Enhanced Energy Efficiency of Hybrid Reluctance Actuators by Bias Flux Adaptation

This paper investigates the impact of magnetic bias flux variations on the energy efficiency of hybrid reluctance actuators (HRAs). An analytical model for a variable bias flux HRA is developed to demonstrate the linear relation of the force to current ratio and the bias flux, which is evaluated experimentally by magnetic flux measurements with various permanent magnets. Furthermore, the effects of amplitude and frequency dependencies are analyzed and discussed. To evaluate the energy efficiency, an experimental HRA-based positioning system is dynamically driven and the power consumption is compared for different magnet configurations. The energy efficiency can be improved up to a factor of 3, demonstrating that the bias flux can be used to minimize the energy consumption for a specific operating point.