
1. Mga Prinsipyong Estruktural at mga Bentahe sa Efisiensiya
1.1 Mga Diperensyang Estratektural na Nakakaapekto sa Efisiensiya
Ang mga single-phase distribution transformers at three-phase transformers ay nagpapakita ng malaking diperensya sa estruktura. Ang mga single-phase transformers ay karaniwang gumagamit ng E-type o wound core structure, habang ang mga three-phase transformers naman ay gumagamit ng three-phase core o group structure. Ang pagkakaiba-iba ng estruktura na ito ay direktang nakakaapekto sa efisiensiya:
- Ang wound core sa mga single-phase transformers ay optimizes ang magnetic flux distribution, nababawasan ang high-order harmonics at ang mga kaugnay na losses.
- Nagpapakita ang datos na ang mga single-phase wound-core transformers ay may 10%–25% mas mababang no-load losses at ~50% mas mababang no-load currents kumpara sa mga traditional three-phase laminated-core transformers, kasama ang significantly reduced noise levels.
1.2 Pagsasalamin ng Prinsipyo na Nagsisilbing Pagbabawas ng Losses
- Ang mga single-phase transformers ay nagproseso lamang ng single-phase AC, simplifying ang disenyo sa pamamagitan ng pag-alis ng phase differences at magnetic potential balancing issues na inherent sa mga three-phase systems.
- Sa mga three-phase transformers, ang unbalanced loads ay nagdudulot ng additional losses: ang rotating magnetic fields sa core joints at transverse flux leakage sa lamination seams ay nagdudulot ng pagtaas ng energy dissipation.
- Ang mga single-phase transformers ay iwas sa mga isyung ito dahil sa independent magnetic paths, enhancing ang operational efficiency.
1.3 Mode ng Power Supply na Nag-o-optimize ng Line Losses
- Ang mga single-phase transformers ay nagbibigay-daan sa "small capacity, dense distribution, short radius" na mode ng power supply. Sa pamamagitan ng pagsasakatuparan malapit sa load centers, nababawasan nila ang low-voltage supply radii, na nagreresulta sa pagbawas ng line losses.
- Ang practical applications ay gumagamit ng single-pole suspension mounting, na nagpapasimple ng material costs at nagpapahusay ng installation efficiency—ideal para sa rural at urban fringe grid upgrades.
2. Mga Bentahe sa Paggamit ng Material at Manufacturing Cost
2.1 Pagbabawas ng Costs sa Pamamagitan ng Material Savings
- Ang mga single-phase transformers ay gumagamit ng 20% less core material at 10% less copper kumpara sa equivalent-capacity three-phase units.
- Ito ay nagpapababa ng manufacturing costs ng 20%–30%.
2.2 Case Study: Rural Grid Renovation
- Sa Shexian County, matapos ang pag-adopt ng single-phase transformers:
- Nabawasan ang low-voltage line construction costs ng ~20%.
- Nabawasan ang substation area construction costs ng ~66%.
- Kahit na mas mataas ang initial investment (halimbawa, ¥5,000 para sa 50kVA single-phase vs. ¥4,500 para sa three-phase), ang Life Cycle Cost (LCC) sa loob ng 10 taon ay mas mababa: ¥22,585 (single-phase) vs. ¥57,623 (three-phase).
2.3 Cost-Effective Power Supply Modes
- Ang mga single-phase systems ay gumagamit ng two-wire high-voltage lines (10% savings) at two- or three-wire low-voltage lines (15% savings), na nagreresulta sa pagbawas ng engineering costs.
- Ideal para sa mga rural grids na may mahahabang lines at scattered loads.
2.4 Mga Bentahe sa Produksyon
- Ang simpler structure ay nagbibigay-daan sa mass production, na nagpapahusay ng adoption ng advanced technologies tulad ng amorphous alloy cores, na nagpapababa pa ng costs.
3. Analisis ng Applicability sa Iba't Ibang Scenario
Application Scenario
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Key Features
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Case Details
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Transformation Effect
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Advantages
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Rural Power Grids
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Long supply radii, high line losses, poor voltage quality
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Shexian County: 30kVA three-phase transformer replaced with two single-phase units (50kVA + 20kVA)
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Line loss ↓ from 12% to 2.2%; voltage compliance ↑ from 97.61% to 99.9972%
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Solves "low-voltage" issues, improves reliability
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Urban Residential Areas
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Concentrated loads, voltage drops at peak times
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Ankang Dongxiangzi: 250kVA three-phase replaced with six 50kVA single-phase units
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Line loss ↓ from 5.3% to 2.2%; end-point voltage stabilized
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Shortens supply radius, enhances voltage quality
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Street Lighting Systems
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Energy-saving potential via voltage adjustment
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Single-phase V/V₀ transformers reduce voltage to 200V at night, saving 16% for 70W high-pressure sodium lamps
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Lower line losses, smart control for efficiency
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Energy savings via intelligent control
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4. Mga Rekomendasyon para sa Rational Application
4.1 Capacity Selection
- Core Principle: "Small capacity, dense distribution":
- Rural areas: ≤20kVA; urban areas: ≤100kVA.
- Wiring:
- ≤40kVA: 1 circuit; ≥50kVA: 2 circuits; prioritize single-phase three-wire system.
- Formula: P=kf⋅Kt⋅∑PN=Kx⋅∑PNP = k_f \cdot K_t \cdot \sum P_N = K_x \cdot \sum P_NP=kf⋅Kt⋅∑PN=Kx⋅∑PN (where kfk_fkf: load factor; KtK_tKt: simultaneity factor).
4.2 Installation Methods
- Independent: Para sa scattered villages; ensures proximity to loads.
- Branch-Type: Para sa flexible power switching.
- Mainline-Type: Para sa three-phase areas na walang three-phase loads.
- Prioritize single-pole mounting para sa space-saving at easy maintenance.
4.3 Hybrid Power Supply
- Single-phase loads ≤15% of three-phase loads: direct summation; else, convert to equivalent three-phase loads.
- Load Matching:
- Single-phase: residential loads; three-phase: industrial motors.
- Seasonal fluctuations: Use on-load capacity-adjustable transformers.
4.4 Operation and Maintenance
- Smart Monitoring: Remote data collection and metering.
- Protection Devices:
- High-voltage side: PRWG or HPRW6 drop-out fuses.
- Lightning protection: gapless composite insulator surge arresters.
- Low-voltage side: isolating switches + molded-case circuit breakers for safety.
4.5 Economic Considerations
- LCC Advantage: Lower long-term costs despite higher initial investment (e.g., ¥22,585 vs. ¥57,623 over 10 years).
5. Mga Tren at Prospekto sa Hinaharap
- Material Innovations:
- Amorphous alloy and wound cores will further reduce no-load losses by 70%–80% and 10%–15%, respectively.
- Smart Grid Integration:
- IoT-enabled monitoring and AI-driven optimization enhance real-time management.
- Renewable Energy Synergy:
- Facilitate rural distributed PV/wind integration, improving energy absorption.
- Standardization:
- Guidelines like Rural Power Grid Upgrade Technical Principles will refine application norms.