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Ashley Hall
Ashley Hall
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一月 27, 2026 6:29 下午 回复至: Why the no-load power factor of an induction motor / transformer is very low? #332299
Magnetizing current is largely reactive, producing low real power at no-load.
一月 27, 2026 1:00 上午 回复至: what is the difference between voltage transformer and power transformer? #332149A voltage transformer, often called an instrument or potential transformer, is designed to reproduce system voltage at a lower, safe level for metering and protection devices with high accuracy and low burden. A power transformer is built to transfer significant power between circuits, prioritizing efficiency and thermal performance rather than precise ratio accuracy. Voltage transformers operate at low VA ratings and are part of measurement circuits, while power transformers handle kVA or MVA, feeding loads or other network sections. Their insulation, construction and testing requirements differ accordingly.
In an ideal transformer, apparent power remains constant between primary and secondary. Voltage and current change inversely according to the turns ratio. Real transformers incur copper, core, and stray losses, so input power equals output power plus losses.
Urbanization, renewable integration, grid modernization, utility investment cycles, and regulatory efficiency mandates drive demand.
Transformers form voltage tiers between generation, transmission, and distribution, ensuring impedance matching, fault withstand, and regulation coordination.
Total losses = core losses + copper losses; P_{loss} = P_{core} + I^2R plus stray and dielectric losses for detailed studies.
一月 24, 2026 12:45 上午 回复至: What affects the price list of power transformers in the Philippines? #331563Price depends on kVA rating, voltage class, cooling, copper and steel costs, logistics, and local utility specifications and standards.
Parallel operation allows utilities to increase total kVA capacity, share load, improve redundancy, and maintain service continuity during maintenance. For safe paralleling, transformers must match in voltage ratio, vector group, impedance, and phase displacement. Mismatches cause circulating currents, thermal stress, and uneven load distribution. Parallel banks also enhance system flexibility for seasonal and industrial load variations.
kVA, voltage taps, regulation, and noise performance guide selection for audio electronics.
Internal faults trigger protection that isolates the transformer and de-energizes downstream feeders, causing localized outages until switching restores service.
Inside a power transformer you find the magnetic core, primary and secondary windings, insulation systems (paper, pressboard, spacers), clamping structures, core/coil assembly supports, oil channels or ducts, and, in oil-filled units, the insulating liquid itself. Bushings connect windings to external circuits, while internal leads route current to tap changers. Many designs include temperature sensors, winding supports, and internal shields to control electrical stress and stray flux. Each component is selected to withstand electrical, thermal, and mechanical stresses over decades.
一月 21, 2026 2:26 上午 回复至: Is it possible to determine the average age of a transformer’s paper insulation by any method? #330752There is no method that can determine the exact average age of paper insulation, but there are well-established indirect techniques to estimate its remaining life. The most common is furan analysis of the oil, which correlates furan concentration with the degree of polymerization (DP) of cellulose. DP gives a good indication of mechanical aging. Additional methods include trend analysis of moisture, acidity, CO/CO? ratio in DGA, and historical thermal loading. These together allow a reasonable estimate of insulation aging, but never a precise “age” in years.
GE control transformers supply low-voltage AC for relays, contactors, PLC I/O, and automation equipment in industrial and utility switchgear.
A current transformer for meters measures line current by scaling high primary currents to small secondary currents suitable for metering and billing. It maintains ratio accuracy and isolation for safe measurement.
GlobeCore offers bitumen modification systems capable of producing blended emulsions and cutbacks with consistent product quality.
十一月 12, 2025 12:07 上午 回复至: Interested in pigment dispersion using AVS-100. Need pricing and performance data. #327549The AVS-100 provides ultrafine pigment dispersion with uniform particle distribution. Typical particle size reduction is to 0.2-0.5 ?m. Throughput and energy data will be provided.
GlobeCore supplies cavitation systems worldwide. Local technical support can be arranged remotely or via partner distributors.
Both AVS-100 and AVS-150 electromagnetic mills work on the same vortex layer principle. The AVS-150 has a larger chamber volume, higher throughput, and more powerful inductor, allowing continuous operation with coarser materials or higher loads.
十一月 8, 2025 11:44 上午 回复至: I was considering the TOR-80 or the TOR-100. What is the difference and the price? Rob #327208The TOR-80 is a semi-automatic breakdown voltage tester up to 80 kV, while the TOR-100 is a fully automatic version up to 100 kV with programmable voltage rise rate and data storage. We will provide a quotation for both models including technical datasheets and lead time.
十一月 7, 2025 3:09 下午 回复至: Need quotation of breakdown voltage tester TOR-80 and detailed brochure. #327130The TOR-80 is a semi-automatic breakdown voltage tester for insulating oils up to 80 kV. It conforms to IEC 60156 standards. We will send a quotation, brochure, and lead time information.
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