION 28 AND RULE 23 JNL. No.....

IE 930384 -2(5) The wake effect of one generator in an array, may reduce the power output of a downwind generator suitated at less than fifteen times rotor diameter (15D) distance from upwind generator, thereby greatly reducing output or array (Wind Farm) over total area of same. The object of the present invention is to provide a wind power generation system in which the above problems are greatly minimised or completely eliminated.

Unlike standard Wind Turbines (WT) as above described, this invention takes into consideration, the two most fundamental wind energy factors:A) . Max WT alt. above ground level / (or sea level) within the parameters of practical and structural and economic reality to achieve max. power output for WT unit.

B) . A reduction of wake effect to half wake distance between WT unit at same alt., thereby vastly increasing number of W.T. and power output per Wind Farm unit area, i.e. (MW per Sq.Mile or per Sq.Km), by locating alternative WT units at different altitudes on two or three Wind Energy Plains (WEP).

Ref. is made to Fig. 10, Fig. 11 and Fig.12 - reduction of wake effect distance is achieved by use of two/ (three) adjacent contra - rotating Rotors per WT unit.

(NOTE: Wind Farm Planning to achieve max. output using this WT invention requires 3 dimension Wind Speeds Analysis - by Wind Tunnell model and Computer study to establish best location - altitude relationship for each WT unit within context of extra Wind Farm terrain & roughness factor to achieve max. Wind Farm Power outputagain with ref. to Fig.10, Fig.11 & Fig.12). ......./ 930384 -3The invention will now be described more particularly with reference to accompanying drawings which show by way of example only (a) First embodiement of Wind Energy generator, comprising a special design lattice steelwork support tower, supporting two contra-rotating WT units. (b) A modified similar type tower crane, supporting three contra - rotating WT units. The W.T. units are suspended from special Tower Crane in such manner as to be easily lowered to ground for replacement or repair, with minimum waste of time and inconvenience to ensure max. continous power output from Wind Farm Array.

The invention will now be described more particularly with reference to accompanying drawings. In the drawings:Fig; 1 is a front elevation of complete WT unit showing lattice steelwork Tower Crane Unit, with balanced jibs supporting WT nacelles. Main features of invention are : (a) Structural lattice steel tower, similar to standard builders tower crane. (b) Lattice steelwork sectional balanced jibs designed to carry total dead and live loading of operational WT unit. (c) Tensioned rustproof steel or composite plastic stays, designed to stabilise complete WT Unit at max. wind speeds. (d) Tensile support cables to jibs (B) from inclined jib (B1), and rotating tower section (A1 ) , WT hoisting cables are shown (H), operated as normally used in builders tower crane to hoist WT from ground to fixed location on jib, and ..../ -4locked in position by mechanical or electrical solenoid operated locked system. Electric winch (F) and pully system (E)shown on Fig. 6 and Fig. 7.

Electrical connections at jib level between demountable WT Unit and Power Take Off Cables - incl. control cables - are by male / female weatherproof plug and socket system (not shown).

FIG;2 shows side elevation of WT Unit, showing vertical spatial relationship of WT 1 - 2 and WT 3, all WT being downwind of job axis point on tower crane.

FIG.3 shows plan of WT unit, showing horizontal spatial relationship of WT 1 - 2 7 WT 3, and WT layout system to ensure max. power output from each WT in relation to each other..

Fig. 4 & Fig. 5 shows in diagramatic form WT Unit configuuration for two complex and treble WT complex respectively.

FIG.6 shows front elevation in larger detail of rotating jib section of WT Unit, indicating position of cable pulleys (E) and main electric cable winches (F) for hoisting WT into fixed position on jibs (B - B).

Preferred WT system is a single aerofoil counter-balanced blade driving through suitable gearbox at variable speed sychronous fixed frequency electric generator.

FIG.7. shows plan in larger detail of rotating jib section, and various components. R. indicates jib rotating turntable and its specific location at top of steel lattice tower (A) and tensile stays (C) for maximum structural stability of WT Unit.

......./ IE 930384 -5FIG.8 & FIG.9 shows respectively, plan and vertical elevation of jib rotating system R. which consists of horizontal steel frame unit (G) supporting central axis C/C jib (B), rotating on steel frame turntable (T). Rotating frame (G) is centralised on turntable by long steel solid vertical shaft (V) through central axis C/A rings fixed in tower (A) and rotating tower section (A).

Rotating mechanism consists of large sprocket chain (S) carried on pins attached to fixed turntable (T) and encircling small sprocket wheel geared electric motor (J), attached to steel frame (G). Small steel castor which bearing (K) are in rotating frame (G).

