In the fields of power system operation and maintenance, high-voltage equipment factory testing, and scientific research experiments, the selection of high-voltage testing equipment directly affects the accuracy of testing results, the safety of equipment operation, and even the personal safety of operators. However, facing the wide variety and complex parameters of high-voltage testing equipment in the market, how to scientifically and accurately select has become a practical challenge for many power workers and enterprise procurement personnel.
1, Clear testing requirements, voltage level matching is the primary prerequisite
The first step in selection is to clarify the actual testing requirements of our unit. The person in charge of Wuhan UHV technology pointed out that voltage level matching is the primary consideration for the selection of all high-voltage testing equipment. Taking partial discharge detection system as an example, the equipment specifications required for 10kV distribution network and 110kV substation are completely different. Similarly, the selection of DC high-voltage generators also needs to be determined based on the voltage requirements of the test object: for detecting 10kV cables and low-voltage lightning arresters, 30kV-60kV is sufficient; To detect cables and high-voltage lightning arresters of 35kV and above, it is necessary to choose a level of 120kV and above. For series resonant devices, they are usually suitable for high-voltage cross-linked cables ranging from 6kV to 500kV, generators, GIS and SF6 switches, transformers, and other equipment with different voltage levels.
2, Pay attention to core parameters, accuracy, current, and stability are indispensable
On the basis of voltage level matching, it is also necessary to focus on core parameters such as equipment accuracy, output current capability, and stability.
In terms of accuracy, the required accuracy level should be strictly determined in accordance with GB/T or DL/T related standards. Taking the DC high-voltage generator as an example, the national standard requires a voltage accuracy of ≤± 1%, but some cheap devices on the market have the problem of "false standard accuracy". The voltage accuracy of the direct current high voltage generator produced by Wuhan UHV can reach ± 0.3%. It adopts a high-frequency voltage doubling circuit design, effectively avoiding voltage virtual labeling and fluctuation problems.
The output current capability cannot be ignored either. There are significant differences in the current requirements for different testing scenarios: the current required for conventional cable and insulator insulation testing is relatively small, ranging from 0.5mA to 10mA; The leakage current test of lightning arrester and the charging test of high-voltage capacitor require a current of 10mA-100mA or even higher. It is recommended to reserve a current margin of 10% -20% when purchasing to avoid slow voltage rise and inability to reach the specified test voltage due to insufficient current.
In terms of stability, ripple coefficient is a core parameter that many people tend to overlook. The lower the ripple, the more stable the output voltage, and the smaller the testing error. The national standard requires a ripple factor of ≤ 1%, and high-quality equipment can achieve ≤ 0.5%. Wuhan UHV has optimized the filtering circuit and PWM pulse width modulation technology to control the ripple coefficient within 0.3%, making it particularly suitable for scenarios with high precision requirements such as scientific research experiments and precision component testing.
3, Balancing environmental factors and safety protection
The environmental conditions at the test site are also important considerations for selection. For outdoor equipment with high frequency of use, it is recommended to choose models with dust-proof and waterproof enclosures. When the winter temperature in northern regions drops to minus 15 ℃, the LCD screen response of some devices may slow down, and wide temperature screen models should be selected. In addition, the volume, weight, and ease of handling of equipment such as series resonant devices also need to be considered to adapt to the actual working environment of the power sector and industrial and mining enterprises.
The safety protection function is the bottom line requirement for the selection of high-voltage equipment. The equipment should have multiple safety protection functions such as overvoltage protection, overcurrent protection, and short circuit protection. The direct current high voltage generator of Wuhan UHV adopts high-frequency voltage doubling circuit and multiple protection unit design, which can achieve precise voltage boosting and ensure operational safety.
4, Comprehensive evaluation and selection of reliable suppliers
Selection is not only about choosing equipment, but also about choosing partners. The person in charge of Wuhan UHV technology suggests that suppliers with modular design, intelligent control, and localized service capabilities should be given priority in procurement. Series resonant devices and other equipment are usually composed of variable frequency control power supplies, excitation transformers, reactors, capacitive dividers, etc. It is necessary to ensure that the quality and performance of each component meet the requirements. Meanwhile, the manufacturer's after-sales service and technical support capabilities are also crucial to ensure timely and effective assistance during equipment use.
It is reported that Wuhan UHV Power Technology Co., Ltd. has developed into a leader in the high-voltage electrical measurement industry after nearly 22 years of meticulous cultivation. Its products cover more than 100 types in 15 major categories, including series resonance test devices, partial discharge testing systems, high-voltage insulation withstand voltage, transformer testing, circuit breaker testing, relay protection, etc. The company has always adhered to technological innovation and management innovation, winning a good reputation in the industry with high-quality products, reasonable prices, and first-class reputation.
The selection of high-voltage testing equipment is a systematic project that requires comprehensive consideration of various factors such as voltage level, accuracy requirements, current capacity, stability, environmental adaptability, safety protection, and supplier services. Only through scientific selection and precise matching can the safety, accuracy, and efficiency of power equipment testing be ensured. With the continuous development and technological progress of the power industry, high-voltage testing equipment is constantly evolving towards intelligence, modularity, and high precision, providing a more solid guarantee for the safe and stable operation of the power system.