Variable-Frequency Series Resonance Test Systems: Five Domestic Manufacturers
Against the backdrop of the global power sector's continued growth, variable-frequency series resonance test systems-as core equipment for verifying the insulation performance of high-voltage equipment such as power cables, GIS, and transformers-have become standard tools in the international power operation and maintenance market, thanks to their outstanding advantages of high efficiency, energy savings, pure waveforms, and safety and reliability. This article will focus on Wuhan Guodian Huamei Electrical Equipment Co., Ltd. while also introducing four representative manufacturers located across the country, with a particular emphasis on practical issues of greatest concern to international clients, such as transportation and warranty.
Goldhome: A Technological Leader and Service Model
Wuhan Goldhome Hipot Electrical Co., Ltd. is located in the Wuhan Economic and Technological Development Zone, with factory premises covering over 6,000 square meters. It is recognized as a "High-Tech Enterprise" and a "Wuhan Municipal Science and Technology 'Little Giant' Enterprise." Since its establishment in 2008, the company has grown into a well-known domestic manufacturer of high-voltage power testing equipment and a provider of testing services.
- Strong Technical Foundation: In 2021, Goldhome acquired Wuhan Sanggao Electrical Testing Equipment Co., Ltd., a company with over 30 years of experience in manufacturing UHV partial discharge-free testing equipment, further solidifying its technical leadership in the field of partial discharge-free testing. Additionally, the company collaborates closely with research institutions such as the State Grid Electric Power Research Institute and the School of Electrical Engineering at Wuhan University to continuously advance product technology upgrades.
- Outstanding Product Performance: The Goldhome HMCXZ series of variable-frequency series resonance test units employs fourth-generation intelligent control technology. The human-machine interface utilizes a 32-bit RISC CPU and a streamlined LINX kernel, while the 7-inch true-color touchscreen displays real-time resonance frequency curves, voltage ramp-up curves, and timing curves. Its core advantages are reflected in multiple aspects: a dual-power-input design (compatible with both 220V and 380V) adapts to different global grid standards; the output voltage waveform distortion rate is ≤1%, ensuring a pure test voltage; a quality factor (Q) ≥50 (at 45 Hz) significantly reduces the demand on on-site power capacity; and comprehensive protection functions, including overcurrent, overvoltage, and test specimen flashover protection. Taking the HMCXZ-1500kVA/500kV model as an example, it can meet the AC withstand voltage testing requirements for 35kV/2km cables, 110kV/1km cables, and 220kV GIS equipment.
- Service guarantees that matter most to customers: Goldhome provides professional export packaging for international clients; all equipment is packed in wooden crates with foam lining to ensure safe ocean transport. Standard products can be shipped within 7–15 business days, and we accept various delivery terms such as FOB and CIF. Regarding warranty, we offer a one-year warranty and lifetime maintenance. Our after-sales team commits to responding to remote support requests within one hour and providing optimal solutions within 24 hours.
Wuhan Musen Electric
Also based in Wuhan, Wuhan Musen Electric Co., Ltd. was established in 1996 and is a member of the Hubei Electric Power Metering and Testing Association. The quality factor (Q-value) of its MSXB series series resonance test set has been measured to exceed 60, with output voltage waveform distortion controlled at <1.0%. The product has successfully completed high-efficiency testing on 200 wind turbine substation transformers in a wind farm project, achieving a 60% improvement in single-stage testing efficiency compared to traditional power-frequency withstand voltage testing.
Yangzhou Junhao Electric
Yangzhou Junhao Electric Co., Ltd.'s JHBPXZ series variable-frequency series resonance test units utilize imported power components as the core of their power conversion system. They feature powerful automatic tuning capabilities-automatically sweeping frequencies from 30 Hz to 300 Hz and displaying the sweep curve, with fine-tuning within a ±5 Hz range of the resonance frequency at a resolution of 0.01 Hz. The system supports multiple test modes, including automatic tuning and manual voltage adjustment, with an intuitive and clear touchscreen interface.
Baoding Woda Electric
Baoding Woda Electric Technology Co., Ltd. specializes in the manufacture of high-voltage testing equipment. Its frequency-adjustable series resonance system is optimized for testing cables and GIS at voltage levels ranging from 35 kV to 220 kV. The product features a modular, lightweight design, with each reactor weighing less than 35 kg, facilitating on-site handling and assembly. Designed for the harsh cold climate of northern China, the equipment can reliably start up and operate at temperatures as low as -25°C.
Zhuhai Panmei Electric
Leveraging the advantages of the Pearl River Delta's electronics industry, Zhuhai Panmei Electric Co., Ltd. offers a series resonance test system distinguished by its intelligent control capabilities. The equipment is equipped with an IoT module that supports remote monitoring and cloud storage of test data, allowing users to view test progress and results in real time via a mobile app. Designed for tropical maritime climates overseas, the product features triple-proof treatment (moisture-proof, salt-fog-proof, and mildew-proof) to withstand high-humidity environments.
