Longitudinal End Effect in a Variable Area Linear Resolver and its Compensating Methods

Linear permanent magnet machines are increasingly used in industrial applications where they need position sensors to improve their performance. Variable Reluctance resolvers are one the best position sensors that can be used in unfriendly environment conditions, with high mechanical vibration, wide temperature variation and polluted environments. However, conventional VR resolvers suffer from complicated winding process, undesirable performance under eccentricities, and high position error in two-pole applications. So, in this paper a new linear resolver is proposed based on the sinusoidal variation of common area between the moving and the stationary parts. Then, the influence of longitudinal end effect on the accuracy of the sensor is discussed and finally three compensating methods are proposed. All the simulations are done using 3-D time stepping finite element analysis (3-D TSFEA). Then, the out signals are imported into Matlab in order to calculate the position error.