Instantaneous Power Supply (IPS)

07:28 / Posted by tech data / comments (1)

Now-a-days the instant power supply (IPS) is one of the most important things in one’s life. The main function of the IPS is to give power to the residential loads continuously for sometimes while there is a load shedding or failure of mains. In Bangladesh, in most cities , the electricity board / the authority do not provide mains supply for 24 hours in a day, for demand is more than generation. Actually our demand (in Bangladesh) is 4500MW whereas the generation is 3800MW only. So in peak hours we always get victim of load shedding. In rural areas the condition is far worse. Even in our country, load shedding occurs 4/5 times in a day. So from this view we can say the power situation in Bangladesh is not reliable.

an Instant Power Supply (IPS) using MOSFET. Actually, the power handling capability and switching rate of the MOSFET is better than the transistor that is why we choose the MOSFET based IPS. IPS gives long back up time and lower cost. When current is failed, it requires 1 second to recognize it. While UPS require only 10 msec. The wave of all device is sine wave but the wave of IPS is square wave. Because of square wave and more delay time electrical equipment cab be reset.For these two reason the use of IPS is not feasible and it is not suitable for IT or telecom or medical equipment.The operation of generator and IPS are same but generator are used to cover larger area than that of IPS.The Uninterruptible Power Supply (UPS) systems which are not suitable for powering those equipments which have rotating machinery such as induction motors and blowers. Also for computer systems, which make use of linear power supplies, square wave input with higher noise level.
In addition product features, Rahimafrooz (One of the largest group in Bangladesh) invented IPS with the art inverter technology. and the built-in Centre Processing Unit that continuously monitors and controls the automatic functions of the IPS. Rahimafrooz IPS are designed to meet power requirements for home and office appliances like light, fan, audio visual equipment, fax, PABX, etc. and can be plugged in directly with the main supply.The Range is available from 250 VA to 10.00 KVA models.

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Power Generation feature in Bangladesh

10:04 / Posted by tech data / comments (0)

In the mordern age the demand of electricity increasing day by day. But generation of electricity is not increases so fast in Bangladesh. So it occurs load-shedding, hampered production.In october 30, 2008 , reliable base of generation capacity is about 4,300 Megawatts (MW), with peak output on most days between 3,500 and 3,800 MW. But peak demand is estimated to exceed 5,000 MW on most days so many customers find themselves getting cut off when they most need power.

Here is a over all brief of power generation in Bangladesh.
Single line diagram of Dhaka area -1 Single line diagram of Dhaka-2Power plants in Dhaka area-2 Power plants in Dhaka area-1Single line diagram of Chittagong area Power Plants in ChittagongSingle line diagram of Khulna areaPower plants in Khulna

Single line diagram in Mymensingh area
Power plant in Mymensingh

Single line diagram in sylhetPower plant in SylhetSingle line diagram of Rajshahi areapower plant in Rajshahi
All information @2007

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Wartsila Power Plant

07:31 / Posted by tech data / comments (0)

This plant is setup by Wartsila, Finnish Company, under the agreement with Khulna Power Company Limited (KPCL). It is the first private power plant project in Bangladesh. It has started its production since October 13, 1998. It supplies power to our national grid. The plant has two sections; the main generating section is mounted on two separate barges floating on water; and the rest of the plant including administration building, workshop, store house, fire house, fuel storages, data management section etc are situated on the ground. It is the only power plant in Bangladesh that is running under full computer control monitoring & protection system. This plant has both the ISO9002 & ISO14001 certifications from the International Standard Organization (ISO) for its best quality management and environment management.
The management authority of the power plant has employed service-man in consideration of per MW generating capacity of the power plant. In that respect the total manpower of this plant is
Marine Engineers 4
B. Sc Engineers 24
Diploma Engineers 46
M. Sc 2
Workers 50
Total manpower 126
Although for maintaining good management there are 126 working persons instead of 110.
The plant has two symmetrical power generating units, such as –
1. Tiger 1 &
2. Tiger 3.
Both are mounted on two separate barges. Tiger -1 has nine (9) generators and Tiger-3 has ten (10) generators. So, total numbers of generators are nineteen (19). Each has 6.5 MW generating capacity. So total generating capacity of
Tiger-1 = 9 x 6.5 MW = 58.0 MW (app)
Tiger-3 = 10 x 6.5 MW = 65.0 MW (app)
A single generator is being kept standby condition for maintenances purposes & sudden failure protection. Generators are v-type reciprocating synchronous diesel engine [engine configuration - 19x18V32LN]. The fuel used for the engines is Heavy Fuel Oil (HFO).
Information:September 28, 2002

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DC Power Transmission

11:22 / Posted by tech data / comments (0)

For some year past, the transmission of electric power by DC has been receiving the active consideration of engineers due to its numerous advantages.Advantage
. It require only two conductors a compared to three for AC transmission.

