Simulation of modified tubular linear permanent magnet generator for wave energy conversion in Indonesia

Conventional tubular linear permanent magnet generator (LPMG) is composed of permanent magnets which are placed in translator, and stator which is made of iron. However, this topology suffers from the relatively huge cogging force due to the interaction between the magnet and the iron, also a large core losses from hysteresis and eddy current. To reduce the force and the losses, modified design of LPMG was proposed by reducing the iron proportion of the stator. The modified tubular LPMG would be applied for 1 kW
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wave energy power plant in the south coast of Java, Indonesia. The reduction of the iron was then compensated by increasing number of stator winding turn to maintain the output power as desired. Resulted design was then simulated by using finite element magnetic software of FEMM to check the output values based on magnetic flux distribution. The results of the simulation showed that the modified design needs 11.4% more stator winding turns to produce equal power. However, the cogging force and the mechanical loss decreases by 24.7%. The design also reduces 57.2% of both hysteresis loss and eddy current loss, and 57.1% of weight.