The direct-drive Permanent Magnet Linear Generator (PMLG)-based Ocean Wave Energy Converter (OWEC) generates variable AC voltage, which cannot be directly utilized by the load. This paper presents a two-stage methodology to convert variable AC voltage to a constant amplitude AC voltage. First, a standard rectifier is used to convert variable AC voltage into variable DC voltage. After that, a cascaded buck–boost inverter is employed to achieve the constant frequency AC voltage. Systematic design and circuit analysis, along with working principle and voltage control strategy, are presented. A small scale laboratory prototype of PMLG associated with buck–boost inverter is developed to validate the proposed concept.