Precision Power Monitoring: High-Accuracy Dual-Ratio Outdoor Digital Current Transformer Solution Monitor ng Precise sa Power: Solusyon sa High-Accuracy Dual-Ratio Outdoor Digital Current Transformer

Pinangaylan sa Solusyon:​​
Ang aming napakabagong Outdoor Current Transformer (CT) solusyon nagpadama ang ​Multi-Tap Dual-Ratio Sensing​ ngadto sa ​Digital Merging Unit (MU)​​ aron mopahibalo og adaptive ug high-precision nga pagkalkula sa kuryente alang sa mga dynamic power environments sama sa renewable integration sites. Kini nga IEC 61850-compliant nga sistema nagwala sa tradisyonal nga trade-offs sa accuracy/reliability pinaagi sa pag-enable sa real-time ratio switching ug digital data output.

​Breakdown sa Core Technology​

1. ​Dual-Ratio Sensing Core​
• ​Innovation:​​ Embedded multi-tap windings suporta sa ​200:5 ug 1200:5​ ratios sa usa ka CT body.
• ​Adaptability:​​ Software-controlled ratio selection pinaagi sa MU.
• ​Nasulbad nga Problema:​​ Awtomatikong nagsunod sa measurement range aron mapiguraan ang drastic load shifts (e.g., solar farm daylight fluctuations o wind farm cut-in/cut-out) walay pisikal nga intervention o overdesigned CTs.
2. ​High-Precision Digital Merging Unit (MU)​​
• ​Accuracy:​​ Exceeds ​​<0.2S Class​ (per IEC 60044-1/IEC 61869) para sa revenue metering (ANSI C12.1) ug protection functions (IEEE C37.90).
• ​Output:​​ Native ​IEC 61850-9-2 LE​ sampled values over Ethernet.
• ​Calibration:​​ Digital signal processing compensates for phase errors & non-linearity.

​Key Features & Advantages​

• ​Dual-Ratio On Demand:​​ Switch seamlessly between 200:5 (low load/high sensitivity) ug 1200:5 (high fault current) pinaagi sa software commands – ​walay rewiring needed.
• ​Substation-Ready:​​ Native digital output (9-2 LE) integrates directly into IEC 61850-based protection relays, meters, ug control systems.
• ​Future-Proof Accuracy:​​ <0.2S accuracy ensures compliance with strictest revenue metering standards ug enables high-impedance differential protection.
• ​Robust Outdoor Design:​​ IP67-rated enclosure, UV-resistant polymer housing, ug corrosion-resistant materials ensure reliability in harsh environments (-40°C to +70°C).
• ​Reduced Installation Cost:​​ Single CT installation replaces need for multiple conventional CTs or burdensome auxiliary units.
• ​Enhanced Grid Stability:​​ Precise, real-time data enables faster protection response for fluctuating fault currents (e.g., inverter-based resource faults).

​Implementation: Renewable Energy Use Case​

• ​Scenario:​​ 200 MW Solar/Wind Farm connection to 138kV substation. Fault currents range from near-zero (offline inverters) to 30kA+ (full output grid fault).
• ​Challenge:​​ Conventional CTs compromise accuracy at low current (200:5 needed) but saturate at high fault currents (1200:5 needed).
• ​Our Solution:​​
1. Install dual-ratio CTs at point of interconnection (HV bus/circuit breaker).
2. During normal operation (<50% load), MU selects ​200:5 ratio​ – capturing granular data for precise energy accounting and flicker monitoring.
3. Upon fault detection (rapid current rise), MU auto-switches to ​1200:5 ratio​ in <5ms – preventing saturation, maintaining accuracy, and enabling relays to clear faults reliably.
4. Sampled values transmitted digitally via 9-2 LE to protection relays, meters, and SCADA – eliminating analog wiring errors and converter delays.

​Why This Solution Wins​

• ​Eliminates Saturation Risk:​​ Maintains accuracy across 100:1 dynamic range (e.g., 30A to 3000A primary).
• ​OPEX Savings:​​ Remote configuration/ratio switching reduces site visits.
• ​Safety Boost:​​ Digital isolation replaces dangerous CT secondary opens.
• ​Data Integrity:​​ Digital output avoids signal degradation from EMI/RFI.
• ​Compliance Ready:​​ Designed to meet IEEE 1547-2018 fault ride-through requirements for renewables.