- 您需要先登录才可以创建新话题。
Richard Mcdaniel
Richard Mcdaniel
已创建论坛回复
-
作者帖子
-
Severe faults such as insulation breakdown, winding short, gas generation, overpressure, or arc flash can rupture tank walls. Lack of oil protection, Buchholz trip, or sudden pressure relay failure accelerates catastrophic events.
Transformer power factor in service is mostly determined by the connected load, not the transformer itself. To improve overall system power factor, engineers install shunt capacitors, synchronous condensers or active filters near inductive loads. These devices supply reactive power locally, reducing reactive current through the transformer. At no load, transformers show low power factor because magnetizing current is mostly reactive, but this has small real power impact. In insulation testing, lowering dielectric losses through proper drying and oil treatment improves the measured insulation power factor.
A large power transformer is generally a high voltage, high MVA unit used in transmission or major substation applications, typically tens to hundreds of MVA and voltage levels from about 69 kV up to 765 kV or more. These transformers step up generator voltage to transmission levels or step down transmission voltage to sub transmission or distribution levels. They are physically massive, oil filled, and equipped with radiators, bushings, on load tap changers and advanced monitoring. Large power transformers are critical grid assets with long lead times, complex transport logistics and high replacement cost.
一月 26, 2026 1:57 下午 回复至： Why is a transformer mounted on a power pole in distribution networks? #332060Same concept as above: economical LV distribution, rural access, and simplified servicing.
Constructing a power transformer involves core design, coil winding, insulation layering, mechanical assembly, tank fabrication, oil filling and degassing, integration of bushings, tap changers, and cooling radiators. After assembly, the unit undergoes routine and type tests before deployment.
一月 25, 2026 10:16 下午 回复至： How is a power transformer pole unit refurbished after overload and hotspot failures? #331926Utilities replace bushings, repair tap changers, dry windings, and process oil to remove moisture and gases; failed coils may be rewound.
一月 25, 2026 6:35 上午 回复至： What functions does a power factor transformer serve in power systems? #331807The term power factor transformer usually refers to transformers within a power factor correction system, rather than a special transformer alone. Such transformers supply capacitor banks, harmonic filters or synchronous condensers at suitable voltages while providing isolation and impedance. Their role is to enable connection of reactive compensation equipment so that the overall plant or feeder power factor improves. This reduces reactive power drawn from the grid, lowers losses and can help avoid utility penalties for low power factor.
Short-circuit duty is set by system fault levels, transformer impedance, and mechanical design strength of windings, core clamps, and leads. The transformer must withstand specified fault currents for defined durations without mechanical or thermal damage. Higher system fault levels require stronger mechanical bracing and careful winding geometry. Standards define test levels for dynamic and thermal short-circuit withstand, verifying that the transformer can survive realistic worst-case faults in the network.
Services include oil analysis, DGA, PD diagnostics, tan-delta, FRA, OLTC overhaul, bushing replacement, rewinding, retrofilling, rigging, and commissioning.
Requirements include thermal limits, dielectric withstand, partial discharge thresholds, efficiency, impedance tolerance, loss guarantees, BIL, and OLTC switching performance within IEEE/IEC standards.
一月 23, 2026 6:35 下午 回复至： How are transformers in a power plant used for voltage regulation and grid connection? #331518Power plants use generator step-up (GSU) transformers to raise generator voltage for transmission, and station service transformers to supply auxiliary loads.
一月 22, 2026 12:44 下午 回复至： What does a power transformer symbol represent on electrical diagrams? #331257It represents an isolated magnetic coupling between windings that changes voltage levels while providing galvanic isolation in circuits.
Key components of the US-6S include the control cabinet, vacuum unit (e.g., BV-1000), compressor, technical oil heater, vapor condenser, condensate collection tank, furnace chamber, sliding carriage, and doors with pneumatic or motorized drives. Each part is engineered to ensure uniform drying, vacuum maintenance, and safe operation throughout the drying cycle.
For single phase S = V cdot I; for three phase S = sqrt{3}VI.
一月 20, 2026 5:11 下午 回复至： How does a power transformer change voltage levels between circuits? #330621Electromagnetic induction transfers AC power; the turns ratio defines voltage conversion.
Core-coil assembly refers to the structural unit consisting of laminated steel core, primary and secondary windings, insulation spacers and clamping. This assembly defines the magnetic path, leakage flux, impedance, losses and mechanical strength against short circuit forces.
Core steel grade, lamination technique, flux density, stacking pattern, insulation coatings, and geometry influence efficiency, noise, and thermal behavior.
一月 19, 2026 10:09 下午 回复至： How do power transformers manufacturers certify products for industrial and grid environments? #330414Certification involves IEC/IEEE compliance, type tests, routine tests, insulation coordination, seismic qualification, and factory acceptance testing. For grid use, utilities require interoperability, protection interface data, and documented reliability metrics.
The UVB-2 modification plant blends polymers such as SBS or crumb rubber with bitumen. It includes dosing, mixing, and homogenization systems.
The bitumen filtration unit ensures continuous cleaning of bitumen flow up to 15 m³/h with automatic mesh replacement and temperature control.
-
作者帖子