Patent ID: 8169096

Claim:
A fluid power generator, comprising: a rotating member that rotates by fluid force; a generator motor that is mechanically linked with the rotating member and that is configured to function both as a generator and as a motor; a rotation speed meter that measures a rotation speed of the generator motor; a controller that controls the generator motor; a position signal generator that generates a position signal representing a relative position of an electromagnetic coil to a permanent magnet in the power generator; a driving signal generator that generates a driving signal specifying a driving time period of the electromagnetic coil, based on the position signal; and a regeneration signal generator that generates a regeneration signal specifying an electric power regeneration time period of the electromagnetic coil, based on the position signal, wherein the generator motor is operable in multiple different operation modes including: (i) a mixed mode of performing a driving operation in parallel with a power generation operation, and (ii) a driving mode of performing only the driving operation; wherein in the mixed mode, the voltage application time period is set to appear periodically during each half cycle period of the position signal, and the electric power regeneration time period is set to appear in at least part of a residual time period other than the voltage application time period, and wherein the controller selects one of the multiple operation modes and controls the generator motor in the selected operation mode to keep the rotation of the rotating member irrespective of the variation in flow rate of the fluid.