The Foundation: Adherence to Technical Standards

Professional-grade DC High-Voltage Generators are manufactured in strict compliance with international and industry standards, which guarantee their safety, accuracy, and reliability. A key governing standard is the DL/T 848.1-2019, "General specification for high voltage test devices - Part 1: High voltage DC generator." This standard outlines the technical requirements, testing methods, and inspection rules for these devices, ensuring they meet rigorous performance criteria for voltage stability, measurement accuracy, and ripple coefficient :cite[2]. Furthermore, system-level testing for High-Voltage Direct Current (HVDC) installations is guided by standards such as IEC 61975, which covers comprehensive testing procedures from low-power transmission to dynamic performance evaluation :cite[6].

Core Technologies and Modern Topologies

The fundamental purpose of a DC High-Voltage Generator is to step up a low input voltage to a much higher DC level. While traditional circuits are effective, recent advancements have focused on achieving higher efficiency, greater power density, and higher voltage gains.

• Cascaded Voltage Multiplier Circuits: Many modern generators utilize a cascade or series connection of multiple voltage multiplier stages :cite[3]. This approach, often based on designs like the Cockcroft-Walton multiplier network, allows for the generation of extremely high voltages from a smaller, more manageable input voltage. This topology is particularly effective because it can achieve a high voltage gain without requiring an excessively large transformer turns ratio :cite[5].

• Resonant Converter Designs: To maximize efficiency and reduce electrical stress on components, advanced generators employ resonant topologies like the LLC resonant circuit. A significant advantage of this design is that it enables power switches on the primary side to operate with Zero-Voltage Switching (ZVS) and output diodes on the secondary side with Zero-Current Switching (ZCS). This dramatically reduces switching losses and electromagnetic interference (EMI), leading to conversion efficiencies that can exceed 93% in high-power applications :cite[7].

• Modular and High-Power Designs: For very high power and voltage requirements, such as in industrial accelerators, modular designs are implemented. One documented approach involves using a core with an equilateral triangle structure, where secondary coils are divided into multiple stages. Each stage performs three-phase full-wave rectification to output 30 kV, and these stages are connected in series to achieve a massive output of 1.2 MV. Such systems can achieve an energy conversion efficiency greater than 95% and are often insulated with high-purity SF6 gas :cite[9].

Key Applications in Industry

DC High-Voltage Generators are critical for a wide range of field and laboratory tests. Their primary applications include:

• DC Withstand Tests: Evaluating the insulation strength of power cables, generators, and transformers.

• Leakage Current Measurement: Assessing the condition of insulating materials under sustained high voltage.

• Surge Arrester Testing: Specifically for metal-oxide varistor (MOV) surge arresters, these generators are used to measure the critical reference voltage (U_1mA) and the leakage current at 0.75 U_1mA :cite[4]:cite[10].

Conclusion

The DC High-Voltage Generator remains a cornerstone of electrical safety and reliability programs. Through continuous innovation in power electronics—such as the adoption of cascaded multiplier cells and resonant converter topologies—these devices have become more efficient, compact, and capable than ever before. Adherence to established standards ensures they provide the accuracy and safety required for critical high-voltage testing, making them an essential asset for utility companies, industrial plants, and research institutions worldwide.