1、 Insulation and voltage withstand test of power equipment

Power cable testing

Cross linked polyethylene cable (XLPE): used for handover testing and preventive testing of 10kV to 35kV cables, replacing traditional power frequency withstand voltage testing, and effectively detecting cable insulation layer defects, joint faults, or moisture issues.

Long distance cables: Through ultra-low frequency withstand voltage technology (such as 0.02Hz), cables with a length of more than 10 kilometers can be tested, solving the problem of testing large capacity equipment.

Testing of large generators and electric motors

Used for insulation testing of stator windings of large and medium-sized generators in thermal power and hydropower plants, simulating the distribution of electric fields under operating conditions, and detecting insulation aging or partial discharge.

For example, the single phase electric capacity of a 600MW generator can reach 0.31-0.34 μ F, requiring precise control of the testing process by ultra-low frequency equipment.

Power capacitors and transformers

Test the voltage resistance and dielectric loss of power capacitors, and evaluate their stability under high electric fields.

Perform partial discharge detection on transformer windings to prevent the risk of insulation breakdown.

2、 Industrial equipment maintenance and testing

Petrochemical equipment

Test the insulation performance of explosion-proof motors and pumps in corrosive environments to ensure safe operation.

For example, the withstand voltage testing of high-voltage electrical equipment in oil fields needs to adapt to harsh conditions such as humidity and salt spray.

Rail Transit and Mining Equipment

The voltage withstand test of power cables for subway and high-speed rail ensures the reliability of the contact network and signal system.

Insulation testing of high-voltage equipment in underground mines to prevent malfunctions caused by moisture or mechanical damage.

3、 Research and Special Field Applications

Geophysical exploration

By using ultra-low frequency signals to penetrate geological formations, we can study geological structures or locate the distribution of oil and gas resources.

For example, identifying electrical differences in underground mineral deposits in resource exploration.

Medical and Biotechnology

High voltage power calibration of medical imaging equipment (such as CT and X-ray machines) to ensure imaging resolution.

Used in biological experiments for cell electrofusion or electroporation techniques, providing a stable high-voltage electric field.

Research on New Materials

Test the dielectric properties of new insulation materials, such as nanocomposite dielectrics, under ultra-low frequency electric fields.

4、 Technical advantages and compliance with standards

Advantages of replacing traditional methods

Volume and capacity optimization: Compared to power frequency withstand voltage equipment, the capacity is only 1/500, the weight is reduced by more than 80%, and it is easy to operate on site.

Safety: Avoid cumulative damage to insulation caused by DC withstand voltage, in accordance with the recommended standards of the International Electrotechnical Commission (IEC).

Compliant with industry standards

Meet the testing requirements of the power industry standard DL/T849.4-2004, applicable to equipment such as cables and generators.

For example, the withstand voltage test of a 35kV cable requires the application of an ultra-low frequency AC voltage that is three times the rated voltage (i.e. 63kV peak).

Huazheng Electric HZDP-60kV VLF Hipot Tester