. There is no inductance, capacitance, phase displacement and surge problem in Dc transmission.

. Due to the absence of inductance, the voltage drop in a Dc transmission line is less than the AC line for the same load and sending end voltage. For this reason, a DC transmission line has better voltage regulation

. There is no skin effect in DC system. Therefore entire cross-section of the line conductor is utilized .

. For the same working voltage, the potential stress on the insulation is less in case of DC system than that in AC system. Therefore, a DC line required less insulation.

. A DC line has less corona loss and reduces interference with communication circuits.

. The high voltage DC transmission is free from the dielectric losses, particularly in the case of cables .

. In DC transmission, there are no stability problems and synchronizing difficulties.

Disadvantage

. Electric power cannot be generated at high DC voltage due to communication problems.

. The DC voltage cannot be stopped up for transmission of power at high voltages

. The DC switches and circuit breakers have their own limitations .

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AC Power Transmission

11:02 / Posted by tech data / comments (0)

The large network of conductors between the power station and the consumers can be broadly divided into two parts such as, transmission system and distribution system. Each part can be further sub-divided into two- primary transmission and secondary transmission and primary distribution and secondary distribution.
Advantages

· The power can be generated at high voltages.

· The DC voltage cannot be stepped up for transmission of power at high voltages.

· The DC switches and circuit breakers have their own limitations.

Disadvantages

. An AC line requires more copper than DC line

. The construction of AC transmission line is more complicated than Dc transmission line.

. Due to skin effect in the AC system the effective resistance of the lines is increased.

. An AC line has capacitance. Therefore, there is a continuous loss of power due to charging current even when the line is open .

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Types of circuit breaker

11:17 / Posted by tech data / comments (1)

MCB (Miniature Circuit Breaker)—rated current not more than 100 A. Trip characteristics normally not adjustable. Thermal or thermal-magnetic operation. Breakers illustrated above are in this category. MCCB (Moulded Case Circuit Breaker)—rated current up to 1000 A. Thermal or thermal-magnetic operation. Trip current may be adjustable.Air circuit breaker—Rated current up to 10,000 A. Trip characteristics often fully adjustable including configurable trip thresholds and delays. Usually electronically controlled, though some models are microprocessor controlled. Often used for main power distribution in large industrial plant, where the breakers are arranged in draw-out enclosures for ease of maintenance.

Vacuum circuit breaker—With rated current up to 3000 A, these breakers interrupt the current by creating and extinguishing the arc in a vacuum container. These can only be practically applied for voltages up to about 35,000 V, which corresponds roughly to the medium-voltage range of power systems. Vacuum circuit breakers tend to have longer life expectancies between overhaul than do air circuit breakers. Sulfur hexafluoride -High-voltage circuit-breakers have greatly changed since they were first introduced about 40 years ago, and several interrupting principles have been developed that have contributed successively to a large reduction of the operating energy. These breakers are available for indoor or outdoor applications, the latter being in the form of breaker poles housed in ceramic insulators mounted on a structure.
Current interruption in a high-voltage circuit-breaker is obtained by separating two contacts in a medium, such as SF6, having excellent dielectric and arc quenching properties. After contact separation, current is carried through an arc and is interrupted when this arc is cooled by a gas blast of sufficient intensity.


Future perspectives:In the near future, present interrupting technologies can be applied to circuit-breakers with the higher rated breaking currents (63 kA to 80 kA) required in some networks with increasing power generation.
Self blast or thermal blast circuit breakers are nowadays accepted world wide and they are in service for high voltage applications since about 15 years, starting with the voltage level of 72.5 kV. Today this technique is also available for the voltage levels 420/550/800 kV.

