Electronic Current Transformer (ECT) Solution: Ekonomikong Pinagmumulan ng Pag-a-update
I. Mga Sakit ng Ulô: mga Hamon sa Pagsasabog ng Tradisyonal na Substation
Ang mga tradisyonal na electromagnetic current transformers (CTs) ay nagbibigay ng maraming isyu sa mga lumang substation:
- Matataas na Gastos sa Pagsasabog: Ang pagpalit ng mga tradisyonal na CTs ay nangangailangan ng malawakang brownout, konstruksyon, at updates sa protection panels, cabling, at grounding systems. Ang kabuuang gastos ay lumalampas sa 50%.
- Mababang Katugmaan: Ang mga bagong aparato ay may mismatch sa interface kasama ang legacy secondary systems (hal. relays, meters), kaya nangangailangan ng karagdagang conversion devices.
- Paglimita ng Espasyo: Ang mga lumang substation ay may limitadong espasyo. Ang mga tradisyonal na CTs ay malaki at mabigat, kaya mahirap i-raise at posibleng magkaroon ng paglalago ng pundasyon.
- Mahabang Commissioning: Ang pagsasabog ay nangangailangan ng multi-system integration testing. Ang maikling oras ng brownout ay nagdudulot ng pagkaantala sa restoration ng grid.
II. Solusyon: ECT (Electronic Current Transformer) na Mas Murang Pagsasabog
Makamit 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 Komprehensibong Gastos sa Pagsasabog**
|
Item ng Gastos |
Tradisyonal na CT Retrofit |
ECT Retrofit Solusyon |
Pagbabawas ng Gastos |
|
Instalasyon ng Aparato |
Crane/Civil Works/Foundation Reinforcement |
Direktang 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: Nagpadala ng 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 timbang ng ECT <15kg (vs. ~150kg para sa tradisyonal na CTs), nagbibigay-daan sa manual installation.
- Compact Size: Diameter ≤200mm, fits original CT mounting brackets.
- Flexible Rogowski Coil: Maaaring ilagay sa paligid ng umiiral na primary conductors, walang pangangailangan ng disassembly ng busbar.
- 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:
Na-install 12 ECTs (Class ±0.5S) upang palitan ang tradisyonal 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.
