In the field of electrical maintenance and power system safety, ensuring the integrity of high-voltage equipment is paramount. The DC High-Voltage Generator stands as a critical instrument for conducting dielectric withstand tests and insulation strength evaluations. This article explores the technology behind intelligent DC High-Voltage Generators and their application in modern industry.

What is a DC High-Voltage Generator?

A DC High-Voltage Generator is a specialized device designed to produce a stable and adjustable high-voltage direct current for testing purposes. It is widely used by power utilities, industrial plants, and research institutions for testing items such as power cables, transformers, surge arresters like Zinc Oxide (ZnO) units, and generators. The core function is to verify the insulation capability of electrical equipment by applying a voltage higher than its normal operating level.

Core Technology and Features

Modern intelligent models, often referred to as Intelligent DC High-Voltage Generators, incorporate advanced technologies to ensure precision and safety. They utilize PWM high-frequency pulse width modulation and medium-voltage frequency multiplication circuits. This design, supported by components like high-performance IGBTs, leads to high voltage stability and a low ripple coefficient of ≤1.0% :cite[1]. Key features include:

• High-Precision Measurement: Voltage and current measurement accuracy can achieve 1.0% (full scale), providing reliable data for leakage current tests :cite[1].

• Intelligent Functions: Many devices come with LCD screens for real-time monitoring, automatic test modes for ZnO arresters (including a dedicated 0.75 U_DC-1mA function), and computer interfaces for data transfer :cite[1].

• Comprehensive Safety Protections: Built-in protections include over-voltage, over-current, and faulty grounding alarms, with nano-second-level response times to safeguard both the operator and the equipment :cite[1].

Applications and Usage

The primary application of a DC High-Voltage Generator is in DC dielectric withstand tests and leakage current measurements :cite[1]:cite[5]. Typical use cases include:

• Performing DC withstand voltage tests on high-capacity power cables.

• Measuring the conduction current of metal-oxide surge arresters.

• Testing the insulation strength of rotating machinery like generators and transformers.

Safety during operation is critical. Tests must be performed by certified professionals following safety codes. Procedures include using discharge rods to safely dissipate energy from large capacitive test objects and ensuring proper grounding :cite[1].

Standards and Technical Parameters

The production and use of these devices are guided by industry standards such as the Chinese DL/T 848.1-2019 :cite[1]. Furthermore, the accuracy of high-voltage measurement instrumentation is governed by national standards like GB/T 16896.3-2024, which sets requirements for digital recording instruments used in tests with alternating and direct voltages :cite[10]. These devices typically offer output voltages ranging from 60 kV to 400 kV and currents from 1 mA to 10 mA, packaged in portable designs for field use :cite[5].

Conclusion

The intelligent DC High-Voltage Generator is an indispensable tool for maintaining the reliability and safety of electrical power systems. By leveraging advanced PWM technology and robust safety features, it provides accurate and reliable results for critical high-voltage tests. As technology evolves, the integration of digital controls and compliance with international standards will further enhance its capabilities, solidifying its role as a cornerstone of power system diagnostics.