Development of Linear Power Generator: Conversion of Vibration Energy of a Vehicle to Electric Power

Abstract

This paper proposes a linear power generator, which can convert any mechanical vibration energy of a vehicle to electric energy. A mover of the proposed linear power generator, which includes permanent magnets, is linearly driven through a stator, by vibrations. Nd Fe-B magnets in the mover are placed so that the same magnetic poles face each other, in order to make the large change in magnetic flux in the coils of the stator. The coils are placed in the stator with the same interval of magnets. Alternate coils connected in a series were wound in opposite directions to the next coil. The stator was covered with a magnetic material case that has pole pieces between the coils. Therefore, the magnetic flux is extended through the case and reduces cancellation of the flux in the coils of the stator. At first, a button type magnet was substituted with equivalent electric current in accordance with measurements from simulations. The distribution of the magnetic field and electromotive force were calculated by numerical simulations in order to determine the ideal size of the linear power generator. The linear power generator and an experimental apparatus were then produced on the basis of this simulation. The performance of the linear power generator was tested by experiments and showed that the power generation ability was 4 times greater in comparison with the magnetic metal case without the pole pieces. The proposed linear power generator is considered to be useful for the conversion of mechanical vibration energy to electric energy.