Design of a prototype of PM vernier electrical generator with power electronic unit for a wave energy plant

Wave energy is a very promising source of renewable energy, but its usage is limited by nature of sea waves, which deliver slow reciprocating movement. For this reason, linear electrical generators perfectly suit this application. Geared systems are used in order to make the generator more compact, but they suffer from low reliability and require regular maintenance. Direct drive systems are more reliable but less efficient in terms of mass-power ratio of a generator. There is topology called vernier electrical generator that utilizes a principle of magnetic harmonic gear. It has high mass-power ratio under low speed and does not require separate gearing unit. However, vernier generators are notorious for high phase inductance which considerable limits their power. This paper describes a design of a topology of linear permanent magnets vernier electrical generator (LPMVEG), having relatively low phase inductance and electronic unit, which has function of compensation of reactive power. Collaborative design of generator and power electronics allows achieving a higher mass power ratio of the proposed device.