DESC:FIELD OF INVENTION :

The present invention belongs to evolution of efficient and innovative design technique for lighting the field of play such as stadium and more specifically for the world’s largest cricket stadium with the usage of latest technologies aimed at enhanced energy efficiency and increased operational life span of the lighting system.

BACKGROUND OF INVENTION AND OBJECT OF THE INVENTION :

The conventional way of lighting a cricket stadium field of play has been through the usage of high mast towers with a group of several metal halide light fixtures on each mast. Considering the enormous size of the stadium, proximity to the airport and to have a seamless 360-degree unobstructed view for all the spectators, the conventional way of lighting with the high mast towers imposed a huge challenge to the lighting design. This led to rethink the approach for achieving the lighting requirements to international standards and resulted in the evolution of the current design.

DESCRIPTION OF THE INVENTION:

1. To accommodate a crowd of 1,10,000 the space occupied by the stadium including the stands is approximately 300 m length and 350 m breadth.
2. To have a continuous 360 degree unobstructed view for all the spectators.
3. Avoiding the shadow of the 30 m cantilevered roof for the upper bowl on the Field of play.
4. Close proximity of the site to the airport leading to a maximum permitted height of 50.16 m from the finished ground level.
5. Very little setback available in certain locations where the high mast towers should be located to achieve the lighting requirements.
6. Lux requirements as per ICC guidelines for broadcasting for international event as well as lux requirements for lighting for national and practice are as given below.

Considering the massive dimensions of the stadium, and the requirement as indicated in point number 2, the approximate distance of the mast location from the centre of the ground varied from 160 to 200 m away. Further to avoid the shadow of the roof from falling on the ground, the estimated height of the high mast tower required was in excess of 120 m high which is not available anywhere in the world. Further considering the aviation height restrictions it was not feasible to go in for the high mast option for designing the lighting for the stadium.

To mitigate this the light fixtures were fixed on the edge of the roof, which would
1. Avoid the shadow of the roof falling on the ground because of the lighting.
2. Bring the light fixtures closer to the centre of the pitch thereby reducing the number of light fixtures required to achieve the illumination and hence reduce the power consumption.
However, considering the nature of the roof, which is a 30 m, cantilevered one, the light fixtures could not be supported in clusters similar to conventional high masts owing to the heavy weight. Hence, barring the 30 deg. no light zone from the pitch the light fixtures were distributed throughout the roof, reducing the point load on the structure and giving the following advantages from a lighting design perspective

1. Distributing the light fixtures throughout the roof reduces the drastic varying
intensities of lighting across the stadium compared to the conventional high masts where large cluster of light fixtures are grouped in one location.
2. The risk of a player’s losing sight of the ball among the lighting is reduced as the lights are distributed evenly and the intensity at any location on the field is less compared with the conventional high mast lighting.

Because of the high lux level requirements laid out in the ICC guidelines, it has been a conventional practice to use high wattage (approx. 2 to 2.2kW) metal halide lamps in the design of cricket stadium field of play lighting. This concept introduces the usage of LED light fixtures in cricket application considering the below advantages of LED fixtures

1. Longer operating hours
2. Zero switch on time after switch off (unlike metal halide lights, which require some time for heating up).
3. Lesser maintenance requirements
4. Higher energy efficiency

LED light fixtures specifically tailor-made for the application were developed and used in the design. Typical site design is illustrated in Fig. 3, 4, 5 and 6.

Design simulation and output:
The simulation of the lighting design was carried out using the Calculux software. Also, the same was simulated in 3D in the BIM platform using the Autodesk REVIT software. 580 numbers of LED lights were used for achieving the following results.

The actual values of lux measured at site are as given below.

Note the uniformity values specified in the achieved column with two values are vertical, horizontal uniformity values respectively and where single values are indicated correspond to horizontal uniformity.

Lighting Power distribution and Control system architecture:

The power supply to the lighting system is fed from a grid supply backed up by 100 % DG to enhance the reliability of the power distribution system feeding the lighting system. The power distribution schematic is as Fig. 1.

