Static and dynamic analysis of a permanent magnet rectilinear Lawsʹ relay actuator

The authors describe a study of a rectilinear version of the Laws’ relay actuator. Finite element analysis is used to model the device and to obtain its static characteristics, with the analysis being coupled to a nonlinear statevariable time domain simulation to determine the dynamic performance. It is shown how a number of dimensional changes to the magnetic circuit and the use of alternative soft magnetic materials enable the performance of the initial design to be considerably improved. The modelling is validated using two prototype actuators, with good agreement being obtained between simulated and measured results.