DEMIKS lightning impulse testing equipment has been installed in Anshan, strengthening the company’s capabilities in high-voltage power equipment testing. (Supplied to Rongxin Transmission in Wolong)

Recently, the complete lightning impulse testing system delivered by Shanghai DEMIKS Power Technology Co., Ltd. has successfully completed on-site installation, wiring and commissioning, and has been officially put into use in the high-voltage testing laboratory of Liaoning Rongxin Electric Drive Co., Ltd. of Wolong Electric Group. It will carry out standardized lightning impulse withstand voltage testing for high-voltage frequency converter cables and high-power power electronic products, and build a high-voltage insulation safety line to ensure the quality of industrial high-power electrical drive products leaving the factory.

Project Cooperation Background: Leading enterprises’ quality control upgrades drive demand for high-end testing equipment.

Wolong Group’s Liaoning Rongxin Electric Drive is a benchmark manufacturer in China for high-power high-voltage frequency converters, SVG static var generators, port and ship shore power supplies, and energy storage PCS converters. Its products are widely supplied to high-energy-consuming heavy industries such as thermal power, metallurgy and mining, long-distance oil and gas pipelines, cement and building materials, new energy storage, and port shore power. Within the factory area, 6kV and 10kV high-voltage frequency converter cables, special flame-retardant power cables, energy storage high-voltage DC cables, as well as various high-power frequency converter units and high-voltage cabinets, all undergo lightning impulse tests according to national standards. These tests verify the insulation’s ability to withstand transient over-voltages caused by lightning strikes, check for insulation bubbles, minor scratches, and assembly stress defects, and prevent major production accidents such as insulation breakdown, machine shutdown, and production line stoppage during thunderstorms after product commissioning.

With the continuous expansion of Rongxin Transmission’s overseas trade orders and North American UL certification projects, the waveform accuracy and peak voltage regulation capability of its existing aging testing equipment could no longer meet the stringent standards of overseas type testing. Therefore, the company decided to upgrade its entire lightning impulse testing unit. After multiple rounds of technical parameter bench-marking, prototype performance testing, and delivery cycle verification, Shanghai DEMIKS Power successfully secured this equipment supply order, leveraging its customized topology design, mature experience in delivering complete high-voltage test chambers, and comprehensive localized after-sales service capabilities.

Product Solution Highlights: Adaptable to high-power industrial product testing, while also meeting the testing needs of general cables and special power supplies.

The complete lightning impulse testing system delivered this time consists of three core modules: the impulse generator body, the high-voltage divider, and the measurement and control console . The vertical modular impulse generator body is adapted to the mobile layout of the workshop and is equipped with load-bearing universal casters for flexible switching of the test area. The high-precision resistive-capacitive voltage divider accurately acquires the 1.2/50μs standard lightning impulse waveform. The integrated measurement and control console integrates an industrial control computer, a digital oscilloscope, and a programmable voltage regulation unit, which can automatically store the voltage waveform and breakdown alarm data of each impulse, automatically generate a traceable type test report, and is compatible with the data verification specifications of third-party CMA institutions.

The equipment has undergone several scenario-specific optimizations for Rongxin Transmission’s testing scenarios:

1. Upgraded cable testing capabilities : Can perform cold and hot lightning impulse tests on 6~35kV high-voltage frequency converter shielded cables, coal mine explosion-proof and flame-retardant cables, port weather-resistant marine cables, and energy storage DC high-voltage cables. Strictly implements GB/T 3048.13 and IEC 60840 national standards and international specifications. Screens for latent partial discharge hazards in cable insulation through 10 consecutive impulses to both positive and negative poles.
2. High-power power electronic equipment compatibility testing : It can complete the factory sampling inspection of high-voltage frequency converter power units, SVG cabinets, and shore power rectifier power supplies, verify the insulation matching level of the whole machine, and match the reference impulse insulation level (BIL) of the whole industrial transmission system.
3. Standardized output of foreign trade project reports : The system has built-in test report templates for CE and UL certifications. The exported data can be directly used for type testing applications for overseas projects, helping Rongxin Transmission expand into the European, American and Middle Eastern overseas industrial control equipment markets.
4. Enhanced durability for workshop conditions : The generator cabinet features an optimized dust-proof and rustproof structure, making it suitable for the dusty and temperature-fluctuating environments of heavy industrial plants. This reduces the aging rate of high-voltage components and extends the overall lifespan of the equipment.

Industry Value: Empowering upstream and downstream collaboration to improve the quality control system of the high-power power electronics industry chain.

Wolong Liaoning Rongxin Electric Drive mainly produces high-power frequency conversion equipment, which relies on matching high-voltage cables to complete power transmission between cabinets and equipment ends. The lightning strike resistance performance of the cable insulation is the core prerequisite for the long-term stable operation of the entire transmission system. The lightning impulse testing equipment delivered by DEMIKS Power this time fills the hardware gap in Rongxin’s factory for independent lightning impulse type testing of high-voltage cables and finished products: In the past, some special types of samples needed to be sent to third-party laboratories for testing, which resulted in long testing cycles and easy damage to samples due to logistics bumps; now the factory can independently complete the sampling inspection of the entire batch and the type testing of new products, reducing the new product R&D verification cycle by more than 30% and significantly improving the efficiency of batch order delivery.

From an industry chain perspective, this collaboration establishes a seamless quality control collaboration link between “high-end high-voltage testing equipment suppliers and leading high-power electrical drive manufacturers.” Shanghai DEMIKS Power has deep expertise in the high-voltage testing equipment sector, specializing in lightning impulse testing devices, series resonant withstand voltage equipment, partial discharge detection systems, and power frequency withstand voltage complete sets of equipment. Its clients include power equipment manufacturers, authoritative third-party testing institutions, power grid and substation operation and maintenance units, and new energy storage integrators. Based on this benchmark case, DEMIKS can further provide high-voltage frequency converter manufacturers, wire and cable manufacturers, and energy storage equipment factories with customized one-stop solutions encompassing high-voltage laboratory overall planning, equipment supply, installation, commissioning, and operation and maintenance.

Enterprise’s subsequent layout plan

Shanghai DEMIKS Power stated that it will subsequently arrange on-site technical personnel in the Anshan area to regularly conduct equipment accuracy calibration and hands-on training for operators. Leveraging the scenario-based technical experience gained from this benchmark project with Wolong Group, it will continuously iterate the waveform control algorithm of the lightning impulse generator, optimize the specialized test modules for grid-type energy storage equipment and high-power electrolytic hydrogen production rectifier power supplies, and provide highly reliable high-voltage testing equipment compatible with domestic and international certification standards for industrial control power electronics, special cables, and new energy storage sectors. This will support the domestic high-end power manufacturing industry chain and enhance the global market competitiveness of domestically produced high-power electrical drive products and special cables through stringent lightning impulse insulation testing standards.

Industry category terms: Lightning impulse testing of high-voltage frequency converter cables, type testing of high-power high-voltage frequency converters, insulation withstand voltage testing of energy storage PCS.