Abstract: A method of controlling a brushless permanent-magnet motor having a phase winding and a rotor, includes applying voltages of first and second opposing polarities to the phase winding when the rotor is oscillating about a parking position, measuring a plurality of first times, each first time including a time taken for current flowing through the phase winding in response to an applied voltage of the first polarity to exceed a threshold and measuring a plurality of second times, each second time including a time taken for current flowing through the phase winding in response to an applied voltage of the second polarity to exceed the threshold. The method includes determining which of an average magnitude of the plurality of first times and an average magnitude of the plurality of second times has the smaller average magnitude, and determining an amplitude peak of the plurality of times having the smaller average magnitude.

Abstract: The invention relates to an electrical energy conversion system (11) which is particularly suited for use in wind energy conversion systems. The system includes two magnetically separated permanent magnet machines (25, 27) linked by a freely rotating rotor (19) housing permanent magnets (39). The first machine is typically a synchronous generator, and the second an induction generator. The synchronous generator (25) has a stationary stator (21) which is connectable to an electrical system such as an electricity grid, and the induction generator (27) has a rotor (17) which is connectable to a mechanical drive system such as, for example, a wind turbine.

Abstract: The invention relates to an electrical energy conversion system (11) which is particularly suited for use in wind energy conversion systems. The system includes two magnetically separated permanent magnet machines (25, 27) linked by a freely rotating rotor (19) housing permanent magnets (39). The first machine is typically a synchronous generator, and the second an induction generator. The synchronous generator (25) has a stationary stator (21) which is connectable to an electrical system such as an electricity grid, and the induction generator (27) has a rotor (17) which is connectable to a mechanical drive system such as, for example, a wind turbine.