Megawatt Power Ltd, a leading company in Bangladesh in manufacturing world class Distribution and Power Transformers for 11 KV and 33 KV class as per customer requirement. The Transformers are designed, manufactured and tested in accordance with the latest national and international standard including IEC, ANSI/IEEE, BS, DIN, NEMA etc.
Design and Development
In house software developed by qualified IT Professional in assistance of design personnel are used to further ensure the reliability and accuracy of designs and to incorporate specific requirement of customers, if any and in translating their needs into product specification.
- Design are made for optimization in terms of
- Labour and material costs.
- Capitalization of losses.
- Specified performance characteristics such as impedance, temperature rise, efficiency & noise levels.
- Mechanical design with fittings & accessories for specifying maximum overall dimensions and weights.
- Distribution of voltage stresses under impulse, lighting and switching surge conditions.
- The ability of withstand the thermal and dynamic effects of short circuit.
- Analysis of those areas where high electrical stresses can occurs.
- Calculations for minimizing stray losses, hot spots, Electrical gradients etc by electrical and mechanical field analysis.
The magnetic core of the transformer is built up of Cold Rolled Grain Oriented (CRGO) magnetic steel lamination. Hi-B grade and laser scribed lamination is used to reduce the no load losses and noise level. Lamination are cut at angle of 450. Core leg and yoke lamination are interleaved in mitred joints in order to facilitate the passage of magnetic flux and to avoid hot spots and reduce no load losses, no load current and noise level.
The windings are designed to optimize Dynamic, Thermal, Mechanical & electrical Stresses depending upon the current & Voltage requirements. Spiral, Cross over, Helical, Continuous Disc, Partly interleaved or fully interleaved windings are used depending on the specific design criteria as per customer requirement.
The HV & LV winding are normally either round or rectangular high conductivity electrolytic copper conductor that are super enamel and paper insulated. In HV winding, one or more copper strip or super enamel insulated wire are used and in LV winding, one or more copper strip with insulated with pure cellulose paper are used. These windings made by winding machine with proper tension. Dovetailed key spaces are employed to give the winding extra strength. Axial and redial cooling ducts in and between sections of the windings allow the free flow of oil around the conductor.
The tank and its cover are made from high quality sheet steel. Normally these tanks are in rectangular or oval shape and side walls are corrugated or oval shape tube unit called radiator are inserted in order to increase the cooling surface area. Each tank is tested under pressure to detect any leakage in tank and radiator. All surfaces are thoroughly cleaned by sand blasting before painting. Exterior surfaces are painted with a primer coat and not less than two finish weather resistant coat.
Tapping and tap changer
MPL used mostly off line tap changer and on load tap changer as per customer requirement. In order to match the voltage ratio to local system condition, the high voltage winding have several tapings which are connected to the off load tap changer mounted on the Tank cover. The tap changer allows the increase or decrease of a certain number of turns in the high voltage side in order to compensate for a voltage drop or to adapt the transformer to an unstable supply, so that the rated low voltage can be maintained.
- ONAN (Oil Natural & Air Natural).
- ONFA (Oil Natural & Forced Air).
- HT Bushing with terminal connectors.
- LT Bushing with terminal connectors.
- Tap Changer.
- Conservator tank.
- Oil level indicator.
- Thermometer (for 3 Phase).
- Lifting Lugs.
- Silicagel Breather.
- Name Plate.
- Oil Drain Valve.
- Earthing plug.
- Buchholz relay ( as per customer requirement).
Tapping and tap changer
- MPL ensure quality test facility as to IEC, VDE, ANSI and BS 171 and every transformer is tested the following tests before delivery.
- Ratio Test.
- Polarity and phase relation test.
- Insulation resistance test.
- No load loss test.
- Full load test at rated current & frequency.
- Excitation current test.
- Percent of Impedance test and efficiency test.
- Induced voltage test.
- Dielectric strength of oil.
- Function of Tape changing Test.
- Temperature rise test.
- Oil leakage test.