Power electronics and control of two-voltage-level flywheel based all-electric driveline

A novel all-electric driveline comprising a flywheel with a permanent magnet doubly wound synchronous motor/generator is presented. The flywheel machine with a double set of windings divides the system in two voltage levels: a low voltage/power level, which is connected to the main energy storage source (e.g. battery) and a high voltage/power level, which is connected to the traction machine. A DC/DC + DC/AC converter makes the connection between the battery and the flywheel low voltage windings. An AC/DC/AC converter connects the flywheel high voltage windings to the wheel machine. A complete simulation of the system has been made in Simulink. Vector control based speed regulators have been designed and successfully simulated. DC link voltage control has been achieved by using synchronous rectification. Power estimation has been used during regenerative braking in order to charge the flywheel with the power generated from the vehicle speed reduction. Simulations have verified the functionality of the proposed system.