Efficiency of a Regenerative Direct-Drive Electromagnetic Active Suspension

The efficiency and power consumption of a direct-drive electromagnetic active suspension system for automotive applications are investigated. A McPherson suspension system is considered, where the strut consists of a direct-drive brushless tubular permanent-magnet actuator in parallel with a passive spring and damper. This suspension system can both deliver active forces and regenerate power due to imposed movements. A linear quadratic regulator controller is developed for the improvement of comfort and handling (dynamic tire load). The power consumption is simulated as a function of the passive damping in the active suspension system. Finally, measurements are performed on a quarter-car test setup to validate the analysis and simulations.