Part nos. Part names
101 11 KV HT Source From Grid
102 1000 kVA 11/0.433kV Transformer
103 E/M
104 FOP Main PCC Panel
105 FOP Main Lighting Panel-1 Left Wing
106 FOP Main Lighting Panel-2 Right Wing
107 Lighting DB’S 1 to 24
108 40 KVA UPS-1
109 UPS Panel-1
110 EMR Lighting DB’S 1 to 2
111 Lighting DB’S 25 to 48
112 UPS Panel-2
113 EMR Lighting DB’S 3 to 4
114 630 kVA 0.415 kV DG 4
115 630 kVA 0.415 kV DG 3
116 630 kVA 0.415 kV DG 2
117 630 kVA 0.415 kV DG 1
118 DG Sync Bus-2
119 B/C
120 DG Sync Bus-1
121 Other Stadium Loads
122 HT Cable
123 LT Cable

The entire lighting control system has been designed with an architecture, which enables to operate the lighting of the stadium in four modes

To achieve the illumination with various modes as specified above custom-made distribution boards (total 48 no’s normal and 4 no’s emergency) controlled by contactors provided in the outgoing feeders of the panel feeding power supply to these distribution boards. These contactors receive signal from a lighting controller through cabling. The lighting controllers are integrated with a scene/ mode selector which allows to select the event mode for which lights have to be switched ON. The system architecture for the lighting control system is as given Fig. 2a and Fig. 2b.
Part nos. Part names
201 Limp Envision Manager Server
202 Envision Gateway
203 Network Gateway
204 Timer Clock
205 Contactor Coil of Practice LDB
206 Relay Control Moduel
207 Network Power supply
208 User Control Panel
209 A
210 Contactor Coil of National LDB
211 Contactor Coil of International LDB
212 CAT 6 Cable
213 2CX1.5 SQ.MM Cable

Part nos. Part names
301 A
302 Relay Control Moduel
303 Network Gateway
304 User Control Panel
305 Contactor Coil of Practice LDB
306 Contactor Coil of National LDB
307 Contactor Coil of International LDB
308 CAT 6 Cable
309 2CX1.5 SQ.MM Cable

The benefits/Unique features of the design as per the invention given herein:

The lighting design blends with the stadium and there are no odd lighting towers standing out that spoils the aesthetics of the surroundings.

By fixing the light fixtures on the edge of the roof and focussed towards the field of play the amount of light pollution in the sky to the surrounding areas is reduced compared to the conventional high mast structures.

This is the first cricket stadium in India to be designed with LED light fixtures for the field of play lighting complying with ICC requirements for broadcasting.

The existing Motera stadium before demolition had 10 towers, each with 50 no’s of 2.2 kW lights. Hence, the total power consumption during an international event was 1100 kWHr. However, in the latest design the power consumption has come down to 717 kWHr (i.e. 35 % lesser).

In comparison with the previous world’s largest cricket stadium (Melbourne cricket stadium) where 840 no’s of 2kW lights are available (resulting in a total power consumption of 1680 kWHr) the energy consumption at this new stadium is just 43 %.

From the above table it is evident that the lighting design is highly energy efficient thereby contributing to a sustainable environment and reducing the carbon footprint towards a greener environment.

The arrangement specifically involves elimination of high masts typically known and used for lighting of large stadiums and elimination of shadows suffered in prior art. It also eliminates the variations of lighting across the stadium. It also advantageously controls the intensity of light at all locations, thereby providing a clean and clear vision to all players and spectators. It also advantageously reduces power consumption when calculated overall thereby achieving high energy efficiency. Further this design allows customised lighting fixtures and also arrangements without suffering to rely on standardised available products.

As per the invention, in a large stadium with a cantilevered roof, barring the estimated degree of no light zone from the pitch the light fixtures are arranged spaced apart and continuously throughout the roof, thereby reducing the suffered point load on the structure and advantageously providing better lighting design. With this arrangement one has distributed the zones into multiple zones such as in cricket stadium – pitch zone, infield zone and outfield zone, etc. and vertical illumination and horizontal illumination can be calculated and lighting arranged accordingly.

The arrangement in a typical circular stadium with cantilevered roof will provide a seam less 360 degree unobstructed reliable visibility to the spectators and unobstructed reliable visibility to the players which is very essential for a good game. All sufferings of prior art has been overcome and Lux requirements of lighting as per statutory guidelines can be easily achieved with this concept of lighting which is to distribute the lighting across the roof.

The invention has been described with certain examples and embodiments only for the purpose of disclosing the enabling and working of the invention. And variables which are obvious are well within the scope of this invention.

The applicant relies upon the provisional specification and drawings filed in this application and shall be considered as part and parcel of complete specification
,CLAIMS:WE CLAIM :

1. A lighting arrangement for a circular stadium with a cantilevered roof comprising of :-

- providing a plurality of light fixtures spaced apart but continuously along the edge of the roof and focused towards the field of play of the stadium,
- providing power through panel feeding power supply to the plurality of light fixtures, having a plurality of distribution boards, outgoing feeders, contactors and controller, all of which combinedly and selectively control the plurality of light fixtures.

the said arrangement characterised in that the visibility is 360° and lower energy consumption and further elimination of high mast structural units conventionally mounted behind the stadium, and

the said arrangement characterized in that there is elimination of shadows and elimination of high mount masts.