High-Precision and Stability Solutions for Low-Voltage Current Transformers (LV CT) Solusyon sa High-Precision ug Stability alang sa Low-Voltage Current Transformers (LV CT)
I. Pagkabasehan sa Solusyon
Sa mga aplikasyon nga nanginahanglan og mataas nga presisyon sama sa smart grids, pagbasa sa renewable energy, ug industrial power monitoring, ang mga tradisyonal nga low-voltage current transformers (LV CTs) kasagaran molabay sa mga hamubo sama sa insuficient nga presisyon, significant nga drift sa temperatura, ug dili maayo nga long-term stability. Aron mapasabot ang 0.2S/0.5S-class nga mataas nga presisyon sa pagbasa, kining solusyon nagproposa og komprehensibong improved design para sa electromagnetic LV CTs pinaagi sa core material innovation ug structural optimization.
II. Core Technical Solutions
- Upgraded High-Permeability Core Materials
• Nanocrystalline/Amorphous Alloy Ultra-Thin Strips:
Ang cores gipabaluktot gamit ang 0.02–0.025mm ka thick nanocrystalline o amorphous alloy strips, nailupad ang initial permeability (μi) sa daghan pa sa 1.5×10⁵ H/m. Kini nag-eliminate sa excitation current ug minimizes ratio/phase errors.
• Magnetic Domain Optimization:
Ang directional magnetic field annealing nag-eliminate sa core stress, nag-enhance sa flux uniformity, ug nag-reduce sa hysteresis losses under high-frequency harmonics. - Magnetic Shielding and Anti-Interference Structures
• Multi-Layer Composite Magnetic Shielding:
Adunay dual Permalloy + copper mesh shielding layers nga gi-add sa palibot sa core aron suppresihon ang external AC magnetic field interference ug mitigate DC bias effects.
• Orthogonal Winding Process:
Ang segmented orthogonal winding technology para sa secondary windings nag-reduce sa distributed capacitance ug leakage inductance, nag-improve sa frequency response (accuracy deviation < ±0.1% within 1–5kHz bandwidth). - Temperature Compensation and Signal Processing
• Dynamic Temperature Compensation Circuit:
Integrated high-linearity NTC/PTC sensors real-time compensate for temperature drift in core permeability and winding resistance (temp. drift coefficient ≤ ±10 ppm/°C).
• High-Stability Sampling Resistor:
Low-drift metal foil resistors (ΔR/R < ±5 ppm/°C) with four-terminal Kelvin connections ensure current-to-voltage conversion accuracy. - Encapsulation and Insulation Reinforcement
• Vacuum Potting Process:
High-purity epoxy resin potting at 10⁻³ Pa eliminates bubbles and internal stress, enhancing mechanical strength and thermal stability.
• Multi-Layer Insulation Architecture:
Polyimide film + silicone composite interlayer insulation achieves dielectric strength >15 kV/mm and partial discharge <5 pC (@1.5Ur).
III. Performance Advantages
|
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 better 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. Application Scenarios
Kini nga solusyon labi nga angay 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
