The factory testing process of cable manufacturing enterprises has a long-standing practical problem that troubles the procurement and production departments: the product line covers voltage levels of 10kV, 35kV, 110kV, and even higher, and the cable length ranges from several hundred meters to several kilometers. Configuring a separate series resonant device for each specification means high equipment investment and factory space occupation; However, a set of fixed configuration devices often cannot cover all experimental requirements.
Can one device adapt to all cables? "This is a question repeatedly asked by the procurement department of the cable factory. The answer given by Wuhan UHV Power Technology Co., Ltd. is: yes. The secret lies in modularity.
Reactors can be connected in series or parallel, with one configuration covering the entire voltage and length
The core of modularity lies in the reactor. The Wuhan UHV series series series resonant device adopts a multi section series parallel reactor structure - the series connection of reactors can increase the output voltage and is suitable for high voltage level testing; Parallel connection of reactors can increase output current and is suitable for high-capacity (long cable) testing. By flexible combination, a set of devices can adapt to multiple voltage levels and cable lengths.
Taking the UHV-75kVA/75kV scheme as an example, the device is equipped with three reactors, each with a capacity of 25kVA/25kV/1A/110H. Three sections in parallel can complete an AC withstand voltage test of 1.5km for a 10kV/300mm ² cable, with a test frequency of 35.01Hz and a test current of 2.73A. Three sections in series can complete a withstand voltage test of 0.35km for a 35kV/300mm ² cable, with a test frequency of 30.65Hz and a test voltage of 52kV. The same equipment can be freely switched between two voltage levels of 10kV and 35kV by changing the combination of reactors.
The UHV-135kVA/108kV scheme goes further by configuring 4 reactors (each 33.75kVA/27kV). The 10kV/300mm ² cable can measure up to 3km, while the 35kV/300mm ² cable can measure up to 1km. The UHV-405kVA/270kV scheme is equipped with 6 reactors (each 67.5kVA/45kV), expanding the coverage to 4.5km for 10kV cables, 2km for 35kV cables, and 0.5km for 110kV cables.
In a joint experiment in Chongqing, the UHV series device deployed by Wuhan UHV includes six 67.5kVA/27kV high-voltage reactors. Through flexible combination, it successfully completed the withstand voltage test of 8km 10kV/300mm ² cable and 3km 35kV/300mm ² cable. From several hundred meters to eight kilometers, from 10kV to 35kV, a complete set of equipment covers.
Lightweight design: Say goodbye to cranes, two people can complete testing
Another value brought by modularity is lightweight. The series resonant device eliminates the need for bulky high-power voltage regulating devices and power frequency test transformers, and the system weight and volume are generally 1/10 to 1/30 of ordinary test devices.
The entire unit of Wuhan UHV series is lightweight and easy to use on site. For high-capacity requirements, multiple low-power devices can be used in parallel - this design eliminates the need for cranes for high-capacity resonant devices above 1000kVA, and reduces personnel from the industry's conventional seven or eight people to just two people to complete testing work. The equipment has the advantages of small size, light weight, and easy transportation, making it very suitable for cable factory production environments with multiple testing stations and frequent equipment transportation.
The Deep Value of Modular Design: Reducing Total Cost of Ownership
For cable factories, the significance of modularity lies not only in the initial cost savings brought by the "one machine for multiple uses" policy, but also in the comprehensive benefits of long-term operation.
Firstly, there is no need to purchase equipment separately for each voltage level and length. A set of equipment can cover various cable testing requirements from 10kV to 110kV. Secondly, modular design supports flexible combination of reactors and variable frequency power supplies, adapting to different voltage levels from 10kV to 750kV. When the product line expands or there is a change in testing requirements, it is only necessary to add power resistors or upgrade power modules, without the need for a complete replacement. Furthermore, the single piece lightweight design significantly reduces the labor cost and equipment transportation time, and improves the turnover efficiency of the testing station.
Wuhan UHV has formed a series of mature schemes, including UHV-75kVA/75kV to UHV-750kV/6A integrated testing platforms. These solutions are all based on modular architecture design, and the reactors can be flexibly combined. Users can choose the basic configuration according to their own product coverage range and expand as needed in the future.
The testing requirements of cable factories have never been "one cable, one configuration". The value of modular series resonant devices lies in the investment of one set of equipment to cover all the testing needs of a product line - this is the true "one machine, multiple uses".
