Electronic Current Transformer (ECT) Solution: Economically Driven Retrofit Solusyon sa Electronic Current Transformer (ECT): Pagpapabago na Pinagbibigyan ng Ekonomiya
I. Mga Punto ng Sakit: Mga Hamon sa Pagsasabog ng Tradisyunal na Substation
Ang mga tradisyunal na electromagnetic current transformers (CTs) ay nagbibigay ng maraming isyu sa mga lumang substation:
- Mataas na Gastos sa Pagsasabog: Ang pagpapalit ng mga tradisyunal na CTs ay nangangailangan ng malaking power outages, civil construction, at updates sa mga protection panels, cabling, at grounding systems. Ang kabuuang gastos ay lumalampas sa 50%.
- Mababa ang Katugmaan: Ang mga bagong device ay may interface mismatches sa mga legacy secondary systems (e.g., relays, meters), kaya kailangan ng karagdagang conversion devices.
- Pagpapahintulot sa Espasyo: May limitadong espasyo ang mga lumang substation. Ang mga tradisyunal na CTs ay malaki at matibay, kaya mahirap i-hoist at maaaring mag-require ng paglalawak ng foundation.
- Mahabang Commissioning: Ang mga pagsasabog ay kasama ang multi-system integration testing. Ang maikling outage windows ay nagdudulot ng pagkaantala sa grid restoration.
II. Solusyon: ECT (Electronic Current Transformer) Economical Retrofit
Matutugunan ang isang upgrade path ng "minimizing retrofit cost, maximizing compatibility with existing systems" sa pamamagitan ng teknolohiya ng ECT:
**▶ Pangunahing Ekonomiko na Bentahe: Malaking Pagbawas sa Comprehensive Retrofit Cost**
|
Cost Item |
Conventional CT Retrofit |
ECT Retrofit Solution |
Cost Savings |
|
Equipment Installation |
Crane/Civil Works/Foundation Reinforcement |
Direct Stud Mounting |
**↓ 40% construction cost** |
|
Cabling |
Multi-strand Copper Cables + Extensive Wiring |
Fiber Optic / Digital Signal Lines |
**↓ 60% cable cost** |
|
Secondary Equipment Interface Retrofit |
Protection Panels & Meter Replacement Required |
Compatible with Traditional Analog Output |
**↓ 80% secondary retrofit cost** |
|
Outage Duration |
≥7 Days (Full Substation Shutdown) |
≤3 Days (Partial Outage) |
**↓ 50% outage loss** |
**▶ Compatibility Design: Seamless Integration with Existing Infrastructure**
- Hybrid Interface Output:
Ang ECTs ay may built-in Analog Output (4-20mA/0-5V) + Digital Output (IEC 61850-9-2), compatible sa tatlong scenario: - Legacy Protection Devices: Konektado diretso sa umiiral na current input terminals.
- Digital Protection Systems: Ipadala ang GOOSE messages via Merging Units (MUs).
- Metering Systems: Simultaneous output ng analog signals para sa meter sampling.
- Plug-and-Play Installation:
- No Crane Required: Ang bigat ng ECT <15kg (vs. ~150kg para sa conventional CTs), pinapayagan ang manual installation.
- Compact Size: Diameter ≤200mm, fits original CT mounting brackets.
- Flexible Rogowski Coil: Maaaring ilagay sa umiiral na primary conductors, walang busbar disassembly.
- Adaptive Power Supply Scheme:
- Laser Power Supply: Energy delivered via fiber optics embedded in insulators, eliminating separate power supplies.
- Busbar Power Harvesting: Inductive power harvesting uses primary current for self-supply, suitable for passive environments.
III. Value Realization: Rapid Return on Retrofit Investment
|
Retrofit Phase |
Core Value of ECT Solution |
Economic Impact |
|
Pre-construction & Construction |
Shortens Schedule by 70% |
Reduces Outage Loss ≥ ¥2 million |
|
Commissioning |
Plug-and-play, no calibration for legacy protection |
Commissioning Costs **↓60%** |
|
Operation & Maintenance |
No magnetic saturation, wideband measurement (0.1Hz~5kHz) |
Maintenance Frequency Reduced by 90% |
|
Long-term Expansion |
Pre-installed digital interfaces support future smart substation upgrades |
Avoids secondary retrofit investment |
IV. Representative Case Study: 110kV Gudu Substation Retrofit
- Original Configuration: Electromagnetic CTs (Commissioned 1985)
- Retrofit Solution:
Ininstall ang 12 ECTs (Class ±0.5S) upang palitan ang mga tradisyunal na CTs. Output signals:
→ 4-20mA fed into existing relay protection devices.
→ IEC 61850-9-2LE fed into newly installed smart control cabinets. - Economic Results:
- Total Investment Reduced by 42% (Primarily saved on cabling, civil works, commissioning).
- Outage Time Reduced from originally planned 7 days to 2.5 days.
- Compatibility Verified: Conventional differential protection operating time maintained at 15ms, with no failure to trip / maloperation.
V. Bakit Pipiliin ang ECT Economical Retrofit?
- Controlled Cost: Retrofit budget reduced by 30%-50%, ROI < 3 years.
- Risk Mitigation: Maintains existing protection logic, avoiding system reconfiguration risks.
- Smooth Evolution: Compatible with today's analog systems, supporting tomorrow's digital grid.
- Emergency Replacement: Faulty CT replacement completed in as little as 48 hours.
