Recognising the short lead times and reduced cost of installing substations in a modular format, many sectors are choosing this option over the brick-and-mortar structures traditionally used to house substations. According to David Claassen, Managing Director of Trafo Power Solutions, which designs and supplies modular substations fitted with dry-type transformers, the reasons are not hard to find.
Modular substations are fast becoming the preferred format in applications ranging from industrial sites to data centres to mining and the oil and gas sector, delivering benefits such as quick deployment, lower installation costs and more flexibility.
“The trend towards modular substations is now well established in many sectors,” says Claassen. “There are many different options and designs, from substations installed in shipping containers to others supplied in larger or more specifically purpose-designed E-houses.”
Standard shipping containers – in either 20-foot or 40-foot configurations – provide an economical and safety-compliant format for substations that need to be transported over land or by sea. Claassen notes that the dimensions facilitate cost-effective logistics, and generally ensure quicker availability of on-board space when arrangements need to be made for shipping on container vessels. The containerised substation concept was where the idea of modular substations originated, as it allows for the units to be moved easily.
“More recently, we have seen the concept develop into much larger substation sizes – but the benefits remain,” he says. “These can generally be constructed quite simply with structural steel with fire-rated insulation to enhance the safety rating of the installation.”
Compared to constructing a conventional brick-and-mortar building on site, with all the related civils work required, the modular option quickly shows a range of benefits. Especially in remote locations, any building work can become complex, costly and time-consuming. The costs include transporting various building materials to site over long distances, as well as finding and employing scarce skills and supervision.
“This traditional route also involves taking all the electrical components to site – and then installing, testing and commissioning them in conditions that are often less than ideal,” Claassen adds. “By contrast, a modular substation can be constructed for the most part in a fully equipped factory, which is more conducive to quality and speed.”
Once the modular substations are shipped to site, there is minimal work to be done before they can be commissioned and put to work. Modular substations can also be designed with state-of-the-art technology for improved reliability, easier maintenance and reduced running costs.
Claassen highlights that dry-type transformers add considerable value to the modular substation concept, as these can be installed inside a container or e-house. He explains that the safety levels intrinsic to dry-type transformers mean they do not need a separate enclosure outside the modular structure.
“The dry-type transformer is simply another aspect of the electrical arrangement in a substation that can be readily modularised,” he says. “For safety and other reasons, an oil-filled transformer would still need its own infrastructure due to the risk of fire, explosion or oil spills.”
He highlights that this is counteractive to the modular philosophy which makes this substation format so popular. By using a dry-type transformer, however, the need for a separate transformer bay, fire protection and suppression facilities, and outside cabling, can be avoided. With a dry-type transformer inside the substation, there is also a reduction in the overall footprint.
For more information visit: www.trafo.co.za
