Fault-tolerant isolated converter in low-voltage technology for automotive AC auxiliary power

A impressive demand for auxiliary AC power supplies has emerged in response to the increasing number of entertainment and tool equipment powered up on-the-move from the low-voltage battery onboard an automobile or boat. As most of these products feature the same typical power architecture, new solutions are looked for in order to reduce cost and improve reliability. This paper proposes a new topology starting from the well-known 2-switch flyback converter, followed up with multiple secondary windings and voltage multiplier circuits. The duty cycle is varied in relationship to the desired sinusoidal reference. All power switches and capacitors are rated under 50V, while this design example is expected to deliver fault-tolerant 120V, 60Hz, 250W for the required automotive or boating auxiliary power.