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Circuit breaker

10:05 / Posted by tech data / comments (0)

A circuit breaker is an automatically-operated electrical switch which is designed to protect an electrical circuit from damage caused by overload or short circuit. Unlike a fuse which operates once and then has to be replaced, a circuit breaker can be reset (either manually or automatically) to resume normal operation.

Circuit breakers are made in varying sizes, from small devices which protect an individual household appliance up to large switchgear designed to protect high voltage circuits feeding an entire city.

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Q-Point Sports wear Ltd

02:24 / Posted by tech data / comments (0)



This is another one project named Q-point sportswear ltd is a garments ( 100% export oriented) especially for shirt making . This project taking bus bar trunking system on their factory. This project started on 28 October,2008.



Here all the packets of different accessories are keeping on the floor. All the equipments are arrived from Italy. This was a FOB shipment.



Here are all the standard length of 500A , 160A GDA BBT with 50A Cutting Trolley BBT (Red color) & 40A, 25A SP & TP GLS machine & lighting BBT . The GDA are standard length of 4m , 40A, 25A are 3m length & cutting BBT are 2m each segment.



After opened the packets, all the tap of Box , End feed unit, flexible elbow, fixing hanger were kept on the table in a decent arrangement.



Workers are working on the floor to installation the lighting BBT . Actually this is a factory of 44,000 sft which takes to complete 15 days. The time takes longer only for prefabricated steel structure. If it is a building structure then it will be 7 days to complete the project.



After connecting the tap of box in the power BBT the looking sight get more smart & the alluminium housing almost same with the prefabricated structure may be impressed you.



The substation of this factory is 315KVA.

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Bata factory

00:52 / Posted by tech data / comments (1)

Tongi, Gazipur.
Bata is a multinational company . It is the largest shoe manufacturing company of Bangladesh. They have a world wide business. This is the substation room of Bata Shoe Company (Bangladesh) Ltd,Tongi, Dhaka ,Bangladesh.

This substation room is designed by siemens Bangladesh.

This is a LT switchgear panel having two nos 400A MCCB ,1 no 600A MCCB circuit breaker ,1 nos 160A MCCB,100A MCB& 63A MCB each. The Red, Yellow, Blue indicating the L1,L2,L3 Phases.The busbar is used here is Cu of 80x10 size.

This the out side of the LT panel

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Introduction of BBT components

01:09 / Posted by tech data / comments (0)

End feed unit: Power comes through cable & feeded in this unit. The front side is connected with the standard legth of 3m(siemens, BBI, EAE),3.05 (Powerduct) or 4m (Graziadio, gersan) bbt. It's dimension varies on current ratings.
















Flexible elbow : This is used as elbow for low rating (25A -40A)bus bar system. The cable is normally 0.5m length.

















Standard length : This in orginally main Busbar Trunking System. It's of two types. One is feeder length has no plug in point. Another is straight length. The length is normally 3m/3.05m/4m varies by brand. If it requires special size then it would very from minimum 400mm -2900m. For 4m standard length small piece is minimum 400mm-1.9m & large size is 1.91m-2.99m.
















Horizontal elbow: It is very important for turn to angle. Standard 90 deg. If required specific degree angle then it need to specially ordered.







Expansion Unit : It is a tool use for coneecting one bolt joint nut.





One bolt joint: It is use for jointing to straight length.


Centre feed unit: This part feeds power and delivered it two side same time.







Tap off box: This is tap of box. If required power then tapped it with the plug in point with a circuit breaker.
T Elbow: It is a special elbow.Feed power from one side & delivered it in two sides.



End cap: It should connect be connect at the end of power bbt.




Fixing hanger: It is use for hanging the busbar trunking system.












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Cross Section of Busbar Trunking System

21:45 / Posted by tech data / comments (2)

Actually BBT consist a very simple technology. Here is a cross section of 25A BBT . If you keenly look , you can able to understand the technique. Cable are arranged in a insulation strip where L1,L2,L3 & N are showing.
A rectangular plug element on the cable strip uses through which male part of plug enter here to power the light or machine.
Here the naked side of the cable. This insulation strip putting in a rectangle aluminium casing & use as a standard length of 3m length. This standard length has both male & female side which continuously create a long power route.

But for high power bus the technology is quite different than lighting bus. Joints are very strong. Medium range busduct follows single bolt joint element where high power bus follows double bolt joints.
Medium power bus hanging on roof.

Bus duct in a sweater factory.

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