REO MOTORISED VARIABLE TRANSFORMERS USED FOR MARINE PROPULSION CONVERTER DEVELOPMENT

Modular multi-phase inverters developed specifically for the international military and commercial marine markets by Converteam of Rugby (formerly ALSTOM Power Conversion) are subject to continual development to ensure maximum control and efficiency.

Converteam’s VDM25000 Converters provide PWM control for 15-phase marine propulsion motors. Helping to prove these converters are two motorised 150kVA variable transformers supplied by REO UK, which are employed both at the development and production stages for the VDM25000.

At Converteam’s Rugby site, one of the REO transformers is used to provide a variable 3-phase power supply (0-4160V) to produce different load conditions. This enables the company to prove new power electronics components as they are introduced during the product lifecycle.

REO’s motorised transformer, which provides more effective supply control than an earlier manually operated unit, feeds a test cell that tests the power conversion modules under real operating conditions. During tests, the 700A test current is dissipated in an oil-cooled load reactor.

The second REO transformer is installed at Converteam’s Glasgow site for testing assembled converters modules.

Converteam’s VDM25000 has three channels each feeding 5 of the 15 phases to the propulsion induction motor, an arrangement that allows parallel redundancy at lower capability levels. Each phase is driven with an H-bridge to maximise output capability and gain net improvements in signature and efficiency.