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GDTF-4500kVA/750kV Variable Frequency Series Resonant Test System (6A)
GDTF-4500kVA/750kV Digital Intelligent Variable Frequency Series Resonant Test System (4500kVA, 0-750kV AC, 6A) with 10-Stage 75kV/6A Dry-Type Epoxy-Cast Reactors, 30-300Hz Frequency Range, Automatic Frequency Sweep, 10.1-inch Industrial Touch Screen, Comprehensive Protection, Containerized Transport, for 500kV Substation GIS, Power Transformer, Long XLPE Cable, Bushing, Instrument Transformer AC Withstand Voltage Test.
- Description
- Specifications
- Applications
- Advantages
- FAQ
- Recommended Products
Description
The GDTF-810kVA/270kV is a high-capacity, field-optimized variable frequency series resonant test systemexclusively designed for 220kV substation large-capacity electrical equipment AC withstand voltage tests. It fully complies with DL/T 849.6-2016 and GB 50150-2016 standards, adopting the series resonance principle to generate high voltage and large current with only a small input power, solving the problem of traditional test transformers being too heavy and having insufficient capacity for extra-long cables and large GIS equipment.
The system consists of a variable frequency control power supply, an excitation transformer, six identical 45kV/3A dry-type epoxy-cast reactors, and a 0.5-class standard capacitor divider.The reactors can be flexibly connected in series or parallel to adapt to different test voltage and current requirements. Equipped with a 7-inch color touch screen and advanced automatic frequency sweep algorithm, it can automatically find the resonance point within 30 seconds, complete the entire test process with one click, and store all test data for traceability. With comprehensive safety protection including over-voltage, over-current, flashover, zero-start, and emergency stop, it ensures safe operation in harsh field environments. Ideal for commissioning and preventive maintenance tests of 220kV extra-long XLPE power cables, large GIS, power transformers, bushings, insulators, and switchgear.
Specifications
| Parameter | Specification |
|---|---|
| Input Power | 3-phase 380V±10%, 50Hz |
| Rated Output Capacity | 4500kVA |
| Rated Output Voltage | 0–750kV AC (RMS) |
| Rated Output Current | 6A (10 series) / 12A (5 series 2 parallel) / 20A (3 series 3 parallel + 1 series) / 30A (2 series 5 parallel) / 60A (10 parallel) |
| Reactor Configuration | 10×75kV/6A dry-type epoxy-cast reactors |
| Combination Modes | 75kV/60A, 150kV/30A, 225kV/20A, 375kV/12A, 750kV/6A |
| Operating Frequency Range | 30Hz–300Hz |
| Frequency Resolution | 0.1Hz |
| Frequency Stability | ≤0.01% |
| System Quality Factor (Q) | ≥30 (typical 30–50) |
| Output Waveform Distortion | ≤1% |
| Voltage Measurement Accuracy | ≤±1.5% F.S |
| Current Measurement Accuracy | ≤±1.5% F.S |
| Test Modes | Automatic test, Manual test, Timed test, Step boost test |
| Timing Range | 0–9999s adjustable |
| Display | 10.1-inch industrial color touch screen |
| Data Storage | 2000 groups (with time stamp) |
| Data Export | USB flash drive, PDF report generation |
| Remote Control | Optional 100m wireless remote control |
| Protection Functions | Zero-start, Over-voltage, Over-current, Flashover, Emergency stop, Ground detection, Over-temperature, Interlock |
| Continuous Operation Time | 5 minutes at full load, 1 minute at 1.1×rated voltage |
| Operating Temperature | -10℃ ~ +40℃ |
| Operating Humidity | ≤85%RH (non-condensing) |
| Altitude | ≤3000m |
| Transport | Standard 20ft container |
| Compliance | DL/T 849.6-2016, GB 50150-2016, GB/T 16927.1-2011, IEC 60060-1, IEC 61010-1 CAT III 1000V |
Applications
Core Test Objects (500kV Substation)
- GIS & gas-insulated switchgear: 500kV large-scale GIS, circuit breakers, disconnectors, busbars
- Power transformers: 500kV main power transformers and autotransformers (including neutral point tests)
- XLPE power cables: 500kV/1600mm² cables ≤2.5km, 220kV/1200mm² cables ≤5km, 110kV/800mm² cables ≤10km
- Bushings & insulators: 500kV transformer bushings, post insulators, suspension insulators
- Instrument transformers: 500kV current transformers (CT) and voltage transformers (VT)
- Reactors & capacitors: 500kV shunt reactors and power capacitors
Typical Usage Scenarios
- Substation commissioning: new 500kV substation equipment acceptance tests according to GB 50150-2016
- Preventive maintenance: periodic insulation strength tests
- Power plant testing: 500kV generator transformer and auxiliary equipment tests
- Third-party inspection: compliance testing and certification
- Construction site testing: on-site test of newly installed equipment
- Factory type tests: manufacturer factory acceptance tests (FAT)
Advantages
97% Energy Saving vs Traditional Test Transformers
Series resonance principle reduces input power to only 1/Q of output power → small input power, light weight, easy to transport
Flexible 10-Stage Reactor Combination
10 modular reactors can be connected in series or parallel → one system covers all test requirements from 10kV to 500kV
4500kVA Ultra-High Capacity
Sufficient current for 2.5km 500kV XLPE cables and large 500kV GIS equipment → no under-testing, ensures accurate results
Automatic Resonance Finding
One-click auto sweep finds resonance point within 45 seconds → eliminates manual tuning, improves test efficiency
Pure Sine Wave Output
Waveform distortion ≤1% → meets strict requirements of national and international standards
Comprehensive Safety Protection
FAQ
Q: What is the principle of variable frequency resonant test system?
A: It uses the series resonance principle: adjust the output frequency of the power supply to make the reactor inductance resonate with the test sample capacitance, generating high voltage and large current on the test sample with only a small input power.
Q: What is the difference between GDTF-4500kVA/750kV and GDTF-2700kVA/900kV?
A:
- GDTF-4500kVA/750kV: 750kV peak output, 4500kVA capacity, 6A rated current at 750kV, tests up to 2.5km 500kV XLPE cables, optimized for 500kV high-current applications
- GDTF-2700kVA/900kV: 900kV peak output, 2700kVA capacity, 3A rated current at 900kV, tests up to 2km 500kV XLPE cables, optimized for 500kV high-voltage applications Both use the same variable frequency series resonance technology and automatic frequency sweep function.
Q: How long does it take to find the resonance point?
A: The automatic frequency sweep algorithm can find the resonance point within 45 seconds for most test samples.
Q: What is the maximum length of 500kV XLPE cable that can be tested?
A: With 6A rated current at 750kV, it can test up to 2.5km of 500kV/1600mm² XLPE power cable, 5km of 220kV/1200mm² XLPE power cable, or 10km of 110kV/800mm² XLPE power cable.
Q: Can it be used for both power frequency and variable frequency tests?
A: Yes. The 30–300Hz wide frequency range supports both power frequency (50Hz) and variable frequency (20–300Hz) tests according to different standards.
