Patent ID: 7733066

Claim:
A power generation apparatus comprising: an AC energization synchronous generator; a switching device which connects to a network disposed on a stator side of the AC energization synchronous generator; an energizing device which applies a variable frequency AC to a secondary winding of the AC energization synchronous generator; a controller which controls the switching device and the energizing device; a first detector which detects a network side of the switching device; a second detector which detects a voltage of the switching device on a stator side; and a calculator which calculates a slip frequency of the AC energization synchronous generator from a frequency of a stator side voltage generated by energizing a secondary side of the AC energization synchronous generator at a predetermined frequency and makes the secondary side excitation frequency to be coincident with the calculated slip frequency, while the switching device is open; wherein the controller enables changing of an energization current so as to make an amplitude of a stator voltage generated by exciting the secondary side at the slip frequency to be coincident with an amplitude of the network voltage, and enables changing of an excitation frequency so as to make a phase of a stator voltage generated by exciting the secondary side at the slip frequency to be coincident with a phase of a network phase; wherein when the amplitude of the stator voltage is not larger than a predetermined value, the controller controls the secondary side excitation frequency to be fixed in the calculated slip frequency; and wherein when the amplitude of the stator voltage is larger than the predetermined value, the controller controls both of the amplitude of the stator voltage and the slip frequency to be fixed, so that the slip frequency, the phase and the amplitude of the stator voltage and the network voltage take values within predetermined ranges.