Rotary solar converter
AssigneeKoolbridge Solar, Inc.
InventorPaul Wilkinson Dent
Life of this patent
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Abstract
An advantageous method of converting solar energy from a photovoltaic array into alternating current for feeding into the electricity grid is described based on the use of an inventive rotary machine. The inventive rotary machine has a rotor and a set of stator coils which are excited in a first mode by a polyphase current derived from the solar array and simultaneously in a second, orthogonal mode by a polyphase voltage derived from the electricity grid.
Claims18
A rotary electrical machine for transferring electrical power from a Direct Current (DC) power source to an Alternating Current (AC) electricity grid, comprising:
- An induction motor driven from said DC source by a polyphase switching circuit to produce rotation of the rotor;
- A synchronous induction generator coupled to said electricity grid to transfer power to said AC electricity grid,
- wherein said induction motor and said induction generator use the same stator, the same stator coils and the same rotor.
A rotary electrical machine comprising:
- A stator lamination stack of magnetic material;
- a rotor disposed within said stator and free to rotate on bearings;
- a number N of stator coil windings disposed at regular angular spacings within slots in said stator lamination stack,
- wherein the stator coils are excited simultaneously by a first polyphase electrical excitation having a phase increment of M1×360/N degrees and a second polyphase electrical excitation having a phase increment of M2×360/N degrees and integers M1 and M2 are chosen such that electrical coupling between the first and the second polyphase excitations is substantially zero.
A method of converting Direct Current to Alternating current for feeding into the electricity grid, comprising:
- Generating a set of non-sinusoidal motor drive waveforms to drive the stator coils of an induction motor;
- connecting said same stator coils to one or more service drop transformers of said electricity grid such that Alternating Current having a sinusoidal waveform is transferred into said electricity grid and substantially none of said non-sinusoidal motor drive waveforms is coupled into said electricity grid.
A method of feeding current and transferring power into the electricity grid from an energy source, comprising:
- generating electrical drive signals using said energy source at a frequency substantially different than the frequency of said electricity grid;
- connecting said electrical signals and said electricity grid to the same stator coils of a rotary electrical machine having a single stator and a single rotor such that current is fed into the electricity grid at its own frequency thereby achieving said transfer of power.
Dependencies are inferred from the claim text.