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後藤 零
後藤 零
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January 28, 2026 at 2:28 am in reply to: Why is step up transformer used in power transmission? #332361後藤 零Member
Stepping voltage up reduces current and I²R losses, improving line efficiency and enabling long-distance bulk power transfer.
後藤 零MemberYes. Even without load, transformers draw magnetizing current and incur core losses (hysteresis and eddy currents). Large oil-filled units may also have auxiliary consumption from cooling fans, pumps, and monitoring equipment.
January 25, 2026 at 2:18 pm in reply to: What causes power transformer hum in grid equipment? #331867後藤 零MemberTransformer hum is primarily caused by magnetostriction in the core. As magnetic flux reverses each cycle, core laminations slightly expand and contract, creating mechanical vibrations at twice the line frequency (100/120 Hz) and harmonics. Loose clamping, aging insulation, and structural resonances in the tank, radiators, and mounting structures can amplify the audible noise. High load levels and harmonics further intensify the vibration. Proper core clamping, damping materials, and acoustic design are used to reduce hum in substations.
January 25, 2026 at 8:54 am in reply to: What are the uses of power transformers in electrical networks? #331825後藤 零MemberThey connect generation to transmission, and transmission to distribution, enabling efficient long-distance transfer and safe end-user supply.
January 24, 2026 at 10:22 pm in reply to: How much does a power transformer cost for utility installation? #331743後藤 零MemberSubstation power transformers (tens to hundreds of MVA) cost from hundreds of thousands to several million USD depending on voltage class and cooling.
January 23, 2026 at 1:09 am in reply to: Who are major power distribution transformer manufacturers? #331365後藤 零MemberMajor distribution transformer manufacturers include global OEMs and numerous regional producers that specialize in MV/LV step-down units and pole- or pad-mount transformers. They supply utilities, rural electrification schemes, and industrial/commercial campuses. Key capabilities are high-efficiency core designs, eco-friendly fluids, standardized ratings, and fast delivery. Many manufacturers focus on 25-5,000 kVA classes, offering both oil-filled and dry-type construction for indoor and outdoor use.
January 21, 2026 at 11:37 pm in reply to: How long does a typical gearbox oil change take with the CMM-G? #331081後藤 零MemberThe CMM-G is designed for rapid servicing, capable of completing the full oil change cycle – draining, flushing, and refilling – in less than one hour. This quick turnaround helps minimize turbine downtime, improving overall wind farm availability and reducing lost production from extended maintenance windows.
January 21, 2026 at 3:33 pm in reply to: Which types of transformers or size ranges are best suited for use with LFD? #330958後藤 零MemberLFD is best suited for medium and large power transformers, typically from 5-10 MVA and above, where the mass of cellulose insulation is high and conventional external heating becomes inefficient. It is especially effective for HV and EHV units with thick windings, disc insulation, and long moisture diffusion paths. For small distribution transformers, the complexity and setup effort of LFD is usually not justified, while for large grid transformers it is often one of the most efficient deep-drying methods available.
January 21, 2026 at 7:26 am in reply to: What applications require a high voltage power transformer in transmission systems? #330824後藤 零MemberHV power transformers connect generation to transmission networks, step-up for long-distance lines, and step-down for substation distribution.
January 21, 2026 at 4:13 am in reply to: I wanted to ask whether a breakdown voltage test performed at 60 Hz is acceptable. #330778後藤 零MemberYes – a 60 Hz breakdown voltage test is generally acceptable as long as it’s performed to the correct standard and you report it that way. The common BDV standards treat “power frequency” as a band, not a single number: ASTM D877 specifies an AC test in the 45-65 Hz range, so 60 Hz is within spec. IEC 60156 is also a power-frequency method (typical sources are around 50/60 Hz). What matters more than 50 vs 60 is that you keep everything else consistent (electrode type/gap, voltage rise rate, oil temperature, conditioning, and cleanliness). If you’re trending results, don’t mix methods (e.g., D1816 vs D877 vs IEC 60156) without clearly separating them.
January 20, 2026 at 1:00 pm in reply to: What is the maximum number of transformers that can be displayed simultaneously on one screen or on a single TOR-5 system server? #330561後藤 零MemberIn practice, the limit is not defined by the TOR-5 hardware itself, but by the server configuration and the SCADA or web interface used to display the data. A single TOR-5 server can usually handle dozens of transformers in parallel, as each unit only transmits a small set of parameters with low data rate. The real constraint is screen ergonomics: most operators comfortably monitor 8-16 transformers on one dashboard, using grouping and alarms rather than trying to view everything at once.
後藤 零MemberA power transformer transfers electrical energy between voltage levels using electromagnetic induction while providing isolation and impedance.
January 18, 2026 at 11:42 pm in reply to: What information is listed on a power transformer nameplate? #330262後藤 零MemberA nameplate lists manufacturer, serial number, year, kVA/MVA rating, primary and secondary voltages, connection vector group, frequency, cooling class, impedance, temperature rise, insulation levels, weight, oil volume and standards. Some nameplates show tap ranges and no load/load losses. Nameplates identify the unit and define its electrical capabilities for operators, protection engineers and maintenance personnel.
November 9, 2025 at 10:18 am in reply to: Looking for a zeolite drying system for DCM – can you assist? #327294後藤 零MemberGlobeCore specializes in oil purification equipment, not solvent-based DCM drying systems. For this application, a chemical-grade zeolite dryer from a solvent-processing supplier would be required.
September 15, 2025 at 8:00 am in reply to: ¿Qué hace una máquina de filtrado de aceite dieléctrico de alta eficiencia? #325398後藤 零MemberLa máquina GlobeCore para aceites dieléctricos elimina agua (<10 ppm), gases y partículas, restaurando la rigidez dieléctrica. Se utiliza en mantenimiento de transformadores, subestaciones y centros de distribución eléctrica.
September 10, 2025 at 8:02 am in reply to: What is the oil filtration process for industrial oils? #325082後藤 零MemberThe oil filtration process includes preheating, coarse and fine filtration, vacuum drying, and degassing. GlobeCore systems automate this entire cycle, ensuring oils meet operational specs. They’re used in energy, mining, metal processing, and aviation sectors.
September 9, 2025 at 12:40 pm in reply to: What is a breakdown voltage tester and how does it work? #324960後藤 零MemberIt applies increasing voltage until the oil fails electrically. To get valid results, the oil must be moisture-free. GlobeCore’s vacuum dehydration machines are used globally to prepare oils for BDV testing in power substations.
後藤 零MemberAeroShell 308 is a synthetic ester-based turbine oil for jet engines requiring high-temperature protection. GlobeCore systems clean and dry AeroShell 308, extending its operational life.
後藤 零MemberExxon Turbo Oil 2380 is a synthetic jet engine oil formulated for low deposit formation and long drain intervals. GlobeCore purification units remove moisture and gases, extending its usable life.
August 2, 2025 at 2:26 pm in reply to: Why is transformer filtration needed and how is it done? #323514後藤 零MemberFiltration removes particulates, moisture, and gases from insulating oil, restoring its breakdown voltage and cooling capacity. GlobeCore provides mobile and stationary filtration units for on-site or industrial-scale oil servicing.
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