Ultra-Low Frequency High Voltage Generator (VLF High Voltage Generator, usually refers to a 0.1Hz sine wave high voltage generator used for medium and high voltage cables in power systems



(6kV-35kV, some up to 66kV) for AC withstand voltage testing. Compared with traditional power frequency (50Hz) withstand voltage testing, ultra-low frequency technology utilizes the principle that frequency is proportional to capacitive current, reducing the required power supply capacity by about 500 times, making the equipment compact and lightweight, very suitable for on-site outdoor operations. It is currently the standard recommended solution to replace DC withstand voltage testing (which causes cumulative damage to cross-linked polyethylene XLPE cables). According to the latest technical standards for 2025-2026 (such as DL/T 849.4-2019) and market application conditions, here is a detailed guide: 1. Core principles and advantages Working principle: output frequency is 0.1Hz (or optional 0.05Hz/0.02Hz) sine wave high voltage. Since