GB 50150-2016 and DL/T 596-2021 require AC withstand voltage tests on capacitive equipment such as XLPE cables to verify insulation performance. However, power-frequency test equipment is large and heavy, difficult to transport at sites such as substations and cable tunnels, and the test power supply capacity is often insufficient. Procurement personnel need an alternative that can adapt to field conditions and meet standard requirements. DL/T 849.4-2004 "General Technical Specifications for Very Low Frequency High Voltage Generators" provides a technical basis for 0.1 Hz very low frequency testing.
The ZSVLF-70/0.5 very low frequency withstand voltage test device has an output frequency of 0.1 Hz, an output voltage peak of 70 kV, and a waveform distortion of ≤5%. At 0.1 Hz, the reactive power required by the test object is only 1/500 of that at power frequency, and the equipment weight and volume are significantly reduced, making it convenient for outdoor field use. The device is suitable for indoor and outdoor environments, with an operating temperature of -10°C to +40°C and humidity ≤85%RH, meeting most field conditions. The output voltage can be adjusted via the panel or programmable interface, the voltage rise process is stable, and it has overvoltage and overcurrent protection functions.
This device is mainly used for handover tests and preventive tests of 10 kV and 35 kV XLPE cables, and can also be used for insulation withstand voltage testing of capacitive equipment such as generators and motors. When purchasing, it is necessary to confirm that the test object capacitance matches the device load capacity, and to verify the test voltage and duration according to the requirements of GB/T 3048.8 and DL/T 474.4-2018. The device has an output peak voltage of 70 kV, suitable for very low frequency withstand voltage tests of equipment at voltage levels of 35 kV and below.
