The aim of this thesis is to design a controllable DC-link output voltage for isolated slotless tubular linear generators (STLG), which is capable of directly harnessing wave and solar thermal energies. For supplying stable DC-link voltage to load, a suitable voltage regulation circuit is designed based on the integrate system performance assessment. Electrical and mechanical parameters in this refined STLG design are involved to analyze the operational behaviors through magnetic equivalent circuit analysis at different operating modes. From the theoretical modeling and experimental results, both the AC-side and DC-side properties of generator outputs can then be thoroughly investigated. Finally, based on the performance of controllable rectifier model, a three-phase PWM rectifier has been established, and then the regulated DC-link voltage can be implemented using a DSP-based controller combined with required peripheral circuits.

The objective of this thesis is to design a multilevel converter circuit for driving slotless tubular linear generators (STLG) on retrieving renewable energy application. With the changing speeds and reciprocating directions of the movers, the electric energy generated from the STLG will exhibit large fluctuations and is hard to be used directly. Based on machine modeling and mover reference frame projection, a converter circuit and a data acquisition (DAQ)-based drive control scheme have been developed. From the experimental results, the control scheme implemented on the converter circuit can provide acceptable multilevel dc outputs at various operating modes.