High Voltage Variable Frequency resonance Withstand Voltage Test Equipment For Power Equipment Testing

The SXBP portable variable frequency series resonance withstand voltage test system is an integrated high-voltage testing device developed for AC insulation tests of power equipment rated up to 110kV. It combines resonance technology, modular design and portable construction to simplify on-site high-voltage testing operations.

Equipped with dry-type epoxy-cast reactors and excitation transformers, the system features reduced size, low transportation difficulty and reliable insulation performance. The flexible reactor combination design allows users to configure different test capacities according to specific requirements, enabling one complete set of equipment to cover testing applications for power transformers, GIS, switchgear, high-voltage cables, bushings, generators and motors.

Ideal for substations, construction sites and power equipment manufacturers, the SXBP series provides a versatile solution for commissioning tests, preventive maintenance tests and factory withstand voltage inspections, helping improve testing efficiency and field operation convenience.

• Power Cable Insulation Testing: Supports AC withstand voltage tests for medium and high-voltage XLPE power cables ranging from 10kV to 110kV, helping identify insulation defects and improve cable operation safety.
• Substation Equipment Withstand Testing: Widely used for insulation verification of GIS, circuit breakers, current transformers, voltage transformers and main transformers up to 110kV class.
• Generator & Motor Insulation Testing: Provides reliable AC withstand voltage testing solutions for high-voltage motors, generators and other rotating electrical machines in power plants and industrial applications.

The complete series resonance test system is composed of four essential modules: a variable frequency power supply unit, excitation transformer, dry-type air-core reactors, and capacitive voltage divider. These components work together to provide stable and efficient high-voltage AC output for insulation withstand testing.

• Lightweight Configuration for On-Site Applications
  The system adopts a portable design with individual modules weighing less than 50kg, making transportation and deployment easier in complex environments. It is especially suitable for field operations in substations, underground cable galleries and construction sites with limited access conditions.
• Highly Adaptable Reactor Architecture
  Featuring a building-block reactor design, the test modules can be combined according to required output voltage and test capacity. This flexible configuration improves equipment utilization and enables testing of different cable lengths and high-voltage apparatus.
• 30Hz–300Hz Frequency Adjustment Capability
  The variable frequency output system covers a wide operating range from 30Hz to 300Hz. By utilizing resonance compensation technology, it significantly reduces the demand for test power capacity while maintaining stable high-voltage performance.
• Excellent Waveform Performance
  The output voltage adopts a low-distortion sine wave design, with waveform distortion rate ≤1%. The stable output characteristics help ensure accurate insulation evaluation and protect test objects from abnormal voltage stress.
• Fast Setup with Operator-Friendly Design
  Optimized connection interfaces and clearly labeled terminals simplify field installation. The intuitive operation interface helps testing personnel complete setup, parameter adjustment and test execution with minimal training.
• Multiple Protection Layers for Safe Operation
  The intelligent control unit monitors the entire testing process in real time. Protection mechanisms against excessive voltage, excessive current, temperature rise, breakdown and resonance instability provide reliable safety during high-voltage testing.
• Complete Test Record Management
  The system supports automatic storage of test results, including voltage-time curves and breakdown records. These functions facilitate data review, technical analysis and standardized test report generation.

A Variable Frequency Series Resonance Test System is a specialized high-voltage test platform that uses resonance principles to generate high AC test voltage.

During operation, the control unit adjusts the output frequency so that the reactor and the capacitance of the tested equipment reach resonance. Under resonance conditions, the system can achieve high-voltage output with a relatively small power supply capacity, making it suitable for on-site insulation testing.

This technology is widely used in power transmission and distribution systems for evaluating insulation strength and operational reliability.

The portable series resonance testing equipment is designed for insulation withstand tests on a wide range of electrical assets, such as:

• XLPE insulated power cables
• GIS and high-voltage switchgear
• Circuit breakers and disconnecting equipment
• CT/PT transformers
• Distribution and power transformers
• High-voltage bus ducts
• Large motors and generators

The system is widely used in electrical equipment manufacturing, power utilities, engineering projects and maintenance departments for acceptance testing and preventive testing.

A typical variable frequency series resonance test system consists of:

1. Variable frequency power supply unit
2. Excitation transformer
3. Reactor modules
4. Voltage measurement divider
5. Digital control and protection system
6. Test cables and auxiliary accessories

The modular configuration provides excellent flexibility, allowing users to select different reactor combinations based on the required test voltage and load characteristics.

The system provides several advantages for high-voltage AC withstand testing:

• Efficient high-voltage generation
  The resonance method greatly improves energy utilization and reduces the capacity requirement of the test power source.
• Portable structure for field applications
  Compact modular components make transportation, installation and operation easier at different testing locations.
• High-quality test waveform
  The output waveform distortion is controlled within ≤1%, providing accurate and stable test voltage.
• Wide application range
  Flexible reactor combinations support testing requirements for cables, transformers, GIS and other high-voltage equipment.
• Stable performance in harsh environments
  The system features strong anti-interference capability for reliable operation in substations and industrial sites.
• Convenient testing process
  The intelligent operating system provides simple control procedures and improves testing productivity.

The system provides an adjustable output frequency range of:30Hz to 300Hz

By changing the operating frequency, the equipment can achieve resonance conditions for different capacitive test objects, improving test efficiency and voltage stability.