Hybrid electromagnetic suspension

Hybrid electromagnetic suspension (HES or H-EMS) is a type of magnetic suspension system used in some high-speed ground transport and maglev applications. It combines elements of both electromagnetic suspension (EMS) and electrodynamic suspension (EDS) to provide stable levitation, reduced energy consumption, and operation over a broader range of speeds.

Hybrid electromagnets—devices that integrate both a permanent magnet element and an electromagnet coil—have existed in various forms since the early 20th century. These hybrids enabled adjustable magnetic fields by superimposing the controllable field of an electromagnet atop the constant field of a permanent magnet. In more recent decades, research into electropermanent magnet (EPM) systems—where a passive permanent magnet’s field is switched on and off with brief current pulses—has informed H-EMS designs that reduce continuous power consumption.

In a hybrid electromagnetic suspension, levitation is achieved through a combination of actively controlled electromagnets and permanent-magnet-assisted passive forces. This hybrid scheme takes advantage of EMS’s ability to levitate vehicles from rest while leveraging EDS’s efficiency and diminished control demands at higher speeds.^[1]

At low and medium speeds, electromagnets maintain the required air gap between vehicle and guideway using closed-loop control. At higher speeds, passive magnetic forces—from permanent magnets or induced fields in conductive guideways—contribute lift, reducing power needs and control complexity compared with pure EMS setups.^[2]

Concepts of hybrid electromagnetic suspension have been explored since the late 1970s in the U.S., Japan, and Germany, motivated by the limitations of both EMS (high energy use, tight control) and EDS (inability to levitate at zero speed without auxiliary wheels).^[3] Japan tested hybrid designs in small maglev prototypes during the 1980s–1990s. Similar research occurred under Germany’s Transrapid programme and through U.S. federal maglev initiatives.^[4]

Hybrid electromagnetic suspension is gaining interest in the hyperloop industry due to its capacity for standstill levitation, high-speed stability, and reduced reliance on rare-earth magnets.^[5] It can simplify infrastructure relative to EDS systems and relax precision requirements compared to pure EMS configurations.^[6]

Spanish company Zeleros explored H-EMS in the LEVIATAN project, funded by the Valencian Institute of Business Competitiveness (IVACE) during 2021–2022. The project created a large-scale electromagnetic levitation demonstrator to validate hybrid levitation principles for hyperloop applications.^[7]

In the Netherlands, Hardt Hyperloop conducted H-EMS testing at its European Hyperloop Center, publicly demonstrating stable levitation under controlled low-pressure conditions.^[8]

Hybrid electromagnetic suspension has been validated in academic contexts as well. During European Hyperloop Week, teams have presented H-EMS-based prototypes; for instance, the Hyperloop UPV team demonstrated levitation and guidance performance using hybrid systems during track tests.^[9]

No large-scale commercial transport system currently operates solely on H-EMS. Nonetheless, it features in experimental maglev prototypes, urban transit demonstrators, and hyperloop systems, and is used in laboratory-scale test beds and low-cost maglev freight research.^[6]

• Standstill levitation without mechanical wheels
• Lower energy consumption at high speeds
• Increased ride stability via combined passive and active forces
• Potential compatibility with both maglev and hyperloop infrastructure designs

• Greater system complexity vs. pure EMS or EDS
• Rare-earth magnets needed for achieving maximum performance
• Limited operational history in long-term or large-scale deployment