Design and experimental characterisation of a linear reciprocating generator

The paper describes the design and experimental characterisation of a small reciprocating linear permanent-magnet generator which has been developed for on-board generation of electrical power for telemetry vibration monitoring systems. A comprehensive design methodology, which embraces both the electromagnetic and mechanical design, is described. The electromagnetic design synthesis is based around analytical field solutions which allow the optimisation of the generator parameters, and is further verified by nonlinear electromagnetic finite-element analysis. Nonlinear structural finite-element analysis is employed to aid the design of flexural disc springs with the desired stiffness and stroke. The utility of the design methodology is illustrated by a design study and extensive experimental characterisation of a prototype device.