Komprehensibong Solusyon para sa Pagpapahusay ng Performance ng Transmission Transformers: Pagsasama-sama ng Paggamit ng Cooling at Pagbawas ng Magnetic Circuit Losses

1. Background at Challenges

Sa patuloy na paglago ng mga load sa kuryente at ang mas mahigpit na mga pangangailangan para sa matatag na operasyon ng grid, ang mga transmission transformers ay nakaharap sa malubhang mga hamon sa pagkakataon ng operasyon, kontrol ng pagtaas ng temperatura, at matagal na kapani-paniwan. Ang labis na temperatura ng operasyon ay nagpapabilis ng pagtanda ng mga materyales ng insulation, nagbabawas ng habang-buhay ng kagamitan, at nagsisimula ng mas mataas na panganib ng pagkasira. Ang mataas na magnetic circuit losses (kasama ang iron loss at copper loss) ay nagbabawas ng efisiensiya ng paggamit ng enerhiya, na nagreresulta sa hindi kinakailangang mga gastos sa operasyon. Upang tugunan ang dalawang pangunahing isyu na karaniwang natatagpuan sa mga transmission transformers—labis na pagtaas ng temperatura at mataas na magnetic circuit losses—ginawa ang komprehensibong solusyon na ito.

2. Layunin ng Solusyon

• Malaking Pagbawas sa Operating Temperatures: Kontrolin ang temperatura ng top-oil at winding hotspot ng transformer sa ligtas na hangganan ng operasyon.
• Epektibong Pagbawas ng Magnetic Circuit Losses: Tumutuon sa pagbawas ng no-load losses (iron loss) at load losses (copper loss), na nagpapataas ng kabuuang efisiensiya ng operasyon.
• Pagpapalaki ng Operational Reliability: Bawasan ang rate ng pagkasira dahil sa sobrang init at labis na losses, na nagpapahaba ng serbisyo ng transformer.
• Optimization ng Total Life Cycle Cost: Ipaglaban ang ekonomikong efisiensiya ng transformer sa pamamagitan ng pag-save ng enerhiya at bawas na pagsasala.

3. Puso ng Mga Paraan ng Mitigation

Ang solusyon na ito ay gumagamit ng isang integradong estratehiya ng "Source Control of Losses + Enhanced Heat Dissipation Capability + Precise Condition Management":

3.1 Cooling System Optimization and Upgrade, Improving Heat Dissipation Efficiency (Addressing Temperature Rise)

• Employ High-Efficiency Cooling Methods:
• Forced Air Cooling (OFAF/ODAF): I-retrofit ang umiiral na naturally air-cooled (ONAN) o air-forced cooled (ONAF) transformers, o i-equip ang mga bagong yunit ng high-performance axial fans. Piliin ang efficient, low-noise, at weather-resistant fans kasama ng intelligent airflow control (halimbawa, automatic start/stop batay sa temperatura o variable frequency drive adjustment) upang malaking mapabuti ang air convection efficiency sa ibabaw ng radiator at mabilis na alisin ang init.
• Forced Oil Water Cooling (OFWF): Inuuna para sa ultra-high-capacity transformers, mga yunit na may mataas na load factors, o ang mga nag-operate sa mataas na ambient temperatures. Nakakamit ng high-efficiency oil pumps at plate heat exchangers upang gamitin ang mataas na specific heat capacity ng tubig para sa epektibong heat exchange. Kailangan ng suporta ng water treatment systems (upang i-prevent ang scaling at corrosion) at reliability assurance mechanisms (halimbawa, dual water circuits, standby pumps).
• Heat Pipe Assisted Cooling: Ilagay ang heat pipe modules sa mga critical points sa radiators upang epektibong maipadala at ilabas ang lokal na hot spot heat sa pamamagitan ng phase-change principle.
• Optimize Radiator Structure and Layout:
• Gamitin ang mga radiator na may taas na surface area (halimbawa, finned, panel radiators) at optimized flow path designs.
• Siguraduhin ang smooth flow paths para sa cooling media (air o water), i-eliminate ang lokal na flow restrictions, at i-improve ang uniformity ng heat dissipation.
• (Para sa air cooling) I-optimize ang posisyon ng fan at duct design upang siguraduhin ang uniform na coverage ng airflow sa ibabaw ng radiator, na minamaliit ang dead zones.
• Intelligent Cooling Control:
• Awtomatikong i-adjust ang output ng cooling system (fan speed/number, oil pump flow rate) batay sa real-time monitoring ng temperatura ng oil, winding temperature, at ambient temperature. Nakakamit ang on-demand cooling, na nagbibigay ng tiyak na heat dissipation effectiveness habang inii-minimize ang energy consumption ng auxiliary equipment.

