20800kVA/260kV Mobile AC Resonant Test System For High-Voltage Cable Testing

The HMCXZ-20800kVA/260kV AC resonant test system is designed for AC withstand voltage testing of power cables and other high-voltage electrical equipment. With a rated capacity of 20,800kVA and a rated voltage of 260kV, the system is suitable for field testing applications involving power cables rated up to 220kV.

The system uses variable frequency resonance technology to perform AC high-voltage tests. Its operating frequency range is 20–300Hz, and it is designed for test objects with a capacitance of up to 1μF, subject to the specified test conditions.

Unlike conventional equipment that requires separate transportation and repeated assembly, this system integrates the variable frequency power supply, excitation transformer, high-voltage reactors, voltage divider, and related components onto a dedicated mobile test platform.

The integrated design helps reduce on-site assembly work and supports high-voltage testing at substations, cable installation sites, and power engineering projects.

1. High-Capacity AC Resonant Testing

• Rated capacity: 20,800kVA
• Rated voltage: 260kV
• Rated current: 80A
• Operating frequency: 20–300Hz
• Applicable test object capacitance: Up to 1μF
• Output voltage waveform distortion: ≤1%
• Continuous operation: 180 minutes at rated load
• System quality factor: Q ≥50 at 300Hz
• Partial discharge: <10pC, as specified in the technical agreement

The system is designed for high-voltage AC withstand testing where stable output and controlled test conditions are required.

2. Integrated Mobile Test Platform

The main equipment is installed on an integrated platform with a hydraulic operating mechanism. The platform supports the transition between transportation and testing configurations.

Its main functions include:

• Hydraulic lifting and lowering
• Hydraulic deployment of test components
• Remote and manual operation
• Extendable support structures
• Platform leveling
• Cable winding and storage
• Transportation and storage of integrated equipment

The system can be deployed at the test site without conventional crane-based lifting and repeated component assembly, subject to site conditions and the specified operating procedure.

3. Variable Frequency Power Supply

The system is equipped with one HMCXZ-450kW variable frequency power supply.

Main parameters:

• Rated output power: 450kW
• Input voltage: Three-phase AC 380V ±10%
• Input frequency: 50Hz
• Output voltage: Single-phase, 0–350V continuously adjustable
• Frequency range: 20–300Hz
• Output waveform distortion: ≤1.0%
• Output voltage instability: ≤1.0%
• Cooling method: Forced air cooling

The variable frequency power supply adjusts the output frequency to establish the resonant condition required for the test.