FIG . 10 Shows in graphical form the established theory (Davenport - 1963) for the effect of various ground toughness factors, in wind speeds at various altitudes over same. Max. power output is achieved at max. altitude consistent with basic structural integrity for WEP. The best Wind Energy sites are found in flat coastal areas with minimum roughness factor Z = 0.16 as shown on diagram.

FIG.11 & FIG.12 respectively show in diagramatic form plan and cross section of Wind Farm (one sq. mile) involving No.20 WT Units. In Wind Farm layout the minimum proven max power output distance between WT Units in single layer WEP is 15 times diameter of WT of 150. This large distance, however involves very large areas of land / sea for very limited number of WT thereby making Wind Energy Projects completely uneconomical. This problem can be overcome in this invention by use of 2 or 3 WEP (Wind energy Plains) as shown in Section Fig. 12 - i.e. WEP (1), WEP (2), & WEP (3), i.e. No.3 WEP, thereby vastly increasing power output from Wind Farm (WF) modular areas - 1 Sq. mile.

In the example WF module illustrated in F i g . 11 , No. 20 WT Units as shown. Assume a 600 - 1000 kw, WT Unit is used for WF total Energy capacity is 36 - 60 MW per sq. mile, which at 400' alt. (120m) would provide 50 - 60?0 capacity power output in MW hours, i.e. better than most oil, coal or nuc. power plants. ......./ -6FIG.13 shows in simplified Logarithmic form Wind Speed as percentage of Gradient Wind Speed over grounds of varying roughness, indicating max. economic power output at, 400 500 ft. (120m - 150m) alt. above smooth ground near coast of min . roughness factor Z - 0.16.

FIG, 14, FIG.15 & FIG.16 are included in this Patent Spec, as independent proof that WF max. power output for min land /sea economic alt. above ground level.

FIG.14 shows wind power V - U Wind Speeds between 2-12 m/g (4.5 - 26.8mph) .

FIG.15 shows graph indicating increase in Wind spped duration at higher alt. 122m as against 47m (400 ft - 150 ft) Data taken from Wi nd Farm Survey for Medicine Bow NY, U.S.A.

FIG.16 shows eight hour av.(1600 - 2400 h) wind spped profiles observed at Lopik in Nederlands, during 12 seperate days (March 1st - March 12th), during which the average Wind direction was indicated (Survey by Rijkoort 1963) Lopik is 30 miles (50 km) from coastline, located in fairly built up area.

(Roughness factor Z - 0.20).

It will of course be understood that this invention is not limited to the specific details described herein, which are given by way of example only, and that various modifications and alterations are possible within the scope of the invention.

Claims (3)

CLAIMS : 25 What I claim is : (1) A sectional lattice steel type crane tower stabilized against max. wind forces by a number of tensioned rustproof steel or composite plastic cables fixed to deep tensile foundations, supporting two controlled horizontally rotating 30 balanced sectional lattice steel type jibs, from which are suspended Wind Turbines of similar weight and construction,
1. IE 930384 -7and which remotely controlled by cable form ground level based control centre. Preferred Wind Turbines of single (counter balanced) or double blade type (variable speedfixed frequency power output), only and disposed downwind 5 in relation to jibs and support tower.
2. 2. (2) A Wind Turbine support unit as described in Claim (1), supporting three downwind Wind Turbine unites, the third Wind Turbine being suspended from semi-vertica 1 jib set at an angle to vertical tower at higher level, than two 10 laterally suspended Wind Turbines to form trefoil of 'Shamrock' pattern of Wind Turbines per each support tower unit.
3. 3. (3) A Wind Turbine support tower unit - as described in Clauses 1 & 2 above, which is designed and manufactured 15 in a smiliar manner to builders tower crane and which may be assembled and erected on site in similar manner, by ground based hydraulic or geared cable pulley jack-up erection system and which may be erected to any suitable altitude consistant with max. WT power output within 20 the context of array layout and overall site contours for array max. power output. (A) A Wind Farm Array using Wind Turbine Support System as described in clauses 1,2 / 3 overleaf, in which the Wind Turbines are planned to operate at different altitudes 25 - i.e. different Wind Energy Plans (WEP) in relation to each other, to achieve minimum distance and wake turbulence between adjacent wind turbines, to achieve max. Wind Turbine density in minimum Wind Farm Array area unitin onshore or offshore site. 30 (5) A Wind Farm Array as described in Clause 4, above, designed specifically to form integral part of a Wind Energy-Pumped hydro Electric Complex of large multi-megawatt capacity suitable for connection to National Electricity Grid.