Solutions na May Mataas na Katumpakan at Katatagan para sa Low-Voltage Current Transformers (LV CT)
I. Paliwanagan ng Solusyon
Sa mga aplikasyon na may mataas na presisyon tulad ng smart grids, pagmamasid sa enerhiyang renewable, at pagmomonitorya ng industriyal na kuryente, madalas nang haharapin ng mga konbensiyonal na low-voltage current transformers (LV CTs) ang mga hamon tulad ng hindi sapat na katumpakan, malaking temperature drift, at mahinang long-term stability. Upang matugunan ang 0.2S/0.5S-class na high-precision metering requirements, inuunlad ng solusyong ito ang isang komprehensibong disenyo para sa electromagnetic LV CTs sa pamamagitan ng pagsulong sa core material at structural optimization.
II. Pangunahing Teknikal na Solusyon
- Na-upgrade na High-Permeability Core Materials
• Nanocrystalline/Amorphous Alloy Ultra-Thin Strips:
Ang cores ay inililigpit gamit ang 0.02–0.025mm na nanocrystalline o amorphous alloy strips, na nagpapataas ng initial permeability (μi) ng higit sa 1.5×10⁵ H/m. Ito ay siyang nagpapababa ng excitation current at nagpapakonti ng ratio/phase errors.
• Magnetic Domain Optimization:
Ang directional magnetic field annealing ay nagwawala ng stress sa core, nagpapataas ng flux uniformity, at nagpapakonti ng hysteresis losses sa ilalim ng high-frequency harmonics. - Magnetic Shielding at Anti-Interference Structures
• Multi-Layer Composite Magnetic Shielding:
Idinagdag ang dual Permalloy + copper mesh shielding layers sa paligid ng core upang supilin ang external AC magnetic field interference at bawasan ang DC bias effects.
• Orthogonal Winding Process:
Ang segmented orthogonal winding technology para sa secondary windings ay nagpapababa ng distributed capacitance at leakage inductance, na nagpapataas ng frequency response (accuracy deviation < ±0.1% sa 1–5kHz bandwidth). - Temperature Compensation at Signal Processing
• Dynamic Temperature Compensation Circuit:
Ang integrated high-linearity NTC/PTC sensors ay real-time compensate para sa temperature drift sa core permeability at winding resistance (temp. drift coefficient ≤ ±10 ppm/°C).
• High-Stability Sampling Resistor:
Ang low-drift metal foil resistors (ΔR/R < ±5 ppm/°C) na may four-terminal Kelvin connections ay nagse-set ng current-to-voltage conversion accuracy. - Encapsulation at Insulation Reinforcement
• Vacuum Potting Process:
Ang high-purity epoxy resin potting sa 10⁻³ Pa ay nagwawala ng bubbles at internal stress, na nagpapataas ng mechanical strength at thermal stability.
• Multi-Layer Insulation Architecture:
Ang polyimide film + silicone composite interlayer insulation ay nagpapataas ng dielectric strength >15 kV/mm at partial discharge <5 pC (@1.5Ur).
III. Mga Kahanga-hangang Katangian
|
Parameter |
Conventional CT |
This Solution |
Improvement |
|
Accuracy Class |
0.5–1.0 |
0.2S/0.5S |
Ratio/Phase errors ↓50% |
|
Temp. Drift Coeff. |
±100 ppm/°C |
±10 ppm/°C |
10x mas mabuti ang stability |
|
Long-Term Stability |
±0.3%/year |
±0.05%/year |
Lifetime error controllable |
|
Phase Error (1%In) |
>30' |
<5' |
Phase precision ↑6x |
|
Operating Temp. |
-25°C~+70°C |
-40°C~+85°C |
Enhanced extreme-environment adaptability |
IV. Mga Application Scenarios
Ang solusyong ito ay partikular na angkop para sa:
• Power Metering: Smart meters, distribution network automation systems (compliant with IEC 61869-2 standard)
• Renewable Energy Monitoring: High-precision current sampling in PV inverters and energy storage systems
• Industrial Control: Fault current detection in VFDs and motor protection devices
• Lab Standards: Serving as 0.2S-class standard transformers for value transfer
