Description

Technical Parameters

Product Overview & Applications

20kV/150kV Partial Discharge-free Power Frequency AC High-Voltage Testing is a fundamental and severe test applied to electrical equipment to verify the integrity and quality of its insulation system. The core objective is to ensure the insulation can withstand its rated power frequency (50 Hz or 60 Hz) AC voltage for a specified time without breakdown or the presence of significant Partial Discharges (PD).

Product Features and Advantages

1.Uses SF6 gas insulation, oil-free and eco-friendly, compact and lightweight.
2.Minimal partial discharge, excellent insulation, meets high-precision testing requirements.
3.Full Chinese touchscreen operation, highly automated, simple and intuitive setup.
4.Equipped with multiple safety protections and emergency stop, stable and reliable operation.
5.Automatically boosts voltage, times, and saves data,enhances testing efficiency.
6.Wide temperature adaptability, high seismic resistance, suitable for harsh environments.

Operating Conditions

1.Electrically Quiet Laboratory:This is the most critical condition for PD-freemeasurement. The lab must be a shielded room (Faraday cage)to block external electromagnetic interference (radio, grid noise) that can be mistaken for partial discharges.

2.Temperature & Humidity:Stable, room temperature (e.g., 10°C to 40°C) and low humidity (< 60% non-condensing). Fluctuations can affect measurement stability and cause surface condensation on the test object, leading to false PD signals.

3.Clean, Dry Environment:The area must be free of dust, moisture, and conductive contaminants to prevent surface leakage and flashover.

4.Stable Mains Power: A clean, stable AC power supply (380V/400V, 3-phase) is required. Using an online UPS or voltage stabilizeris essential to protect against sags, surges, and noise that could corrupt the test voltage waveform and PD measurements

Additional Information

The Key Component:

1.HV Test Transformer:150kV, 20kVA.Must have very low internal partial discharge levels itself ( < 5 pC at 150kV).

2.Coupling Capacitor: 1000 pF, 150kV.Must also be PD-free.

3.PD Measuring Impedance (Quadripole): Matched to the coupling capacitor and test object capacitance.

4.PD Detector / Analyzer
Measures apparent charge in picoCoulombs (pC). Can be an oscilloscope with a bandwidth of at least 100kHz-1MHz, or a dedicated digital PD analyzer.

5.Low-Pass Filter / HV Filter: Installed between the transformer and the test object.

6.Shielded Room: Metal enclosure (Faraday cage) with 80-100dB attenuation.

Maintenance FAQ

Q: What is the main difference between a standard AC Hipot test and a "PD-free" AC Hipot test?

A: A standard AC Hipot test is a withstand test-it only checks if the insulation breaks down under high voltage. A PD-freetest is a quality test. It not only checks for breakdown but also verifies that the insulation is of such high quality that it does not produce any significant Partial Discharges (PD), which are tiny internal sparks that cause long-term degradation.

Q: What does "20kVA" and "150kV" mean for this system?

A: 150kV:The maximum high voltage the system can produce (150,000 Volts). This determines the stress level you can apply.

20kVA (20,000 Volt-Amps):The power ratingof the system. It defines the maximum load (in terms of capacitive or resistive current) the system can drive while maintaining a stable, clean voltage waveform. A 20kVA rating is suitable for testing equipment with significant capacitance, like long cables, large bushings, or transformers.

Q: Why is "Power Frequency" (50/60 Hz) important?

A:Power frequency testing applies the same type of stress the equipment experiences in real-world operation. It is considered the most realistic and rigorous test for insulation quality. Other methods (like VLF) are used for portability, but 50/60 Hz is the benchmark for factory and type testing.

Q: What kind of equipment do you test with this system?

A: It is used for high-quality assurance testing of critical high-voltage components, including:

Power Transformersand Instrument Transformers (VTs/CTs)

High-Voltage Bushings

Gas-Insulated Switchgear (GIS)

Power Cablesand their accessories (joints, terminations)

Rotating Machines(large motors and generators)

Q: What are the most critical requirements for the test environment?

A:The two most critical requirements are:

A Shielded Room (Faraday Cage):Essential to block external electromagnetic noise (from radios, cell phones, power lines) that can be mistaken for PD signals.

An Electrically "Clean" Power Supply:A stable mains supply, often conditioned by an Uninterruptible Power Supply (UPS)or voltage regulator, is needed to prevent noise and waveform distortion from affecting the sensitive PD measurements.

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Technical Specifications

Main configuration including :

1. Power Noisy Filter
2. Console
3. Isolation Transformer
4. PD free SF6-insulated Test Transformer
5. Current Limit Resistor
6. Capacitive Voltage Divider

20kVA/1580kV PD Free HV Test Set