Direct power control of a permanent magnet linear generator in a free piston energy converter

The free piston energy converter (FPEC) is a new type of power unit for hybrid electric vehicle. In a FPEC, an internal combustion engine driven permanent magnet linear generator (PMLG) may be utilized to produce electrical energy. A three-phase active rectifier topology together with its controller is presented for controlling the generator output. The PMLG loaded with an active rectifier is modeled in a stationary frame. Then, a direct power control method is employed for dc-bus voltage regulation and power factor correction. Simulation results show that the proposed method can achieve the desired dc-bus voltage and maximize the active power flow of the generator.