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SFC – Static Frequency Converter

The SFC (Static Frequency Converter) is a high-performance, three-phase digital frequency conversion system designed specifically for transformer testing. Built with IGBT-based architecture and intelligent microprocessor control, it replaces traditional motor-generator sets while delivering flexible, efficient, and precise performance.

With capacities ranging from 20 kVA to 10 MVA and cooling options (air or water) depending on size, the SFC provides variable output frequency and voltage with excellent waveform quality, supporting testing of dry-type and oil-filled transformers up to 500 MVA.

Function

  • Converts fixed 50/60 Hz grid input into adjustable-frequency and voltage output

  • Enables transformer testing across a wide range of power, voltage, and frequency

  • Eliminates need for motor-generator sets, voltage regulators, and switchgear

  • IGBT-based PWM ensures high waveform quality and precision

  • Supports harmonic injection and partial discharge testing

  • Remote control via industrial PC or laptop with user-friendly software

  • Designed for both stationary and mobile testing platforms

Technical Specifications

Input Side

  • Input Voltage: 415–690 V ±5%

  • Input Frequency: 50/60 Hz

  • Input Protection: AC inductor and circuit breaker

  • AC–DC Converter Types: Passive diode or active IGBT

  • Switching Frequency: 2–12 kHz

  • Current Feedback: Current transducers

  • Harmonic Compensation: Up to 25th harmonic

  • Flicker & Voltage Unbalance Compensation: Yes

Output Side

  • Output Voltage Range: 350–580 V AC

  • Output Frequency Range: 10–500 Hz

  • Output Power Range: 20 kVA – 10 MVA

  • Scaling Resolution: 0.1 V / 0.1 Hz

  • Output Distortion (THDU): <3% at 50–60 Hz

  • System Losses: 3–5% (application dependent)

  • Load Compatibility: Resistive, inductive, capacitive, or mixed

Standards & Testing Support

  • Compliance: IEC / ANSI

  • Transformer Testing Capability: Dry and oil-filled transformers, 250 VA – 500 MVA

Control & Interface

  • Control: Intelligent Microcontroller (IMC)

  • Monitoring: Voltage, current, temperature, water flow/pressure

  • Interface: Profibus with LAN remote diagnostics

  • Software: Displays system parameters, controls voltage/frequency, alarms

  • Harmonic Injection: Supported

  • Safety: Built-in supervision and hardware-integrated protection

Environmental & Mechanical

  • Ambient Temperature: 5 °C to 45 °C

  • Relative Humidity: <95%, non-condensing

  • Protection Class: IP21

  • Cooling:

    • Air-cooled (50–2000 kVA)

    • Water-cooled (2000–10,000 kVA)

Optional Features

  • High-frequency filtering for partial discharge

  • EMI filters (input), sine filters (output)

  • Internet-enabled remote diagnostics

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