Product category: Electrically heated systems, Pre-heating furnaces, Other control systems
On load Variable Voltage Transformer - from 200 to 30,000 kVA Technical Performances LV or HV primary voltage Galvanic Insulation between primary and secondary windings Linear, on load voltage variation NoDCComponent Friendly simplified interface with supervisiory systems 100 % custom made equipment
Cost savings Efficiency higher than 98 % High power factor No addition of harmonics to the mains Power delivered always adapted to the load Reduced sizes
Magnetic circuit VARIVOLT is a rotating core transformer. The magnetic circuit consists of 2 flat bored yokes, and cylindrical rotating cores. Cores are made of magnetic steel strips radially stacked around a shaft. The cores are driven in rotation by an external motor. The cores are the only mobile parts.
Windings Galvanic insulation is acheived thanks to separated primary and secondary windings. The induction and the voltage per turn is constant, resulting in high efficiency and power factor. HV or LV primary windings are in most cases standard. LV secondary windings comprise a grooved copper conductor, allowing 0 to 100 % variation of the maximum secondary voltage.
Sliding contact The sliding contact is made of special copper to facilitate high current transfers. Helical mouvement of the sliding contact along the winding allows voltage variation without arcing. The oil filled VARIVOLT minimises corosion of the sliding contacts and guarantees several years of maintenance free use.
Bernard Bonnefond was founded in 1925. Over the last thirty years the company has specialized in developing electro-technical products to better serve its French and foreign customers, including : Preliminary studies and custom tailoring of each piece of equipment to perfectly match each customer unique specification. Supply of “turnkey”packages, field installation, start- up, commissioning and operator training. Technical support to maintenance crews ,as well as engineering and design assistance for new projects. More than 80 % of BB production is exported