Strukturên Nû û Çawî yên Deyvekirina 10kV Transformersa Bixwekîya Bilindan

1.Peyvên Nû yên Winding ji bo Transformerên High-Voltage High-Frequency ên Sîn 10 kV

1.1 Struktûra Ventilated Zoned û Partially Potted

• Dewa pêşkên ferrite yên forma U hatin daqiq kirin bi xwe biçin biryara magnektikê were formkirin, an yê bike destpêka wekî modulanên core série/paralel. Bobinan primary û secondary hatin destnîşan kirin ser dêwanên straight yên core ya çep û rast, di demê de plane ya matbo core were bikar bûn wekî layer boundary. Peyvanên ji taypa yekem hatin gorupkirin ser yek sêm. Litz wire were tercih kirin wekî material winding bi tenê rengê ku hewce ye ku herzênde high-frequency bigere.

• Tenasîn high-voltage (an primary) tenê li ser resin epoxy were potted. PTFE sheet were qabat kirin di navbera primary û core/secondary de bi tenê rengê ku hewce ye ku insulation reliable were. Surface secondary were qabat kirin bi paper insulation an tape.

• Bi rakirina channels ventilation (gaps di navbera windings û di navbera secondary windings de li ser dêwanên çep û rast) û gaps di navbera magnetic cores de, dizaynê wê zêdetir dikare berhevkirina heat were çêkirin, bi tenê rengê ku weight û cost were gereke, hemî ji gelek dielectric strength were mirin—wê bikar bibe ji bo vebijarkên isolation ≥10 kV.

1.2 Modular Design û Shielding Electric Field bi Litz Wire Grounded

• Modulanên winding high-voltage û low-voltage were potted separately û ewer li ser unit core were assembled. Air gaps were rakirin di navbera modulan de bi tenê rengê ku assembly û cooling were gereke, û modulanên damaged were bike bikeyên wergerin di navbera faults de, bi tenê rengê ku maintainability were zêde bike.

• Shielding layers electric field bi Litz wire grounded were seretin di navbera inner û outer sides de ya high-voltage winding. Ew high-frequency electric field were tevahiyen di navbera region epoxy-potted high-dielectric-strength de, bi tenê rengê ku risk partial discharge (PD) were zêdetir bigere, bêtirin ku spacing winding nêzîk bike bi tenê rengê ku electric field suppression were gereke.

• Litz wire shielding layer were bike open-circuited bi single-point grounding, bi tenê rengê ku electric field shaping were bicîh bikin, bêtirin ku eddy current losses significant were bigere. Channels ventilation were rakirin di navbera windings û core de, bi tenê rengê ku semi-ventilated cooling û miniaturization were hêsan bikin.

1.3 Segmented Winding û Shaping Electric Field

• Coaxial sleeves û segmentation ribs were seretin bi bobinan insulation, bi tenê rengê ku primary û secondary windings were interleaved bi “segment groups.” Ew zêdetir voltage gradients inter-layer û equivalent parasitic capacitance were gereke, suppressing conducted EMI û improving voltage distribution uniformity.

• Number of segments n û layer count were determined via formulas analytical or empirical (e.g., n = −15.38·lg k₁ − 18.77, where k₁ is the minimum value among primary/secondary self-capacitance and mutual capacitance ratios), achieving an optimal trade-off among volume, leakage inductance, and parasitic capacitance—ideal for high-power, high-voltage, high-frequency operation.

1.4 Composite Windings û Integrated Water Cooling

• Core were divided into two winding zones. Approach composite winding were used: first composite winding (e.g., primary) were wound from inner to outer layers with leads reserved; then, in the second zone, the second composite winding (e.g., secondary) were wound in reverse using the reserved leads. This expands inter-layer gaps and reduces residual charge, enhancing high-voltage reliability and lifespan.

• Relief slots were machined on the outer core wall to integrate non-contact water-cooling channels, improving thermal performance without risking mechanical damage during assembly. Composite insulation uses PI/PTFE laminates arranged in a stepped configuration to ensure adequate creepage distance and high-quality potting fill.

1.5 Techniques Nû yên Winding û Pathways Loss Control

Technology PDQB (Power Differential Quadrature Bridge) winding were introduced: through optimized winding topology and layout, skin and proximity effects—and thus high-frequency losses—are significantly suppressed. This achieves coupling efficiency >99.5% in reported cases, along with 10 kV isolation capability, controllable leakage inductance, and low distributed capacitance—making it suitable for customized 30–400 kW, 4–50 kHz high-voltage high-frequency applications.

