Sofia – electric buses rapidly charged thanks to the VX25

Electromobility is a major issue for urban transport companies all over the world. At the beginning of 2020, electric buses were put into operation by Stolichen Avtotransport, the public bus company for the Bulgarian capital city of Sofia. The buses come from Chariot Motors, while the fast-charging stations are from Gemamex Motion Co.

These stations are in-house developments based on inverter technology, and they can charge both supercapacitor and lithium iron phosphate batteries. The stations are designed for AC or DC power supplies and are available for outputs of up to 450 kW per module.

Three enclosures are united to form one

A “3-in-1” type of design for outdoor use was specially developed for the charging stations of the city buses. It comprises three VX25 enclosures joined together, with final dimensions of 1,200 x 2,200 x 1,400 mm (W/H/D).

The enclosures contain, for example, electrical equipment, and frequency inverters, and they are each with three 150-kVA transformers. The stations are controlled via a PLC, a sensor video terminal and special signalling and communication equipment. In addition, the enclosures have their climate control, consisting of a special climate control unit for outdoor installation, industrial fans with external grilles and filters, as well as heaters that have to operate within a temperature range of -35 to +45°C.

Thanks to the wide range of Rittal components, Gemamex can easily implement a large variety of charging stations for different power types, with a high IP protection category and – thanks to the powder coating - an attractive design. The stable construction accommodates components weighing 2,600 kg in total. “Nearly 80 percent of the structural elements are from Rittal. This reduced the number of subcontractors and led to time savings in our production process while also cutting the design and material costs,” says Georgi Genchev, Managing Director of Gemamex Motion Co.