Energy recovery and energy-saving control of a novel hybrid electromagnetic active suspension system for electric vehicles

Active suspension systems have great potential for improving ride comfort and driving safety. However, their high energy consumption contradicts current energy-saving and emission-reduction goals, limiting their widespread application. To improve vehicle dynamic performance while reducing the energy consumption of active suspension systems, this paper proposes a novel hybrid electromagnetic active suspension system (HEAS) integrating a hydraulic-electromagnetic energy-regenerative module (HERM) and a linear motor (LM). A permanent magnet synchronous motor (PMSM) and a rectifier are modeled as an equivalent DC voltage source, with an improved Buck-Boost converter designed to establish a steady-state energy recovery circuit. A steady-state DC-DC control strategy is proposed for this model to regulate the output force of the HERM while enabling energy recovery. The validity of the modeling of the equivalent voltage source and HERM is verified by bench tests. Based on this, the LM and HERM are synergistically controlled using a modified skyhook control strategy to achieve suspension active control, semi-active control, and energy recovery simultaneously. The results showed that, under Class-C road excitation, the proposed active suspension improved body acceleration and suspension dynamic deflection by 21.5 % and 12.7 %, respectively, compared to passive suspension (PS). In addition, it reduced energy consumption by 67.8 % compared to the linear motor active suspension (LMAS) while achieving an energy recovery of 29.9 W. The proposed system can be used as a practical solution to simultaneously improve vehicle dynamics performance, reduce energy consumption, and enable energy recovery.