2. Structures Common yên Winding ji bo Transformerên High-Voltage High-Frequency ên Sîn 10 kV

2.1 Configurations Basic yên Winding û Application Scenarios

• Multi-layer cylindrical: Process manufacturing mature; easy to insert inter-layer insulation and cooling channels; suitable for medium-to-high voltage continuous windings.

• Multi-segment layered: Multiple axial segments separated by insulating paper rings; effectively reduces inter-layer voltage gradient and field concentration; commonly used in HV windings to mitigate partial discharge.

• Continuous (disc-type): Composed of multiple disc sections stacked axially; offers good mechanical strength and thermal performance; suitable for high-capacity/higher-voltage applications.

• Double-disc: Two discs per group, connected in series/parallel; ideal for high-current or special-purpose HV windings.

• Helical: Single/double/quadruple helix; simple structure; suitable for high-current LV windings or on-load tap-changing windings; limited in turn count.

• Tîrka alûmînîy silindarî: Yek çarçov pê şertî yên alûmînîy; bavên herêmî yên serbesta wekhevi û yêşilîy; destûr ji bo windîngên HV kêmtirin.

În wêneyên windîngên HV bi xebatî yên standarde yên transformerekan dînastî yên elektrîk û ziyadetir çêkirin an berferd bikin ji bo transformerekan high-voltage high-frequency-yan di klasa 10 kV de pirzandina insulation û performansa termal.

2.2 Wêneyên Windîng û Processan bi Xebatî yên High-Voltage High-Frequency

• Rêza silindarî (layered) taybet: Windîng ên HV navendî, LV derve (an vice versa); dizayn ên multi-layer bi insulation ên inter-layer li ser distribûsina high potential differences; layout ên segmented dikarin bikar bînin ji bo optimizasyona electric field distribution û PD performance.

• Segmentation û interleaving: Windîng ên HV dibîne ser coils ên din dikarin bikar bînin û li ser rêzan staggered/segmented bike dikare werbigire jêrîna voltage gradient û parasitic capacitance, suppress conducted EMI, û improve voltage uniformity.

• Faraday û electrostatic shielding: Tîrka copper foil an conductive layers divê were bike li ser primary/secondary an li ser windings, grounded li ser pointa yekem, ji bo reduce common-mode capacitance û coupling noise; shielding divê were bike matching winding width û away from sharp edges ku dikare puncture insulation.

• Conductor û current density optimization: Litz wire, stranded conductors, an tîrka copper foil herî pelî hatine ji bo HV/high-current secondaries ji bo suppress skin/proximity effects, reduce AC resistance (Rac) û copper loss; current density (J) û temperature rise controlled within window û safety regulation limits.

• Insulation û creepage design: Use of barriers, end margins, sleeved terminals, û combined inter-layer/inter-winding insulation; creepage distance û clearance designed according to pollution degree û voltage class; vacuum impregnation/potting may be applied to enhance dielectric strength û thermal conductivity.

În layout û process considerations closely tied to balancing insulation level, parasitic parameters, û power rating—key to achieving reliable 10 kV isolation in engineering practice.

2.3 Implementation Methods for High-Voltage Secondary Output (Strongly Dependent on Winding Structure)

• Voltage multiplier rectification: Multi-stage voltage doubling on the rectifier side significantly reduces voltage stress û parasitic capacitance per winding stage, easing insulation design. However, it is sensitive to load transients/short circuits û prone to surge currents. In practice, no more than two stages are typically used, requiring current-limiting û protection strategies.

• Series/parallel combination: The secondary is split into multiple coil packs, which are internally or post-rectifier connected in series/parallel to achieve desired voltage/power. All packs share the same magnetic circuit, facilitating modular design û voltage balancing—ideal for high-power output.

Both methods require integrated design with winding segmentation, shielding, û insulation windows to balance voltage stress, efficiency, EMI, û thermal performance.

2.4 Structural Selection Guidelines (Quick Engineering Reference)

• Prioritizing electric field uniformity û PD control: Prefer segmented or continuous (disc-type) HV windings, combined with Faraday shielding, end margins, û barriers; vacuum impregnation/potting recommended when necessary.

• Prioritizing high current û low copper loss: Use Litz wire or copper foil for secondary; employ interleaved or sandwich winding internally to minimize leakage inductance û Rac; reinforce outer shielding û insulation.

• Prioritizing assembly û maintainability: Adopt modular secondary coil packs with series/parallel connections for easy voltage balancing, testing, û fault isolation; select voltage multiplier rectification (≤2 stages) or series/parallel combination on the rectifier side based on power û transient requirements.