Paghahanap ng Matalas na Kapangyarihan: Solusyon ng Digital na Current Transformer na May Mataas na Katumpakan at Dual-Ratio para sa Outdoor

Buod ng Solusyon: Ang aming nakaraang Outdoor Current Transformer (CT) na solusyon ay naglalaman ng Multi-Tap Dual-Ratio Sensing at Digital Merging Unit (MU) upang ibigay ang mapagkakayari at mataas na presisyong pagsukat ng kuryente para sa mga dynamic na power environment tulad ng renewable integration sites. Ang IEC 61850-compliant na sistema na ito ay nagbibigay ng real-time ratio switching at digital data output upang mawala ang tradisyonal na trade-offs sa pagitan ng accuracy at reliability.

Paghihiwalay ng Puso ng Teknolohiya

1. Dual-Ratio Sensing Core
• Inobasyon: Naka-embed na multi-tap windings na sumusuporta sa 200:5 at 1200:5 ratios sa loob ng iisang CT body.
• Pag-aangkop: Software-controlled na pagpipili ng ratio sa pamamagitan ng MU.
• Problema na Nasolusyunan: Awtomatikong pag-aadjust ng measurement range upang makapag-accommodate ng drastic na pagbabago ng load (halimbawa, solar farm daylight fluctuations o wind farm cut-in/cut-out) nang walang pisikal na intervention o overdesigned na CTs.
2. High-Precision Digital Merging Unit (MU)
• Precisyon: Lumampas sa <0.2S Class (ayon sa IEC 60044-1/IEC 61869) para sa revenue metering (ANSI C12.1) at protection functions (IEEE C37.90).
• Output: Native IEC 61850-9-2 LE sampled values over Ethernet.
• Calibration: Digital signal processing na nag-compensate para sa phase errors & non-linearity.

Mga Pangunahing Katangian at Advantages

• Dual-Ratio On Demand: Switch seamlessly between 200:5 (low load/high sensitivity) and 1200:5 (high fault current) via software commands – walang rewiring needed.
• Substation-Ready: Native digital output (9-2 LE) integrates directly into IEC 61850-based protection relays, meters, and control systems.
• Future-Proof Accuracy: <0.2S accuracy ensures compliance with strictest revenue metering standards and enables high-impedance differential protection.
• Robust Outdoor Design: IP67-rated enclosure, UV-resistant polymer housing, and 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).

Implementasyon: 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).
• Aming Solusyon:
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.

Kamusta Ang Solusyong Ito Nanalo

• 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.