Electricity and Control June 2024

TRANSFORMERS, SUBSTATIONS + CABLES : PRODUCTS + SERVICES

The advantages of using MV XLPE cables

production of paper insulated lead cables, the ac cessories such as jointing and termination kits are not easy to find. ƒ The shortage of skills for splicing, jointing and ter mination of paper insulated cable is also driving customers to move to XLPE cable. Many PILC ca ble failures reportedly result from suspected poor workmanship related to the skills gap. ƒ Although PILC cable performs better in providing radial water blocking properties with the lead sheath which is completely impermeable, XLPE is also available in cost-effective water blocking formats for both longitudinal and radial water blocking. It can be supplied on request, by leading cable manufac turers such as Aberdare Cables in South Africa. ƒ XLPE cables are more flexible than PILC cables which are more rigid especially for larger sizes. This means XPLE can be used where a shorter bending radius is required. ƒ Environmental considerations also play a role. Pa per insulated lead cable is oil impregnated with mineral oil or PIB and, with its lead sheath (heavy metal), it presents a higher risk of environmental contamination than XLPE. Consequently, XLPE is favoured in many situations where an environmen tal analysis is a key aspect in design decisions. Aberdare Cables Pty Ltd in South Africa offers XLPE cables up to 132 kV for customers across Africa and around the world. For voltages higher than 132 kV, XLPE cables can be provided by Aberdare cables through its parent company, Hengtong Group in China. are being planned to double the production space in Regensburg. As a first step, three additional production bays with an investment value of around 20 million euros will go into operation by mid-2025.” Expanding and increasing production volume at the Suzhou site near Shanghai, China, will see additional capacities for VACUTAP ® tap-changer variants available from July 2024, to shorten delivery times primarily for Chinese customers and transformer manufacturers. At the end of July 2024, a new production building will go into operation at the Humboldt/ Tennessee, USA plant for bolt-on tap-changers. With investments amounting to USD3 million, capacities in Humboldt have been ex panded by 45% and will be increased by a further 25% by 2025. Provision has already been made for future ex pansion and sufficient reserve space has been secured. Capacities will also be expanded in 2024 at the production sites for transformer accessories and instrumentation of MESSKO in Oberursel, as well as in Italy at CEDASPE in Milan and Reinhausen Italy in Trissino, to meet the sharp rise in demand. □ For more information visit: https://aberdare.co.za/

Responding to the rapidly increasing global demand for transformers and energy technology, Maschinenfabrik Reinhausen (MR) is investing in an unprecedented ex pansion of its production capacities. Managing Director Wilfried Breuer states: “We are investing proactively and substantially in all areas that help us to meet the needs of our customers in the best possible way. We have ini tiated a number of measures to increase our workforce, invest in tools and production areas, and optimise our infrastructure.“ Managing Director Holger Michalka, who is respon sible for production and infrastructure worldwide, em Paper insulated lead cables (PILC) have been in use for more than 100 years in medium voltage applications from 6.6 kV up to 36 kV, as well as in high voltage systems. PILC has been preferred over the years due its high dielectric strength, low dissipation factor, relatively low dielectric loss, low sensitivity to dc testing and proven reliability. However, it has become less popular as it is being replaced by cross-linked polyethylene (XLPE) cables due to factors impacting its cost-effective use. Many cable manufacturers around the world have discontinued production of PILC in response to the reduction in demand. XLPE as an insulating medium has a lower dielec tric constant, lower dielectric loss and high dielectric strength and operates at higher temperatures, enabling the cable to be more efficient, carrying more current than the same size cable of paper insulation impregnated ca ble. XLPE is generally preferred by customers for factors relating to ease of use, efficiency, fewer accessories and less complexity, among others. Some of the factors that favour XLPE rather than PILC for MV cables are set out below. ƒ XLPE has a higher current rating compared to the same size PILC cable due to the fact that XLPE has a higher operating temperature. ƒ For PILC cables, the installation, maintenance and repair processes are more complex, intensive, time consuming and high on cost compared to XLPE cables. ƒ As many factories worldwide have discontinued Investing in production for the energy transition

XLPE cables offer a number of advantages for MV applications.

MR is increasing its production capacity of transformers, tap-changers and related energy technologies to meet high demand globally.

phasises: “Our investment priorities are at the Regensburg site in Germany, in the USA, China, Italy and Oberursel near Frankfurt, Germany. At the lead factory in Regensburg, we are starting to ex pand production lines, test benches and building infrastructure, to increase capacity by 25% by 2025 – particularly for high-demand products. Further steps

28 Electricity + Control JUNE 2024