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Fatima Alhassan
Fatima Alhassan
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Fatima AlhassanMember
Typical set: GSU step-up, station service, unit auxiliary, excitation transformers.
January 27, 2026 at 12:03 pm in reply to: How can you measure the vector group of a large power transformer? #332237Fatima AlhassanMemberApplied-voltage phase rotation tests and phasor comparison between HV and LV terminals verify clock notation (e.g. Dyn11). Used for parallel operation and protection.
January 26, 2026 at 2:43 pm in reply to: Why is neutral earthing used in a power transformer? #332067Fatima AlhassanMemberNeutral grounding controls fault currents, stabilizes phase voltages, and enables relay coordination. Variants include solid, resistive, and reactance grounding.
January 26, 2026 at 2:12 pm in reply to: Why is an automatic voltage regulator used with a power transformer? #332062Fatima AlhassanMemberAVRs compensate for feeder voltage variations and maintain acceptable LV levels for end users, improving power quality.
January 25, 2026 at 4:37 pm in reply to: What markets drive power transformers sales worldwide? #331885Fatima AlhassanMemberTransmission and distribution utilities, industrial plants, renewable integration, data centers, rail traction, mining, and oil & gas drive global demand.
January 25, 2026 at 6:51 am in reply to: What does the turn ratio test of a power transformer verify? #331809Fatima AlhassanMemberThe turns ratio test verifies correct voltage ratio between windings, proper vector group, polarity, and tap settings. Deviations may indicate winding deformation, shorted turns, or tap changer faults.
January 24, 2026 at 3:25 pm in reply to: Where are Siemens power transformer solutions deployed? #331689Fatima AlhassanMemberSiemens transformers are deployed in transmission and distribution substations, HVDC converter stations, renewables, mining, petrochemical, rail, and heavy industrial campuses.
January 24, 2026 at 3:35 am in reply to: What causes reactive power consumption in transformers? #331585Fatima AlhassanMemberReactive power is consumed by the transformer’s magnetizing current and leakage inductance. To establish alternating flux in the core, a magnetizing component of current lags the voltage and contributes to reactive power draw, even at no-load. Leakage inductance around windings and stray capacitances also affect reactive power behavior. Under load, the combination of magnetizing current and the load’s own reactive characteristics determines the overall power factor and reactive demand seen by the upstream network.
January 23, 2026 at 4:01 pm in reply to: How are power pole transformers tested for oil dielectric breakdown during routine maintenance? #331498Fatima AlhassanMemberPole transformers undergoing maintenance may have oil samples sent for dielectric breakdown voltage testing. The test measures the oil’s ability to withstand electric stress without arcing, indicating contamination or moisture.
Fatima AlhassanMemberIt performs voltage conversion between generation, transmission, and distribution voltage tiers. By stepping voltage up for bulk transmission and down for end users, transformers reduce losses and ensure safe utilization.
January 21, 2026 at 6:14 pm in reply to: How does the US-6S ensure even drying throughout the transformer core? #331002Fatima AlhassanMemberUniform drying is achieved through a combination of controlled heating media (oil or electric heaters), circulating fans, and precise vacuum regulation. The circulation and exhaust systems promote consistent temperature distribution, while a sealed vacuum chamber prevents external air ingress. This integrated design ensures moisture is removed evenly from all core regions.
January 21, 2026 at 11:08 am in reply to: What functions does a power plant transformer perform in generation and step up processes? #330877Fatima AlhassanMemberIn a power plant the generator step up transformer connects the generator stator to the high voltage transmission network. It raises generator voltage to transmission levels which minimizes current and line losses for long distance transport. These transformers must handle high short circuit currents, continuous high load and frequent grid disturbances. Auxiliary transformers in the plant also step down voltage for station service loads such as pumps, cooling systems and control power, ensuring reliable operation of all plant subsystems.
January 21, 2026 at 9:17 am in reply to: What is the particle size of SBS after grinding in a GlobeCore colloid mill in PMB? #330851Fatima AlhassanMemberIn practice, after processing SBS in a GlobeCore colloid mill, the typical particle size in PMB is in the range of 1-10 microns, depending on gap setting, shear rate, and polymer grade. This size is small enough to ensure uniform dispersion and fast swelling in bitumen. Finer grinding mainly improves curing speed and storage stability, while going much below a few microns brings little additional benefit for PMB performance.
January 21, 2026 at 6:23 am in reply to: Where are hi-power transformers used in industrial systems? #330810Fatima AlhassanMemberHigh-power transformers feed megawatt-scale loads such as smelters, arc furnaces, refineries, chemical plants, mining equipment, and rolling mills.
January 20, 2026 at 3:23 pm in reply to: What is the permissible pH level for transformer oil? #330596Fatima AlhassanMemberIn practice, transformer oil should remain neutral to slightly acidic, and pH is not usually the primary control parameter, but it is still indicative of oil aging. For fresh mineral oil, pH is typically in the range of about 6.5 to 7.5. During service, slight acidification is acceptable, but a pH dropping below roughly 5.5-6.0 usually indicates significant oxidation and formation of acidic by-products. At that point, further testing of acid number (TAN) and sludge formation becomes more important than pH alone.
January 18, 2026 at 9:55 pm in reply to: What is the function of a drain valve on a power transformer? #330252Fatima AlhassanMemberA drain valve allows controlled removal of insulating oil during sampling, maintenance or tank emptying.
November 11, 2025 at 2:00 pm in reply to: Need pricing for rotary vacuum pump model GC40-620, nine units, including delivery time, shipping to France, and warranty details. #327508Fatima AlhassanMemberThe GC40-620 rotary vane vacuum pump provides 620 m³/h flow rate and low residual pressure suitable for transformer service units. Pricing, warranty, and lead time will be included.
November 11, 2025 at 5:52 am in reply to: Need an offer for an oil degassing unit, model CMM-0.6. Please indicate delivery time, price (net and incl. tax), and shipment to Germany. #327478Fatima AlhassanMemberThe CMM-0.6 transformer oil purification unit removes moisture, gases, and solid impurities. Standard delivery time is 6-8 weeks. The system is shipped fully assembled, tested, and ready for operation. Pricing and transport options to Germany will be included.
Fatima AlhassanMemberGlobeCore manufactures a full line of transformer oil filtration and purification systems. Capacities range from 0.6 to 24 m³/h. Equipment includes multi-stage filtration, heating, and vacuum dehydration. A quotation and specifications will be provided.
November 9, 2025 at 8:44 am in reply to: Inquiry about low-frequency transformer drying equipment for use in production of new transformers not filled with oil. #327288Fatima AlhassanMemberGlobeCore manufactures low-frequency transformer drying systems for factory use. These systems provide uniform heating of windings and cores using low-frequency current technology. Technical parameters and pricing will be provided upon request.
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