3.2 Core Material and Structural Optimization, Reducing Iron Loss (Core Magnetic Loss Control)

• Select High-Performance Core Materials:
• Inuuna ang high-permeability, low-unit-loss cold-rolled silicon steel sheets (halimbawa, HiB steel) o mas advanced na amorphous alloy materials (na nagbibigay ng significant advantages para sa no-load loss reduction).
• Strictly control silicon steel sheet thickness, flatness, at insulation coating quality upang i-minimize ang hysteresis losses at eddy current losses.
• Optimize Core Design and Manufacturing Processes:
• Ipapatupad ang step-lap stacking techniques upang i-minimize ang magnetic reluctance sa joints, na nagreresulta sa pagbawas ng additional iron losses.
• Precisely control core stacking factor at clamping force upang tiyakin ang uniform magnetic path distribution at iwasan ang local over-saturation.
• (Applying Advanced Technologies) Explore techniques tulad ng laser scribing (Laser Scribbling) upang pa-optimize ang material magnetic domain structure.
• Optimize core grounding methods at shielding upang i-reduce ang stray losses sa structural components.

3.3 Winding Design Optimization and Process Improvement, Reducing Copper Loss (Key Magnetic Loss Control)

• Optimize Winding Structure and Electromagnetic Design:
• Precisely calculate ampere-turn distribution, optimize conductor cross-section shape (halimbawa, using continuously transposed cables - CTC o self-bonding transposed cables - TTC) upang i-minimize ang circulating current at eddy current losses.
• Reasonably select conductor material (high-conductivity oxygen-free copper) at current density, effectively reducing DC resistance losses habang sinusunod ang temperature rise constraints.
• Optimize winding height, diameter, at radial dimensions upang kontrolin ang leakage flux at i-reduce ang stray losses.
• Advanced Manufacturing Processes:
• Ensure uniform winding compactness using constant-tension winding equipment.
• Employ advanced Vacuum Pressure Impregnation (VPI) o resin casting processes upang tiyakin ang thorough filling ng gaps ng insulating materials, improving thermal conductivity at mechanical strength, na nag-aambag sa heat dissipation at pagbawas ng partial discharges.

3.4 Magnetic Circuit Condition Monitoring and Proactive Maintenance (Closed-loop Management, Ensuring Long-term Performance)

• Implement Precise Magnetic Circuit Condition Monitoring:
• Comprehensively assess magnetic circuit health by integrating online monitoring (halimbawa, Dissolved Gas Analysis - DGA, high-frequency partial discharge monitoring, vibration/acoustic noise monitoring, infrared thermography) at offline testing (periodic winding deformation testing, no-load & load loss testing, core ground current testing).
• Focus Monitoring: Signs of core multi-point grounding faults, abnormal loss fluctuations, overheating ng magnetic shields at clamping structures.
• Establish a Preventive Maintenance Mechanism:
• Develop targeted magnetic circuit maintenance plans based on condition monitoring data at operational history.
• Periodically inspect core and clamping structure grounding: Tiyakin ang reliable single-point grounding, promptly detect at rectify multi-point grounding faults (na significantly increase iron losses at cause overheating).
• Inspect magnetic shields, clamps, at iba pang structural components: Check for looseness, overheating, o discharge traces; promptly eliminate abnormalities.
• During core/lid lifting inspections, conduct focused checks at maintenance sa core lamination joints at clamping condition.
• Perform in-depth diagnostic analysis sa detected upward trends sa abnormal losses upang identify root causes at implement corrective actions.

4. Inaasahang Benepisyo

• Significant Reduction in Temperature Rise: Inaasahan na ang operating temperatures (lalo na ang hotspot temperatures) ay maepektibong macontrol, na may reductions na umaabot sa projected targets (halimbawa, 15-25%), na malaking nag-aalis ng thermal aging stress sa insulation.
• Effective Reduction in Magnetic Circuit Losses:
• Iron loss (No-Load Loss): Inaasahang pagbawas ng 20-40% sa pamamagitan ng bagong materyales at proseso (lalo na significant kapag ginagamit ang amorphous alloys).
• Copper loss (Load Loss): Inaasahang pagbawas ng 10-25% sa pamamagitan ng optimized winding design.
• Overall efficiency improvement ng 1-3 percentage points, na nagbibigay ng considerable economic benefits at carbon emission reduction.
• Substantial Improvement in Reliability: Ang mga panganib ng pagkasira dahil sa sobrang init at magnetic circuit abnormalities ay malaking nababawasan, na nagpapalaki ng availability ng kagamitan at nagpapahaba ng serbisyo ng buhay.
• Optimized Total Life Cycle Cost: Kahit na may potentially mas mataas na initial investment (halimbawa, high-performance materyales, advanced cooling systems), ang benepisyong nakukuha mula sa long-term energy savings, bawas na pagsasala, at extended lifespan ay mas substantial, na nagreresulta sa favorable Return on Investment (ROI).

5. Applicable Scope

Ang solusyon na ito ay applicable sa newly built at in-service oil-immersed transmission (power) transformers sa 35kV voltage level at ibabaw. Ang mga specific measures ay maaaring customized at implemented batay sa capacity, voltage level, operating environment, criticality, at kasalukuyang kondisyon ng transformer.